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)

Comparison of human leukocyte antigen (HLA) frequencies in patients with hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCC) and in patients with HCV-associated non-Hodgkin's lymphoma (NHL) has not been addressed previously. To this aim, we investigated the distribution of HLA class II alleles in two selected groups of HCV-infected patients. Group 1 included 50 patients with HCV-associated NHL; group 2 included 29 patients with HCV-associated HCC. A control group included 144 hospitalized patients without NHL or HCC and who were negative for HCV, hepatitis B virus, and human immunodeficiency virus antibodies. Polymerase chain reaction sequence DRB1 and DQB1 specific-primer methods were used. DRB1*1101/DQB1*0301 haplotype, which mainly favors the spontaneous clearance of HCV infection, was lower in HCC subjects than in controls, whereas HLA-DRB1*1104/DQB1*0301, was higher in NHL patients. These findings suggest different pathogenic pathways in HCC and in NHL development. In patients with HCV-associated HCC, a major protective role of DQB1*0301 allele, rather than DRB1*11, was found, probably because of a better HLA class II-associated virus clearance. By contrast, the same allele as HLA-DRB1*04 showed an increase in HCV-associated NHL. These data suggest that NHL and HCC development may be associated to a different response with respect to chronic HLA class II-restricted antigen presentation (perhaps a switch toward CD4+Th2 response in NHL?) or, alternatively, that these alleles could be in linkage disequilibrium to unrelated gene(s), or are in synergy with other immunomodulatory genes that may confer increased risk for NHL.
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PMID:Hepatitis C virus-related hepatocellular carcinoma and B-cell lymphoma patients show a different profile of major histocompatibility complex class II alleles. 1555 90

The extreme polymorphism in the human leukocyte antigen (HLA) class I region of the human genome is suggested to provide an advantage in pathogen defence mediated by CD8+ T cells. HLA class I molecules present pathogen-derived peptides on the surface of infected cells for recognition by CD8+ T cells. However, the relative contributions of HLA-A and -B alleles have not been evaluated. We performed a comprehensive analysis of the class I restricted CD8+ T-cell responses against human immunodeficiency virus (HIV-1), immune control of which is dependent upon virus-specific CD8+ T-cell activity. In 375 HIV-1-infected study subjects from southern Africa, a significantly greater number of CD8+ T-cell responses are HLA-B-restricted, compared to HLA-A (2.5-fold; P = 0.0033). Here we show that variation in viral set-point, in absolute CD4 count and, by inference, in rate of disease progression in the cohort, is strongly associated with particular HLA-B but not HLA-A allele expression (P < 0.0001 and P = 0.91, respectively). Moreover, substantially greater selection pressure is imposed on HIV-1 by HLA-B alleles than by HLA-A (4.4-fold, P = 0.0003). These data indicate that the principal focus of HIV-specific activity is at the HLA-B locus. Furthermore, HLA-B gene frequencies in the population are those likely to be most influenced by HIV disease, consistent with the observation that B alleles evolve more rapidly than A alleles. The dominant involvement of HLA-B in influencing HIV disease outcome is of specific relevance to the direction of HIV research and to vaccine design.
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PMID:Dominant influence of HLA-B in mediating the potential co-evolution of HIV and HLA. 1559 17

Before the discovery of HFE, reports suggested that hemochromatosis patients with the ancestral haplotype (or some element thereof) have more severe iron overload than those without the haplotype. We performed univariate and multivariate analyses of the relationships of human leukocyte antigen (HLA)-A*03 and HLA haplotype A*03-B*07 to iron measures (serum iron concentration, transferrin saturation, and serum ferritin concentration at diagnosis and units of phlebotomy to achieve iron depletion) in hemochromatosis probands homozygous for HFE C282Y diagnosed in medical care. Iron overload was defined by demonstration of hepatic iron index of > or =1.9 or removal of > or =2.0 g Fe by therapeutic phlebotomy. We tabulated the phenotype frequencies of HLA-A*03 and the frequencies of common HLA haplotypes A*01-B*08, A*02-B*44, A*03-B*07, and A*03-B*14 in three groups of white adults: (1) 141 hemochromatosis probands with C282Y homozygosity; (2) 195 index cases with IgG subclass deficiency (IgGSD) or common variable immunodeficiency (CVID), disorders typically linked to Ch6p, and (3) 750 control subjects. Among probands, 86 men and 42 women had iron overload. Frequencies of HLA-A and -B alleles in probands did not depart significantly from Hardy-Weinberg equilibrium. The phenotype frequency of A*03 did not differ significantly between men and women in the each of the respective three groups. The frequency of haplotype A*03-B*07 was greater in men than women with hemochromatosis (0.3081 vs. 0.1455; P = 0.0019). The frequency of A*03-B*014 was significantly greater in women than men with hemochromatosis (0.1182 vs. 0.0407, respectively; P = 0.0134). Mean values of most iron measures were not affected by numbers of copies of A*03 or by presence of A*03-B*07 in either men or women in univariate analysis. ANOVA models of sex, age at diagnosis, and all HLA alleles and haplotypes in probands were used to determine effects of these variables on iron measures. ANOVA models revealed that (1) there were no significant predictors for serum iron concentration; (2) B*14 is associated with higher transferrin saturation in women and lower transferrin saturation in men; (3) A*01-B*08 is associated with a trend of higher serum ferritin levels; and (4) A*03-B*14 is associated with exaggeration of the age-associated upward trend in units of phlebotomy to achieve iron depletion. In hemochromatosis probands with HFE C282Y homozygosity, we conclude that (1) disparate frequencies of HLA haplotypes A*03-B*07 and A*03-B*14 occur in men and women and (2) HLA-A*03 and HLA-A*03-B*07 are not independent variables associated with iron overload severity.
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PMID:HLA haplotype A*03-B*07 in hemochromatosis probands with HFE C282Y homozygosity: frequency disparity in men and women and lack of association with severity of iron overload. 1560 98

We identified polyglandular autoimmune (PGA) syndrome type III in a 24-year-old nurse with common variable immunodeficiency (CVID). An immune-mediated disorder, membranoproliferative glomerulonephritis, was diagnosed when she was 15 years old. Clinical examination and laboratory findings revealed a PGA syndrome due to the presence of hypergonadotropic hypogonadism, insufficient growth hormone response and thyroid autoimmunity. The patient had neither adrenal disease nor hypoparathyroidism. Therefore we concluded that this patient has PGA syndrome type III. This is an interesting case, because we could not find any previous report of such coexistence between PGA type III and CVID in a Medline search. Coexistence of these two entities may be a result of autoimmunity and the association of both conditions with human leukocyte antigen.
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PMID:Polyglandular autoimmune syndrome type III accompanied by common variable immunodeficiency. 1678 52

Within human immunodeficiency virus type 1 (HIV-1)-infected patients, there are those who have been infected for more than 10 years with a CD4+ cell count of >500 cells microl(-1) and who remain asymptomatic without antiretroviral therapy; these patients are designated long-term non-progressors (LTNPs). In a set of 16 LTNPs, viral dating, DNA viral load, quasispecies heterogeneity and antibody (Ab) titres against gp160 and beta2 microglobulin (beta2m) were determined. Plasma viral RNA and CD4+ and CD8+ T-cell numbers were estimated in more than three samples per patient. Host genetic characteristics, such as Delta32-CCR5 genotype and human leukocyte antigen (HLA) genotype and supertypes, and clinical-epidemiological factors were evaluated. Dating of global populations and of DNA and RNA viral quasispecies identified two subsets of patients: one displaying only ancestral sequences and the other displaying predominantly modern sequences. The ancestral patients displayed a significant reduction in RNA and DNA viral loads, quasispecies heterogeneity, CD8+ cell number, anti-gp160 Ab titres and beta2m level, and they were also associated with better use of safe-sex practices and higher presence of the HLA sB58 supertype than the modern subset. Viral dating has therefore permitted the segregation of LTNPs into two subsets that show very different virological, immunological, host and clinical-epidemiological characteristics. Moreover, whereas the modern subset displayed low levels of virus replication, the ancestral group displayed not only a very limited virus replication, often to undetectable levels, but also very slow or arrested viral evolution, maintaining the close relationship of the viral population to the transmitted virus.
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PMID:A subset of human immunodeficiency virus type 1 long-term non-progressors is characterized by the unique presence of ancestral sequences in the viral population. 1565 55

Immune activation is thought to play a major role in the pathogenesis of human immunodeficiency virus (HIV). This effect may be particularly relevant in Africa, where endemic coinfections may contribute to disease progression, perhaps as a consequence of enhanced immune activation. We investigated the expression of CD38 and human leukocyte antigen (HLA)-DR on T cells in 168 HIV-seropositive volunteers in Uganda. We observed higher levels of CD4(+) and CD8(+) T cell activation in Uganda, compared with those reported in previous studies from Western countries. Coexpression of CD38 and HLA-DR on both CD4(+) and CD8(+) T cell subsets was directly correlated with viral load and inversely correlated with CD4(+) T cell counts. In antiretroviral therapy (ART)-naive volunteers, viral load and CD4(+) T cell count had stronger associations with CD8(+) and CD4(+) T cell activation, respectively. Virus suppression by ART was associated with a reduction in T cell activation, with a stronger observed effect on reducing CD8(+) compared with CD4(+) T cell activation. The presence of coinfection was associated with increased CD4(+) T cell activation but, interestingly, not with increased CD8(+) T cell activation. Our results suggest that distinct mechanisms differentially drive activation in CD4(+) and CD8(+) T cell subsets, which may impact the clinical prognostic values of T cell activation in HIV infection.
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PMID:T cell activation in HIV-seropositive Ugandans: differential associations with viral load, CD4+ T cell depletion, and coinfection. 1568 82

Antigen presentation and immune activation are essential to the effective control of infectious diseases. In 485 North American adolescents at high risk for genital Chlamydia trachomatis infection, we found 2 human leukocyte antigen variants (DRB1*03-DQB1*04 and DQB1*06) to be associated with recurrent Chlamydia infection (adjusted relative odds [RO], >2.0; P<.01, for both variants). A G-C-C haplotype corresponding to variants at IL10 (encoding interleukin-10 [IL-10]) promoter positions -1082, -819, and -592 was underrepresented in individuals with recurrent infection (RO, 0.59; P=.046). These genetic associations were independent of nongenetic factors, including number of sex partners, race, sex, duration of follow-up, and human immunodeficiency virus type 1 seropositivity. Consistent with the observed IL10 association, cervical secretions in female adolescents without the IL10 G-C-C haplotype had elevated IL-10 concentrations after Chlamydia infection, which may reflect involvement of a Chlamydia-specific mechanism for genetically mediated, differential IL-10 expression in the genital tract.
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PMID:Human leukocyte antigen and cytokine gene variants as predictors of recurrent Chlamydia trachomatis infection in high-risk adolescents. 1574 44

A patient with cervical non-Hodgkin lymphoma was treated with chemotherapy. Fourteen months after the diagnosis of the lymphoma, an endometrial adenocarcinoma was detected as a secondary malignant tumor. The patient was treated with surgery followed by radiotherapy. Approximately 7 years after the diagnosis of endometrial cancer, vaginal invasive squamous cell carcinoma was diagnosed as the third primary malignancy, and a second-line palliative radiotherapy was applied. Seven months after the last radiotherapy, postradiational sarcoma in the vagina was diagnosed. Congenital and acquired immune system disorders, viral oncogenes, and various human leukocyte antigen (HLA) types were investigated. Total blood count and lymphocyte subset analysis were performed, and CD4+ lymphopenia was detected. Serologic tests were carried out for human immunodeficiency virus, hepatitis B virus, human papillomavirus, Epstein-Barr virus, and herpes simplex virus infection. Epstein-Barr virus viral capsid antigen IgG was found positive. Low-risk human papillomavirus panel was detected by Hybrid Capture method in the cervical smear. The HLA investigation revealed HLA-A2, HLA-A3, HLA-B57, HLA-B35, HLA-B4, HLA-B6, HLA-DR3, HLA-DR1, HLA-DR51, HLA-DR52, HLA-DQ6(1), and HLA-DQ7(3). The patient died because of the disease.
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PMID:A case with multiple gynecological malignancies. 1582 28

Polymorphisms of genes in the human leukocyte antigen (HLA) complex, particularly those encoding HLA-DR, have been suggested as markers of susceptibility to Kaposi's sarcoma (KS). We conducted a case-control study comparing 147 homosexual men who developed KS after infection by human immunodeficiency virus-1 (HIV-1) and human herpes virus 8 (HHV8) with 147 matched dually infected men without HIV-associated KS (HIV-KS) from the Multicenter AIDS Cohort Study. HLA-B, DRB1, DRB3, DRB4, DRB5, and DQB1 polymorphisms were examined by high-resolution DNA-based methods. Differences in distributions of genetic variants were tested by conditional logistic regression. Previously reported relationships with HLA-DRB1 alleles could not be confirmed. Instead, other associations were observed. In univariate analysis, KS was weakly associated with B*2702/5 (odds ratio (OR)=0.40, 95% confidence interval (CI)=0.18-0.91). Similar or stronger associations, positive or negative, were seen for haplotypes containing class II alleles: DRB1*1302-DQB1*0604 (OR=3.67, 95% CI=1.02-13.1), DRB4 (DR53) haplotype family members [OR=0.52, 95% CI=0.32-0.85], and DRB3 (DR52) haplotype family members (OR=1.69, 95% CI=1.07-2.67). The B*1402-DRB1*0102 haplotype, which invariably contains the V281L mutation in the 21-hydroxylase gene governing adrenal steroid biosynthesis, occurred in five cases and one control (OR=5.0, 95% CI=0.58-42.8). In a final multivariable analysis, only DRB1*1302-DQB1*0604 (OR=6.43, 95% CI=1.28-32.3, P=0.02) remained significantly associated with KS. Associations of HLA-DRB families with HIV-KS could reflect underlying immune dysregulation. The HLA B*1402-DRB1*0102 haplotype associated with increased risk of KS might represent an antigen-presenting pathway unfavorable for immune response to HHV8. Alternatively, the relationship might hold a clue to the predilection of KS for men because that haplotype harbors the mutant form of the 21-hydroxylase gene.
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PMID:HLA-B, -DRB1/3/4/5, and -DQB1 gene polymorphisms in human immunodeficiency virus-related Kaposi's sarcoma. 1590 98

Multiple mechanisms are used by the human immunodeficiency virus type 1 (HIV-1) to interfere with host-cell immune effector functions. The 27-kD Nef protein has been shown to down-modulate specific genes of the major histocompatibility complex class I (MHC-I) on the surface of infected primary T cells, facilitating their escape from lysis by cytolytic T lymphocytes. Macrophages, as the other major immune cell type targeted by the virus, also contribute to the transmission, persistence, and pathogenesis of HIV-1. Yet, whether Nef modulates MHC-I expression on HIV-infected primary macrophages remains unclear. Currently available infectious HIV-1 molecular clones, which express a reporter gene, only infect T cells and/or do not express Nef. To overcome these limitations, we generated macrophage-tropic green fluorescent protein (GFP)-tagged HIV-1 viruses, which express the complete viral genome, and used these to assess the expression of human leukocyte antigen (HLA)-A2 on the surface of productively infected macrophages. The reporter viral genomes were replication-competent and stable, as Nef, p24 antigen, and GFP expression could be detected by immunostaining of infected, monocyte-derived macrophages (MDM) after more than 2 months postinfection. Fluorescence-activated cell sorter analyses of infected macrophages and T cells revealed that although wild-type reporter virus infection induced a statistically significant decrease in the density of surface HLA-A2, down-regulation of HLA-A2 was not seen in cells infected with reporter viruses encoding a frameshift or a single point mutation in Nef at prolines 74P and P80. The impact of Nef on HLA-A2 surface expression in MDM was also confirmed by confocal microscopy. These results suggest that the mechanisms of HLA-A2 down-modulation are similar in primary T cells and macrophages.
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PMID:HLA-A2 down-regulation on primary human macrophages infected with an M-tropic EGFP-tagged HIV-1 reporter virus. 1600 Mar 90


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