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Query: UMLS:C0024312 (lymphopenia)
 4,859 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

HIV infection is known to induce a progressive T helper/inducer (CD4) lymphopenia and to impair the functional activities of residual cells. The present studies examined the relationship between the CD4 cell count and three functional assays: T cell colony formation in semisolid media, the capacity of PHA-stimulated cells to express IL-2 receptors, and their ability to synthesize and secrete IL-2. Cells from antibody-positive homosexuals with normal numbers of CD4 cells (greater than 700/microliters) showed defective reactivity in two assays, colony growth, and IL-2 receptor expression. These defects became progressively more pronounced in homosexuals with moderate (400-700 cells/microliters) and severe (less than 400/microliters) reductions in assays for IL-2 production by PHA-stimulated lymphocytes. Mixing experiments suggest that cells from HIV-infected men nonspecifically inhibit the colony growth of normal cells; this abnormality could be reversed by addition of exogenous IL-2. These data suggest that defective colony growth and reduced IL-2 expression are functional abnormalities directly resulting from HIV infection. Furthermore, these changes can precede the CD4 lymphopenia induced by this viral infection.
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PMID:Defective T cell colony formation and IL-2 receptor expression in HIV-infected homosexuals: relationship between functional abnormalities and CD4 cell numbers. 252 69

HLA-A, -B, -C, -DR, and -DQ antigens were determined by serology and in cases of severe lymphopenia by RFLP-DNA typing in 51 Caucasians with a diagnosis of AIDS (32 with opportunistic infections and 19 with secondary cancers). In addition, 86 HIV-1 seropositive and 39 HIV-1 seronegative drug abusers and 148 healthy controls were also studied. No significant differences in HLA antigen frequencies were found in comparison of HIV-1 seropositive and HIV-1 seronegative drug abusers with controls, suggesting that HLA polymorphism does not represent a genetic risk for infection with HIV-1. In contrast, a significant increased frequency of B35 (p less than 0.01) and CW4 (p less than 0.01) was observed in both groups of AIDS patients as compared to controls. Moreover, DR2 was increased in frequency in patients with opportunistic infections (p less than 0.01) and DR3 was completely absent in patients with secondary cancers (p less than 0.05). In the latter group, the DR5 frequency was increased, although nonsignificantly. These findings provide strong evidence for the existence of HLA-linked factors of susceptibility and host resistance to AIDS.
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PMID:HLA antigens are risk factors for development of AIDS. 278 69

The authors report on two patients who presented with sudden loss of vision, due to irodocyclitis and retinochoroiditis in one patient and optic neuritis in the other. AIDS was diagnosed in both patients on the basis of a positive HIV antibody assay, lymphopenia, and a reduced helper-to-suppressor subset ratio. Soon afterwards, the patient with retinochoroiditis developed the full-blown picture of AIDS with cerebral involvement. Neither anticytomegaly treatment with DHPG nor triple therapy for toxoplasmosis was able to prevent the fatal course. The patient died within six months. In contrast, the patient with optic neuritis recovered full visual acuity. So far there has been no relapse, nor any opportunistic infection in other organs.
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PMID:[Initial diagnosis of acquired immunologic deficiency syndrome (AIDS) by the ophthalmologist]. 282 95

Serum and CSF from 32 patients with idiopathic ALS, 30 age-matched controls and 30 MS patients were investigated regarding immunoglobulin concentration and virus-specific antibodies, the lymphocytes in the peripheral blood and lymphocyte subsets were also investigated. ALS patients' results were compared with findings in MS and controls. The ALS patients had significantly higher IgG concentration in serum than the controls, marked lymphopenia, reduction of CD2, CD8 and Leu 7 positive cells and increase of the CD4/CD8 ratio and of SIg-positive lymphocytes. Compared with the MS patients, the ALS patients showed similarity in T-subset distribution with a lower standard deviation. No HTLV-I and HIV antibodies were found in any group and no significant differences in antibody distribution to Toxoplasma G, herpes simplex, cytomegalovirus, measles and mumps viruses were evident. All ALS patients were investigated at an early disease stage, therefore, our findings seem to support the conclusion that the immune alterations are related to the mechanisms of the disease and not to complications of its evolution.
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PMID:Immunity assessment in the early stages of amyotrophic lateral sclerosis: a study of virus antibodies and lymphocyte subsets. 326 63

HIV infection in pediatric patients is a multisystem chronic disease that manifests as a clinical spectrum from asymptomatic infection through symptomatic infection with opportunistic infections and malignancies. The hematopoietic system is involved early in the systemic manifestations of this disease. The hematologic abnormalities seen are most probably a reflection of persistent viral infection, inflammation, and immune dysregulation, and may be complicated by secondary infections, chronic disease, drug toxicities, and nutritional deficiencies. Anemia and lymphopenia are commonly found in adult AIDS patients. Although both are also seen in pediatric patients, lymphopenia is much less common. Atypical lymphocytes with plasmacytoid characteristics have been identified in both adults and children. Pediatric bone marrow evaluation has shown an increase in plasma cells and plasmacytoid lymphocytes. Besides these findings, adult marrow findings include an increase in reticulum and lymphocytes appearing in a diffuse or aggregate pattern.
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PMID:Human immunodeficiency virus (HIV) infection in children. 332 80

Persistent generalized lymphadenopathy during HIV infection is now a well classified syndrome featuring multiple chronic lymph node enlargement frequently associated with further symptoms (diarrhea, nocturnal sweating, loss of weight, fever): it is invariably accompanied by serious alterations of the cell-mediated immunity including lymphopenia, reduced number of helper lymphocytes in circulation, inversion of the helper/suppressor ratio, lower proliferative response in vitro and deficient delayed skin sensitivity tests. Minor opportunistic infections are also more frequent, the most widespread being chronic oral candidiasis. Whenever several of these signs are associated in a single patient, especially if the immunitary deficit is severe, an immunomodulating treatment is indicated to improve the lymphocyte functionality and finally to modify any evolutive tendency. The Authors give the preliminary results of a pilot study carried out on 12 patients with LAS/ARC treated with Thymopentin at a dosage of 50 mg by intra muscular injection on alternate days for cycles of 30 days. Compared with 14 untreated patients, the subjects receiving therapy showed a more stable immunological picture, and improvement in subjective symptoms and a better therapeutic response to minor opportunistic infections.
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PMID:Thymopentin (TP-5) therapy during lymphadenopathy syndrome (LAS/ARC): preliminary report. 333 53

The incidence of lymphopenia, thrombocytopenia and neutropenia was studied in 105 homosexual men with HIV infection. Lymphopenia was common in patients with AIDS (75%), but its incidence in PGL (24%) was not significantly different from that in asymptomatic anti-HIV positive (15%) homosexual men. Neutropenia and thrombocytopenia were found in patients with AIDS or PGL, but not in asymptomatic anti-HIV positive homosexuals. The study suggests that the neutropenia and thrombocytopenia in these patients were due to autoimmune destruction of neutrophils and platelets.
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PMID:Incidence and mechanism of neutropenia and thrombocytopenia in patients with human immunodeficiency virus infection. 362 Mar 53

B cell dysregulation is a hallmark of human immunodeficiency virus infection. Since B lymphocytes comprise two distinct subpopulations, CD5+ and CD5- cells, we addressed their individual phenotypic and functional behavior. Seropositive patients with both limited and advanced disease progression had an increased percentage of peripheral blood CD5+ B cells, compared to seronegative controls (20.1 +/- 2.1 and 22.7 +/- 5.7, respectively, vs 17.0 +/- 3.4 in controls); however, due to the lymphopenia and reduced number of circulating B cells in infected individuals, the absolute number of CD19+CD5+ lymphocytes was actually reduced. Although HIV-specific antibodies were synthesized spontaneously in vitro only by CD5- B cells, a 10-fold lower degree of spontaneous, non-HIV-specific activation was also displayed by unstimulated CD5+ B cells. These findings indicate that B cell dysregulation during HIV infection involves both the CD5- and the CD5+ B cell compartments; moreover, in view of the putative role of CD5+ B cells in autoimmune phenomena and IL-10 production, these data reinforce the possibility that B cell dysfunction might be causally involved in AIDS pathogenesis.
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PMID:B cell activation and human immunodeficiency virus infection. V. Phenotypic and functional alterations in CD5+ and CD5- B cell subsets. 750 25

Some infants infected with human immunodeficiency virus type 1 (HIV-1) rapidly develop a fatal disease characterized by a severe lymphopenia. To explain the immune dysfunction, we proposed a mechanism by which a nongeneration of CD4+ T cells is caused by HIV-1 infection of thymic cells. To examine this hypothesis, we infected primary triple-negative (TN; phenotypically CD3- CD4- CD8-), CD1a- TN, or CD1a+ TN thymic cell subsets. Our data indicate that by flow cytometry, TN, CD1a- TN, and CD1a+ TN cells remain CD4 negative throughout the culture period. We demonstrated that TN and CD1a+ TN thymic cell subsets are susceptible to HIV-1 as is the entire thymic cell population, whereas CD1a- TN cells are not. A limited number of infected TN cells are expressing HIV-1 but the level of transcription is very high in permissive cells, as detected by in situ hybridization. We then performed blocking experiments on TN cells to examine the mechanism of HIV-1 entry into these cells. CD4 (OKT4a) monoclonal antibody blocks their infection. Finally, infection experiments on two subpopulations of TN cells (CD2+ CD7+ and CD2- CD7-) indicate that infected TN cells may correspond to both immature thymocytes and thymic dendritic cells. These data are of particular interest since infection of thymic stromal cells might result in an impairment of T-cell differentiation, which may explain a nongeneration of functional CD4+ T-cell population in the thymus. This phenomenon may play a role in AIDS pathogenesis, in particular in infants born from seropositive mothers.
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PMID:Two subpopulations of human triple-negative thymic cells are susceptible to infection by human immunodeficiency virus type 1 in vitro. 751 58

This study describes a series of immunological investigations carried out on a group of 37 HIV-seropositive children, aged 3-4 years, in two different stages of disease defined according to the CDC classification; the Primary stage, an asymptomatic one, showing abnormal immune function (P1-Class, B-Subclass) and the Secondary stage, 6-8 months later, in which patients exhibited non-specific findings, i.e., loss of weight, persistent generalized lymphadenopathy and hepatosplenomegaly, associated with abnormal immune function (P2-Class, A-Subclass). In both stages, immune function was considered 'abnormal' when lymphopenia and a decrease of the CD4/CD8-cell ratio were found. The phenotypes CD16+/56+ (NK) and HLA-DR+/CD3+ (T-activated?)-positive cells, were assessed by flow cytometry, and the following supplementary systemic humoral markers were investigated in homologus serum samples; total HIV(gp)-antibody, HIV(p24)-antibody and p24-antigen presence. If at the primary stage, no significant difference from to the reference values corresponding to the age was noticed, at the Secondary stage the obtained data is presented separately in two subgroups, namely the A-subgroup characterized by the presence of total HIV(gp)-antibody, the presence of HIV(p24)-antibody and the absence of p24-antigenaemia, and the B-subgroup, where total HIV(gp)-antibody was present, HIV(p24)-antibody absent and p24-antigenaemia present. A significant decrease of CD16+/56+ (NK)-cells was found within the two subgroups. As far as HLA-DR+ from CD(3+)-cells was concerned, only those within the B-subgroup showed a high percentage level, compared to the reference values. The importance of the present findings, linked to immune monitoring of HIV infection among children, is discussed.
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PMID:Changes of blood CD16/CD56 (NK) and HLA-DR/CD3-positive lymphocyte amounts in HIV-infected children, as related to clinical progression and p24-antigen/p24-antibody presence. 752 81


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