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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Uncertainty has existed as to whether a T-cell deficiency exists in human immunodeficiency virus (HIV) infection different from that inherent in the reduced T-cell numbers characteristic of the disease. Heretofore, methods for measuring T-cell responses in patients have been carried out with systems requiring monocytes as accessory cells. In the presence of high concentrations of interleukin-2, however, highly purified T cells respond in a monocyte-independent fashion to antibody reactive with the CD3 component of the antigen receptor complex Ti/CD3. Highly purified T cells of HIV-infected patients responded subnormally in this anti-CD3/IL-2 system, even in the case of patients who were asymptomatic or had only lymphadenopathy. The defective T-cell responses occurred over a wide range of concentrations of the anti-CD3. Neither poor IL-2 receptor function as reflected by responses to limiting dilutions of IL-2 nor IL-1 receptor function as defined by incremental proliferation when IL-1 is added accounted for this defect, which also correlated poorly with T4 and T8 numbers. These results suggested that the T-cell abnormality was closely related to Ti/CD3 function, was not specifically or restrictively associated with T4 cells, and was not due to defective IL-2- or IL-1-receptor functions. The amount of HIV RNA in 10(5) T lymphocytes from the patients amounted to less than that found in one cell of a standard HIV infected laboratory cell line (CEM), using slot-blot hybridization. Thus the T-cell deficiency we have observed was not likely to be due directly to cell killing by HIV resident in the T4 cells. Other factors may be important in inducing the immunodeficiency, some of which are discussed.
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PMID:Impairment in T-lymphocyte responses during early infection with the human immunodeficiency virus. 278 31

Unique laboratory abnormalities, found in pediatric patients with clinical features of immunodeficiency, led to the original observation that a syndrome of acquired immunodeficiency (AIDS) was also occurring in pediatric populations. Initial observations which demonstrated the nonspecific findings of polyclonal hypergammaglobulinemia and T-cell deficiency were followed by confirmatory findings when testing for the AIDS retrovirus became available. In the pediatric population availability of antibody testing and viral isolation became critical in differentiating primary immunodeficiency disorders which involved both the B- and T-cell systems from AIDS associated with retrovirus infection. At this time based upon clinical, epidemiologic, immunologic, and serologic studies, the syndrome of pediatric AIDS can be distinguished from other primary and secondary pediatric immunodeficiency disorders.
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PMID:Laboratory investigation of pediatric acquired immunodeficiency syndrome. 301 72

Two infants with immunodeficiency with predominant T-cell defects received transplants of HLA-identical bone marrow cells along with thymopoietin pentapeptide (TP-5) treatment and no prior immunosuppressive therapy. Both patients achieved durable engraftment with early reconstitution of cell-mediated immunity. The study of cell surface antigens with monoclonal antibodies (MoAb) revealed that the early appearance of T-cell subsets defined by OKT4 and OKT8 MoAb occurred. Neither of the patients showed any signs or symptoms of graft versus host disease over a 1-year period. This experience suggests that patients with T-cell deficiency who do not benefit from thymic hormones alone can be successfully treated by bone marrow transplantation. The association of TP-5 with bone marrow transplantation seems to induce an early and stable reconstitution and to protect against fatal post-transplant infection.
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PMID:Bone marrow transplantation and thymopoietin pentapeptide treatment in two infants with immunodeficiency with predominant T-cell defects. 638 71

By a sensitive enzyme-linked immunosorbent assay, inactive variant nucleoside phosphorylase (NP) protein could be quantitated in red cells and cultured skin fibroblasts from the probands and parents in four families with enzyme-deficient members. Three different mutant alleles could be identified that, in the homozygous state, could lead to T-cell immunodeficiency. The mutant alleles formed proteins that differed from normal NP protein by their stability, catalytic activity, or isoelectric charge. Thus, sensitive biochemical techniques can demonstrate the presence of different mutations for purine NP. Any of the mutations can be responsible for a lack of purine NP and the development of the characteristic T-cell deficiency syndrome.
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PMID:Purine nucleoside phosphorylase deficiency. Measurement of variant protein in four families with enzyme-deficient members by an enzyme-linked immunosorbent assay. 677 6

We have previously described a new type of selective T-cell deficiency (STD) characterized by persistent infections reminiscent of severe combined immunodeficiency (SCID). We show here that STD patients carry a mutation of zap-70 resulting in a loss of the activity of this kinase. The thymus of zap-70-/- patients shows the presence of CD4CD8 double positive cells in the cortex, however, only CD4 but not CD8 single positive cells are present in the medulla. Peripheral CD4+ T cells from the zap-70-/- exhibit markedly reduced tyrosine phosphorylation, fail to produce IL-2, and do not proliferate in response to TCR stimulation by mitogens or antigens. Thus Zap-70 kinase appears to be indispensable for the development of CD8 single positive T cells as well as for signal transduction and function of single positive CD4 T cells.
Immunodeficiency 1995
PMID:Selection transduction defect (STD) due to Zap-70 kinase deficiency. 774 39

Allogeneic bone marrow transplant (BMT) recipients have increased susceptibility to infections for prolonged periods after phenotypic reconstitution of donor cells. This immunodeficiency status is characterized by multiple T-cell functional abnormalities. This study was designed to investigate several signaling pathways involved in T-cell activation during this period of immune deficiency. In initial experiments using equal numbers of CD3+ cells or highly purified T-cell subpopulations obtained from normal controls and BMT recipients, we confirmed that abnormal T-cell proliferation after CD3 cross-linking, phytohemagglutinin stimulation, or phorbol myristate acetate (PMA) stimulation of peripheral blood mononuclear cells from BMT recipients was due to a qualitative T-cell deficiency rather than to low numbers of circulating T cells. We next investigated the ability of the T-cell receptor/CD3 complex to transduce signals via receptor-associated protein tyrosine kinases. In all BMT recipients, CD3 cross-linking induced protein tyrosine phosphorylation of several proteins in a similar fashion to that seen in controls, including phosphorylation of a 21-kD protein that represents the zeta subunit of the receptor itself. Further investigation showed that CD3 cross-linking and PMA stimulation did not increase 42-44-kD mitogen-activated protein kinase (MAPK) activity. The failure of MAPK activation in BMT recipients occurred despite tyrosine phosphorylation of the 42-44-kD proteins, which, in normal controls, parallels enzyme activation. Our results indicate that T-cell immunodeficiency in BMT recipients is associated with a selective failure of MAPK activation, possibly related to abnormal posttranslational positive regulation of this enzyme.
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PMID:Defective activation of mitogen-activated protein kinase after allogeneic bone marrow transplantation. 882 56

Primary immunodeficiency comprises a heterogeneous group of disorders. Autoimmune and/or rheumatic manifestations are not uncommon in these patients. It may be the first and/or sole sign before the underlying disease is established. This study focuses on the children of primary immunodeficiency with autoimmune disease to survey the clinical and laboratory finding retrospectively. From January 1985 to June 1998, ten patients (M:F = 9:1) of primary immunodeficiency with at least one well defined autoimmune disease were identified. The underlying immunodeficiency included three with Bruton's disease, three with common variable immunodeficiency, one with hyper-IgM, one with primary CD4 T-cell deficiency and two with Wiskott-Aldrich syndrome. The autoimmune manifestations include arthritis in six, ulcerative colitis in one, and autoimmune hemolytic anemia in three children. The major treatment was steroid and non-steroid anti-inflammatory drug. Infection could be controlled with antibiotics and intravenous immunoglobulin in all save one. The morbidity among these patients included bronchiectasis with pulmonary hypertension in three, joint stiffness, short stature, and delayed puberty in two. In conclusion, autoimmune diseases are frequently seen in patients with primary immunodeficiency. It could be the first and/or sole sign of disease. The possibility of immunodeficiency should be kept in mind when evaluating patients with autoimmune diseases.
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PMID:Autoimmune manifestations in patients with primary immunodeficiency. 1091 Jun 21

The case of a 29-year-old Caucasian woman with 45 X0 karyotype, known as Turner's syndrome, and a recently diagnosed selective T-cell deficiency is reported. The main clinical features of the patient were recurrent sinopulmonary infections and a negative skin test with seven common recall antigens. Laboratory findings included lymphocytopenia, highly elevated CD45RA/CD45R0 ratio, as well as reduced expression of the co-stimulatory molecules CD154, CD86, CD80 and CD28 on CD4+ cells in combination with disturbed lymphocyte transformation in vitro. Markedly decreased levels of interleukin (IL)-2R, both on lymphocyte surface as well as the soluble analog, suggest a new form of x-linked immunodeficiency associated with Turner's syndrome.
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PMID:Selective T-cell deficiency in Turner's syndrome. 1110 46

Patients with a moderate X-linked combined immunodeficiency (XCID) owing to a single missense mutation in the common gamma chain (gammac) gene (L-->Q271) were found to have a progressive T-cell deficiency. Blood T cells from four older subjects with XCIDL-->Q271 were studied to ascertain the basis of that progression. Few CD4+ T cells displayed the phenotype (CD45RA+ CD62L+) or deletion circles from T-cell receptor (TCR) Vbeta-gene rearrangements found in recent thymic emigrants. These deficiencies were more severe in older males with XCIDL-->Q271. Relative frequencies of fresh CD4+ and CD8+ T cells that bound annexin V, an early indicator of programmed cell death, or propidium iodide, an indicator of cell necrosis, were greater in XCIDL-->Q271 T cells than in normal fresh T cells. The binding of annexin V and propidium iodide to XCIDL-Q271 T cells increased marginally after stimulation with anti-CD3, but binding by fresh or stimulated XCIDL-Q271 T cells exceeded that found in normal stimulated T cells. Also, telomeres from XCIDL-->Q271 CD4+ T cells were shortened in these patients compared to normal young adults. It therefore appears that the thymus is dysfunctional and that mature T cells are not effectively rescued from apoptosis or replication senescence via gamma-mediated pathways in XCIDL-->Q271.
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PMID:Genesis of progressive T-cell deficiency owing to a single missense mutation in the common gamma chain gene. 1190 33

Genetic defects in T-cell function lead to susceptibility to infections or to other clinical problems that are more grave than those seen in disorders resulting in antibody deficiency alone. Those affected usually present during infancy with either common or opportunistic infections and rarely survive beyond infancy or childhood. The spectrum of T-cell defects ranges from the syndrome of severe combined immunodeficiency, in which T-cell function is absent, to combined immunodeficiency disorders in which there is some, but not adequate, T-cell function for a normal life span. Recent discoveries of the molecular causes of many of these defects have led to a new understanding of the flawed biology underlying the ever-growing number of defects. Most of these conditions could be diagnosed by means of screening for lymphopenia or for T-cell deficiency in cord blood at birth. Early recognition of those so afflicted is essential to the application of the most appropriate treatments for these conditions at a very early age. The latter treatments include both transplantation and gene therapy in addition to immunoglobulin replacement. Fully defining the molecular defects of such patients is also essential for genetic counseling of family members and prenatal diagnosis.
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PMID:Primary cellular immunodeficiencies. 1199 95


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