Showing papers on "Sickle cell anemia published in 2014"

Management of Sickle Cell Disease: Summary of the 2014 Evidence-Based Report by Expert Panel Members

Abstract: Importance Sickle cell disease (SCD) is a life-threatening genetic disorder affecting nearly 100 000 individuals in the United States and is associated with many acute and chronic complications requiring immediate medical attention. Two disease-modifying therapies, hydroxyurea and long-term blood transfusions, are available but underused. Objective To support and expand the number of health professionals able and willing to provide care for persons with SCD. Evidence Review Databases of MEDLINE (including in-process and other nonindexed citations), EMBASE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, CINAHL, TOXLINE, and Scopus were searched using prespecified search terms and keywords to identify randomized clinical trials, nonrandomized intervention studies, and observational studies. Literature searches of English-language publications from 1980 with updates through April 1, 2014, addressed key questions developed by the expert panel members and methodologists. Findings Strong recommendations for preventive services include daily oral prophylactic penicillin up to the age of 5 years, annual transcranial Doppler examinations from the ages of 2 to 16 years in those with sickle cell anemia, and long-term transfusion therapy to prevent stroke in those children with abnormal transcranial Doppler velocity (≥200 cm/s). Strong recommendations addressing acute complications include rapid initiation of opioids for treatment of severe pain associated with a vasoocclusive crisis, and use of incentive spirometry in patients hospitalized for a vasoocclusive crisis. Strong recommendations for chronic complications include use of analgesics and physical therapy for treatment of avascular necrosis, and use of angiotensin-converting enzyme inhibitor therapy for microalbuminuria in adults with SCD. Strong recommendations for children and adults with proliferative sickle cell retinopathy include referral to expert specialists for consideration of laser photocoagulation and for echocardiography to evaluate signs of pulmonary hypertension. Hydroxyurea therapy is strongly recommended for adults with 3 or more severe vasoocclusive crises during any 12-month period, with SCD pain or chronic anemia interfering with daily activities, or with severe or recurrent episodes of acute chest syndrome. A recommendation of moderate strength suggests offering treatment with hydroxyurea without regard to the presence of symptoms for infants, children, and adolescents. In persons with sickle cell anemia, preoperative transfusion therapy to increase hemoglobin levels to 10 g/dL is strongly recommended with a moderate strength recommendation to maintain sickle hemoglobin levels of less than 30% prior to the next transfusion during long-term transfusion therapy. A strong recommendation to assess iron overload is accompanied by a moderate strength recommendation to begin iron chelation therapy when indicated. Conclusions and Relevance Hydroxyurea and transfusion therapy are strongly recommended for many individuals with SCD. Many other recommendations are based on quality of evidence that is less than high due to the paucity of clinical trials regarding screening, management, and monitoring for individuals with SCD.

Controlled trial of transfusions for silent cerebral infarcts in sickle cell anemia

Abstract: Background Silent cerebral infarcts are the most common neurologic injury in children with sickle cell anemia and are associated with the recurrence of an infarct (stroke or silent cerebral infarct). We tested the hypothesis that the incidence of the recurrence of an infarct would be lower among children who underwent regular blood-transfusion therapy than among those who received standard care. Methods In this randomized, single-blind clinical trial, we randomly assigned children with sickle cell anemia to receive regular blood transfusions (transfusion group) or standard care (observation group). Participants were between 5 and 15 years of age, with no history of stroke and with one or more silent cerebral infarcts on magnetic resonance imaging and a neurologic examination showing no abnormalities corresponding to these lesions. The primary end point was the recurrence of an infarct, defined as a stroke or a new or enlarged silent cerebral infarct. Results A total of 196 children (mean age, 10 years) we...

Nonmyeloablative HLA-Matched Sibling Allogeneic Hematopoietic Stem Cell Transplantation for Severe Sickle Cell Phenotype

Abstract: Importance Myeloablative allogeneic hematopoietic stem cell transplantation (HSCT) is curative for children with severe sickle cell disease, but toxicity may be prohibitive for adults. Nonmyeloablative transplantation has been attempted with degrees of preparative regimen intensity, but graft rejection and graft-vs-host disease remain significant. Objective To determine the efficacy, safety, and outcome on end-organ function with this low-intensity regimen for sickle cell phenotype with or without thalassemia. Design, Setting, and Participants From July 16, 2004, to October 25, 2013, 30 patients aged 16-65 years with severe disease enrolled in this nonmyeloablative transplant study, consisting of alemtuzumab (1 mg/kg in divided doses), total-body irradiation (300 cGy), sirolimus, and infusion of unmanipulated filgrastim mobilized peripheral blood stem cells (5.5-31.7 × 10 6 cells/kg) from human leukocyte antigen–matched siblings. Main Outcomes and Measures The primary end point was treatment success at 1 year after the transplant, defined as a full donor-type hemoglobin for patients with sickle cell disease and transfusion independence for patients with thalassemia. The secondary end points were the level of donor leukocyte chimerism; incidence of acute and chronic graft-vs-host disease; and sickle cell–thalassemia disease-free survival, immunologic recovery, and changes in organ function, assessed by annual brain imaging, pulmonary function, echocardiographic image, and laboratory testing. Results Twenty-nine patients survived a median 3.4 years (range, 1-8.6), with no nonrelapse mortality. One patient died from intracranial bleeding after relapse. As of October 25, 2013, 26 patients (87%) had long-term stable donor engraftment without acute or chronic graft-vs-host disease. The mean donor T-cell level was 48% (95% CI, 34%-62%); the myeloid chimerism levels, 86% (95% CI, 70%-100%). Fifteen engrafted patients discontinued immunosuppression medication with continued stable donor chimerism and no graft-vs-host disease. The normalized hemoglobin and resolution of hemolysis among engrafted patients were accompanied by stabilization in brain imaging, a reduction of echocardiographic estimates of pulmonary pressure, and allowed for phlebotomy to reduce hepatic iron. The mean annual hospitalization rate was 3.23 (95% CI, 1.83-4.63) the year before, 0.63 (95% CI, 0.26-1.01) the first year after, 0.19 (95% CI, 0-0.45) the second year after, and 0.11 (95% CI, 0.04-0.19) the third year after transplant. For patients taking long-term narcotics, the mean use per week was 639 mg (95% CI, 220-1058) of intravenous morphine–equivalent dose the week of their transplants and 140 mg (95% CI, 56-225) 6 months after transplant. There were 38 serious adverse events: pain and related management, infections, abdominal events, and sirolimus related toxic effects. Conclusions and Relevance Among 30 patients with sickle cell phenotype with or without thalassemia who underwent nonmyeloablative allogeneic HSCT, the rate of stable mixed-donor chimerism was high and allowed for complete replacement with circulating donor red blood cells among engrafted participants. Further accrual and follow-up are required to assess longer-term clinical outcomes, adverse events, and transplant tolerance. Trial Registration clinicaltrials.gov Identifier:NCT00061568

Parent education and biologic factors influence on cognition in sickle cell anemia

Abstract: Children with sickle cell anemia have a high prevalence of silent cerebral infarcts (SCIs) that are associated with decreased full-scale intelligence quotient (FSIQ). While the educational attainment of parents is a known strong predictor of the cognitive development of children in general, the role of parental education in sickle cell anemia along with other factors that adversely affect cognitive function (anemia, cerebral infarcts) is not known. We tested the hypothesis that both the presence of SCI and parental education would impact FSIQ in children with sickle cell anemia. A multicenter, cross-sectional study was conducted in 19 US sites of the Silent Infarct Transfusion Trial among children with sickle cell anemia, age 5-15 years. All were screened for SCIs. Participants with and without SCI were administered the Wechsler Abbreviated Scale of Intelligence. A total of 150 participants (107 with and 43 without SCIs) were included in the analysis. In a multivariable linear regression model for FSIQ, the absence of college education for the head of household was associated with a decrease of 6.2 points (P = 0.005); presence of SCI with a 5.2 point decrease (P = 0.017); each $1000 of family income per capita with a 0.33 point increase (P = 0.023); each increase of 1 year in age with a 0.96 point decrease (P = 0.023); and each 1% (absolute) decrease in hemoglobin oxygen saturation with 0.75 point decrease (P = 0.030). In conclusion, FSIQ in children with sickle cell anemia is best accounted for by a multivariate model that includes both biologic and socioenvironmental factors.

Sickle cell disease in India.

Abstract: The clinical manifestations of sickle cell anemia in India seem to be milder than in Africa and Jamaica. Mostly homozygous sickle cell anemia patients seek treatment for vaso-occlusive crises, which have greatest incidence during the rainy season, followed by winter. It is interesting to note that both sickle cell anemia patients and carriers (heterozygotes) have iron deficiency. alpha Thalassemia is one of the major epistatic factors responsible for amelioration of the disease. Simple measures like vaccination in childhood, adequate oral intake of fluids with electrolytes during vaso-occlusive crises, and avoidance of exposure to extreme temperatures reduce the number of patients with vaso-occlusive crises. Premarital counseling and prenatal diagnosis also help reduce the number of births of homozygous children.

Ischemia-reperfusion injury in sickle cell anemia: relationship to acute chest syndrome, endothelial dysfunction, arterial vasculopathy, and inflammatory pain.

Abstract: Ischemia-reperfusion (I/R) physiology, also called reperfusion injury, instigates vascular and tissue injury in human disease states. This review describes why sickle cell anemia should be conceptualized in this fashion and how I/R physiology explains the genesis of characteristic aspects of vascular pathobiology and clinical disease in sickle cell anemia. The nature of I/R and its relevance to sickle cell anemia are discussed, with an emphasis on the acute chest syndrome, endothelial dysfunction with aberrant vasoregulation, circle of Willis vasculopathy, and inflammatory pain. Viewing sickle disease from this perspective elucidates defining pathophysiology and identifies a host of novel potential therapeutic targets.

Vasculopathy, inflammation, and blood flow in leg ulcers of patients with sickle cell anemia

Abstract: Chronic leg ulcers are frequent and debilitating complications of sickle cell anemia. Inadequate blood supply has been postulated to be an important factor in their occurrence and delayed healing. Little is known about their microcirculatory and histopathological changes. We evaluated the microcirculation of lower extremity ulcers with laser speckle contrast imaging and infrared thermography and obtained clinical and laboratory characteristics in 18 adults with sickle cell anemia and chronic leg ulcers. Skin biopsies were obtained in four subjects. Subjects had markers of severe disease, anemia, high degree of hemolysis, inflammation, and thrombophilia. The highest blood flow was present in the ulcer bed, progressively less in the immediate periwound area, and an unaffected control skin area in the same extremity. Microscopic examination showed evidence of venostasis, inflammation, and vasculopathy. Blood vessels were increased in number, had activated endothelium and evidence of thrombosis/recanalization. High blood flow may be due to chronic inflammation, cutaneous vasodilatation, venostasis, and in situ thrombosis. These changes in skin microcirculation are similar to chronic venous ulcers in the non-sickle cell disease (SCD) population, thus suggesting that leg ulcers may be another end-organ complication with endothelial dysfunction that appears in patients with SCD at a younger age and with higher frequency than in the general population.

Phase 1 Study of the E-Selectin Inhibitor GMI 1070 in Patients with Sickle Cell Anemia

Abstract: Background Sickle cell anemia is an inherited disorder of hemoglobin that leads to a variety of acute and chronic complications Abnormal cellular adhesion, mediated in part by selectins, has been implicated in the pathophysiology of the vaso-occlusion seen in sickle cell anemia, and selectin inhibition was able to restore blood flow in a mouse model of sickle cell disease Methods We performed a Phase 1 study of the selectin inhibitor GMI 1070 in patients with sickle cell anemia Fifteen patients who were clinically stable received GMI 1070 in two infusions Results The drug was well tolerated without significant adverse events There was a modest increase in total peripheral white blood cell count without clinical symptoms Plasma concentrations were well-described by a two-compartment model with an elimination T1/2 of 77 hours and CLr of 196 mL/hour/kg Computer-assisted intravital microscopy showed transient increases in red blood cell velocity in 3 of the 4 patients studied Conclusions GMI 1070 was safe in stable patients with sickle cell anemia, and there was suggestion of increased blood flow in a subset of patients At some time points between 4 and 48 hours after treatment with GMI 1070, there were significant decreases in biomarkers of endothelial activation (sE-selectin, sP-selectin, sICAM), leukocyte activation (MAC-1, LFA-1, PM aggregates) and the coagulation cascade (tissue factor, thrombin-antithrombin complexes) Development of GMI 1070 for the treatment of acute vaso-occlusive crisis is ongoing Trial Registration ClinicalTrialsgov NCT00911495

Imaging flow cytometry for automated detection of hypoxia-induced erythrocyte shape change in sickle cell disease.

Abstract: In preclinical and early phase pharmacologic trials in sickle cell disease, the percentage of sickled erythrocytes after deoxygenation, an ex vivo functional sickling assay, has been used as a measure of a patient's disease outcome. We developed a new sickle imaging flow cytometry assay (SIFCA) and investigated its application. To perform the SIFCA, peripheral blood was diluted, deoxygenated (2% oxygen) for 2 hr, fixed, and analyzed using imaging flow cytometry. We developed a software algorithm that correctly classified investigator tagged "sickled" and "normal" erythrocyte morphology with a sensitivity of 100% and a specificity of 99.1%. The percentage of sickled cells as measured by SIFCA correlated strongly with the percentage of sickle cell anemia blood in experimentally admixed samples (R = 0.98, P ≤ 0.001), negatively with fetal hemoglobin (HbF) levels (R = -0.558, P = 0.027), negatively with pH (R = -0.688, P = 0.026), negatively with pretreatment with the antisickling agent, Aes-103 (5-hydroxymethyl-2-furfural) (R = -0.766, P = 0.002), and positively with the presence of long intracellular fibers as visualized by transmission electron microscopy (R = 0.799, P = 0.002). This study shows proof of principle that the automated, operator-independent SIFCA is associated with predictable physiologic and clinical parameters and is altered by the putative antisickling agent, Aes-103. SIFCA is a new method that may be useful in sickle cell drug development.

Hydroxyurea is associated with lower prevalence of albuminuria in adults with sickle cell disease

Abstract: Background. Albuminuria is an early manifestation of sickle cell nephropathy. Prior small case series suggests benefit of hydroxyurea in reducing albuminuria, with a similar trend noted in pediatric studies. We aimed to comprehensively evaluate hydroxyurea use and prevalence of albuminuria in adult sickle cell patients. Methods. We performed a cross-sectional study of 149 adult patients followed between 2000 and 2011 in a comprehensive sickle cell clinic. All patients were assessed for albuminuria either by direct measurement or by urinary chemical strip (dipstick) testing. Urinary albumin-to-creatinine ratios (UACRs) were available for 112 patients. Hydroxyurea exposure was defined as ≥3 months of therapy before the assessment of albuminuria. Albuminuria was defined as either UACR ≥30 mg/g or ≥1+ proteinuria on two separate dipsticks. We constructed a multivariate logistic regression model to assess the association between hydroxyurea and albuminuria. Results. The prevalence of albuminuria was lower among patients on hydroxyurea (34.7 versus 55.4%; P = 0.01) as was median albumin excretion (17.9 versus 40.5 mg/g; P = 0.04). In multivariate analysis, hydroxyurea was associated with a lower likelihood of albuminuria (odds ratio 0.28, 95% CI: 0.11–0.75, P = 0.01), adjusting for age, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use, tricuspid regurgitant jet velocity, hypertension and acute chest syndrome. Conclusions. In our population of sickle cell patients, those using hydroxyurea were less than one-third as likely to exhibit albuminuria. Hydroxyurea use may prevent development of overt nephropathy or the progression of sickle cell disease nephropathy to end-stage renal disease, and its use for this indication merits further investigation.

Hydroxyurea therapy contributes to infertility in adult men with sickle cell disease: a review

Abstract: Hydroxyurea therapy, a chemotherapeutic agent, is the only US FDA approved therapy for the prevention of vaso-occlusive pain in sickle cell disease (SCD). The National Institutes of Health has sponsored two Phase III randomized, placebo-controlled trials, initially in adults, and subsequently in children with sickle cell anemia (SCA). Despite the overwhelming evidence that hydroxyurea therapy is beneficial to children and adults with SCA, individuals with SCA and their families express reservations about its use, in part because of the concerns about fertility, particularly in men. As adolescent boys with SCD are now expected to reach their reproductive years, a new concern is emerging about the role of hydroxyurea therapy as a barrier to their progeny. This review will systemically evaluate compromised fertility in men with SCD, and the evidence that hydroxyurea therapy is associated with further decreasing fertility in men with SCD.

Reticulocytosis and anemia are associated with an increased risk of death and stroke in the newborn cohort of the Cooperative Study of Sickle Cell Disease

Abstract: Prior analyses of the Cooperative Study of Sickle Cell Disease (CSSCD) newborn cohort identified elevated white blood cell (WBC) count, low baseline hemoglobin and dactylitis between the ages of 1 and 2 years as markers of severe disease. Reticulocytosis was also associated with severe disease. Here, we further analyzed data collected on enrolled CSSCD infants for the predictive value of those markers for stroke and death later in life. Three hundred fifty-four CSSCD subjects were identified who had absolute reticulocyte counts (ARC) measured during infancy (2 to 6 months of age). Infants with higher ARC had significantly increased risk of stroke or death during childhood; lower hemoglobin levels also increased the risk but to a lesser degree than ARC. WBC levels and dactylitis were not predictive of death or stroke. These data suggest that reticulocytosis among asymptomatic infants with sickle cell anemia is associated with an increased risk of death or stroke during childhood.

Improved hydroxyurea effect with the use of text messaging in children with sickle cell anemia

Abstract: Background In children with sickle cell anemia (SCA), hydroxyurea reduces morbidity, but adherence is frequently suboptimal. Because most families of children with SCA have access to cellular telephone services, we assessed the impact of text messaged reminders as a tool to improve adherence to hydroxyurea. Procedure All patients <19 years of age with HbSS or HbSβ0thalassemia who were treated with hydroxyurea at a maximal tolerated dosage (MTD) at St. Jude Children's Research Hospital Comprehensive Pediatric Sickle Cell Program and who received automated text message reminders (SIMON®) were retrospectively identified. Laboratory parameters, hospitalizations, and medication possession ratios (MPR) prior to and after initiation of SIMON® were compared to assess the impact of SIMON®. Results Of the 97.3% of families with access to a cell phone, 91% elected to receive text message reminders. Among 55 children receiving hydroxyurea at MTD, laboratory parameters reflected waning medication compliance during the 12 months prior to SIMON®. Following initiation of SIMON®, children had higher mean corpuscular volumes, hemoglobin levels and fetal hemoglobin percentages and lower absolute reticulocyte counts and bilirubin levels, suggesting improved medication adherence. Hospitalizations were uncommon before and after SIMON®, and medication possession ratios (MPRs) were high before and after SIMON®, neither was significantly changed. Conclusions SIMON® was feasible and improved hematologic parameters in children with SCA receiving hydroxyurea at a MTD. Future work will include extension of this technology to children with other chronic medical conditions who require daily use of medication. Pediatr Blood Cancer 2014;61:2031–2036. © 2014 Wiley Periodicals, Inc.

Abnormal pulmonary function and associated risk factors in children and adolescents with sickle cell anemia.

Abstract: Obstructive and restrictive pulmonary changes develop in children with sickle cell disease, but reports conflict as to the type of change that predominates. We prospectively performed spirometry, plethysmography, and lung diffusing capacity in 146 children aged 7 to 20 years with hemoglobin SS or Sβ(0)-thalassemia. Nineteen percent of the patients had obstructive physiology as defined according to guidelines of the American Thoracic Society. In addition, 9% had restrictive physiology and 11% had abnormal but not categorized physiology. Increasing age, patient-reported or family-reported history of asthma or wheezing, and higher lactate dehydrogenase concentration were independent predictors of obstruction as reflected in lower forced expiratory volume in the first second/forced vital capacity. In conclusion, abnormal pulmonary function, most often obstructive, is common in children with hemoglobin SS and Sβ(0)-thalassemia. Full pulmonary function testing should be performed in children with hemoglobin SS or Sβ(0)-thalassemia, especially with history of asthma or wheezing and accentuated elevations in hemolytic markers.

Blood pressure abnormalities in children with sickle cell anemia

Abstract: Background Kidney disease is an important cause of morbidity and mortality in patients with sickle cell anemia (SCA). The factors that affect progression of renal disease are unknown, especially in children and adolescents. Alterations in blood pressure, including hypertension and lack of the normal nocturnal dip in blood pressure, are important determinants of diabetic nephropathy and other renal diseases and may play a role in sickle cell nephropathy. Our primary hypothesis was that children with SCA who have microalbuminuria will demonstrate less nocturnal dipping of blood pressure compared to patients without microalbuminuria. We also investigated other potential factors associated with microalbuminuria. Procedure This prospective study of 52 adolescents with SCA followed in the Children's Medical Center Dallas Comprehensive Sickle Cell Center characterized 24-hour ambulatory blood pressure profiles and presence of microalbuminuria. Stepwise logistic regression was performed to identify significant independent factors that are associated with microalbuminuria. Results Thirty-five percent of patients were identified as having previously unrecognized hypertension, and 17% had pre-hypertension (blood pressure greater than the 90th percentile but less than the 95th percentile). Fifty-six percent of patients lacked the normal nocturnal dip in blood pressure. In addition, 21% had microalbuminuria, and their percent nocturnal dip was significantly less than those without microalbuminuria (P = 0.01). Conclusions Blood pressure abnormalities are common in adolescents with SCA and are a possible modifiable risk factor in the progression of sickle cell nephropathy. Pediatr Blood Cancer 2014;61:518–522. © 2013 Wiley Periodicals, Inc.

DNA polymorphisms at BCL11A, HBS1L-MYB and Xmn1-HBG2 site loci associated with fetal hemoglobin levels in sickle cell anemia patients from Northern Brazil.

Abstract: Increased levels of fetal hemoglobin (HbF, α2γ2) may reduce sickle cell anemia severity due to its ability to inhibit HbS polymerization and also reduce the mean corpuscular HbS concentration. We have investigated the influence of three known major loci on the HbF trait (HBG2, rs748214; BCL11A, rs4671393; and HBS1L-MYB, rs28384513, rs489544 and rs9399137) and HbF levels in SCA patients from the State of Para, Northern Brazil. Our results showed that high levels of HbF were primarily influenced by alleles of BCL11A (rs4671393) and HMIP (rs4895441) loci, and to a lesser extent by rs748214 Gγ-globin (HBG2) gene promoter. The SNPs rs4671393 and rs4895441 explained 10% and 9.2%, respectively, of the variation in HbF levels, while 4.1% of trait variation was explained by rs748214. The results can be considered as in accordance with the pattern of ancestry displayed by the SCA patients: 39.6% European, 29.6% African and 30.8% Native American, and reinforce the suggestion that studies of association between genetic modifiers and clinical and laboratory manifestations in Brazil must be controlled by ancestry.

Albuminuria correlates with hemolysis and NAG and KIM-1 in patients with sickle cell anemia

Abstract: Background Although hyperfiltration and albuminuria are common pathological conditions, kidney injury (KI) biomarkers have been seldom studied in individuals with sickle cell anemia (SCA).

Alpha thalassemia protects sickle cell anemia patients from macro-albuminuria through its effects on red blood cell rheological properties.

Abstract: While chronic hemolysis has been suspected to be involved in the development of glomerulopathy in patients with sickle cell anemia (SCA), no study focused on the implications of blood rheology. Ninety-six adults with SCA at steady state were included in the present cross-sectional study. Three categories were defined: normo-albuminuria (NORMO, n = 41), micro-albuminuria (MICRO, n = 23) and macro-albuminuria (MACRO, n = 32). Blood was sampled to measure hematological and hemorheological parameters, and genomic DNA extraction was performed to detect the presence of α-thalassemia. The prevalence of α-thalassemia was lower in the MACRO group compared with the two other groups. Anemia was more severe in the MACRO compared with the NORMO group leading the former group to exhibit decreased blood viscosity. Red blood cell deformability was lower and red blood cell aggregates strength was greater in the MACRO compared to the two other groups, and this was directly attributed to the lower frequency of α-thalassemia in the former group. Our results show the protective role of α-thalassemia against the development of sickle cell glomerulopathy, and strongly suggest that this protection is mediated through the decrease of anemia, the increase of RBC deformability and the lowering of the RBC aggregates strength.

A GCH1 haplotype confers sex-specific susceptibility to pain crises and altered endothelial function in adults with sickle cell anemia.

Abstract: GTP cyclohydrolase (GCH1) is rate limiting for tetrahydrobiopterin (BH4) synthesis, where BH4 is a cofactor for nitric oxide (NO) synthases and aromatic hydroxylases. GCH1 polymorphisms are implicated in the pathophysiology of pain, but have not been investigated in African populations. We examined GCH1 and pain in sickle cell anemia where GCH1 rs8007267 was a risk factor for pain crises in discovery (n = 228; odds ratio [OR] 2.26; P = 0.009) and replication (n = 513; OR 2.23; P = 0.004) cohorts. In vitro, cells from sickle cell anemia subjects homozygous for the risk allele produced higher BH4. In vivo physiological studies of traits likely to be modulated by GCH1 showed rs8007267 is associated with altered endothelial dependent blood flow in females with SCA (8.42% of variation; P = 0.002). The GCH1 pain association is attributable to an African haplotype with where its sickle cell anemia pain association is limited to females (OR 2.69; 95% CI 1.21-5.94; P = 0.01) and has the opposite directional association described in Europeans independent of global admixture. The presence of a GCH1 haplotype with high BH4 in populations of African ancestry could explain the association of rs8007267 with sickle cell anemia pain crises. The vascular effects of GCH1 and BH4 may also have broader implications for cardiovascular disease in populations of African ancestry.

Pain control in sickle cell disease patients: use of complementary and alternative medicine.

Abstract: Objective To examine the factors associated with the use of complementary and alternative medicine (CAM) as reported by patients attending an adult sickle cell clinic at a tertiary institution. Design Cross-sectional survey. Setting This study was conducted in a university tertiary care adult sickle cell clinic. Subjects Adult sickle cell patients. Method Following Institutional Review Board approval, a questionnaire was administered to patients in a sickle cell clinic to examine their use of CAM for managing pain at home and while admitted to the hospital. Results Of the 227 respondents who completed the questionnaire, 92% experienced pain lasting from 6 months to more than 2 years. Two hundred and eight (91.6%) indicated that they have used CAM within the last 6 months to control pain. The frequency of CAMs use was higher among females, singles, those with more education, and higher household income. Conclusions This study shows that a substantial majority of sickle cell patients live with pain on a regular basis and that there is substantial CAM use in the adult Sickle cell disease population. Being female and having a high school or higher education were significantly correlated with the use of CAM in sickle cell patients. A variety of CAM therapies are used, with the most common being prayer.

Prominent role of platelets in the formation of circulating neutrophil-red cell heterocellular aggregates in sickle cell anemia

Abstract: High leukocyte counts are often observed in sickle cell anemia (SCA) and are associated with increased clinical severity. In vivo animal model studies indicate that the adhesion of leukocytes, particularly neutrophils, to the vessel wall may promote subsequent secondary red blood cell (RBC)

Plasma Concentration of Platelet-Derived Microparticles Is Related to Painful Vaso-Occlusive Phenotype Severity in Sickle Cell Anemia

Abstract: High plasma level of microparticles (MPs) deriving mainly from erythrocytes and platelets has been detected in sickle cell anemia (SCA) patients. Flow cytometry was used to determine the concentration of MPs in two groups of SCA patients exhibiting marked differences in painful vaso-occlusive crisis rates [a non-severe group (n = 17) and a severe group (n = 12)], and in a control group composed of healthy subjects (n = 20). A 3- to 4-fold increase of total MP plasma concentration was detected in SCA patients. Higher platelet-derived MPs concentration was detected in the severe SCA group while erythrocyte-derived MPs concentration was increased in the non-severe SCA patient group only. Our results suggest that plasma concentration of MPs shed by platelets is a biomarker of the vaso-occlusive phenotype-related severity.

Neurologic complications of sickle cell disease.

Abstract: Sickle cell disease (SCD) is a group of genetic blood disorders that vary in severity, but the most severe forms, primarily homozygous sickle cell anemia, are associated with neurologic complications Over the last 90 years it has become established that some patients will develop severe arterial disease of the intracranial brain arteries and suffer brain infarction Smaller infarctions and brain atrophy may also be seen and over time there appear to be negative cognitive effects in some patients, with or without abnormal brain imaging Focal mononeuropathies and pneumococcal meningitis are also more common in these patients Brain infarction in children can largely be prevented screening children beginning at age 2 years and instituting regular blood transfusion when the Doppler indicates high stroke risk (> 200 cm/sec) Iron overload and the uncertain duration of transfusion are disadvantages but overall this approach, tested in a randomized clinical trial, reduced first stroke by over 90% Secondary stroke prevention has not been subjected to a randomized controlled trial except for one recently stopped comparison of regular transfusions compared to hydroxuyrea (results favored transfusion) The usual stroke prevention agents (such as aspirin or warfarin) have not been rigorously tested Magnetic resonance imaging and positron emission tomography give evidence of subtle and sometimes overt brain injury due to stroke in many adults, but a preventive strategy for adults with SCD has not been developed Bone marrow transplantation is the only cure, but some non-neurologic symptoms can be controlled in adults with hydroxuyrea

The effect of hydroxyurea on compound heterozygotes for sickle cell-hemoglobin D-Punjab—A single centre experience in eastern India

Abstract: Background Although hydroxyurea is the only effective agent for the treatment of sickle cell disease, published experience with this drug is limited to treatment of homozygous sickle cell anemia and HbS/β thalassemia. The role of hydroxyurea in the treatment of patients with HbSD-Punjab, a rare hemoglobinopathy with phenotypic expression similar to that of sickle cell anemia is unknown. Procedure Over a period of 10 years, we followed 42 patients with HbSD-Punjab, of which 20 presented with severe clinical manifestations (≥3 episodes of VOC and/or ≥2 units of blood transfusion in the previous 12 months). These 20 patients were enrolled for treatment with hydroxyurea at a dose of 10 mg/kg/day and followed prospectively for a period of 24 months. Results The frequency of VOC decreased significantly and none of them required blood transfusion while receiving hydroxyurea. The HbF, total hemoglobin, MCV, MCH, and MCHC levels increased significantly, whereas HbS, WBC, platelet count, total serum bilirubin, and LDH levels decreased significantly in all the patients. No short-term drug toxicity was observed. Conclusion This study describes the use of hydroxyurea therapy in patients with HbSD-Punjab. Low dose hydroxyurea (10 mg/kg/day) was found to be effective in reducing the clinical severity in patients with HbSD-Punjab without any short-term toxicity. In view of easy affordability amongst poor patients, widespread acceptability by patients and doctors, the need of infrequent monitoring and its potential effectiveness, low dose hydroxyurea is suitable for treatment of patients with HbSD-Punjab. Pediatr Blood Cancer 2014; 61:1341–1346. © 2014 Wiley Periodicals, Inc.