Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the last years high dose intravenous immunoglobulin (i.v.IG) has clearly modified the therapeutic approach toward autoimmune hemocytopenia. Their introduction has promoted the studies on the i.v.IG mechanisms of action: the hypothesis most widely accepted is the blockade of Fc-receptors in the reticuloendothelial system. It was hypothesized that low levels of anti-red blood cell antibodies contained in the i.v.IG preparations might be responsible for the Fc-receptor blockade. On this basis, anti-Rh(D) immunoglobulin has been successfully tested in Rh-positive patients with idiopathic thrombocytopenic purpura (ITP). The present paper describes the presumed mechanisms of action, clinical indications, side effects and cost of the anti-Rh(D) immunoglobulin. Until now, anti-Rh(D) has been chiefly employed in patients with ITP and human immunodeficiency virus-related ITP. However, at present, new clinical indications are emerging from studies in patients with autoimmune neutropenia, both using the intravenous and the intramuscular route. Anti-Rh(D) immunoglobulin has proved, in our and in other Authors' experience, a safe and easy to be administered treatment, at low cost and slightly lower in efficacy compared with i.v.IG.
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PMID:[Anti-Rh(D): an efficacious therapeutic alternative in autoimmune hemocytopenias]. 826 53

Thrombocytopenia is a common complication of human immunodeficiency virus (HIV) infection. Its pathogenesis has not yet been established. An increased platelet destruction either due to the nonspecific deposition of circulating immune complexes on platelets or to the presence of specific antiplatelet antibodies as well as direct infection of megakaryocytes by HIV with a resulting decrease in platelet production have been reported as possible mechanisms. About 30-50% of patients with moderate thrombocytopenia may show spontaneous remission. Patients with either severe thrombocytopenia (platelet count < 20 x 10(9)/l) or bleeding are usually first treated with corticosteroids or azidothymidine. If improvement does not occur, further therapeutic approaches are the same as for chronic idiopathic thrombocytopenic purpura. HIV-associated thrombocytopenia has no prognostic significance with regard to AIDS risk.
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PMID:[Thrombocytopenia associated with HIV infection]. 836 15

Patients with human immunodeficiency virus-type 1-immune thrombocytopenic purpura (HIV-1-ITP) have elevated polyethylene glycol (PEG)-precipitable immune complexes (ICs) composed of IgG, IgM, and complement that are threefold to sevenfold higher than in healthy control subjects. These complexes contain anti-F (ab')2 as well as anti-idiotype antibodies versus anti-HIV-1gp120. Because anti-F (ab')2 and anti-idiotype antibodies correlate with thrombocytopenia (r = .83 [J Clin Invest 77:1756, 1986] and r = .90 [J Clin Invest 89:356, 1992], respectively) we studied the binding of ICs to platelets and monocytes as well as their role in platelet-monocyte rosette formation. ICs bind to platelets in a saturation-dependent manner (optimum at 10 micrograms/mL; 0.5% of serum conc). Binding to platelets could not be inhibited with platelet saturating concentrations of aggregated IgG or with monoclonal antibody (MoAb) IV.3 versus FcR gamma II. Platelet binding could be inhibited with Fab anti-C3, anti-Clq, or anti-C4 by 57%, 40%, and 46% respectively, not with control Fab (P < .001). Monocytes from HIV-1-ITP patients form rosettes with normal platelets 16.8 +/- 5.2 rosettes/100 monocytes compared with 4.8 +/- 0.8 control monocytes plus normal platelets (P = .009). Gel-washed HIV-1-ITP platelets formed 19 +/- 2.0 rosettes with U937 cells compared to 6.3 +/- 1.0 for normal platelets (P = 0.001). Arming of U937 cells with HIV-1-ITP ICs (5 micrograms/mL) formed 36.7 +/- 2.5 rosettes compared with 10.6 +/- 1.2 for control ICs (P < .01). Rosetting of armed U937 cells could be inhibited with MoAbs versus the alpha chains of CD11a (LFA-1), 11b (Mac-1), or 11c (p150,95) by 67%, 70%, and 61%, respectively (P < .007), whereas binding of ICs to U937 cells was unaffected. Isotype-matched control as well as MoAbs versus antigens on U937 cells (CD13, CD33) or the anti-FcR gamma II receptor had no effect. However, Fab fragments of polyclonal anti-C3 inhibited rosette formation by 78% (P < .01); control Fab had no effect. Thus, platelet-monocyte rosette formation is not Fc dependent. It is complement receptor dependent and requires the cooperation of all three leuCAM integrins.
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PMID:Role of leuCAM integrins and complement in platelet-monocyte rosette formation induced by immune complexes of human immunodeficiency virus-type 1-immune thrombocytopenic purpura patients. 848 17

Our objective was to examine the efficacy and toxicity of continuous, low-dose interferon-alpha therapy for human immunodeficiency virus-related immune thrombocytopenic purpura (HIV-ITP) in a Phase II clinical trial overseen by a community-based consortium of physicians conducting clinical trials in HIV-related diseases. Sixteen patients with HIV-ITP defined by prospective clinical criteria were enrolled; the majority had failed other therapies for HIV-ITP. Baseline and serial measurements were made of platelet counts, complete blood counts, serum chemistries, platelet-associated immunoglobulin, and CD4+ T-lymphocyte counts; subjective symptoms and bleeding were recorded. Three million units of interferon-alpha 2b were self-administered by subcutaneous injection every Monday, Wednesday, and Friday for 16 weeks. Thirteen participants were evaluable for response. One obtained a complete response, eight had partial responses, and four had no response to interferon-alpha therapy. The mean absolute platelet count of the group rose from 15.5 x 10(9)/L at baseline to 47.3 x 10(9)/L at 2 weeks and remained in this range for the duration of the study. CD4+ T-lymphocyte counts and serum chemistries did not change significantly during therapy. Ability to detect platelet-associated immunoglobulin did not change in a predictable manner in relation to platelet count response. Hematologic toxicity was limited to one episode of granulocytopenia, which resolved after a lowering of zidovudine dosage. Subjective toxicities were mild and tolerable, and minor bleeding problems improved in all participants so affected. Low-dose, continuous therapy with interferon-alpha resulted in meaningful increases in the platelet counts of the majority of study participants with HIV-ITP. Interferon-alpha was safe and tolerable for most participants with HIV-ITP at the dosage and schedule employed in this study. Interferon-alpha for clinically significant thrombocytopenia and who have failed to respond to zidovudine.
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PMID:Continuous low-dose interferon-alpha therapy for HIV-related immune thrombocytopenic purpura. 854 45

We report the results of intravenous anti-D (WinRho, WinRho SD) therapy in 261 non-splenectomized patients treated at the New York Hospital-Cornell Medical Center over the period from 1987 to 1994. Children (n = 124) and adult patients (n = 137) with classic immune thrombocytopenic purpura (ITP; n = 156) or human immunodeficiency virus (HIV) related thrombocytopenia (n = 105) and acute (n = 75) or chronic (n = 186) disease at the time of the initial anti-D treatment were studied. In addition, 11 previously splenectomized patients were treated as a separate group. Our objectives were to evaluate the following. (1) Efficacy of anti-D: The response after the initial infusion was analyzed according to clinical parameters, such as patient's age, HIV status, gender, disease duration, pretreatment platelet count, and hemoglobin value, as well as treatment-related factors, including the dose of anti-D, the solvent detergent treatment of the preparation, and the type of administration. (2) Use of anti-D as maintenance therapy: The duration of response after the initial infusion and the results of subsequent treatments were evaluated. (3) Safety/toxicity of anti-D: Postinfusion reactions and hemoglobin decrease after treatment were studied. Anti-D is a safe treatment providing a hemostatic platelet increase in greater than 70% of the Rh+ non-splenectomized patients. The group with the best results is HIV- children, but all patient groups respond and the effect lasts more than 21 days in 50% of the responders. Duration of response is not influenced by HIV status; furthermore, HIV+ patients show no adverse effects on hemoglobin decrease or HIV disease progression. Patients with chronic ITP after splenectomy have minimal or no response to intravenous anti-D.
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PMID:Intravenous anti-D treatment of immune thrombocytopenic purpura: experience in 272 patients. 910 86

Nondenaturing gel electrophoresis was used to study the nucleotide substrate-induced conformational change in reverse transcriptase (RT) of human immunodeficiency virus type 1 (HIV-1). Dead-end complex was formed between HIV-1 RT, dideoxynucleotide chain-terminated primer, and DNA template in the presence of deoxynucleotide triphosphate (dNTP) complementary to the next position on the template. Complexes which form in the absence of the next complementary dNTP were disrupted by adding excess poly(rA)/oligo(dT) or heparin just prior to electrophoresis. Dead-end complex formation by noncomplementary dNTP's or ribonucleotides was at least 2000-fold less efficient than with the complementary nucleotide. When dA was the next nucleotide on the template, analogues of dTTP supported dead-end complex formation with increased apparent Kd (dTTP < dideoxy-TTP approximately alpha-thio-dTTP < dUTP < 3'-azidothymidine triphosphate). A similar relationship was observed for dGTP analogues across from dC on the template (dGTP < dideoxy-GTP < alpha-thio-dGTP << dITP < dideoxy-ITP). The optimal length of the primer/template duplex region for dead-end complex formation was between 20 and 32 base pairs. Primer-template with a mismatched primer terminus did not support dead-end complex formation, and primer terminated with 3'-azidothymidine formed dead-end complex with 25-fold elevated apparent Kd. By contrast, dead-end complex formation on primer terminated with dideoxy-IMP base paired with dC on the template was more efficient than on primer terminated with dideoxy-GMP. Implications for the mechanisms of discrimination between nucleotide analogues by HIV-1 RT are discussed.
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PMID:Nucleotide-induced stable complex formation by HIV-1 reverse transcriptase. 915 15

The influence of immunodeficiency on the course of hepatitis C virus (HCV) infection is still debated, although a worsening effect has been suggested. We compared the characteristics of hepatitis C in two groups of hematologic patients with different levels of immunocompetence who acquired the same virus strain after treatment with contaminated intravenous immunoglobulins (IVIG). Indications for IVIG therapy were idiopathic thrombocytopenic purpura (ITP) in six patients and hypogammaglobulinemia in 7 patients with various hematologic disorders, who were defined immunodeficient (ID). Infection rate was 100%. Five ID patients never developed HCV antibodies despite serum HCV-RNA positivity. The same HCV genotype was shown in 10 patients tested. Moreover, E1-E2 gene partial nucleotide sequencing, performed in four patients, showed identical or closely related amino acid sequences, thus strongly supporting the hypothesis of a common source of infection. Clinical acute infection did not differ significantly between the two groups, but subsequent liver failure developed in five of the seven ID patients and in none of the ITP patients (P = .04). Liver biopsy, performed in three cases, documented HCV as the only cause of liver damage. Six ID patients died, with liver disease being the primary cause of death in four cases and a contributory cause in two cases. Their median survival after IVIG was 12 months, significantly worse than that of ITP patients (P = .0028). We conclude that immunodeficiency markedly worsens the course of IVIG-acquired HCV infection in hematologic patients.
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PMID:Outbreak of hepatitis C virus infection in patients with hematologic disorders treated with intravenous immunoglobulins: different prognosis according to the immune status. 924 66

Idiopathic thrombocytopenic purpura (ITP), an autoimmune disease of children and adults, is characterized by low platelet counts and bleeding through mucous membranes. While not uncommon among otherwise healthy adults and children, ITP is a frequent complication of human immunodeficiency virus (HIV) infection. Anti-D is a gamma globulin (IgG) fraction containing a high proportion of antibodies to the Rh0 (D) antigen of the red blood cells. Clinical studies over the past 10 years have shown intravenous anti-D to be a safe and effective treatment for Rh-positive, nonsplenectomized patients with ITP (classic or HIV-related). While it is unlikely that anti-D is a curative treatment for ITP, repeated infusions can be used to maintain the platelet count at a level sufficient to provide adequate hemostasis (>30,000/microL) and may enable patients to postpone or even avoid splenectomy.
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PMID:Clinical experience with anti-D in the treatment of idiopathic thrombocytopenic purpura. 952 49

A retrospective study was conducted to determine treatment patterns for idiopathic thrombocytopenia purpura (ITP) across the US and to determine the cost of its treatment with high-dose intravenous immunoglobulin (IVIg) and anti-D therapy. Information on the incidence, treatment patterns, hospital care, and costs for ITP was derived from three data bases and supplemented by in-depth case studies from five hospital centers in the US. Data collection forms were developed to collect data on treatment patterns and costs at the five hospital centers. Treatment patterns were analyzed and used to model the comparative costs of IVIg and anti-D therapy. Cost estimations were based on a process and cost-finding analysis reflecting current practice patterns for the use of IVIg and anti-D therapy in an outpatient clinic. The incidence of ITP was estimated at 65 per 10,000 in human immunodeficiency virus (HIV)-positive individuals and 1.5 per 10,000 in HIV-negative individuals. Hospital discharge data from all 1991 and 1992 hospital discharges in Maryland revealed that both Medicare patients and patients who had other payment options spent less time in hospital compared to Medicaid patients. The limited case study data indicate that anti-D therapy increased platelet counts to greater than 25,000/microL in 82% of evaluable episodes and that IVIg-treated patients reached 25,000/microL in 48% of treated episodes. The estimated cost per treated episode of ITP was $4,269 for IVIg and $2,716 for anti-D therapy, reflecting a cost savings of $1,553 per episode. This retrospective study has shown that the use of anti-D therapy is associated with lower costs compared with IVIg treatment in patients with ITP. The shorter infusion time required for anti-D therapy may also contribute to a better quality of life for patients.
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PMID:Idiopathic thrombocytopenia purpura: Treatment patterns and an analysis of cost associated with intravenous immunoglobulin and anti-D therapy. 952 50

Two-thirds of children with acute idiopathic thrombocytopenic purpura (ITP) have a history of an infectious illness a few days to a few weeks before the onset of thrombocytopenia. In a subset of affected children, identification of a specific virus can be made, such as varicella zoster virus, rubella, Epstein-Barr virus, influenza, or human immunodeficiency type 1 virus, indicating an etiological role for preceding viral infection in these children with ITP. While inhibition of thrombopoiesis has been established to play a role in thrombocytopenia associated with infection with some viruses, it does not appear to play a major role in the etiology of most typical ITP cases. Rather, enhanced clearance of platelets by the reticuloendothelial system is considered to be, at least in part, responsible for the thrombocytopenia which occurs during the viremic phase of acute virus infection or which develops days to weeks following the virus illness. Molecular mimicry between viral antigens and host proteins has been implicated in a number of autoimmune phenomena, and may be involved in the enhanced platelet clearance in virus-associated ITP.
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PMID:Virus-associated idiopathic thrombocytopenic purpura. 1035 Nov 37


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