Genetic host factors may modify the course of the hepatitis C virus (HCV) infection. Very recently, a genome-wide scan that reported association of the IL28B locus with response to treatment in HCV infection was published. The aim of the current study was to investigate the relationship of this locus with outcome of HCV infection in a cohort constituted by a total of 731 Spanish individuals. From these, 284 were subjects with persistent infection, 69 were individuals who naturally cleared the virus, and 378 were noninfected subjects. Genotyping of the rs12979860 (C>T) in the IL28B locus was performed using a TaqMan 5 0 allelic discrimination assay. , OR 5 0.32; 95%CI, 0.18-0.57); and lastly, patients with sustained response (60.2% versus 32.1% found in patients with nonsustained response, P 5 3.1 3 10 25 , OR 5 0.31; 95%CI, 0.17-0.56). Conclusion: We have found different rates of viral genotype infection depending on the IL28B variant as well as an association of this locus with natural and treatment-mediated response. (HEPATOLOGY 2010;52:33-37) H epatitis C virus (HCV) infection is estimated to affect 170 million people worldwide. This infection results in a chronic active hepatitis in more than 80% of the infected patients, of which 20%-30% develop progressive fibrosis and cirrhosis, whereas only approximately 10%-20% of the infected people spontaneously eliminate the virus.

Objective. To analyze the associations of HLA class I1 antigens with rheumatoid arthritis (RA) in a Spanish population.Methods. We used DNA oligotyping to determine DR types, DQAl and DQBl alleles, and DR4 variants in 70 unrelated seropositive RA patients and 189 healthy controls living in Spain.Results. A significantly higher frequency of DR4 was seen in RA patients compared with controls (relative risk [RR] = 2.40). The DRlO specificity correlated most strongly with disease susceptibility (RR = 3.84). A significant decrease in the frequency of DR7 was observed in the RA patients (RR = 0.48). DR4-Dw15 (DRB1*0405) was found to be the unique DR4 allele associated with RA (RR = 4.27, P < 0.05), whereas Dw4 (DRB1*0401) and Dw14 (DRB1*0404/0408) showed no association, and both DwlO (DRB1*0402) and Dw13 (DRB1*0403/0407) were negative risk factors for the disease. Approximately one-third of the cases of RA could not be explained by the "shared epitope" hypothesis. Investigation of the DQ alleles associated

Cytotoxic T-lymphocyte antigen 4 (CTLA4) polymorphisms located in the promotor region at positions -318 (C/T) and in exon 1 (49 A/ G) were investigated in 138 Spanish patients (37 men and 101 women) with rheumatoid arthritis and in 305 ethnically-matched healthy controls. When the allelic and genotypic frequencies corresponding to the CTLA4 -318 position were compared, no significant differences between patients and controls were found. However, when the CTLA4 49 A/G polymorphism was analysed, a significant increase of A/G heterozygous individuals among female patients (48.5% vs. 33.8% in controls; P=0.008; OR=2.0) was observed. This increase was absent among males (37.8%, P=NS). Analysis of the CTLA4 49 polymorphism with respect to HLA-DRB1 typing demonstrated a significant increase of A/G heterozygosity in the HLA-DR3-positive patient group compared with HLA-DR3-negative patient group (14/19, 74% vs. 49/119, 41%; P=0.009, OR=4.0). The increase of A/G genotype among HLA-DR3-positive patients was found in both males (4/6, 67%) and females' (10/13, 77%), although statistical differences were only reached in the female group. These results provide new insight into this complex association, confirm previous data from other studies, and suggest that the CTLA4 gene could be involved in the pathogenesis of rheumatoid arthritis.

Behçet's disease (BD) is a multifactorial disorder associated with the HLA region. Recently, the ERAP1 gene has been proposed as a susceptibility locus with a recessive model and with epistatic interaction with HLA-B51. ERAP1 trims peptides in the endoplasmic reticulum to optimize their length for MHC-I binding. Polymorphisms in this gene have been related with the susceptibility to other immune-mediated diseases associated to HLA class I. Our aim was, the replication in the Spanish population of the association described in the Turkish population between ERAP1 (rs17482078) and BD. Additionally, in order to improve the understanding of this association we analyzed four additional SNPs (rs27044, rs10050860, rs30187 and rs2287987) associated with other diseases related to HLA class I and the haplotype blocks in this gene region. According to our results, frequencies of the homozygous genotypes for the minor alleles of all the SNPs were increased among patients and the OR values were higher in the subgroup of patients with the HLA-B risk factors, although differences were not statistically significant. Moreover, the presence of the same mutation in both chromosomes increased the OR values from 4.51 to 10.72 in individuals carrying the HLA-B risk factors. Therefore, although they were not statistically significant, our data were consistent with an association between ERAP1 and BD as well as with an epistatic interaction between ERAP1 and HLA-B in the Spanish population.

IntroductionAccording to genome wide association (GWA) studies as well as candidate gene approaches, Behçet’s disease (BD) is associated with human leukocyte antigen (HLA)-A and HLA-B gene regions. The HLA-B51 has been consistently associated with the disease, but the role of other HLA class I molecules remains controversial. Recently, variants in non-HLA genes have also been associated with BD. The aims of this study were to further investigate the influence of the HLA region in BD and to explore the relationship with non-HLA genes recently described to be associated in other populations.MethodsThis study included 304 BD patients and 313 ethnically matched controls. HLA-A and HLA-B low resolution typing was carried out by PCR-SSOP Luminex. Eleven tag single nucleotide polymorphisms (SNPs) located outside of the HLA-region, previously described associated with the disease in GWA studies and having a minor allele frequency in Caucasians greater than 0.15 were genotyped using TaqMan assays. Phenotypic and genotypic frequencies were estimated by direct counting and distributions were compared using the χ2 test.ResultsIn addition to HLA-B*51, HLA-B*57 was found as a risk factor in BD, whereas, B*35 was found to be protective. Other HLA-A and B specificities were suggestive of association with the disease as risk (A*02 and A*24) or protective factors (A*03 and B*58). Regarding the non-HLA genes, the three SNPs located in IL23R and one of the SNPs in IL10 were found to be significantly associated with susceptibility to BD in our population.ConclusionDifferent HLA specificities are associated with Behçet’s disease in addition to B*51. Other non-HLA genes, such as IL23R and IL-10, play a role in the susceptibility to the disease.

CD81, the scavenger receptor-BI (SR-BI) and the low-density lipoprotein receptor (LDLR) are involved in peripheral blood mononuclear cells (PBMCs) hepatitis C virus (HCV) entry. To investigate if these molecules are altered by HCV, 20 controls and 66 patients: 37 untreated and 29 sustained virological responders, were studied. CD81 and LDLR expression, measured the percentage of cells expressing the HCV-receptors and their mean fluorescence intensity (MFI), was analyzed on lymphocytes and monocytes, as well as SR-BI on monocytes by flow cytometry. RNA was extracted from PBMCs and detection of the HCV-RNA positive and negative strands was performed by strand-specific RT-PCR. A statistically significant increase of CD81 expression was observed on lymphocytes, a higher percentage of LDLR on lymphocytes and monocytes, as well as SR-BI on monocytes was found in the patients as compared to the controls (P < 0.05 in all cases). Untreated patients showed a higher percentage of LDLR(+) lymphocytes than sustained virological responders (P = 0.025). Nineteen sustained virological responders bore the HCV-RNA positive strand in PBMCs; nine of them the negative strand too. Sustained virological responders with occult infection and viral replication, showed a higher expression of LDLR on lymphocytes (P < 0.05) and a higher LDLR MFI on monocytes (P = 0.011) than those without viral replication. In conclusion, HCV exposure modifies expression levels of the receptors studied, being LDLR related with HCV replication, not only in the classic but also in the occult infection.

Our results support involvement of the CASP7 gene in the susceptibility to RA. The higher production of the no functional variant of CASP7 by individuals with a particular genotype could be the basis of this association.

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