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

Blood monocytes were analyzed in 28 patients with chronic lymphocytic leukemia without previous cytotoxic therapy and without recent infection. Using monoclonal antibodies and flow cytometry, monocytes identified by LeuM3 or My4 were low in percentage (2.3%), but absolute numbers were increased in many patients with values exceeding the normal range (120 to 510/microliter) in seven of 28 patients. Monocytosis was more prominent in patients with high leukemic counts, but there was no correlation to clinical stages. Monocytopenia was evident with less than 50 LeuM3+ cells/microliter in three patients. Two-color fluorescence was used for the analysis of cell surface expression of major histocompatibility complex (MHC) Class II molecules, complement receptors, and Fc receptors on the LeuM3+ monocytes. Compared to cells from control donors, there was an increase for MHC class II antigens, complement receptors, and Fc receptors on the monocytes in chronic lymphocytic leukemia, in terms of both the percentage of positive cells among the LeuM3+ monocytes and of fluorescence intensity. This increase was not restricted to patients with monocytosis nor were the molecules always upregulated concomitantly. The increase of antigen expression on LeuM3+ monocytes was more than 50% (1.5-fold) in seven of 22 patients for MHC Class II antigens, in seven of 16 patients for complement receptor and in six of 12 patients for Fc receptor. A similar decrease of antigen expression was observed only in one patient for MHC Class II and in one patient for complement receptor expression. Monocytosis and increased expression of monocyte cell surface antigens described for a large portion of patients might be causally involved in the immunodeficiency in chronic lymphocytic leukemia.
 ...
PMID:Abnormal blood monocytes in chronic lymphocytic leukemia. 340 22

Classic immune thrombocytopenia purpura (ITP) occurs predominantly in women and is associated with either normal or impaired Fc receptor-mediated clearance of antibody-coated cells. Recently, an increasing incidence of thrombocytopenia has been observed in homosexual men, but whether Fc receptor-mediated clearance of antibody-coated cells is normal or impaired in these men is unknown. To study this question, we measured the in vivo clearance of anti-Rho(D) IgG antibody-sensitized 51Cr-labeled autologous red cells in five homosexual men with thrombocytopenia without an evident cause. All five had antibodies to human immunodeficiency virus, and four had circulating immune complexes as determined by a Clq-binding assay. Two of the men tested also had an increase in platelet-associated IgG. In the four homosexual men with platelet counts of 20,000/microL or less, the clearance half-time of IgG-sensitized red cells was prolonged (mean, 106 minutes; range, 72 to 140 minutes) as compared with the clearance of such cells in five hematologically normal men (mean, 39 minutes; range 30 to 50 minutes; P less than .005). One homosexual man with a platelet count of 81,000/microL had a normal clearance half-time (30 minutes). Three patients whose platelet counts increased after corticosteroid therapy were restudied. In all three, the clearance of antibody-coated cells was shortened and returned to normal in the one patient who had achieved a complete remission. No correlation was observed between the presence of platelet-associated IgG or circulating immune complexes and the clearance half-time. These data indicate that severe thrombocytopenia occurring in homosexual men as in some patients with classic ITP is associated with defective in vivo Fc receptor-mediated clearance of antibody-coated cells.
 ...
PMID:Homosexual men with thrombocytopenia have impaired reticuloendothelial system Fc receptor-specific clearance. 360 78

The CD4 molecule, which is known to play an important role in the susceptibility of T lymphocytes to infection by the human immunodeficiency virus (HIV), is also expressed in small amounts on the surface of monocytes. Since monocytes can also be infected by the virus, we investigated peripheral blood monocytes of patients with the acquired immunodeficiency syndrome (AIDS), AIDS-related complex (ARC), and HIV seropositive and seronegative haemophiliacs without symptoms for the expression of the CD4 molecule and for other functionally important surface molecules such as CD11 (C3bi receptor), transferrin receptor, Fc receptor, and the three major histocompatibility complex (MHC) class II antigens HLA-DP, HLA-DR, and HLA-DQ. With immunofluorescence staining and flow cytometry no difference was found between patients and controls for the expression of the CD4 molecule and for the other antigens as assessed by the percentage of positive staining and the specific fluorescence intensity in a double marker analysis. The percentage of CD4+ monocytes was found to be 59.2 +/- 14.4% for 16 patients with AIDS and 52.9 +/- 12.8% for 12 healthy controls. Similar to our results on phenotype, we found no significant difference with respect to the production of tumour necrosis factor (TNF), in that monocytes of AIDS and ARC patients showed an increase in TNF secretion after stimulation with LPS comparable to controls.
 ...
PMID:Monocyte phenotype and function in patients with the acquired immunodeficiency syndrome (AIDS) and AIDS-related disorders. 368 87

Four children with an immunodeficiency involving the absence of leukocyte membrane glycoproteins reacting with anti-LFA-1 and OKM-1 monoclonal antibodies were unable to mediate adherence-dependent leukocyte functions. Even with normal Fc receptor function, their PMN-ADCC and MC-NKC were markedly deficient. Single cell analysis demonstrated deficient antibody-mediated PMN-target cell adherence. Monoclonal antibodies against LFA-1 and OKM-1 reproduced this immunodeficiency in leukocytes from normal adults. LFA-1/OKM-1 mediates a PMN-target cell adhesive step.
 ...
PMID:Defective natural killer cytotoxicity and polymorphonuclear leukocyte antibody-dependent cellular cytotoxicity in patients with LFA-1/OKM-1 deficiency. 609 61

An inherited defect os suppressor T-lymphocytes has been hypothesized in Hashimoto's thyroiditis. To assess this hypothesis, human T-lymphocyte subsets (TG, T lymphocytes with surface receptors for the Fc fragment of immunoglobulin G; TM, T lymphocytes with Fc receptor for immunoglobulin M) have been studied in nine patients affected by the disease. To cells have been previously shown to be suppressors in the pokeweed mitogen-stimulated B-cell differentiation and have proved abnormal in several autoimmune or immunodeficiency disorders. The number of TG lymphocytes in the patients did not differ from that in normal controls. It is possible that 1) suppressor T-lymphocytes are not involved in the pathogenesis of Hashimoto's disease or 2) antigen-specific suppressor T-cells are involved, but too are low in number with respect to total TG.
 ...
PMID:Human T-lymphocyte subpopulations in Hashimoto's disease. 697 Feb 4

The human immunodeficiency virus (HIV) gp120 and gp41 envelope proteins and Staphylococcus aureus protein A (SPA) all have Fc receptor (FcR)-like immunoglobulin binding factor (IBF) activity for the Fc constant fragments of human immunoglobulin G (IgG). Viral IBF may contribute to the pathology of HIV by jamming the network of FcR signals that control FcR-dependent immunity. Conversely, the bacterial IBF SPA has anti-retroviral activity that may involve antagonism of the immunopathological action of viral IBF, strongly suggesting IBF may act as a double-edged sword that might be turned against viral invaders.
 ...
PMID:The role of immunoglobulin binding factors in the pathogenesis and therapy of AIDS. 781 74

Cytomegalovirus has been suggested as a co-factor of disease progression in patients with human immunodeficiency virus type 1 infection. Cytomegalovirus infection is highly prevalent among populations at risk of human immunodeficiency virus 1 infection, and has been associated with both an increased susceptibility to infection and a more rapid course of the disease towards immunodeficiency. Cytomegalovirus can have a direct immunosuppressive effect (through infection of immune cells) and can enhance the replication of human immunodeficiency virus (through the transactivation of the genic immunodeficiency virus expression, the stimulation of cytokine production, and the increase in Fc receptor expression on target cells). The role of cytomegalovirus as a co-factor of the progression towards immunodeficiency in subjects infected with the human immunodeficiency virus type 1 needs to be elucidated with more extensive clinical studies and the application of new molecular biology techniques.
 ...
PMID:Cytomegalovirus as a co-factor of disease progression in human immunodeficiency virus type 1 infection. 791 33

Modified and intact immunoglobulin preparations are available for therapeutic use. The administration of intravenous immunoglobulins (IVI G) gave positive results in Primary Immunodeficiency Syndromes (PIS) (prophylaxis of viral and bacterial diseases), in treatment of secondary immunodeficiencies (hematologic malignancies, bone marrow transplantation), and in some infections. Adverse reactions have been reported during IVIG infusions, but they are rarely serious and do not represent limiting conditions for a short or long term therapy. After the original observation in thrombocytopenic purpura, IVIG have been used as immune modulators in various autoimmune related disorders. Various mechanisms of action are proposed: blockade and down regulation of phagocytic function via Fc receptor, regulation of idiotype-anti idiotype network, suppression of idiotype synthesis, T-B cell interference towards antigen presentation, increase in suppressor lymphocytes, IVIG-cytokine interaction.
 ...
PMID:Immunoregulation of autoimmune disorders: the role of intravenous immunoglobulins. 801 87

We investigated the effect of human immunodeficiency virus type 1 (HIV-1) recombinant gp120 (rec.gp120) on phenotype and function of cultured monocytes. Rec.gp120 significantly reduced the accessory function of monocytes to stimulate autologous lymphocytes with anti-CD3, the Fc receptor-mediated chemiluminescence of monocytes, and the expression of CD4 and Fc receptor I/II, while the expression of the monocyte marker CD14 and major histocompatibility complex class I and II was not influenced. According to these phenotypic results, preincubation of monocytes with rec.gp120 depressed anti-CD3 antibody-induced T cell stimulation and Fc receptor-mediated phagocytosis as determined by chemiluminescence. Interferon-gamma release of lymphocytes induced by purified protein derivative of tuberculin was enhanced by gp120. These effects of isolated gp120 on monocyte immune functions in vitro might contribute to the understanding of the pathophysiology of HIV-1 infection in vivo.
 ...
PMID:HIV-1 envelope protein gp120 affects phenotype and function of monocytes in vitro. 814 26

Previous studies have described the isolation of monoclonal antibodies that neutralize human immunodeficiency virus type 1 (HIV-1). However, although certain antibodies are capable of blocking infection of CD4+ cells, the antibody-HIV-1 complex could potentially remain infectious and enter cells by an Fc receptor-mediated mechanism. Indeed, one goal of HIV-1 therapy with antibodies is the development of reagents capable of killing virus. The present studies with murine monoclonal antibody (MoAb) NM-01 demonstrate complement-mediated lysis of HIV-1. NM-01-dependent virolysis has been visualized by electron microscopy. Virus particles treated with NM-01 and rabbit or human complement undergo a process of outer envelope rupture and loss of the electron-dense core. The involvement of human complement in this process was confirmed by the presence of C9 in association with MoAb NM-01 immune complexes. In contrast, virolysis was not detectable with antibody or complement alone. Moreover, although MoAb NM-01 alone is capable of neutralizing HIV-1, the presence of rabbit complement was associated with over a 10-fold decrease in infectivity. Similar but less pronounced effects were observed with human complement. These findings support a potential role for antibody-dependent complement-mediated virolysis in HIV-1 therapy.
 ...
PMID:Complement-dependent virolysis of HIV-1 with monoclonal antibody NM-01. 836 67


<< Previous 1 2 3 4 5 6 Next >>