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

Human immunodeficiency virus (HIV-1) associated immune deficiency has the characteristics of chronic graft versus host disease (GVHD) caused by human leukocyte antigen (HLA) class 2 incompatibility. The envelope glycoprotein fragment TKAKRRVVEREKR mimics HLA class 1 C molecules serologically, and also mimics an immune regulatory T cell epitope, in the region of amino acids 67 to 71, within the HLA DR beta chain. This beta chain alloepitopic region (between amino acids 67 to 80) furnishes peptides predicted to bind optimally to HLA class 1 B alleles. The hypothesis predicts that viral parameters, such as viral load, and clinical parameters, such as rate of progress to acquired immune deficiency syndrome (AIDS) and severity of the associated immune deficient state, are linked to the HLA B and HLA DR beta chain haplotype in infected patients. Immune suppression is caused by HLA class 1 B restricted CD8+ T cells which normally regulate HLA class 2 DR restricted antigen specific responses. The hypothesis further predicts the severity of immune deficiency to be linked to those HLA DR beta chain allotypes which express the amino-acid glutamine (Q) in position 70.
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PMID:How HIV-1 lentivirus causes immune deficiency disease. 1034 73

Although the HLA B(*)5701 class I allele is highly overrepresented among human immunodeficiency virus (HIV)-infected long-term nonprogressors (LTNPs), it is also present at the expected frequency (11%) in patients with progressive HIV infection. Whether B57(+) progressors lack restriction of viral replication because of escape from recognition of highly immunodominant B57-restricted gag epitopes by CD8(+) T cells remains unknown. In this report, we investigate the association between restriction of virus replication and recognition of autologous virus sequences in 27 B(*)57(+) patients (10 LTNPs and 17 progressors). Amplification and direct sequencing of single molecules of viral cDNA or proviral DNA revealed low frequencies of genetic variations in these regions of gag. Furthermore, CD8(+) T-cell recognition of autologous viral variants was preserved in most cases. In two patients, responses to autologous viral variants were not demonstrable at one epitope. By using a novel technique to isolate primary CD4(+) T cells expressing autologous viral gene products, it was found that 1 to 13% of CD8(+) T cells were able to respond to these cells by gamma interferon production. In conclusion, escape-conferring mutations occur infrequently within immunodominant B57-restricted gag epitopes and are not the primary mechanism of virus evasion from immune control in B(*)5701(+) HIV-infected patients. Qualitative features of the virus-specific CD8(+) T-cell response not measured by current assays remain the most likely determinants of the differential abilities of HLA B(*)5701(+) LTNPs and progressors to restrict virus replication.
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PMID:The differential ability of HLA B*5701+ long-term nonprogressors and progressors to restrict human immunodeficiency virus replication is not caused by loss of recognition of autologous viral gag sequences. 1276 8

Selective IgA deficiency (IgAD) (serum IgA concentration of <0.07 g/l) is the most common primary immunodeficiency in Caucasians, with an estimated prevalence of 1/600. There are strong indications for involvement of genetic factors in development of the disease and the frequency of several extended major histocompatibility complex haplotypes (including HLA-A1, B8, DR3, DQ2) have previously been shown to be increased among Caucasian patients with IgAD.PCR was used to type HLA B, DR, and DQ alleles in 29 Iranian individuals with IgAD and 299 Swedish individuals with IgAD.The results indicate a strong association with the HLA B14, DR1 alleles in Iranian subjects and HLA B8, B12, B13, B14, B40, DR1, DR3, DR7, DQ2 and DQ5 alleles in Swedish subjects.Differences in HLA association of IgAD in Iran and Sweden confirm the notion of a genetic background of the disease and that multiple, potentially different genes within the MHC region might be involved in the pathogenesis of IgAD in different ethnic groups.
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PMID:Human leukocyte antigens (HLA) associated with selective IgA deficiency in Iran and Sweden. 1905 50

The activation of natural killer (NK) cells is modulated by surface molecules. We analyzed NK cells in human immunodeficiency virus (HIV)-exposed seronegative (HESN) individuals by means of molecular typing of HLA B, Cw, and killer cell immunoglobulin-like receptor (KIR) molecules. In HESN individuals, compared with HIV patients, the frequency of the inhibitory KIR3DL1 allele and of the KIR3DL1(+)/Bw4(+) inhibitory complex was reduced, whereas that of the activatory KIR3DS1(+) ligand and the activatory Bw4(+)/3DL1(-)/3DS1(+) complex was increased, resulting in a statistically significant diversion from Hardy-Weinberg equilibrium (KIR3DS1 homozygote) in HESN individuals. The reciprocal equilibrium between inhibitory and activatory NK receptors and their ligands favors NK activation in HESN individuals.
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PMID:Under representation of the inhibitory KIR3DL1 molecule and the KIR3DL1+/BW4+ complex in HIV exposed seronegative individuals. 2139 98

Serology and DNA techniques are employed for Human Leukocyte Antigen (HLA) typing in different transplant centers. Results may not always correlate well and may need retyping with different technique. All the patients (with aplastic anemia, thalassemia, and immunodeficiency) and their donors, requiring HLA typing for bone marrow transplant were enrolled in the study. Serological HLA typing was done by complement-dependent lymphocytotoxicity while DNA-based typing was done with sequence specific primers (SSP). Serology identified 167 HLA A and 165 HLA B antigens while SSP in same samples identified 181 HLA A and 184 HLA B alleles. A11 and B51 were the commonest antigens/alleles by both methods. There were a total of 21 misreads and 32 dropouts on serology, for both HLA A and B loci with HLA A32, B52 and B61 being the most ambiguous antigens. Inherent limitations of serological techniques warrant careful interpretation or use of DNA-based methods for resolution of ambiguous typing.
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PMID:Identification of HLA Class I Misreads/Dropouts Using Serological Typing, in Comparison with DNA-based Typing. 2791 29