Showing papers in "British Journal of Haematology in 1996"

A plasmocyte selective monoclonal antibody (B-B4) recognizes syndecan-1.

Abstract: We developed a new monoclonal antibody. B-B4, which specifically identifies human plasma cells. It strongly reacts with all multiple myeloma cell lines and with malignant plasma cells of all tumour samples of the multiple myeloma patients tested. B-B4 does not react with any peripheral blood, bone marrow or tonsil cells. Cloning of the B-B4 antigen reveals that the monoclonal antibody recognizes syndecan-1. It appears that the monoclonal antibody B-B4 is a suitable marker for human plasmocyte identification among haemopoietic cells and a useful probe for the diagnosis of haematological malignancies. Furthermore, this monoclonal antibody can be used for depletions prior to CD34 grafting.

Human bone marrow stromal cells prevent apoptosis and support the survival of chronic lymphocytic leukaemia cells in vitro

Abstract: Leukaemic cells from most cases of B-chronic lymphocytic leukaemia die rapidly by apoptosis in vitro unless they are cultured in the presence of interleukin-4 or interferon alpha or gamma. We now report prolonged survival of purified CLL cells cultured on bone marrow (BM) derived stromal cells in the absence of exogenous growth factors. In 10 cases of CLL examined 0-61% (mean 14.7%) of the cells were viable after 10 d culture in medium alone, whereas in the presence of BM stromal cells 10-102% (mean 47.0%) of cells were recovered alive (P < 0.005) in 7/10 cases of CLL, cells remained viable after 30 d of culture in BM stromal cells with cell recovery of 12-65%. These long-term cultured CLL cells were Epstein Barr virus negative, shown by the failure to detect the ENBA-2 and BZLF1 genes of EBV by PCR analysis. Identity between day 0 and day 30 CLL cells was demonstrated by sequence analysis of their clonal IgH CDR3 region. Adherence of CLL cells to BM stromal cell layers was critical for their protection from apoptosis. Separation of CLL cells from stroma by 0.45 micron culture filters resulted in loss of the protective effect of the stromal cells. Stromal cells were also able to protect CLL cells from hydrocortisone-induced apoptotic cell death. Our findings provide an in vitro system that can be used to analyse the growth requirements of CLL cells and their chemosensitivity in an in vitro environment that mimics the in vivo milieu.

Trisomy 12 defines a group of CLL with atypical morphology : correlation between cytogenetic, clinical and laboratory features in 544 patients

Abstract: We have analysed the clinical and laboratory features in 544 patients with chronic lymphocytic leukaemia (CLL) with available cytogenetics and fluorescence in-situ hybridization (FISH) analysis for trisomy 12 in half of them, to examine the correlation between chromosome abnormalities and clinical or laboratory parameters. Five chromosome groups were defined: (1) trisomy 12 (18%), detected as the sole abnormality or associated with other changes; (2) del(13)(q12-14) (7%); (3) other abnormal karyotypes (20%); (4) normal karyotype (41%); and (5) no divisions (14%). There were no differences in the age distribution between the five groups. Clinical stages (Binet) were: A (74%), B (12%) and C (14%). Stage A was common in cases with del(13q)(82%), normal (84%) and other abnormal karyotypes (74%), whereas it was less common in trisomy 12 cases (64%) and those with no divisions (48%). Typical CLL morphology was found in 83% of cases; 10% had more than 10% prolymphocytes (CLL/PL) and 7% had other atypical features. CLL with trisomy 12 was the only group with a high frequency of either CLL/PL (31%) or atypical morphology (24%). Atypical morphology and CLL/PL were even more frequent when trisomy 12 was associated with other chromosomal abnormalities (70% v 46%). The incidence of cases with CLL/PL and other atypical morphology was significantly lower in the other chromosome groups (P < 0.001). There were no differences in immunophenotype among the various groups except for a higher frequency of stronger Smlg and FMC7 expression in cases with trisomy 12, particularly those with CLL/PL and other atypical morphology. Our findings confirm that trisomy 12 defines a subgroup of CLL with more frequent atypical morphology, including CLL/PL, stronger SmIg and FMC7 expression, more advanced stages (B and C in 18%) and possibly worse prognosis.

Humanized CD52 monoclonal antibody Campath-1H as first-line treatment in chronic lymphocytic leukaemia.

Abstract: The humanized CD52 monoclonal antibody Campath-1H was used as first-line therapy in nine patients with progressive chronic lymphocytic leukaemia (CLL). Intravenous (n = 5) or subcutaneous (n = 4) injections (up to 30 mg/inj.) were given three times a week for a maximum of 18 weeks. Three patients achieved a complete remission (CR) and five patients a partial remission (PR) (response rate 89%). CLL cells were cleared from blood in all patients and from the bone marrow in seven patients. The response duration time was 8 + -24+ months. Adverse events were mild except for one patient who developed CMV pneumonitis. All patients developed lymphocytopenia (B and T cells) but other haematological toxicities were negligible. Campath-1H is a highly effective and well-tolerated agent in patients with previously untreated CLL and further studies are warranted.

Kaposi's sarcoma-associated herpesvirus DNA sequences in AIDS-related and AIDS-unrelated lymphomatous effusions

Abstract: Primary effusions presenting as the sole lymphoma localization are also known as body-cavity-based-lymphoma (BCBL), and have been shown to carry Kaposi's sarcoma herpesvirus (KSHV) DNA sequences The aim of this study was a comparative analysis of the clinical, pathologic and molecular features of BCBL and lymphomatous effusions secondary to tissue-based lymphomas occurring both in the general population and in HIV-1-infected individuals All the lymphomatous effusion samples (seven AIDS-related and nine AIDS-unrelated) were subjected to an identical multiparameter investigation, including collection of clinical data, analysis of morphology and immunophenotype, as well as the study of viral sequences and genetic lesions In six cases defined as BCBL (four AIDS-related and two AIDS-unrelated), the patients exhibited exclusive or predominant involvement of the body cavities BCBL tended to display indeterminate phenotypes (4/6), whereas all AIDS-related and AIDS-unrelated lymphomatous effusions secondary to tissue-based lymphomas consistently expressed B-cell phenotype Detection of KSHV DNA sequences was restricted to cases of BCBL (3/4 AIDS-related and 1/2 AIDS-unrelated), whereas EBV association (3/4) and expression of EBV-encoded antigens (LMP-1, 2/3; EBNA-2, 1/3) were confined to the AIDS-related BCBL Overall, our results confirm that both AIDS-related and AIDS-unrelated BCBL preferentially associate with peculiar clinical, immunophenotypic and molecular features among lymphomatous effusions and therefore should be singled out as a specific clinico-pathologic entity

Circulating thrombopoietin level in chronic immune thrombocytopenic purpura

Abstract: The circulating thrombopoietin (TPO) level in 43 patients with chronic immune thrombocytopenic purpura (ITP) was examined by an ELISA system. The TPO level (mean +/- SD) in ITP patients was mildly elevated (1.86 +/- 1.17 fmol/ml) compared to that in normal subjects (0.76 +/- 0.21), and was within the normal range in 30% of ITP patients. In contrast, the TPO level in patients with aplastic anaemia was very high, 12.35 +/- 6.42 fmol/ml. There was no correlation between TPO level and platelet count in ITP patients. Splenectomy was performed in two ITP patients, after which platelet counts increased to normal levels and TPO levels showed a transient increase. These data suggest that reactive TPO production against thrombocytopenia in ITP is small when compared to that in aplastic anaemia. Relative endogenous TPO deficiency may play some role in the pathophysiology of thrombocytopenia in ITP patients.

A sensitive sandwich ELISA for measuring thrombopoietin in human serum: serum thrombopoietin levels in healthy volunteers and in patients with haemopoietic disorders

Abstract: A sensitive sandwich enzyme-linked immunosorbent assay (ELISA) has been established to estimate serum thrombopoietin (TPO) concentrations in healthy volunteers and patients with haemopoietic disorders. The ELISA uses a mouse monoclonal antibody (Ab) as the capture Ab and a biotinylated rabbit polyclonal Ab as the detector. The ELISA was reproducible, highly sensitive and specific for human TPO. The coefficients of intra-and inter assay variation were from 3.0% to 4.9% and from 5.9% to 6.1%, respectively. The quantitative limit of the ELISA was 0.09 fmol/ml in serum. The quantitative limit was lower than the normal level. The dose-response curves of serum samples from healthy volunteers and patients with haemopoietic disorders were parallel to the standard curves. The ELISA did not cross-react with a variety of blood components and cytokines to produce false-positive results. The serum TPO concentrations from 29 normal males and 21 females were 0.79 +/- 0.35 and 0.70 +/- 0.26 fmol/ml, respectively. Serum TPO levels in patients with aplastic anaemia (AA), acute lymphocytic leukemia (ALL) and essential thrombocythaemia (ET) were measured using the ELISA. The serum TPO levels in the patients with ET (n = 6, 2.80 +/- 1.55 fmol/ml) were higher than the normal level. The patients with AA (n = 7, 18.53 +/- 12.37 fmol/ml) and ALL (n = 5, 10.36 +/- 5.57 fmol/ml) had significantly higher serum TPO levels than normal individuals. These results indicate that the ELISA specific to TPO should prove useful in measuring the TPO concentration in serum samples.

Pathogenicity of IgA and/or IgM antibodies to heparin-PF4 complexes in patients with heparin-induced thrombocytopenia.

Abstract: Antibodies to heparin-PF4 (H-PF4) complexes have been tested and isotyped in 38 patients who developed severe heparin-induced thrombocytopenia (type II HIT). All patients had a platelet count 30% of the initial value, occurring at least 5d after the onset of heparin. Thrombocytopenia, which rapidly reversed following the withdrawal of heparin, was associated with thrombosis in nine patients. Although IgG isotypes were found in most cases (n=26), the presence of only IgM and/or IgA was observed in 12 patients, including three cases showing a thrombotic complication. Our results indicate that type II HIT may be induced by IgA and /or IgM anti-H-PF4 antibodies even in the absence of IgG isotypes. This finding demonstrates that platelet Fc receptors (FcgammaRII) are not necessarily involved in the pathogenicity of heparin-dependent antibodies and emphasizes the major role of platelet PF4 receptors. The increased expression of the latter following a slight activation by thrombin, and the subsequent binding of IgM and IgA antibodies to H-PF4 on the platelet surface, may directly trigger platelet activation aggregation and thrombosis. Alternatively, thrombocytopenia could be indirectly induced through the mediation of neutrophils, monocytes and lymphocytes which expose receptors for IgA (FcalphaR) or IgM FcmuR). IgM-platelet complexes may also bind and activate complement, leading to platelet activation or destruction. Moreover, the reactivity of the antibodies with glycosaminoglycans-PF4 complexes present on the endothelial surface could also induce endothelial lesions and promote procoagulant activity and predisposition to thrombosis.

Splenic lymphoma with villous lymphocytes: clinical presentation, biology and prognostic factors in a series of 100 patients

Abstract: The diagnosis of splenic lymphoma with villous lymphocytes (SLVL) was assessed by a panel of cytologists in a series of 100 patients. Clinical and biological characteristics were analysed in relation to prognosis. SLVL is a chronic B-cell lymphoproliferative disorder characterized by splenomegaly and the presence, in peripheral blood, of lymphocytes with 'villous' projections. The cytological diagnosis can be difficult in patients without an absolute lymphocytosis which was observed in 24% of cases. B-cells expressed CD19 + , CD20 + , CD22 + , CD24 + and DBA44 + , whereas the expression of CD5, CD10 and CD25 was usually negative. SLVL is a disease of the elderly with a relatively benign clinical course. In the present series the 5-year overall survival was 78%. Deaths in 15 patients were related to disease progression or treatment (nine cases). Patients with a leucocyte count >30 x 10 9 /l or lymphocyte count <4 x 10 9 /l or initially treated with chemotherapy had significantly (P < 0.001) lower overall survival than other patients. From these findings, treatment abstention should be considered in patients with favourable prognostic factors ; on the other hand, the efficacy of conventional chemotherapy remains to be evaluated in patients with unfavourable prognostic factors.

Thrombo-embolic disease after splenectomy for hereditary stomatocytosis.

Abstract: Nine cases of hereditary stomatocytosis (HSt) are presented which show documented thrombotic complications after splenectomy. In three cases, patients became severely ill with pulmonary hypertension and a fourth developed portal hypertension. One unsplenectomized affected adult relative had suspected but unconfirmed thrombotic pathology; the six other affected unsplenectomized adults did not. Since splenectomy is of only limited therapeutic benefit in stomatocytosis, it should be not be performed without careful consideration. A tendency to iron overload, even without hypertransfusion and irrespective of splenectomy, is evident in many of these patients.

Haematological abnormalities in Shwachman-Diamond syndrome

Abstract: We have analysed the haematological parameters in 21 patients with Shwachman-Diamond syndrome (SDS) seen over a 25-year period at our institution. Neutropenia, although present in all patients, was intermittent in two-thirds, constant in the rest and was associated with impaired chemotaxis in all of those patients tested. Fetal haemoglobin (HbF) was elevated in 80% of the patients at some stage, and anaemia and thrombocytopenia was documented in 66% and 24% respectively. Bone marrow samples were taken in over half of the patients. Myelodysplastic syndrome (MDS) developed in seven (33%) patients, five of whom had acquired clonal structural chromosome abnormalities in their bone marrows. In five of the patients with MDS (24%) transformation to acute myeloid leukaemia occurred. Like other constitutional bone marrow failure syndromes. SDS has a predilection to leukaemic transformation hitherto assumed to be in the region of 5-10%. The data presented here suggest that this figure probably represents an underestimate. Shwachman-Diamond syndrome is an interesting model of leukaemia development and greater understanding of the clinical spectrum of this rare disorder should produce further insights into its pathobiology.

Presenting features and prognosis in 72 patients with multiple myeloma who were younger than 40 years.

Abstract: The purpose of this study was to analyse the presenting clinical and laboratory features and the outcome of 72 patients with multiple myeloma (MM) who were younger than 40 years. The records of all Mayo Clinic patients with MM younger than 40 years who were seen between 1 January 1956 and 31 December 1992 were reviewed. Survival was measured from the date when treatment was required to the date of last follow-up or death. The frequency of MM in patients younger than 40 and 30 years in 3278 Mayo Clinic patients was 2.2% and 0.3%, respectively. The main presenting clinical features were bone pain (66%), fatigue (26%), extramedullary plasmacytomas (19%) and bacterial infection (11%). Renal function impairment (creatinine level > or = 177 micromol/l) and hypercalcaemia (serum calcium value > or = 2.75 mmol/l) occurred in 29% and 30% of patients, respectively. Among the 57 patients evaluable for response the objective response rate was 54%. 14/35 patients treated with a single alkylating agent achieved an objective response, whereas 17/22 patients given combination chemotherapy had an objective response (P=0.013). However, this higher response rate did not result in a significantly longer survival. The median survival for the 72 patients was 54 months. Patients with good prognostic features (normal renal function or low beta 2-microglobulin level) had a median survival of 8 years. The actuarial survival at 5 and 10 years after initiation of therapy was 43% and 13%, respectively. In summary, survival in very young patients with myeloma is longer than that observed in series of patients of all ages, especially in those with good prognostic factors.

The impact of prophylactic treatment on children with severe haemophilia

Abstract: Twenty-seven children with severe haemophilia receiving regular prophylactic factor concentrate were evaluated to examine the overall effectiveness of prophylaxis in modern haemophilia care. The median age at the start of prophylaxis was 6.2 years (range 1.3-15.9 years) and the cumulative length of follow-up was 808 months (mean 30, rang 7-76 months). Nine patients required a central venous catheter for venous access (age range 1.3-5.2 years), eight boys could cannulate themselves and in 10 the parents performed regular venepuncture. The mean dose of concentrate given at the time of study was 31.8 U/kg three times weekly (range 12.5.6 U/kg) or 4900 U/kg/year (range 1900-8200). None developed an inhibitor on prophylaxis, though four had previously had an antibody. The median average annual number of bleeds in the 27 patients prior to prophylaxis was 14.7 (range 3.7-35.4). On prophylaxis this fell to 1.5 (range 0-12.5) (P<0.001) and in the group as a whole the frequency of bleeds diminished in successive years on prophylaxis. All 20 children with evidence of arthropathy improved on prophylaxis and eight had reversal of chronic damage such that their joints appeared normal at the time of study. There were reductions in the need for walking aids, in hospital admissions, and in numbers of school days lost for bleeding episodes. All families feel that prophylaxis has brought about an improvement in quality of life.

The effect of iron chelation on haemopoiesis in MDS patients with transfusional iron overload.

Abstract: Long-term follow-up data are presented on changes in peripheral blood counts and Hb requirements of 11 patients with myelodysplastic syndromes (MDS) during iron chelation treatment with desferrioxamine for up to 60 months. The erythroid marrow activity was indirectly evaluated by repeated determinations of the serum transferrin receptor concentration. The efficacy of iron chelation was evaluated by repeated quantitative determination of the liver iron concentration by magnetic resonance imaging. Reduction in the Hb requirement ( > or = 50%) was seen in 7/11 (64%) patients. Five patients (46%) became blood transfusion independent. Platelet counts increased in 7/11 (64%) patients and the neutrophil counts in 7/9 (78%) evaluable patients. All patients in whom iron chelation was highly effective showed improvement of erythropoietic output accompanied by an increase in the serum transferrin receptor concentration. It is concluded that reduction in cytopenia in MDS patients may be accomplished by treatment with desferrioxamine, if the iron chelation is efficient and the patients are treated for a sufficiently long period of time. Exactly how treatment with desferrioxamine works remains a challenge for further investigation.

The Population Genetics of Factor V Leiden (Arg506Gln)

Abstract: Venous thrombosis is a common multifactorial disease, known to be associated with a number of acquired and inherited factors. Until recently, identifiable genetic predispositions towards thrombosis accounted for < 10% of episodes of venous thrombosis; this included deficiencies of protein C, protein S and antithrombin III. However, Dahlback et al (1993) described an inherited form of activated protein C resistance (APCR), subsequently shown to occur in 20–60% of patients with venous thrombosis and 2–5% of the general population (Svensson & Dahlback, 1994). All inherited cases of APCR so far identified have been caused by a single base change, G ! A, at nucleotide 1691 of the factor V gene, causing the arginine at 506 to be replaced by glutamine (Bertina et al, 1994; Greengard et al, 1994; Voorberg et al, 1994). Arg506 is one of the three critical sites at which protein C cleaves and inactivates factor Va, and the Gln506 form, called factor V Leiden, is resistant to cleavage at the mutated site. Hence factor Va Leiden is inactivated 10–20 times more slowly than the native form, leading to excessive thrombin generation and a presumed life-long prothrombotic tendency (Kalafatis et al, 1995). The increased risk is 5–10-fold for heterozygotes and 80-fold for homozygotes (Rosendaal et al, 1995a). It is surprising that an allele causing a disease phenotype in both homozygous and heterozygous states is present at such high frequencies in some populations. In this review a description of the world distribution of factor V Leiden will be given, followed by a consideration of the forces which might determine this distribution and maintain high allele frequencies in the face of apparent negative selection. This information should facilitate the formulation of rational screening programmes and give some insights into the biology of factor V Leiden.

Transfusion‐related acute lung injury due to HLA‐A2‐specific antibodies in recipient and NB1‐specific antibodies in donor blood

Abstract: Transfusion-related acute lung injury (TRALI) is a hazardous but little-known complication of blood transfusion, characterized by non-cardiogenic lung oedema after blood transfusion. Leucoagglutinating antibodies in the donor plasma are considered to play a central role in the pathogenesis of TRALI but no recommended procedure currently exists for their detection, and most of them have not yet been well characterized. Serum samples of two patients who have developed TRALI within 30 min of blood transfusion and the sera of the involved blood donors were investigated for leucocyte antibodies by granulocyte immunofluorescence, granulocyte agglutination and lymphocytotoxicity assays using typed test cells. Suspected specificities of the detected antibodies were confirmed by a luminoimmunoblot assay and the antigen capture assay MAIGA. One case was associated with granulocyte agglutinating anti-HLA-A2 antibodies in the recipient's (i.e. patient's) own blood and the other with donor-related non-agglutinating antibodies directed against the granulocyte-specific antigen NB1. Leucocyte incompatibility between donor and recipient was shown in both cases by crossmatching and typing of the incompatible cells for the appropriate antigen. The results show that TRALI is associated not only with donor- but also with recipient-related leucocyte antibodies. In addition to leucoagglutinating antibodies, non-agglutinating granulocyte-specific antibodies can be also involved. For immunodiagnosis, sera from both must be investigated by a combination of granulocyte and lymphocyte (HLA) antibody screening tests and leucocyte incompatibility verified by crossmatching.

Hepatitis C virus and non-Hodgkin's lymphomas

Abstract: Hepatitis C virus (HCV) seems to be the aetiologic agent of mixed cryoglobulinaemia, and as this 'benign' lymphoproliferative disorder can frequently develop into more aggressive haematological disorders, this study was undertaken to determine the prevalence of HCV infection in non-Hodgkin's lymphomas. 199 unselected subjects treated by three haematological centres in Northeast Italy were investigated for the presence of HCV infection. As controls, the prevalence of HCV infection was determined in a group of patients affected by other haematological malignancies (153 subjects) and in the general population of the same geographical area in the cohort study called the Dyonisos project (6917 subjects). The presence of anti-HCV antibodies was determined by a commercial kit and, in positive cases, by PCR amplification of the 5' untranslated region of the virus. The HCV genotype was also obtained by PCR amplification of the Core region with type-specific primers. The presence of serum cryoglobulins was determined in each case of NHL. HCV infection was significantly (P < 0.00000001) higher in patients with non-Hodgkin's lymphomas (28.0%) when compared with that of the general population (2.9%), and with the group of patients affected by other malignancies (3.1%). The prevalence is particularly high in low-grade (38.4%), as compared with intermediate (11.4%), or high-grade (15.2%) lymphomas. The presence of the virus is significantly (P < 0.000001) associated with the presence of detectable levels of cryoglobulins. On the basis of these findings. HCV seems to play an important role in the development of low-grade non-Hodgkin's lymphomas.

Heparin‐induced skin lesions

Abstract: Six patients who developed heparin-induced skin lesions were tested for the presence of heparin-dependent, platelet-activating IgG irrespective of whether they developed thrombocytopenia. All six patients' sera contained potent heparin-dependent, platelet-activating IgG. However, only two of the six patients developed thrombocytopenia, and both of these patients developed thrombotic complications. One of the four patients who developed skin lesions without thrombocytopenia also developed a characteristic complication of heparin-induced thrombocytopenia (adrenal haemorrhagic infarction). These observations indicate that formation of heparin-dependent, platelet-activating IgG is a consistent feature of patients who develop heparin-induced skin lesions irrespective of whether thrombocytopenia occurs.

The natural history of chronic hepatitis C in haemophiliacs

Abstract: Most haemophiliacs treated with non-virally-inactivated clotting factor concentrates have been infected with hepatitis C virus (HCV). We have studied the natural history of chronic HCV infection by following all 138 HCV-positive patients from our centre for periods of up to 28 years. As well as the clinical and biochemical characteristics, we studied 116 liver samples from 63 patients obtained at elective biopsy (n=103) or autopsy (n=13). 36 (26%) of the patients were HIV positive, and three were chronic carriers of hepatitis B. Evidence of previous exposure to hepatitis A and B was found in 37.2% and 48.1% respectively. Raised transaminase levels were found in 82.6% of patients. 11 of 15 patients with normal transaminases tested by PCR for HCV RNA were positive, indicating that most patients, even in this group, have chronic hepatitis C infection. Cirrhosis was diagnosed by liver histology in 19 patients, and nine patients developed liver failure. The incidence of cirrhosis rose rapidly 15 years after HCV infection to 15.6 per 1000 person-years. Multivariate analysis showed that HIV status, length of time since HCV infection and age at HCV infection were independently associated with both the development of cirrhosis and liver failure. Two patients developed hepatocellular carcinoma; one of these was exposed only to a single batch of FVIII concentrate 11 years earlier. Chronic hepatitis C is increasingly recognized as a major cause for morbidity and mortality in haemophiliacs, especially those who are HIV positive and who were infected at an older age.

Cryosupernatant as replacement fluid for plasma exchange in thrombotic thrombocytopenic purpura

Abstract: The current established treatment of thrombotic thrombocytopenic purpura (TTP) is plasma exchange with fresh frozen plasma (FEP). With this treatment, there is a 49% response after seven exchanges and a 78% survival at 1 month. Although the exact cause of TTP is unknown, the presence of von Willebrand factor (VWF) multimers has been implicated in the disease. Accordingly, it has been suggested that cryosupernatant (plasma from which cryoprecipitate has been removed), which is relatively deficient in VWF multimers, might be an effective replacement fluid during plasma exchange. Patients from six centers were treated by plasma exchange with cryosupernatant. 18 patients who had failed a first course (average 7.7 exchanges) of plasma exchange with FFP. received a further seven exchanges with cryosupernatant. Subsequently, 40 previously untreated patients were exchanged with cryosupernatant. Of the 18 previously treated patients, 11 responded (defined as an increase in platelet count to > 150 x 10(9) /1 and no neurological events) after seven exchanges and 15 (83%) of the patients were alive at 1 month. The response rate in the 40 previously untreated patients was 75% at the end of seven exchanges and 95% of the patients were alive at 1 month. These values are significantly different (P < 0.05) from those reported in our earlier study and in other patients concurrently treated at the same centres with FFP when cryosupernatant was not available. Some patients who have failed to respond to plasma exchange with FFP replacement will respond to further exchange with cryosupernatant. Cryosupernatant replacement may be more effective as first-line treatment of TTP than FFP.

Preceding standard therapy is the likely cause of MDS after autotransplants for multiple myeloma

Abstract: Myelodysplastic syndromes (MDS) and acute myeloid leukaemia (AML) have been reported after autologous transplantation (AT) for lymphoma. It is not clear whether myeloablative therapy used in conjunction with autologous transplantation contributes to the development of MDS/AML or whether the conventional chemotherapy preceding the transplant, and administered over a prolonged period, causes these secondary malignancies. To address this issue, we examined 188 patients with multiple myeloma (MM) who had received AT. 71 patients with no more than one cycle of standard chemotherapy were enrolled in our Total Therapy program, designed to avoid exposure to alkylating agents prior to peripheral blood stem cell mobilization (group 1). The median duration of pretransplant therapy in group 1 was 7.6 months and significantly shorter than the 24 months of 117 patients (group 2) with more prolonged conventional therapy (P = 0.0001). All seven patients developing MDS post-transplantation belonged to group 2 (P = 0.02); the median durations from initial therapy and first transplant were 66 months (range 38-86) and 24 months (range 9-39), respectively. Our findings provide evidence that prolonged standard-dose alkylating agent therapy prior to transplantation, rather than autotransplant-supported myeloablative treatment, is associated with development of MDS/AML. Stem cell damaging alkylator treatment should be avoided, not to compromise PBSC collection, but also to reduce the risk of treatment-related MDS/AML.

Multiple myeloma: almost all patients are cytogenetically abnormal.

Abstract: Over the past decade, knowledge of chromosomal aberrations in different types of leukaemias, especially acute leukaemias, has expanded rapidly. The identification of cytogenetic abnormalities has gained considerable importance in the understanding of leukaemia biology as shown by the prognostic impact of specific chromosomal changes (Bloomfield & De la Chapelle, 1987; Secker Walker, 1990). Several factors have hampered similar progress in multiple myeloma (MM), including the fact that karyotypes in MM are often a complex mixture of numeric and structural changes whereas only one cytogenetic change is noticed in many cases of acute leukaemia. Moreover, the low proliferative rate and variable degree of bone marrow infiltration by tumour cells have hampered the discovery of abnormal mitoses. Banding analysis is the only technique that enables a comprehensive assessment of the chromosomal changes present in the metaphase fraction of cell preparations. The main chromosomal changes described so far are related either to stage III disease or to relapsing patients and, as will be discussed below, some of the reported abnormalities are associated with the progression of disease rather than with its emergence. Metaphases, however, are far from being a consistent finding in MM. This review will focus on some of the in vivo and in vitro conditions that explain, at least partly, the low aberration rate of cytogenetic abnormalities obtained after banding techniques. For a better definition of cytogenetic changes in MM, other methods can be used, and will be briefly reviewed. The determination of DNA content within individual cells is one of these methods; it can be assessed with either fluorescent or histologic dyes, and interphase cells can be studied. Techniques using the complementarity of fluorescent DNA probes representative of DNA sequences from a whole chromosome or part of a chromosome, called fluorescence in situ hybridization (FISH), have also been used in MM. In contrast with banding techniques, FISH analysis enables the investigation of metaphase and interphase cells. The recent reports on FISH in MM confirm that a large number of patients bear aneuploid cells. However, FISH depends on the use of specific DNA probes, and only one or a few chromosomes or chromosomal regions can be examined in a single experiment. Whereas an abnormal karyotype is found in approximately 50% of patients, the use of FISH and DNA content of plasma cells demonstrates abnormalities in nearly 90% of MM patients, irrespective of disease status. Recent reports also demonstrate aneuploidy in at least 50% of patients with monoclonal gammopathy of undetermined significance (MGUS), indicating that cytogenetic abnormalities are a very early event in the spectrum of monoclonal gammopathies. Although there is now a considerable amount of data about the advanced stages of the disease, the synergistic use of the newer technologies, together with the improvement of the banding techniques, is needed for a better assessment of chromosomal changes in MM patients, namely for those with indolent stages. A more accurate definition of cytogenetic changes will help towards a better understanding of their significance in the pathogenesis and evolution of this disease.

Resistance to activated protein C (APCR) in children with venous or arterial thromboembolism.

Abstract: Resistance to activated protein C (APCR), in the majority of cases due to the point mutation Arg 506 Gln of the factor V gene, has emerged as the most important hereditary cause of venous thromboembolism. Using an activated thromboplastin time (aPTT) based method in the presence of APC together with a DNA technique based on the polymerase chain reaction, we investigated 37 children with venous (V: n=19) or arterial (A: n=18) thromboembolism and 196 age-matched healthy controls for the presence of this mutation. In the control group 10 children were detected to be heterozygous for the factor V Leiden mutation, indicating a prevalence of 5.1%. 10/19 children (52%) with venous thrombosis and 7/18 (38%) patients with arterial thromboembolism showed the common factor V gene mutation. Additional inherited coagulation disorders were found in 1/10 (V:10%) and 2/7 (A:28%) APC-resistant patients. Inherited coagulation disorders without APCR were diagnosed in 3/9 (V: 33%) and 2/11 (A:18%) children. Furthermore, we diagnosed exogenous risk factors in 6/10 (V: 60%) and 2/7 (A: 28%) children with thrombosis and APCR. These data are evidence that APCR combined with exogenous reasons may play an important role in the early manifestation of thromboembolism during infancy and childhood.

Rebound after cessation of oral anticoagulant therapy: the biochemical evidence

Abstract: The existence of a phenomenon of rebound hypercoagulability after cessation of oral anticoagulant therapy is controversial. The sensitive procoagulant markers for in vivo thrombin and fibrin formation are potential tools for the reassessment of the presence of each a phenomenon. We examined 19 patients anticoagulated for 6 +/- 2 months (SD, range 3-12) because of venous thromboembolism or myocardial infarction as follows: twice during stable, oral anticoagulation (INR 3.1-3.7) and then on days 1, 2, 3, 4, 5, 7, 9, 11, 13, 15, and > 30 after cessation of oral anticoagulation. Thrombin-antithrombin III complexes (TAT) and fibrinopeptide A (FPA) were measured in addition to the prothrombin times and factors II, V, VII, and X. None of the 19 patients developed clinically manifest thromboembolism within the following 9-18 months. However, the patients' TAT levels increased transiently: rising from 1.5 +/- 0.1 ng/ml (SEM) to 3.0 +/- 0.2 ng/ml on day 4 (P < 0.001), and returned to 1.7 +/- 0.1 ng/ml after day 30 (normals 1.8 +/- 0.33). 17/19 patients showed TAT peak levels above the upper limit of normal between days 3 and 11 (average: day 4), which normalized again after 30 d. 8/19 patients also had transient FPA levels above the upper normal limits ( < 1.81). We conclude that our patients increased their thrombin and fibrin formation transiently and that a subpopulation reached values consistent with a prethrombotic state.

Unrelated donor bone marrow transplantation for children with relapsed acute lymphoblastic leukaemia in second complete remission.

Abstract: Allogeneic sibling bone marrow transplantation (BMT) is the recommended treatment for relapsed childhood acute lymphoblastic leukaemia (ALL), but appropriate donors are only available in 30% of cases. Unfortunately, BMT from unrelated donors (UD) has been associated with high rates of severe graft-versus-host disease (GvHD) and transplant-related mortality (TRM). In an attempt to improve outcome in UD-BMT we have assessed the impact of T-cell depletion using CAMPATH-1 (anti-CD52) monoclonal antibodies in 50 consecutively referred patients with relapsed ALL in second remission. All were previously treated according to MRC protocols UKALL X and XI, and then given chemotherapy on MRC R1 from relapse until UD-BMT, 19 patients had relapsed on and 31 off therapy. Patients and donors were fully matched at HLA-A, -B, -DR and -DQ loci in 29 cases and mismatched in 21 (four mismatched for more than one antigen). Pre-transplant conditioning comprised CAMPATH-1G, cyclophosphamide and total body irradiation. Bone marrow was T-cell depleted in vitro using CAMPATH-1 antibodies. Additional GvHD prophylaxis consisted of cyclosporin A (42 cases), cyclosporin plus methotrexate (four) or none (four). 47 patients engrafted. The incidence of acute GvHD was very low: two patients with grade II disease in the matched group, four with grade II-IV in the mismatched group. Only four patients have chronic GvHD. The actuarial event-free survival (EFS) at 2 years is 53%, with no significant difference between the matched and mismatched group. Further leukaemic relapse was the most important cause of failure. These results are similar to the most favourable published reports for HLA-matched sibling BMT in relapsed ALL.

Acute‐phase response and the hypercoagulable state in pulmonary tuberculosis

Abstract: In our experience, severe pulmonary tuberculosis (PTB) is often complicated by deep venous thrombosis (DVT). Because of the association between inflammation and haemostatic changes that can result in a hypercoagulable state, we have prospectively examined such predisposing factors in representative patients. Sequential analyses in a control group with active PTB showed anaemia, thrombocytosis, elevations in plasma fibrinogen, fibrin(ogen) degradation products (FDP), tissue plasminogen activator (t-PA) and inhibitor (PAI-1) with depressed antithrombin III levels. Age, sex and disease matched individuals with venographically proven DVT had higher FDP (15.8 +/- 14.3 v 3.2 +/- 1.7 micrograms/ml:P < 0.01), t-PA (19.4 +/- 14.9 v 11.3 +/- 0.8 ng/ml:P < 0.01), and functional PAI-1 activity (11.6 +/- 6.3 v 4.2 +/- 4.1:P < 0.01) with lower platelet counts (347 +/- 110 v 563 +/- 230 x 10(9)/1:P < 0.01). Fibrinogen levels in all patients rose during the first 2 weeks of therapy and, together with related disturbances, corrected within 12 weeks. In conclusion, elevated plasma fibrinogen with impaired fibrinolysis coupled with a decrease in antithrombin III and reactive thrombocytosis would appear to favour the development of DVT in PTB.

Diamond-Blackfan anaemia in the U.K.: analysis of 80 cases from a 20-year birth cohort.

Abstract: The UK Diamond-Blackfan Anaemia (DBA) Registry was established with the aim of providing a representative database for studies on the aetiology, pathophysiology and treatment of DBA We have analysed retrospective data from 80 cases (33 male, 47 female) born in the UK in a 20-year period (1975-94), representing an annual incidence of 5 per million live births Ten children from seven families had an apparently familial disorder 13% were anaemic at birth, and 725% had presented by the age of 3 months 67% had macrocytosis at presentation 72% responded initially to steroids, and at the time of study 61% were transfusion-independent (45% steroid-dependent) and 39% required regular transfusions Unequivocal physical anomalies, predominantly craniofacial, were present in 37%, and were more likely in boys (52%) than girls (25%) 18% had thumb abnormalities Height was below the third centile for age in 28%, and 31% had neither short stature nor physical anomalies Four children without physical abnormalities had normal red cell indices, and achieved steroid-independent remission, suggesting transient erythroblastopenia of childhood rather than DBA The birth month distribution of children with sporadic DBA and craniofacial dysmorphism showed a possible seasonality, consistent with a viral aetiology

The epitope specificity of heparin‐induced thrombocytopenia

Abstract: Heparin-induced thrombocytopenia (HIT) is caused by antibodies (HIT-Abs) that bind to a complex of heparin and platelet factor 4. We investigated the epitope specificity of the HIT-Abs, and found that the HIT-Abs recognized solid-phase immobilized complexes with an optimum ratio of four to eight molecules of PF4 per molecule of heparin. To try to define the epitopes within the PF4 molecule, intact and reduced (linearized) PF4 was tested against 29 different sera from patients with HIT. In addition, eight different peptides that spanned the PF4 molecule were studied for their ability to bind to the HIT-Abs either alone or in the presence of heparin. With the exception of a subpopulation of patient samples (5/29, 17%), we found that reduced PF4 and the peptides were uniformly non-reactive with the HIT-Abs in the presence of heparin. Reduced PF4 and PF4 carboxy-terminal peptides with a minimum size of 19 amino acids were recognized by a minority (5/29) of HIT-Abs samples but only when heparin was present. The specificity of this subgroup of samples from patients with HIT was highly restricted and the loss of one amino acid (peptide reduced in length from 19 to 18 amino acids) rendered the peptides non-reactive. The clinical characteristics of these patients were similar to the other HIT patients. These studies demonstrate that the majority of HIT-Abs recognize a noncontiguous conformational epitope on the PF4 molecule that is produced when four to eight PF4 molecules are bound together by heparin.

A comparison of busulphan versus total body irradiation combined with cyclophosphamide as conditioning for autograft or allograft bone marrow transplantation in patients with acute leukaemia. Acute Leukaemia Working Party of the European Group for Blood and Marrow Transplantation (EBMT).

Abstract: We retrospectively compared the outcome in patients in the EBMT database transplanted for acute leukaemia from January 1987 to January 1994 who received busulphan and cyclophosphamide (BU/CY) as a pretransplant regimen versus those who received cyclophosphamide and total-body irradiation (CY/TBI). The patients were matched for type of transplant (autologous bone marrow transplantation (ABMT) versus allogeneic (BMT)), diagnosis (acute lymphoblastic leukaemia (ALL) or acute myeloid leukaemia (AML)), status (early (first complete remission, CR-1) versus intermediate (second or later remission, first relapse)), age, FAB classification for AML, prevention of graft-versus-host disease and year of transplantation. In ABMT recipients (matched paired 530 x 2) with ALL CR-1, AML CR-1 and AML intermediate disease, transplant-related mortalities (TRM) relapse incidence (RI) and leukaemia-free survival (LFS) did not differ significantly in patients treated with BU/CY or CY/TBI. However, in ABMT recipients with ALL intermediate disease, the probability of relapse was 82 +/- 5% (+/- 95% confidence interval) in the BU/CY group compared to 62 +/- 6% in the CY/TBI group (P = 0.002) and the 2-year leukaemia-free survival 14 +/- 4% and 34 +/- 6%, respectively (P = 0.002). In BMT recipients of bone marrow from HLA-identical siblings (matched paired 391 x 2), the TRM, RI and LFS did not differ significantly between the two treatments in all groups. In particular, the 2-year LFS in patients with AML CR-1 was 64 +/- 3% in those treated with BU/CY (n = 237) compared to 66 +/- 3% in those given CY/TBI (n = 237). In all groups the findings were confirmed in a multivariate analysis of prognostic factors. Veno-occlusive disease (VOD) of the liver (P < 0.05) and haemorrhagic cystitis (P < 0.001) was more common in the BU/CY group compared to the CY/TBI group for ABMT and BMT patients. In conclusion, BU/CY and CY/TBI as pretransplant regimens gave similar results in all situations, except ABMT for ALL intermediate stages with more than 2 years from diagnosis to transplantation, where a lower RI and a higher LFS were associated with CY/TBI.