KIR : HLA association with clinical manifestations of HBV infection in Madurai, south India

KIR/HLA ligands immunogenetics markers associated with outcome of hepatitis B virus infection in the Bulgarian population

BACKGROUND

Hepatitis B virus (HBV) infection is one of the most common infections worldwide, having negative impact on world health due to the tendency for chronification with late complications such as liver cirrhosis and hepatocellular carcinoma. Natural killer (NK) cells as part of innate antiviral defense influence the clinical course of HBV infection: elimination of the virus or chronic disease.

AIM

Therefore, we investigated the polymorphisms of the main gene systems, regulating NK-cell function: killer cell immunoglobulin-like receptors (KIRs) and their appropriate HLA class I ligands in 144 HBV infected patients (124 chronic carriers and 20 spontaneously recoved) and 126 ethnically matched healthy controls from the Bulgarian population in a case-control study.

METHODS

KIRs and HLA ligands were determined by PCR-SSP or PCR high-resolution typing methods.

RESULTS

KIR2DL5B allele variant was significantly less frequent in spontaneously recovered (SR) patients compared to healthy controls (10.0% vs. 45.5%, P^corr=0.006). The presence of KIR3DL1*004 allele was higher in chronic HBV carriers (CH) than in controls (33.1% vs. 17.6%, P^corr=0.036). Additionally, SR patients differed from healthy individuals by the lower frequency of HLA-Bw4^Ile80 group ligands (30.0% vs 63.7%, P=0.015). Three KIR genotypes were found more frequent in healthy in comparison with HBV infected individuals: ID2 (13.5% vs 5.6%, P=0.025), KIR genotype containing 6 activating KIRs (18.0% vs 7.6%, P=0.017), and KIR genotype composed of 4 activating and 5 inhibitory KIRs (23.8% vs 5.6%, P=0.001).

CONCLUSION

These data suggest that inherited KIR and HLA class I ligand polymorphisms may influence the clinical course of HBV infection.

A meta-analysis of association of Human Leukocyte Antigens A, B, C, DR and DQ with Human Papillomavirus 16 infection

Human Papillomavirus (HPV) induced cervical cancer (CaCx) is a major health problem in women from both developing and developed regions of the world. This virus accounts for >95% of the CaCx cases with a preponderance of HPV type -16 (65%). Paradoxically HPV-16 is prevalent even in the cervix of healthier women and anti HPV-16 T-cell response is considered critical for the viral clearance. Studies on HLA association with HPV-16 infection and cervical cancer have yielded varied HLA associations in different epidemiological settings. To validate these associations, we performed a meta-analysis of HLA-A, B, C, DR and DQ association with HPV-16 infection. Of the 1409 studies retrieved, 26 qualified for meta-analysis based on stringent inclusion and exclusion criteria. HLA-B*47, B*57, DRB1*10, DRB1*15 and DQB1*0303 were significantly associated with HPV-16 infection (OR = 3.4, 1.8, 1.5, 1.1 and 1.5 respectively). HLA-B*49, B*39, A28 (serotype), C*04 and DRB1*13 were negatively associated with HPV-16 (OR = 0.5, 0.6, 0.7, 0.7, and 0.7 respectively). Certain HLA alleles such as B*07, DRB1*15, DRB1*11 and DRB1*07 showed weakly positive associations. A comprehensive analysis coupling HPV-16 antigenic diversity and the HLA variation in various global populations shall provide further insights into the immunogenetic predisposition to HPV-16 and shall help identify host-parasite co-evolution.

Analysis of swine leukocyte antigen class I gene profiles and porcine endogenous retrovirus viremia level in a transgenic porcine herd inbred for xenotransplantation research

Molecular characterization of swine leukocyte antigen (SLA) genes is important for elucidating the immune responses between swine-donor and human-recipient in xenotransplantation. Examination of associations between alleles of SLA class I genes, type of pig genetic modification, porcine endogenous retrovirus (PERV) viral titer, and PERV subtypes may shed light on the nature of xenograft acceptance or rejection and the safety of xenotransplantation. No significant difference in PERV gag RNA level between transgenic and non-transgenic pigs was noted; likewise, the type of applied transgene had no impact on PERV viremia. SLA-1 gene profile type may correspond with PERV level in blood and thereby influence infectiveness. Screening of pigs should provide selection of animals with low PERV expression and exclusion of specimens with PERV-C in the genome due to possible recombination between A and C subtypes, which may lead to autoinfection. Presence of PERV-C integrated in the genome was detected in 31.25% of specimens, but statistically significant increased viremia in specimens with PERV-C was not observed. There is a need for multidirectional molecular characterization (SLA typing, viremia estimation, and PERV subtype screening) of animals intended for xenotransplantation research in the interest of xeno-recipient safety.

KIR-HLA distribution in a Vietnamese population from Hanoi

The KIR (killer cell immunoglobulin-like receptors) gene family codifies a group of receptors that recognize human leukocyte antigens (HLA) and modulate natural killer (NK) cells response. Genetic diversity of KIR genes and HLA ligands has not yet been deeply investigated in South East Asia. Here, we characterized KIR gene presence and absence polymorphism of 14 KIR genes and two pseudogenes, as well as the frequencies of the ligands HLA-Bw4, HLA-C1 and HLA-C2 in a Vietnamese population from Hanoi (n = 140). Genotyping was performed by polymerase chain reaction with specific sequence primers (PCR-SSP). We compared KIR frequencies and performed principal component analysis with 43 worldwide populations of different ancestries. KIR carrier frequencies in Vietnamese were similar to those reported for Thai and Chinese Han, but differed significantly from other geographically close populations such as Japanese and South Korean. This similarity was also observed in KIR gene-content genotypes and is in accordance with the origin from Southern China and Thailand proposed for the Vietnamese population. The frequencies of HLA ligands observed in Vietnamese did not differ from those reported for other East-Asian populations (p > .05). Studies regarding KIR-HLA in populations are of prime importance to understand their evolution, function and role in diseases.

Analysis of clinical features and pathology of serum HBsAg positive glomerulonephritis

To analyze the relationship between the factors related to the occurrence of HBV-GN and serum HBsAg-positive glomerulonephritis. A total of 56 patients were enrolled in the present study. All enrolled cases were divided into two groups according to whether HBsAg and/or HBcAg was present in renal kidney tissue: patients with Hepatitis B virus-associated nephritis (HBV-GN group, 30 cases) and patients with hepatitis B virus-combined nephritis (HBV-CG group, 26 cases). We sought to analyze the differences in clinical features and pathological characteristics in both groups. The rate of HBeAg positivity in the HBV-GN group was considerably increased in the HBV-CG group (P < 0.05), and the number of patients with HBsAg+HBeAg+HBcAb+ in the HBV-GN group was considerably increased in the HBV-CG group (21 cases vs 10 cases) (P < 0.05). Moreover, the number of MCD patients diagnosed by renal biopsy in the HBV-GN group was reduced compared with the HBV-CG group (1 case vs 7 cases) (P < 0.05). HBV infection and high-virus proliferation status were closely related with HBV-GN.

The impact of KIR-HLA genotype on hepatitis B virus clearance in Iranian infected individuals

Killer cell immunoglobulin like receptors (KIRs) have a principal role in regulating the effector functions of NK cells, particularly in viral infections. The major ligands for KIRs are human leukocyte antigen (HLA) class I molecules. The aim of this study is to investigate the possible association of KIR genes, their known HLA ligands and compound KIR-HLA genotypes with hepatitis B virus (HBV) infection. Our study group consisted of 202 Iranian HBV-infected patients (52 spontaneously recovered, 50 asymptomatic carriers, 50 chronic sufferers and 50with liver cirrhosis) and 100 ethnic-matched healthy control subjects. KIR and HLA genotyping was performed by a polymerase chain reaction-sequence-specific primer (PCR-SSP). The frequencies of the KIR2DL5A, KIR2DS1, and KIR3DS1 genes were significantly elevated in recovered individuals when compared with both control and patient groups. Also, KIR2DL5, and KIR3DP1 full were escalated in recovered individuals in comparison with patient groups. In addition, HLA-Bw4 ligand and HLA-A Bw4 were highly frequent in recovered individuals compared with healthy controls. Furthermore, the KIR3DS1 + HLA-Bw4, KIR3DS1 + HLA-Bw4 ^Iso80 , and KIR3DS1 + HLA-A Bw4 genotypes were significantly more common in recovered individuals than both healthy control and patient groups. Interestingly, AA genotype had less frequency and Bx had higher frequency in recovered individuals compared with both healthy control and patient groups. Our findings suggest a potential impact of the NK cells' activating phenotype that leads to the HBV clearance in infected individuals.

Human leukocyte antigen A, B and Hepatitis B infection outcome: A meta-analysis

AIM

To evaluate the association between HLA A, B with chronic Hepatitis B by comprehensive meta-analysis.

METHODS

We searched PubMed and Cochrane databases, identified relevant studies, evaluated these for quality by New Castle Ottawa scale (NOS) and further analyzed the qualified data sets. Heterogeneity analyses were performed by Cochrane's Q test and I² tests. Pooled Odds ratio (OR) & 95% Confidence Interval (CI) were obtained by fixed effects, using Mantel-Haenszel's method for homogenous studies, and by using DerSimonian and Laird's method for heterogenous studies. Publication bias was determined by the Beggs test and Eggers test and all tests were two tailed to evaluate their significance.

RESULTS

The meta-analyses on 1652 healthy controls and 659 Chronic Hepatitis B (CHB) patients from 8 studies from various continents revealed a HLA B*07 (p value of Odds ratio (pOR)=0.004; OR Fixed effects=0.480 with 95%CI 0.290-0.794) and B*58 (pOR=0.029; OR Fixed Effects=0.020 with 95%CI 0.381-0.949) associated protection for CHB. The identified HLA B*35 associated risk (pOR 0.009; OR Fixed effect 1.445; 95% confidence interval 1.094-1.907) however did not stand the test of random effect model.

CONCLUSION

While HLA B*07 and B*58 are protective against CHB. The HLA B*35 associated marginal risk need to be further validated in well-designed global study on larger cohorts, considering the population, ethnic, epidemiological and HLA diversity at the sequence level: these may throw further light to utilize these markers in predictive medicine.