Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024312 (lymphopenia)
 4,859 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The immune dysfunction in human immunodeficiency virus (HIV) infection is complex and cannot be explained solely on the basis of numerical depletion of T lymphocytes. Inappropriate, uncontrolled activation of the immune system may be involved. In a test of this hypothesis, five HIV-infected children were prospectively treated with prednisone and selected immunologic and virologic indices were analyzed. Subjects had marked T lymphopenia (CD4+ T lymphocytes < 500 cells/ml) and antigenemia (serum p24 antigen > 30 pg/ml) and were free of opportunistic infections. There was a significant drop in serum p24 antigen concentrations from baseline (60.2 +/- 10.1% SEM; P < 0.005) 4 weeks after initiation of prednisone, which returned to baseline concentrations as the prednisone was tapered. Concomitant with this decrease, there was decreased expression of cell surface activation markers (HLA-DR, CD25 (interleukin 2 receptor) and CD26 (Ta-1)) in peripheral T lymphocytes. There was no significant change in either T lymphocyte subset numbers or mitogen and antigen-specific lymphoproliferation. A regulatory dysfunction of the immune system, allowing inappropriate activation of T lymphocytes, may be involved in the pathogenesis of HIV disease, and further studies involving selective immunosuppression in HIV disease are warranted.
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PMID:Immunologic and virologic effects of glucocorticoids on human immunodeficiency virus infection in children: a preliminary study. 790 39

Immune activity during infancy was investigated using blood samples from 30 neonates and 52 healthy infants between 2 and 15 months of age attending for immunization. The purpose of this study was to assess the total immune activity of T cells using soluble interleukin-2 receptor (IL-2R) and interferon-gamma concentrations. These were compared with the proportion of CD4 CD45RO-, IL-2R (CD25)-, and transferrin receptor (CD71)-positive peripheral blood lymphocytes. The median duration of breast-feeding and of introduction of solid feeds was 4.2 and 4.0 months, respectively. Compared to neonates, the mean +/- SE soluble IL-2R concentration peaked at 4 months of age (1670 +/- 94 vs 3060 +/- 252 U/ml; P < 0.0001), as did pooled interferon-gamma levels. The percentage of CD4 CD45RO T cells remained low and the proportion of activated peripheral blood lymphocytes decreased during infancy. We conclude that noncirculatory immune activity is increased during infancy and this is associated with weaning.
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PMID:Immune activation during infancy in healthy humans. 819 12

The objective was to elucidate the immunological abnormalities underlying polymyositis (PM) and dermatomyositis (DM). The phenotype of peripheral blood mononuclear cell (PBMNC) subsets and cell surface expression of activation (CD25 and HLA-DR) and adhesion (LFA-1) molecules was studied in 12 patients with PM and in 10 patients with DM. PBMNC subsets and expression of T-cell activation molecules were evaluated by cytofluorography. Double immunofluorescence and indirect immunoperoxidase techniques were applied to muscle biopsies to define T-cell phenotype and LFA-1/ICAM-1 expression. In PM, the absolute number of circulating cytotoxic (CD8+CD28+) T cells was selectively reduced. T cells showed increased expression of activation molecules, CD25 and HLA-DR, and increased adhesion capacity as the absolute numbers of CD3+CD25+, CD8+HLA-DR+, CD3+LFA-1+('bright') and CD8+ CD8+LFA-1+('bright') cells were higher than in healthy donors and DM patients. In PM muscle biopsies, T cells were mainly CD3+CD8+ and LFA-1+; additionally, endothelial cells and myofibres surrounded by T cells showed positive staining for ICAM-1. In DM, there was a general lymphopenia that led to a decreased absolute number of all T-lymphocyte subsets. It is proposed that in PM, in contrast to DM, LFA-1/ICAM-1 interactions enable activated CD8+ T cells to migrate selectively into the inflamed muscle and to adhere to myofibres, leading to tissue injury.
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PMID:T-lymphocyte immunophenotyping in polymyositis and dermatomyositis. 881 Jun 66

Open-heart surgery with cardiopulmonary bypass (CPB) and abdominal surgery are associated with lymphocytopenia. We measured a panel of adhesion and activation molecules on lymphocytes to clarify possible association of CPB with increased expression of these molecules. Eight patients undergoing open-heart surgery and eight with abdominal surgery were studied. The adhesion molecules CD11a/CD18 (LFA-1_, CD11c/CD18 and CD44 and the activation molecules CD25, CD69, CD71 and MHCII were measured, using monoclonal antibodies and flow cytometry. Lymphocytopenia was observed during CPB and for some hours after both open-heart and abdominal surgery. The proportion of CD11a/CD18-positive lymphocytes rose from 67.6 +/- 8% to 86.4 +/- 3% after aortic declamping (p < 0.05). The expression of activation molecules CD25, CD69 and CD71 was unchanged during and after open-heart as well as abdominal operations. Thus CPB was associated with increased expression of the adhesion molecule CD11a/CD18 on lymphocytes, while the expression of activation molecules on lymphocytes was unchanged.
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PMID:Expression of adhesion and activation molecules on lymphocytes during open-heart surgery with cardiopulmonary bypass. 921 96

We determined in 14 patients with pleural tuberculosis total lymphocyte count, T subsets and NK cells (CD56) in pleura and blood and it was found a preferential accumulation in pleura of CD3 T lymphocytes, TCR alpha beta, mainly CD4 subset, but not T or NK cells. In 5 pleuritis it was studied 40% of V beta TCR subfamilies in blood and pleura and in 2 pulmonary tuberculosis and one pleuritis all V beta and V alpha TCR subfamilies (trough PCR), without be observed a clear clonal expansion. It was not observed correlation among a) pleural and blood lymphocyte cellularity b) the amount of pleural effusion and the existence of lymphopenia or tuberculinic anergia c) levels of ADA and percentage of CD3 and CD4 cells in pleura. In 7 out 11 pleuritis a high expression of IL-2 receptor (CD25) was observed. In 24 patients with pleural and pulmonary tuberculosis there was not correlation between levels of SIL-2R and IL-6 and radiographic extension.
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PMID:[Lymphocyte activation in tuberculous pleuritis . Correlation with adenosine deaminase (ADA), peripheral blood lymphocytes, T cell receptor subfamilies, radiographic extension and levels of Il-6 and soluble Il-2 receptor]. 954 1

The fatal disease induced by SIVsmmPBj4 clinically resembles endotoxic shock, with the development of severe gastrointestinal disease. While the exact mechanism of disease induction has not been fully elucidated, aspects of virus biology suggest that immune activation contributes to pathogenesis. These biological characteristics include induction of peripheral blood mononuclear cell (PBMC) proliferation, upregulation of activation markers and Fas ligand expression, and increased levels of apoptosis. To investigate the role of immune activation and viral replication on disease induction, animals infected with SIVsmmPBj14 were treated with one of two drugs: FK-506, a potent immunosuppressive agent, or PMPA, a potent antiretroviral agent. While PBMC proliferation was blocked in vitro with FK-506, pig-tailed macaques treated preinoculation with FK-506 were not protected from acutely lethal disease. However, these animals did show some evidence of modulation of immune activation, including reduced levels of CD25 antigen and FasL expression, as well as lower tissue viral loads. In contrast, macaques treated postinoculation with PMPA were completely protected from the development of acutely lethal disease. Treatment with PMPA beginning as late as 5 days postinfection was able to prevent the PBj syndrome. Plasma and cellular viral loads in PMPA-treated animals were significantly lower than those in untreated controls. Although PMPA-treated animals showed acute lymphopenia due to SIVsmmPBj14 infection, cell subset levels subsequently recovered and returned to normal. Based upon subsequent CD4(+) cell counts, the results suggest that very early treatment following retroviral infection can have a significant effect on modifying the subsequent course of disease. These results also suggest that viral replication is an important factor involved in PBJ-induced disease. These studies reinforce the idea that the SIVsmmPBj model system is useful for therapy and vaccine testing.
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PMID:Postinoculation PMPA treatment, but not preinoculation immunomodulatory therapy, protects against development of acute disease induced by the unique simian immunodeficiency virus SIVsmmPBj. 1048 16

This study shows that naive CD8 T cells can acquire characteristics of memory T cells in the absence of stimulation with specific Ag simply by the process of homeostatic proliferation under lymphopenic conditions. This Ag-independent T cell differentiation pathway did not result in up-regulation of early activation markers (CD69, CD25, CD71), but expression of several memory markers (CD44, CD122, Ly6C) increased progressively with successive divisions. These markers were then stably expressed, and these cells also became more responsive functionally to specific Ag. Thus, all "memory" phenotype T cells in an individual may not be true Ag-experienced cells and may include naive cells masquerading as memory cells. These findings are specially relevant in cases of disease or treatment-induced lymphopenia such as in HIV-infected individuals or transplant recipients. In addition, this study may have implications for autoimmunity because homeostatic proliferation of naive T cells requires interaction with self peptide plus MHC molecules.
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PMID:Cutting edge: naive T cells masquerading as memory cells. 1092 49

We previously demonstrated that the rat thymus undergoes a progressive remodelling long before the appearance of typical signs of involution [Quaglino, D., Capri, M., Bergamini, G., Euclidi, E., Zecca, L., Franceschi, C., Pasquali Ronchetti, I., 1998. Age-dependent remodelling of rat thymus. Morphological and cytofluorimetric analysis from birth up to one year of age. Eur. J. Cell. Biol. 76, 156-166]. To focus better on the complex remodelling that occurs in the rat immune system during the first year of life, we analysed the phenotype profile of thymocytes, and T lymphocytes from mesenteric lymph nodes and peripheral blood of the same animals by flow cytometry. Two experimental sets were performed simultaneously using the same animal strain, but starting and ending the study at different ages (15 days up to 300 days in the first experimental set, and 90 days up to 360 days of life in the second). In the rat these ages appear to be crucial not only for developmental, maturative and early involutional processes of the thymus, but also of the entire immune system. The main findings were the following: (1) in the thymus, CD8(-)CD4(-) cells increased, CD5(+)alphabeta TCR(-) and CD8(+)CD4(+) thymocytes decreased, while the most mature cell subset appeared well preserved with ageing; (2) in the lymph nodes, T helper and T cytotoxic lymphocytes decreased in the most aged animals. Memory/activated CD4(+)CD45RC(-) T cells decreased, while naive/resting CD4(+)CD45RC(+) cells increased in the youngest animals and decreased in the oldest. CD8(+)CD45RC(-) and CD8(+)CD45RC(+) lymphocytes showed a complex age-dependent trend, and (3) in peripheral blood, minor modifications were evident, such as an age-dependent increase in the alphabeta TCR(+)CD25(+) cell subset. Some of these changes were related to the developmental process, while others could likely be interpreted as early signs of immunosenescence. The role of these modifications in immune system is discussed within the framework of the remodelling hypothesis of immunosenescence. The age-dependent changes in these three lymphoid compartments, however, appear to be different and only partially overlapping, thus suggesting that the maturational, developmental and ageing processes have distinct characteristics in the central and peripheral lymphoid organs.
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PMID:A cytofluorimetric study of T lymphocyte subsets in rat lymphoid tissues (thymus, lymph nodes) and peripheral blood: a continuous remodelling during the first year of life. 1097 83

The patient M.S, 24 years old has been admitted to the Department of Obstetrics and Perinatology of University School of Medicine in Lublin with diagnosis: V pregnancy, bronchial asthma. History taken from the patient revealed four recurrent pregnancy losses. The patient has taken prednisone in the dose 10 mg per day for several weeks. After performing immunological phenotyping of lymphocytes we have found some alterations in the patient's immune status: increased T CD4:TCD8 ratio, increased percentage of B CD19+ and B CD19+5+ lymphocytes, increased percentage of Natural Killer cells CD3(-)16/56+, deficiency of T CD8+ suppressor lymphocytes and increased expression of CD25 and HLA-DR antigens on T CD4+ lymphocytes. According to the obtained results we have increased prednisone dose to 20 mg per day. After forty days of prednisone therapy in the dose mentioned above patient's immunological status has evolution favorably: T CD4:TCD8 ratio decreased, percentage of B CD19+ and B CD19+5+ lymphocytes decreased, percentage of Natural Killer cells CD3(-)16/56+ decreased, the expression of CD25 and HLA-DR antigens on T CD4+ lymphocytes decreased. Due to the PROM (premature rupture of membranes), and obstetric anamnesis the patient was qualified for caesarean section (21st of September 1998). Male baby was born in good general condition (weight 1180 g, Apgar score 8 pts.). The baby was discharged from Prematurity Department 10th of November 1998 in good general status (weight 2180 g). The child was observed for one year after being discharged from the ward, psycho-physical development is normal.
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PMID:[Pregnancy after four recurrent pregnancy losses: a case report]. 1100 58

Primary infection of rhesus macaques with pathogenic strains of simian immunodeficiency virus (SIV) leads to rapid and dynamic changes in both viral load and T cell counts in the peripheral blood. We have performed a sequential analysis of peripheral blood CD4 and CD8 T cells in five macaques during the 8 weeks following SIVmac251 infection. We observed a transient lymphopenia of both CD4 and CD8 T cells during the first 2 weeks, followed by a rebound. The primary phase of infection was associated with changes in the T cells expressing CD25, CD69, or HLA-DR and with a priming of the peripheral blood CD4 and CD8 T cells for a process of apoptosis in vitro that was enhanced by CD95 (Fas) ligation, and was detected in two macaques as early as 7 days after infection. Despite the small numbers of animals studied, the importance of the early transient CD4 and CD8 T lymphopenia was positively correlated with the viral load. No correlation was found, however, between the level of activation markers expressed or of priming for apoptosis in peripheral blood T cells and the viral load. Our findings suggest the possibility that the early activation and priming for apoptosis of CD4 and CD8 T cells may involve indirect, host-related, mechanisms, or alternatively, that the T cells that remain in the peripheral blood during primary infection do not adequately reflect the viral-mediated changes in T cell activation and death that may occur in the lymphoid organs throughout the body.
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PMID:Early changes in peripheral blood T cells during primary infection of rhesus macaques with a pathogenic SIV. 1108 74


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