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)

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

Circulating lymphocyte subset imbalance is associated with type-1 insulin-dependent diabetes mellitus (IDDM). To examine the imbalance in these immunoregulatory cells in Kuwaitis with type-1 diabetes and their first-degree relatives we analysed T-lymphocyte subsets and HLA-DR expression (activation) in 18 IDDM patients with a family history of IDDM and 18 non-diabetic first-degree relatives of the IDDM patients. Both IDDM patients and their first-degree relatives showed a mild lymphopenia. Total T lymphocytes, CD3+ cells, in IDDM patients and their first-degree relatives were reduced compared to control subjects (P < 0.001). Total B lymphocytes, CD19+ cells, was increased in IDDM patients (P = 0.001), but was comparable to controls in IDDM patients' first-degree relatives. No quantitative abnormality was demonstrated in CD4+ cells in IDDM patients; however, these cells were higher in their first-degree relatives (P = 0.0089). Suppressor T lymphocytes, CD8+ cells, in first-degree relatives and controls were not significantly different; however, these cells were significantly reduced in IDDM patients (P = 0.001). The ratio of CD4+/CD8+ cells was higher in IDDM patients and their first-degree relatives compared to controls (P = 0.0007 and 0.0103, respectively). Activated T lymphocytes, HLA-DR+ CD3+ cells, were significantly increased in IDDM patients and their first-degree relatives. HLA-DR3 was the most common antigen found in IDDM patients (77% vs. 20% in controls, P = 0.00021). The second most common antigen was HLA-DR4 (55% vs. 24% in controls, P = 0.0566). However, no relationship was found in the levels of CD3+, CD4+ or CD8+ cells in patients possessing either DR3 or DR4. These results suggest that T-lymphocyte subset imbalance not only characterizes the cellular autoimmunity in the pathogenesis of IDDM but may also be significant in early pre-diabetic stages in those with a family history of IDDM.
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PMID:Abnormal lymphocyte subsets in Kuwaiti patients with type-1 insulin-dependent diabetes mellitus and their first-degree relatives. 874 21

Regulatory T cells (Tregs) are essential for the maintenance of tolerance to self and non-self through cell-intrinsic and cell-extrinsic mechanisms. Peripheral Tregs survival and clonal expansion largely depend on IL-2 and access to co-stimulatory signals such as CD28. Engagement of tumor necrosis factor receptor (TNFR) superfamily members, in particular TNFR2 and DR3, contribute to promote peripheral Tregs expansion and sustain their survival. This property can be leveraged to enhance tolerance to allogeneic transplants by tipping the balance of Tregs over conventional T cells during the course of immune reconstitution. This is of particular interest in peri-transplant tolerance induction protocols in which T cell depletion is applied to reduce the frequency of alloreactive T cells or in conditioning regimens that allow allogeneic bone marrow transplantation. These conditioning regimens are being implemented to limit long-term side effects of continuous immunosuppression and facilitate the establishment of a state of donor-specific tolerance. Lymphopenia-induced homeostatic proliferation in response to cytoreductive conditioning is a window of opportunity to enhance preferential expansion of Tregs during homeostatic proliferation that can be potentiated by agonist stimulation of TNFR.
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PMID:The Role of TNFR2 and DR3 in the In Vivo Expansion of Tregs in T Cell Depleting Transplantation Regimens. 3239 43