Showing papers on "Neopterin published in 1993"
TL;DR: Large amounts of neopterin are produced and released from human macrophages on stimulation with interferon-gamma, which allows insight into the immunopathogenesis of a variety of diseases.
Abstract: Large amounts of neopterin are produced and released from human macrophages on stimulation with interferon-γ. Neopterin is biologically stable, and it can be easily quantified in human body fluids. Ne
227 citations
TL;DR: The macrophage derived substance neopterin is able both to enhance and to reduce cytotoxicity in dependence of pH value and its oxidation state, and it may have a pivotal role in modulation of macrophages mediated effector mechanism.
189 citations
TL;DR: A functional role for the stimulation of tetrahydrobiopterin biosynthesis by cytokines is the formation of a limiting cofactor required for the enzymatic conversion of L-arginine to citrulline and nitric oxide.
Abstract: Biosynthesis of tetrahydrobiopterin starts from guanosine triphosphate by the action of guanosine triphosphate cyclohydrolase I, which yields the first intermediate, 7,8-dihydroneopterin triphosphate. This compound is then converted by subsequent enzymes, 6-pyruvoyl tetrahydropterin synthase and sepiapterin reductase, to tetrahydrobiopterin, the biologically active metabolite. Cytokines such as gamma-interferon or tumor necrosis factor-alpha strongly stimulate the activity of guanosine triphosphate cyclohydrolase I in murine and human cells, yielding a potentiation of intracellular tetrahydrobiopterin concentrations. In human cells, particularly in human monocytes and macrophages, the low activity of 6-pyruvoyl tetrahydropterin synthase leads to the additional accumulation of neopterin derivatives, which leak from the cells after dephosphorylation and are found increased in body fluids of humans with diseases challenging cell-mediated immunity. A functional role for the stimulation of tetrahydrobiopterin biosynthesis by cytokines is the formation of a limiting cofactor required for the enzymatic conversion of L-arginine to citrulline and nitric oxide.
101 citations
TL;DR: Data indicate that cells of the monocyte-macrophage system are already highly activated in the peripheral blood in RA patients with active disease, and are replenished by monocytes that have, with respect to cytokine and mediator production, a considerably lower activation status.
Abstract: One of the hallmarks in rheumatoid arthritis (RA) is the intense activation of the monocyte-macrophage system. In the present investigation, the modulation of blood monocyte activation was studied with regard to the secretion of cytokines and inflammatory mediators, and to the expression of cytokine receptors. Patients with severe active RA underwent repeated leukapheresis procedures that removed all circulating monocytes. Highly enriched monocyte preparations from the first and third leukapheresis were studied. There were striking differences between the two monocyte populations. Cells obtained from the first leukapheresis constitutively released large amounts of prostaglandin E2 (PGE2), neopterin, interleukin 1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha). In particular, IL-1 beta and neopterin production were further enhanced by stimulation with either interferon-gamma (IFN-gamma) or TNF-alpha without a synergistic effect. In contrast, cells derived from the third leukapheresis procedure showed a close to normal activation status with only low levels of cytokine and mediator production as well as a reduced response to cytokine stimulation. The number of the receptors for IFN-gamma and TNF-alpha was not changed between first and third leukapheresis. However, TNF-binding capacity was only detectable upon acid treatment of freshly isolated monocytes. A further upregulation was noted upon 24 h in vitro culture, suggesting occupation of membrane receptors and receptor down-regulation by endogenously produced TNF-alpha. Northern blot analysis of cytokine gene expression was in good correlation with the amount of mediators determined on the protein level. These data indicate that cells of the monocyte-macrophage system are already highly activated in the peripheral blood in RA patients with active disease. These cells can be efficiently removed by repeated leukapheresis and are replenished by monocytes that have, with respect to cytokine and mediator production, a considerably lower activation status.
87 citations
TL;DR: The pharmacokinetics of and biologic response modification by recombinant human interferon-βser (rIFN- βser) were evaluated in 12 healthy male volunteers and serum neopterin levels did not increase above baseline levels until 12 hr after iv dosing and 24 hr after sc dosing.
Abstract: The pharmacokinetics of and biologic response modification by recombinant human interferon-βser (rIFN-βser) were evaluated in 12 healthy male volunteers. Subjects received a single intravenous (iv) injection of 90 × 106 IU of rIFN-βser followed by a single or eight consecutive daily 90 × 106 IU subcutaneous (sc) doses. Blood samples collected after the iv, first sc, and last sc doses and prior to each sc dose were assayed for interferon antiviral activity and the inter-feron-inducible marker neopterin. Following iv administration, serum interferon concentrations generally declined biexponentially, with a mean serum clearance of 0.76 ± 0.28 L/hr-kg, a mean steady-state volume of distribution of 2.88 ± 1.81 L/kg, and a mean terminal half-life of 4.29 ± 2.29 hr as determined by noncompartmental analysis. Following sc administration, absorption of rIFN-βser was prolonged, with serum concentrations generally below 100 IU/mL. No accumulation of rIFN-βser in serum was noted after eight daily sc injections. In contrast, serum neopterin levels did not increase above baseline levels until 12 hr after iv dosing and 24 hr after sc dosing. The mean increase in serum neopterin at 24 hr post iv injection was significantly greater than that at 24 hr post sc dosing.
84 citations
Journal Article•
TL;DR: Imiquimod, as an oral inducer of interferon, may have therapeutic usefulness in human cancers, viral infections, and other diseases, however, before initiation of phase II trials, additional work will be required to establish a tolerated dose and schedule for continued administration.
Abstract: Imiquimod [1-(2-methylpropyl)-1H-imidazo[4,5c]quinolin-4-amine] is a compound of low molecular weight that, when administered p.o., induces interferon-alpha in several animal species and inhibits tumor growth in mice. To determine maximum tolerated dose, toxicity, and biological response in humans, a phase I clinical trial was conducted with 14 eligible cancer patients who received 100-500 mg imiquimod p.o. either once or twice weekly. Imiquimod induced interferon-alpha in serum in 10 of 19 doses of 200-300 mg. Interferon serum levels peaked 8-24 h after treatment and reached a maximum of 23,000 IU/ml in one patient. Significant mean increases (P < 0.01) in serum beta 2-microglobulin (1.5-fold), serum neopterin (3.5-fold), and 2-5A synthetase activity in peripheral blood mononuclear cells (7.9-fold) indicated that 200-300 mg imiquimod had biological and immunological activity in all evaluable patients. Increases in serum interferon, beta 2-microglobulin, and neopterin correlated significantly with dose (P < 0.001). No patient developed measurable antibody to interferon-alpha. Dose-limiting side effects included fatigue, malaise, fever, headache, and lymphocytopenia; no hepatic or renal toxicity or other hematological changes exceeded the normal range. Patients tolerated weekly doses of up to 500 mg, with the longest treatment lasting 4 weeks at 200 mg weekly. Twice-weekly doses up to to 300 mg were tolerated, with the longest twice-weekly treatments being 200 mg for 9 weeks and 100 mg for 25 weeks. No clinical responses were observed. Imiquimod, as an oral inducer of interferon, may have therapeutic usefulness in human cancers, viral infections, and other diseases. However, before initiation of phase II trials, additional work will be required to establish a tolerated dose and schedule for continued administration.
83 citations
TL;DR: Analysis of CSF levels of neopterin may be useful as guidance in following clinical course and effect of treatment and can provide information of value in addition to CSF cell count as a measurement of CNS immune stimulation.
Abstract: Cerebrospinal fluid (CSF) neopterin levels were determined by RIA in individuals with central nervous system (CNS) or human immunodeficiency virus (HIV) infections and in healthy controls. The mean CSF neopterin concentrations were 63.0 nmol/L in 15 patients with acute bacterial meningitis, 54.9 nmol/L in 15 patients with Lyme neuroborreliosis, 32.5 nmol/L in 10 patients with viral meningitis, 130.9 nmol/L in 8 patients with viral encephalitis, 13.9 nmol/L in 15 patients with asymptomatic HIV infection, 26.0 nmol/L in 11 patients with AIDS without dementia, 65.4 nmol/L in 4 patients with AIDS dementia, and 4.2 nmol/L in 24 healthy controls. Although patients with viral encephalitis had higher mean neopterin levels than any other patient category studied, the CSF neopterin concentrations cannot be used to discriminate between viral and bacterial infections. Analysis of CSF levels of neopterin may be useful as guidance in following clinical course and effect of treatment and can provide information of value in addition to CSF cell count as a measurement of CNS immune stimulation.
81 citations
TL;DR: In acute primary HIV-1 infection, significant alteration of cytokine release, possibly induced by viral antigens, could be responsible for both clinical picture and activation of cytotoxic cells through abnormal mechanisms.
Abstract: Objective:To investigate the relationship between cytokine serum levels, peripheral blood lymphocyte subsets and clinical picture in acute primary HIV-1 infection.Patients and methods:Absolute number/μl total lymphocytes, CD4+, CD8+ and natural killer (NK) cells, as well as serum levels of soluble C
80 citations
Journal Article•
TL;DR: Neopterin concentrations provide valuable and statistically independent prognostic information in patients with adenocarcinoma of the colon and when neopterin and tumor stage were investigated for joint prediction, stage failed to be included in the model.
Abstract: Concentrations of neopterin, a sensitive indicator for the activation of cellular immunity, were measured in urine samples of 44 patients with adenocarcinoma of the colon at diagnosis. To judge the relative predictive value of neopterin concentrations, other routine clinical and laboratory variables were concomitantly determined. The patients were then followed up to 10 yr, and the abilities of all variables to predict death from cancer were assessed. Neopterin concentrations were not correlated with either tumor stage or Dukes' stage. In univariate analyses using the product-limit approach, four variables were significant indicators of poor prognosis: presence of distant metastases ( P = 0.0001); high Dukes' stage ( P = 0.0009); high urinary neopterin concentration ( P = 0.0034); and advanced stage ( P = 0.030). Presence versus absence of lymph node metastases was not associated with prognosis. Multivariate survival analyses by the proportional hazards technique demonstrated that neopterin provided statistically independent predictive information in addition to either presence versus absence of distant metastases or Dukes' stage. When neopterin and tumor stage were investigated for joint prediction, stage failed to be included in the model. Thus, neopterin concentrations provide valuable and statistically independent prognostic information in patients with adenocarcinoma of the colon.
65 citations
TL;DR: Findings indicate that there is a vigorous acute inflammatory response and a long-term persistence of intrathecal cellular and humoral immune activity in HSE.
Abstract: Neopterin and beta 2-microglobulin (beta 2M) levels were analyzed in sequential cerebrospinal fluid (CSF) and serum samples from 20 patients with herpes simplex encephalitis (HSE) and 30 patients with acute febrile encephalopathy of other cause (non-HSE). Markedly elevated acute phase CSF levels of neopterin and beta 2M were found in 19 HSE patients, but the levels were only moderately increased in most of those with non-HSE. Neopterin levels were analyzed in an additional 15 HSE patients who died within a month of the onset of neurologic symptoms and correlated with the clinical severity of the HSE. After HSE, but not after non-HSE, increased levels of neopterin and beta 2M persisted for a long time (> or = 13 years). Specific intrathecal IgG activity persisted in all but 2 HSE patients. These findings indicate that there is a vigorous acute inflammatory response and a long-term persistence of intrathecal cellular and humoral immune activity in HSE.
62 citations
TL;DR: The response to a single dose of IFN beta was as great in magnitude as the response to multiple doses, suggesting an alternate-day schedule would maintain biological response.
Abstract: Interferons (IFNs) induce gene regulation in vivo that may be used to identify effective doses, schedules, and potential correlates of therapeutic response. To critically examine minimum effective dose, duration of response, and cumulative effects of repetitive doses, a range of subcutaneous doses of IFN beta ser was studied in 32 healthy human volunteers. IFN-induced products of gene regulation assessed were beta 2-microglobulin, neopterin, and tryptophan in serum and 2',5'-oligoadenylate (2-5A) synthetase activity in peripheral blood mononuclear cells. Eight subjects per group received 0.09, 0.9, 9, or 45 MU of IFN beta. Responses were measured at 24, 48, and 72 h after single and multiple doses. The lowest biologically effective dose was 0.9 MU; significant (p < 0.02) increases were observed at 24 h in beta 2-microglobulin and cellular 2-5A synthetase activity. At the two higher doses, 9 and 45 MU, changes were observed at 24 h in all products (p < 0.01). A dose response (p < 0.01) over the range of 0.09-45 MU was observed for all these serum and intracellular gene products. Changes in neopterin, beta 2-microglobulin, and cellular 2-5A synthetase correlated significantly with each other. The response to a single dose of IFN beta was as great in magnitude as the response to multiple doses, suggesting an alternate-day schedule would maintain biological response.
TL;DR: The cardiac allograft is a major source of cytokines after heart transplantation and the cytokine profile allows the activity of subsets of the mononuclear cell infiltrate to be investigated, and Elevated coronary sinus activity of the macrophage-specific metabolite neopterin suggests Macrophage activation within the allografted.
TL;DR: The concept that weight loss is closely linked to endogenous interferon-γ activity is supported, particularly in patients with higher neopterin and lower tryptophan values.
Abstract: Weight loss is the main symptom of so-called tumor cachexia. The pathogenetic mechanisms underlying cachexia are poorly understood; however, it appears that enhanced formation of cytokines such as interferon-γ and tumor necrosis factor-α are involved. In 94 patients suffering from hematological neoplasias we compared body weight changes with serum neopterin, tryptophan, and kynurenine. Biochemical changes, the formation of neopterin, the degradation of tryptophan are closely related to interferon-γ activity. The majority of our patients had increased neopterin and decreased tryptophan concentrations. Weight loss was seen particularly in patients with higher neopterin and lower tryptophan values. An association between higher neopterin levels and greater weight loss was apparent at study entry and during the follow-up of patients. Our data support the concept that weight loss is closely linked to endogenous interferon-γ activity.
TL;DR: The results would suggest that the immunostimulatory action of MLT requires the concomitant presence of IL-2 and that two of the main target cells for MLT activity in humans are represented by T helper lymphocytes of type 2, which are involved in IL-1-induced eosinophilia by the release ofIL-5, and macrophages, which may inhibitIL-2-dependent immune functions.
Abstract: The mechanisms responsible for the immunostimulatory role of the pineal hormone melatonin (MLT) are still obscure. To investigate the influence of MLT on interleukin-2 (IL-2)-induced immune effects in cancer, we compared the results obtained in 14 cancer patients treated with IL-2 (6 x 106 IU/day s.c. for 5 days/week for 4 weeks) plus MLT (10 mg/day orally) with those seen in 14 patients treated with IL-2 alone and with those obtained from 14 other patients treated with MLT only. All patients were affected by metastatic solid neoplasms. The increase in the mean number of lymphocytes, T lymphocytes, natural killer cells, CD25-positive cells and eosinophils was significantly higher in patients treated with IL-2 plus MLT than in those receiving IL-2 alone. On the contrary, the increase in mean serum levels of the macrophage marker neo-pterin was significantly higher in patients treated with IL-2 alone than in those treated with IL-2 plus MLT. Finally, MLT alone has no significant effect on immune cell mean number and on neopterin secretion. These results would suggest that the immunostimulatory action of M LT requires the concomitant presence of IL-2 and that two of the main target cells for MLT activity in humans are represented by T helper lymphocytes of type 2, which are involved in IL-2-induced eosinophilia by the release of IL-5, and macrophages, which may inhibit IL-2-dependent immune functions.
TL;DR: The data suggest that immune activation phenomena may be involved in the pathogenesis of impaired immune function after exercise and the exercise-induced asthma.
TL;DR: In CSF of RRMS patients neopterin andl-TRP correlated negatively, reflecting the interferon-gamma mediated activation of macrophages in acute relapse, and a significant positive correlation between serum IL-2 levels and duration of acute relapse warrants further evaluation.
Abstract: Cerebrospinal fluid (CSF) and serum levels of interleukin-2 (IL-2), soluble IL-2 receptors (sIL-2R), neopterin,l-tryptophan (l-TRP) and β2-microglobulin ((β2-M) were measured in 31 untreated multiple sclerosis patients in acute exacerbation and 27 normal controls. Twenty-six patients showed the relapsing-remitting type of disease (RRMS); 5 had a chronic-progressive course (CPMS). No changes in serum IL-2 and sIL-2R were found between RRMS patients and controls, whereas serum and CSF levels as well as the CSF/serum ratio of neopterin were significantly elevated in the RRMS group. IL-2 was not detectable in CSF of patients or controls and sIL-2R levels were at the level of the lower detection (LD) sensitivity of the ELISA method. Four of 23 RRMS patients versus 1 of 25 controls showed CSF sIL-2R levels above the LD sensitivity, indicating a trend towards elevation in acute relapse. No difference was found in serum and CSFl-TRP and β2-M of patients and controls. In CSF of RRMS patients neopterin andl-TRP correlated negatively, reflecting the interferon-gamma mediated activation of macrophages in acute relapse. A significant positive correlation (Spearman rank 0.57,P = 0.001) between serum IL-2 levels and duration of acute relapse (mean 30 days) warrants further evaluation.
TL;DR: DHEA was well tolerated by patients with mild symptomatic HIV disease; evaluation of this agent for efficacy in HIV disease would require randomized, controlled trials.
Abstract: Dehydroepiandrosterone (DHEA) is a naturally occurring adrenal steroid reported to have immunomodulatory and antiviral activity in cellular and animal models as well as modest in vitro antiretroviral activity against human immunodeficiency virus (HIV). A phase I dose-escalation study was performed to evaluate the safety and pharmacokinetics of DHEA in subjects with symptomatic HIV disease and an absolute CD4 lymphocyte count between 250 and 600 cells/microliters. Thirty-one subjects were evaluated and monitored for safety and tolerance. The oral drug was administered three times daily in doses ranging from 750 mg/day to 2,250 mg/day for 16 weeks. Some immunological and virological parameters were monitored as well. The drug was well tolerated and no dose-limiting side effects were noted. Dose proportionality was evidenced neither by the serum DHEA nor by DHEA-S time-concentration curves for the three dosing groups. However, the study cohort appeared to consist of two subpopulations with markedly different bioavailability for a given DHEA dose. No sustained improvements in CD4 counts nor decreases in serum p24 antigen or beta-2 microglobulin levels were observed. However, serum neopterin levels decreased transiently by 23-40% at week 8 compared with baseline in all dosing groups. DHEA was well tolerated by patients with mild symptomatic HIV disease; evaluation of this agent for efficacy in HIV disease would require randomized, controlled trials.
TL;DR: Findings show that acute phase reaction occurs in the ascitic compartment in correlation with the development of spontaneous bacterial peritonitis.
Abstract: We investigated 37 patients with ascites and liver cirrhosis in order to examine whether on the basis of correlation of cytokines and acute phase proteins of the ascitic fluid, prognosis of spontaneous bacterial peritonitis can be made. Significantly enhanced levels of interleukin-6, as well as acute phase reactants alpha-1-antitrypsin and C-reactive protein were found in the ascitic fluid of patients with spontaneous bacterial peritonitis. The levels of tumour necrosis factor alpha (TNF-alpha), neopterin, interleukin 2-receptor and granulocyte-macrophage colony stimulating factor were higher in patients with spontaneous bacterial peritonitis, but without statistical significance, whereas no differences were found between the interferon gamma, interleukin-2 and interleukin-1 levels. In addition, interleukin-6, TNF-alpha and neopterin levels were found to correlate significantly with the outcome of the disease. These findings show that acute phase reaction occurs in the ascitic compartment in correlation with the development of spontaneous bacterial peritonitis.
Journal Article•
TL;DR: Weight loss > 10% of body weight is associated with immune activation, and development of AIDS-defining infections, weight loss, and a decline in CD4 + T-cells are confirmed.
Abstract: OBJECTIVE To assess the risk of developing weight loss, a decline in CD4+ T-cell count and AIDS-defining infections using urinary neopterin levels and CD4+ T-cell count. DESIGN Retrospective record review. SETTING A primary care clinic for patients at any stage of HIV infection at the University Hospital in Innsbruck, Austria, to which all patients with HIV-related diseases from the Austrian Tyrol are referred. PATIENTS, PARTICIPANTS Seventy-nine out of the 311 HIV-seropositive individuals attending our clinic between July 1985 and December 1991 participated in the study. The selection was made after complete examination (clinical and laboratory) and follow-up of at least 6 months, up to 48 months (median, 28 months). Patients with severe diarrhoea were excluded. MAIN OUTCOME MEASURES Correlation between body mass index, urinary neopterin and CD4+ T-cell count; development of AIDS-defining infections, weight loss, and a decline in CD4+ T-cells. Weight loss was recognized if > 10% of body weight, and there had been no concomitant AIDS-defining infection for at least 2 months. RESULTS Initial urinary neopterin (P = 0.04), but not initial CD4+ T-cell count (P = 0.94), correlated with the body mass index obtained at the end of follow-up. Using the product-limit method, urinary neopterin predicted weight loss (P 10% of body weight is associated with immune activation.
TL;DR: The data suggest that measurement of serum neopterin may be used, together with clinical examination, to guide the treatment of patients with juvenile dermatomyositis.
Abstract: Serum neopterin concentrations were measured in 15 patients with juvenile dermatomyositis and their correlation with the severity of muscle impairment was evaluated. Neopterin concentrations were measured by radioimmunoassay. When compared with controls (median 0.75 ng/ml; range 0.33-1.18), serum neopterin concentrations were increased in patients with active juvenile dermatomyositis (median 3.21 ng/ml; range 0.95-13.81), but not in patients during remission (median 0.81 ng/ml; range 0.55-1.34). In horizontal and longitudinal studies, serum neopterin was significantly correlated with the severity of muscle strength impairment, whereas serum muscle enzyme values were not. These data suggest that measurement of serum neopterin may be used, together with clinical examination, to guide the treatment of patients with juvenile dermatomyositis.
TL;DR: Determination of urine neopterin, a non-invasive, relatively simple and inexpensive measurement, appears to be the best parameter for assessing and monitoring disease activity and treatment in patients with SLE.
Abstract: OBJECTIVES--To investigate urine neopterin as a parameter of disease activity in an unselected group of patients with systemic lupus erythematosus (SLE) and to study the relation between urine neopterin and certain patterns of organ disease and differing drug regimens in the treatment of SLE. METHODS--Neopterin was determined by high performance liquid chromatography in 115 early morning urine samples from 68 patients with SLE. Serum soluble interleukin 2 receptor (sIL-2R) and antibodies to double stranded DNA (dsDNA) were determined by enzyme linked immunosorbent assay (ELISA), and the erythrocyte sedimentation rate (ESR), plasma C3, C4, and C3 degradation products (C3dg) were measured in corresponding blood samples. Disease activity was scored using the British Isles Lupus Assessment Group (BILAG) index. RESULTS--Urine neopterin was significantly increased in patients with active and inactive SLE compared with the control group and was significantly higher in patients with active than in those with inactive SLE. Urine neopterin did not distinguish between subsets of patients with SLE with particular patterns of organ disease, as defined by the BILAG index, nor was its level primarily influenced by differing drug regimens. Levels of serum sIL-2R, antibodies to dsDNA, the ESR, and plasma C3, C4, and C3dg were also significantly different between the patients with active and inactive SLE. Unlike urine neopterin there was considerable overlap in the values of these parameters between the two activity groups. Highly significant correlations found between urine neopterin and serum sIL-2R, ESR, and plasma C3, C4, and C3dg suggest the close association of neopterin with clinical activity in SLE. Multivariate logistic regression analysis showed that urine neopterin > 300 mumol/mol creatinine was a highly significant predictor of disease activity with an odds ratio of 3.51. CONCLUSIONS--Determination of urine neopterin, a non-invasive, relatively simple and inexpensive measurement, appears to be the best parameter for assessing and monitoring disease activity and treatment in patients with SLE.
Journal Article•
TL;DR: Serum N/C is an early and sensitive marker of immune activation in the 21 days following transplantation, and both rejection and infectious complications are associated with an increased N production in the early postoperative period.
TL;DR: O Ongoing clinical trials should correlate immune changes with response, and trials exploring different schedules of administration using higher, more immunologically active, doses of levamisole should be performed.
Abstract: PURPOSEThis phase I study was conducted to determine the maximum-tolerated dose (MTD) and the immunologic properties of levamisole in cancer patients when administered alone and in combination with interferon gamma (IFN-gamma).PATIENTS AND METHODSTwenty patients with advanced cancer and 36 patients with completely resected melanoma (n = 33) or renal cell cancer (n = 3) received levamisole orally every other day for six doses at 1.0, 2.5, 5.0, or 10.0 mg/kg. Ten days later, patients restarted levamisole and began IFN-gamma 0.1 mg/m2 by subcutaneous injection every other day. Blood samples were collected for measurement of neopterin and soluble interleukin-2 receptor (sIL-2R), and for flow-cytometric analysis.RESULTSThe MTD of levamisole was 5 mg/kg, and this was not changed by the addition of IFN-gamma. Dose-related increases in serum levels of neopterin and sIL-2R were noted. Multiple doses of > or = 5 mg/kg of levamisole were required to elicit immune changes, which were more prominent in patients with m...
TL;DR: Because both values are less than the half-life of phenylalanine (20-30 h) in serum, biopterin measurement offers no advantage in monitoring dietary control in hyperphenylalaninemic patients.
TL;DR: In this paper, the authors test the hypothesis that optimal immunomodulatory activity of IFN-gamma in patients with metastatic melanoma would be obtained at a dose below the maximal tolerated dose (MTD).
Abstract: Interferon-gamma (IFN-gamma) is a potent monocyte/macrophage activating agent that in animal models exhibits a bell-shaped dose-response curve of immunomodulatory activity and antitumor efficacy. Previous clinical trials of IFN-gamma conducted at the maximal tolerated dose (MTD) have been associated with low response rates that may have been due to failure to treat at an optimal immunomodulatory dose (OID). The objective of this study was to test the hypothesis that optimal immunomodulatory activity of IFN-gamma in patients with metastatic melanoma would be obtained at a dose below the MTD. Groups of five patients each were given daily subcutaneous injections of IFN-gamma at doses of 0.01, 0.1, or 0.25 mg/m2. In vivo immunomodulation was assessed by serial measurement of serum neopterin and by flow cytometry. IFN-gamma doses of 0.1 or 0.25 mg/m2 induced significantly greater immunomodulation of monocyte-associated immune parameters than 0.01 mg/m2. Changes in immunologic parameters included marked elevation of serum neopterin levels, significant increases in monocyte expression of CD64, beta 2-microglobulin, and HLA-ABC, and decreased monocyte expression of CD14. The most dramatic decreases in CD14 expression were observed on monocytes obtained from patients treated at 0.25 mg/m2. The 0.25-mg/m2 dose group had significantly lower white blood cell counts on day 14. No bell-shaped curve of immunologic response was observed over the dosage range tested. Based on the similarity of the immunologic effects at 0.1 and 0.25 mg/m2, treatment at the MTD of IFN-gamma (0.25 mg/m2) represents treatment at the OID for patients with metastatic malignant melanoma.
Journal Article•
TL;DR: Serum levels of cICAM-1 in HIV-1-infected individuals with a recently developed ELISA correlated with the absolute number of CD4+ T cells or with disease progression according to the Walter Reed staging classification, but not with the C-reactive protein.
Abstract: The membrane-bound glycoprotein intercellular adhesion molecule 1 (ICAM-1) plays an important role for many cell-contact-dependent immune functions. A soluble, circulating form of ICAM-1 (cICAM-1) has been detected in the serum of healthy persons and increased concentrations in tumor patients have been reported. We measured serum levels of cICAM-1 in HIV-1-infected individuals with a recently developed ELISA. In contrast to HIV-seronegative controls (median value of 294 ng/ml, range of 185-408 ng/ml; n = 22), significantly elevated concentrations were detected in 76 HIV-1-infected persons (median of 487 ng/ml, range of 231-1,524 ng/ml; p < 0.0001). In HIV-1-infected individuals, cICAM-1 values did not correlate with the absolute number of CD4+ T cells or with disease progression according to the Walter Reed staging classification. Concentrations of cICAM-1 correlated with the serum concentrations of IL-6 (p = 0.0015; Spearman's rank correlation analysis) and with urinary neopterin (p = 0.005), but not with the C-reactive protein. Since there is evidence that cICAM-1 can interfere with immunological functions, the high amounts circulating in HIV-1-positive individuals could contribute to the disturbance of the immune system in HIV-1 infection.
TL;DR: Neither a biologically active but non-toxic dose of 300,000 U nIL-2, nor a toxic dose of 1.0 million U resulted in permanent clearance of hepatitis B early antigen (HBeAg).
TL;DR: The effects of IL‐3 and of the pineal hormone melatonin (MLT) on monocyte response to IL‐2 administration were evaluated to evaluate the effects of cytokines and neurohormones may influence the macrophage system.
Abstract: Background. The concomitant activation of macrophage-mediated immunosuppressive events might represent one of the most important biologic factors responsible for the decreased efficacy of cancer immunotherapies, including that of interleukin (IL)-2. In previous studies, the authors observed that the increase in the soluble IL-2 receptor (SIL-2R) and neopterin levels was related to the generation of macrophage-mediated immuno-suppression and associated with a reduced clinical efficacy during IL-2 cancer immunotherapy. Because both cytokines and neurohormones may influence the macrophage system, the current study was done to evaluate the effects of IL-3 and of the pineal hormone melatonin (MLT) on monocyte response to IL-2 administration.
Methods. Peripheral blood monocytes were incubated with different concentrations of IL-2, IL-3, and MLT, either alone or in association.
Results. SIL-2R, neopterin, and tumor necrosis factor-alpha mean concentrations in the medium significantly increased during incubation with IL-2 at a concentration of 100 Cetus units/ml. IL-3 alone, at a dose of 10 ng/ml, also stimulated tumor necrosis factor release; no effect was found on SIL-2R and neopterin. The IL-2–induced neopterin rise was blocked by a concomitant incubation with IL-3 at a dose of 10 ng/ml. Finally, the concomitant incubation with IL-3 and MLT further inhibited neopterin release and significantly decreased IL-2-induced SIL-2R secretion.
Conclusions. These results suggest that IL-3 alone or in association with MLT may modulate macrophage functions during cancer immunotherapy with IL-2 and decrease the IL-2-induced macrophage activation.