HLA-B*57 and IFNL4-related polymorphisms are associated with protection against HIV-1 disease progression in controllers.

Background: HIV-1-controllers maintain HIV-1 viremia at low levels (normally <2000 HIV-RNA copies/mL) without antiretroviral treatment. However, some HIV-1-controllers have evidence of immunologic progression with marked CD4+T-cell decline. We investigated host genetic factors associated with protection against CD4+T-cell loss in HIV-1-controllers. Methods: We analysed the association of interferon lambda 4 (IFNL4)-related polymorphisms and HLA-B haplotypes within Long Term Non-Progressor HIV-1-controllers ((LTNP-C), defined by maintaining CD4+T-cells counts >500 cells/mm3 for more than 7 years after HIV-1 diagnosis) versus non-LTNP-C, who developed CD4+T-cells counts <500 cells/mm3 Both a Spanish study cohort (n=140) and an international validation cohort (n=914) were examined. Additionally, in a subgroup of individuals HIV-1-specific T-cell responses and soluble cytokines were analysed RESULTS: HLA-B*57 was independently associated with the LTNP-C phenotype (OR=3.056 (1.029-9.069) p=0.044 and OR=1.924 (1.252-2.957) p=0.003) while IFNL4 genotypes represented independent factors for becoming non-LTNP-C (TT/TT, ss469415590, OR=0.401 (0.171-0.942) p=0.036 or A/A, rs12980275, OR=0.637 (0.434-0.934) p=0.021) in the Spanish and validation cohort, respectively, after adjusting for sex, age at HIV-1 diagnosis, IFNL4-related polymorphisms and different HLA-B haplotypes. LTNP-C showed lower plasma IP-10 (p=0.019) and higher IFN-γ (p=0.02) levels than the HIV-1-controllers with diminished CD4+T-cell numbers. Moreover, LTNP-C exhibited higher quantities of IL2+CD57- and IFN-γ+CD57- HIV-1-specific CD8+T-cells (p=0.002 and 0.041, respectively) than non-LTNP-C. Conclusions: We have defined genetic markers able to segregate stable HIV-1-controllers from those who experience CD4+T-cell decline. These findings allow for identification of HIV-1-controllers at risk for immunologic progression, and provide avenues for personalized therapeutic interventions and precision medicine for optimizing clinical care of these individuals.

Fine-mapping butyrophilin family genes revealed several polymorphisms influencing viral genotype selection in hepatitis C infection.

Host-viral genetic interaction has a key role in hepatitis C infection (HCV) and maybe in the viral selection. In a preliminary GWAS analysis, we identified BTN3A2 rs9104 to be associated with HCV genotype 1. Therefore, our aim was to determine the influence of BTN family on the selection of HCV genotype. We performed a fine-mapping analysis of BTN gene region in a cohort of chronic HCV infection (N=841), validating significant results in another independent chronic HCV infection cohort (N=637), according to selection of viral genotype. BTN3A2 rs9104, BTN3A2 rs733528, BTN2A1 rs6929846, BTN2A1 rs7763910 and BTN3A3 rs13220495 were associated with viral genotype selection. Interestingly, BTN3A2 rs9104 GG genotype was closely related to genotype 1 infection (80.7% (394/488) compared with genotype 3 infection (53.5% (23/43); P=0.0001) in patients harboring IL28B-CT/TT genotype, although this effect was not observed in IL28B-CC genotype. Similarly, BTN3A3 rs13220495 CC genotype was linked to genotype 3 infection (100% (32/32)) compared to genotype 1 (87.3% (137/157); P=0.028) in patients harboring IL28B-CC genotype, but did not in IL28B-CT/TT genotype. Genetic variants in the butyrophilin family genes may alter susceptibility to infection, selecting HCV genotype and influencing disease progression. BTN3A2 rs9104 was strongly associated with genotype 1 infection and the haplotype BTN3A3 rs13220495 CC+IL28B genotype CC was universal in patients with hepatitis C genotype 3a.

IFNL4 ss469415590 polymorphism is associated with unfavourable clinical and immunological status in HIV-infected individuals.

The IFNL4 ss469415590 polymorphism, in high linkage disequilibrium with the IL28B rs12979860 variant, has been associated with hepatitis C virus clearance. We evaluated whether ss469415590 is associated with clinical and immunovirological parameters in human immunodeficiency virus-infected subjects. We found an independent association of the IFNL4 ss469415590 polymorphism with higher prevalence of AIDS-defining illnesses and lower CD4 T cell numbers. These results suggest the existence of common host defence mechanisms against different viral infections.

Differential expression pattern of microRNAs in CD4+ and CD19+ cells from asymptomatic patients with systemic lupus erythematosus.

OBJECTIVE: The aim of this study was to investigate the pattern of microRNA (miRNA) expression in CD19+ and CD4+ cells from asymptomatic patients with systemic lupus erythematosus (SLE). METHODS: A screening of the expression of 377 miRNAs was performed in human CD4+ and CD19+ cells isolated from the peripheral blood by using a TaqMan Human MicroRNA Array. Validation of differential expression pattern of those was performed using TaqMan assays in these cell populations obtained from a larger cohort of patients and controls. RESULTS: According to the screening assays, three miRNAs were differentially expressed (p value <0.1) in cell populations from both patients and controls: hsa-miR-143, hsa-miR-224 and hsa-miR-576-5p for CD4+ cells, and hsa-miR-10a, hsa-miR-31 and hsa-miR-345 for CD19+ cells. After validation, significant differences (p value <0.05) were confirmed only for hsa-miR-143 and hsa-miR-224 in CD4+ cells and for hsa-miR-10a and hsa-miR-345 in CD19+ cells. In all cases, the miRNAs were over expressed in SLE patients compared with healthy donors. CONCLUSIONS: Our results support a different pattern of miRNA expression in SLE patients.

Influence of donor specific HLA antibodies detected by Luminex in kidney graft survival: a multivariate analysis.

Some studies have demonstrated the clinical relevance of a positive virtual crossmatch in graft survival; nevertheless, other donor and recipient variables influence the outcome of the transplant. The aim of this study was to investigate the relevance of a positive virtual crossmatch in the graft survival performing a multivariate analysis including other pretransplant variables. A total of 879 deceased kidney transplantations were included. Univariate and multivariate analyses were performed using Cox regression model. After performing the multivariate analysis, a positive virtual crossmatch against class I (adjusted HR 6.613; 95% CI 3.222-13.573), class II (adjusted HR 2.419; 95% CI 1.170-5.002) and class I+II (adjusted HR 5.717; 95% CI 1.925-16.975) detected by single antigen Luminex was the variable conferring the greatest relative risk of graft loss. A positive virtual crossmatch predicts a worse kidney graft survival even after correction by other variables and therefore, transplantation of patients with positive virtual crossmatches should be avoided.

Insulin resistance predicts sustained virological response to treatment of chronic hepatitis C independently of the IL28b rs12979860 polymorphism.

BACKGROUND: Insulin resistance has been strongly associated with the attainment of sustained viral response (SVR) in hepatitis C patients. AIM: To determine, in a cohort of Spanish patients with chronic hepatitis C treated with peginterferon plus ribavirin (P+R), whether insulin resistance predicts SVR independently of interleukin-28B rs12979860 polymorphism. METHODS: Insulin resistance was measured as [HOMA-IR = Insulin (IU/mL)*glucose (mmol/L)/22.5]. Genotype, viral load and histological fibrosis using Scheuer score were also measured. Binary logistic regression analysis was used for statistical purposes. RESULTS: In a cohort of 240 patients [78% genotype 1, 24% showing advanced fibrosis, 71% high viral load (≥800 000 IU/mL), 31% IL28b genotype CC and 50% with HOMA >2] treated with P+R, 126 (53%) reached SVR. HOMA-IR index (HOMA <2: 63% vs. HOMA >2: 42%; P = 0.001 and IL28b (genotype CC: 68% vs. genotype CT/TT: 45%; P = 0.002) were significantly associated with SVR. In multivariable logistic regression analysis in the overall cohort, variables independently associated were: viral genotype OR: 0.29 (95% CI: 0.11-0.78), P = 0.01; fibrosis OR: 1.62 (95% CI: 1.22-2.16), P = 0.001; HOMA-IR OR: 1.22 (95% CI: 1.02-1.47), P = 0.03; and IL28B genotype OR: 2.43 (95% CI: 1.45-4.07), P = 0.001. The analyses also showed that degree of steatosis, HOMA-IR >2, mild fibrosis and IL28B CC genotype were significantly related to SVR in patients infected with HCV genotypes 1&4, but not in those with genotypes 2&3. No differences were seen in glucose, insulin level or HOMA-IR index segregated according to IL28B genotypes. CONCLUSION: Our results suggest that insulin resistance, fibrosis stage and IL28B polymorphisms were independent variables associated with sustained viral response.

Influence of the STAT3 genetic variants in the susceptibility to psoriatic arthritis and Behcet's disease.

OBJECTIVE: Signal-transducer and activator of transcription protein 3 (STAT3) gene encodes a transducer and transcription factor that plays an important role in many cellular processes such as cell growth, apoptosis and immune response. Several STAT3 genetic variants have been associated to different autoimmune diseases. Our aim was to reveal the possible STAT3 influence in other immune-mediated diseases such as psoriatic arthritis (PsA) and Behcet disease (BD). METHODS: The STAT3 rs744166 and rs2293152 polymorphisms were genotyped using predesigned TaqMan® assays in a total of 335 PsA patients, 217 BD patients, and 1844 ethnically matched healthy controls of Spanish Caucasian origin. RESULTS: A statistically significant association of the STAT3 rs744166(∗)G allele with PsA was observed (P-value=1.36×10(-3), OR 1.35). The detected effect was more evident when the rs744166(∗)GG homozygote frequencies were compared between PsA patients and controls (genotype P-value=9.77×10(-5), OR 1.82). In contrast, the allele and genotypic distributions of rs744166 polymorphism showed no significant differences between patients with BD and control subjects (allelic P-value=0.80, OR 1.03). Additionally, no evidence of association was detected between the rs2293152 genetic variant and both studied diseases. CONCLUSION: Our results suggest for the first time that the STAT3 gene might be involved in PsA but not in Behcet's disease predisposition.

Association of Toll-like receptor 10 and susceptibility to Crohn's disease independent of NOD2.

Impaired innate inflammatory response has a key role in the Crohn's disease (CD) pathogenesis. The aim of this study was to investigate the possible role of the TLR10-TLR1-TLR6 gene cluster in CD susceptibility. A total of 508 CD patients (284, cohort 1 and 224, cohort 2) and 576 controls were included. TLR10-TLR1-TLR6 cluster single-nucleotide polymorphisms genotyping, NOD2 mutations and TLR10 mRNA quantification were performed using TaqMan assays. Nucleotide-binding oligomerization domain containing 2 (NOD2) and Toll-like receptor (TLR) loci interaction was analyzed by logistic regression and multifactor-dimensionality reduction (MDR). Entropy-based analysis was used to interpret combination effects. One TLR10 haplotype (TLR10(GGGG)) was found associated with CD susceptibility in both cohorts, individuals with two copies had approximately twofold more risk of CD susceptibility than individuals having no copies (odds ratio=1.89, P-value=0.0002). No differences in the mRNA levels were observed among the genotypes. The strongest model for predicting CD risk according to the MDR analysis was a two-locus model including NOD2 mutations and TLR10(GGGG) haplotype (P(c)<0.0001). The interaction gain attributed to the combination of both genes was negative (IG=-2.36%), indicating redundancy or independent effects. Our results support association of the TLR10 gene with CD susceptibility. The effect of TLR10 would be independent of NOD2, suggesting different signaling pathways for both genes.

Donor-specific antibody detection: comparison of single antigen assay and Luminex crossmatches.

Luminex bead-based assays are routinely used in the study of anti-human leukocyte antigen (HLA) donor-specific antibodies (DSA). Single antigen (SA) assays use beads coated with recombinant antigens whereas Luminex crossmatch (Xm-DSA) tests consist of beads coated with isolated donor-specific HLA molecules. The aim of this study was to compare these techniques used to detect DSA. A total of 24 sera recognizing different HLA class I (seven anti-HLA-A and seven anti-HLA-B) as well as class II (seven anti-HLA-DR and three anti-HLA DQ) specificities by complement dependent cytotoxicity were included in the study. These sera were used undiluted and in serial dilutions to perform both class I and II SA and Xm-DSA assays. In the case of Xm-DSA the same serum was checked with different lysates. A total of 42 lysates were used to perform a total of 61 crossmatches: 42 to detect anti-class I and 19 to detect anti-class II antibodies. The maximum positive dilution was higher for SA in 76% of the class I and in 90% of the class II crossmatches. Those cases with a higher sensitivity of the Xm-DSA could not be explained by a larger number of antigen targets.

Investigation of TLR5 and TLR7 as candidate genes for susceptibility to systemic lupus erythematosus.

OBJECTIVES: The aim of this study was to evaluate the relevance of genetic variants of TLR5 (rs5744168) and TLR7 (rs179008) gene in systemic lupus erythematosus (SLE) in a Spanish population. MATERIAL AND METHODS: Our study population consisted of 752 SLE patients and 1107 healthy controls. All individual were of Spanish Caucasian origin. The TLR5 and TLR7 polymorphisms were genotyped using a PCR system with pre-developed TaqMan allelic discrimination assay. RESULTS: No statistically significant differences were observed when the allele and genotype distribution of TLR5 rs5744168 and TLR7 rs179008 polymorphisms was compared between SLE patients and healthy controls. A significant increase frequency in the CC genotype of the TLR5 rs5744168 polymorphism among SLE patients without nephritis was found (93% vs. 87% in SLE patients with nephritis, p=0.03, OR=2.11 95%CI 0.93-3.51). However, this difference did not reach statistical significance in the allele frequencies (p=0.08). CONCLUSION: These results suggest that the tested variations of TLR5 and TLR7 genes do not confer a relevant role in the susceptibility or severity to SLE in the Spanish population.

The STAT4 gene influences the genetic predisposition to systemic sclerosis phenotype.

The aim of this study was to investigate the possible role of STAT4 gene in the genetic predisposition to systemic sclerosis (SSc) susceptibility or clinical phenotype. A total of 1317 SSc patients [896 with limited cutaneous SSc (lcSSc) and 421 with diffuse cutaneous SSc (dcSSc)] and 3113 healthy controls, from an initial case-control set of Spanish Caucasian ancestry and five independent cohorts of European ancestry (The Netherlands, Germany, Sweden, Italy and USA), were included in the study. The rs7574865 polymorphism was selected as STAT4 genetic marker. We observed that the rs7574865 T allele was significantly associated with susceptibility to lcSSc in the Spanish population [P = 1.9 x 10(-5) odds ratio (OR) 1.61 95% confidence intervals (CI) 1.29-1.99], but not with dcSSc (P = 0.41 OR 0.84 95% CI 0.59-1.21). Additionally, a dosage effect was observed showing individuals with rs7574865 TT genotype higher risk for lcSSc (OR 3.34, P = 1.02 x 10(-7) 95% CI 2.11-5.31). The association of the rs7574865 T allele with lcSSc was confirmed in all the replication cohorts with different effect sizes (OR ranging between 1.15 and 1.86), as well as the lack of association of STAT4 with dcSSc. A meta-analysis to test the overall effect of the rs7574865 polymorphism showed a strong risk effect of the T allele for lcSSc susceptibility (pooled OR 1.54 95% CI 1.36-1.74; P < 0.0001). Our data show a strong and reproducible association of the STAT4 gene with the genetic predisposition to lcSSc suggesting that this gene seems to be one of the genetic markers influencing SSc phenotype.

No evidence for genetic association of interferon regulatory factor 3 in systemic lupus erythematosus.

The aim of this study was to determine the potential role of three IRF3 gene polymorphisms (rs2304204, rs7251 and rs2304207) with systemic lupus erythematosus (SLE). Our study population consisted of 610 patients with SLE and 730 healthy controls. All individual were of Spanish Caucasian origin. The IRF3 polymorphisms were genotyped using a PCR system with pre-developed TaqMan allelic discrimination assay. No statistically significant differences were found when allele and genotype distribution of rs2304204, rs7251 and rs2304207 polymorphisms were compared between patients with SLE and controls [overall P values: rs7251, P = 0.06; rs2304204, P = 0.26 and rs2304207, P = 0.36, by chi-squared test on a 3 x 2 contingency table. Overall allelic P values: rs7251, P = 0.8, OR (95%CI) = 1.03 (0.87-1.22); rs2304204, P = 0.2, OR (95%CI) = 1.12 (0.93-1.34) and rs2304207, P = 0.8, OR (95%CI) = 1.02 (0.82-1.26)]. In addition, no evidence of association with haplotypes and clinical features of SLE was found. Our data suggest that the IRF3 polymorphisms do not appear to play a major role in the susceptibility or severity of SLE in a Spanish population.

A large multicentre analysis of CTGF -945 promoter polymorphism does not confirm association with systemic sclerosis susceptibility or phenotype.

OBJECTIVE: To conduct a replication study to investigate whether the -945 CTGF genetic variant is associated with systemic sclerosis (SSc) susceptibility or specific SSc phenotype. METHODS: The study population comprised 1180 patients with SSc and 1784 healthy controls from seven independent case-control sets of European ancestry (Spanish, French, Dutch, German, British, Swedish and North American). The -945 CTGF genetic variant was genotyped using a Taqman 5' allelic discrimination assay. RESULTS: An independent association study showed in all the case-control cohorts no association of the CTGF -945 polymorphism with SSc susceptibility. These findings were confirmed by a meta-analysis giving a pooled OR = 1.12 (95% CI 0.99 to 1.25), p = 0.06. Investigation of the possible contribution of the -945 CTGF genetic variant to SSc phenotype showed that stratification according to SSc subtypes (limited or diffuse), selective autoantibodies (anti-topoisomerase I or anticentromere) or pulmonary involvement reached no statistically significant skewing. CONCLUSION: The results do not confirm previous findings and suggest that the CTGF -945 promoter polymorphism does not play a major role in SSc susceptibility or clinical phenotype.

STAT4 associates with systemic lupus erythematosus through two independent effects that correlate with gene expression and act additively with IRF5 to increase risk.

OBJECTIVES: To confirm and define the genetic association of STAT4 and systemic lupus erythematosus (SLE), investigate the possibility of correlations with differential splicing and/or expression levels, and genetic interaction with IRF5. METHODS: 30 tag SNPs were genotyped in an independent set of Spanish cases and controls. SNPs surviving correction for multiple tests were genotyped in five new sets of cases and controls for replication. STAT4 cDNA was analysed by 5'-RACE PCR and sequencing. Expression levels were measured by quantitative PCR. RESULTS: In the fine mapping, four SNPs were significant after correction for multiple testing, with rs3821236 and rs3024866 as the strongest signals, followed by the previously associated rs7574865, and by rs1467199. Association was replicated in all cohorts. After conditional regression analyses, two major independent signals, represented by SNPs rs3821236 and rs7574865, remained significant across the sets. These SNPs belong to separate haplotype blocks. High levels of STAT4 expression correlated with SNPs rs3821236, rs3024866 (both in the same haplotype block) and rs7574865 but not with other SNPs. Transcription of alternative tissue-specific exons 1, indicating the presence of tissue-specific promoters of potential importance in the expression of STAT4, was also detected. No interaction with associated SNPs of IRF5 was observed using regression analysis. CONCLUSIONS: These data confirm STAT4 as a susceptibility gene for SLE and suggest the presence of at least two functional variants affecting levels of STAT4. The results also indicate that the genes STAT4 and IRF5 act additively to increase the risk for SLE.

PTPN22 C1858T polymorphism and the outcome of hepatitis C virus infection.

The outcome of chronic hepatitis C virus infection varies, depending on viral and host factors. Those mechanisms involved in the control of the innate and adaptive response could have an influence on the outcome of infection. The PTPN22 gene encodes an intracellular lymphoid-specific phosphatase (Lyp) with a lymphocyte activating downregulatory effect. A single-nucleotide polymorphism (SNP) C1858T located on this gene has been associated with autoimmune diseases and bacterial infections. The aim of this study was to assess whether the PTPN22 C1858T polymorphism is related to the outcome of hepatitis C viral infection. A total of 69 patients with spontaneous viral clearance (SVC), 281 patients with chronic hepatitis C (CHC), and 1036 individuals not infected with hepatitis C (NIC) were included in this study. Patients with CHC were stratified according to Scheuer score of hepatic fibrosis from F0-F2 (n = 200) and F3-F4 (n = 81), and according to their response to therapy in patients with sustained responses (SR; n = 103) and non-sustained response (NSR; n = 104). Genotyping of the C1858T polymorphism was performed using TaqMan probes. No statistically significant differences in the distribution of PTPN22 C1858T polymorphism were observed upon comparison of patient group with the NIC group. Also, when the different patient groups were compared to one another, no statistically significant differences were detected: the SVC with the CHC group (10.2% versus 12.5%; p = 0.6), the F0-F2 with the F3-F4 group (11.5% versus 14.8%; p = 0.5), and the NSR with the SR group (11.5% versus 14.6%; p = 0.4). Our results do not support a major role of this polymorphism of the PTPN22 gene in the outcome of chronic hepatitis C virus infection in the Spanish population.

Interactive effects of immunoglobulin gamma and human leucocyte antigen genotypes on clearance and persistence of infection with hepatitis C virus.

Particular alleles of human leucocyte antigen (HLA) and immunoglobulin gamma (GM) and immunoglobulin kappa (KM) allotypes (polymorphic determinants of IgG heavy chains and kappa-type light chains, respectively) are associated with the outcome of several infections. To examine their role in the outcome of hepatitis C virus (HCV) infection, we genotyped 50 individuals with resolved and 117 with persistent HCV infection. None of the GM, KM or HLA-C genotypes by themselves were associated with the resolution or persistence of HCV infection. However, particular combinations of HLA and GM genotypes were associated significantly with the outcome of HCV infection. Subjects with the HLA C1C1 genotype, in the absence of GM ff, were more than seven times [odds ratio (OR) 7.15] as likely to have persistent infection as the subjects who lacked both these genotypes. The presence of GM ff, in the absence of HLA C1C2, was associated with the resolution of infection (OR 0.27). The absence of GM fz, in the presence of HLA C2C2, was also associated with the resolution of infection (OR 0.27). Compared to the subjects who lacked both these genotypes, subjects with GM fz, in the absence of HLA C1C2, were almost four times as likely to have persistent infection (OR 3.91); similarly, subjects with HLA C1C2, in the absence of GM fz, were almost three times as likely to have persistent infection (OR 2.80). These results show, for the first time, interactive effects of GM and HLA genotypes in the outcome of HCV infection.

Caspase 7 influences susceptibility to rheumatoid arthritis.

OBJECTIVE: The aim of this study was to investigate the possible role of the caspase 7 (CASP7) in susceptibility to rheumatoid arthritis (RA). METHODS: Genotyping of three single nucleotide polymorphisms (SNPs) of the CASP7 gene: rs11593766 (G/ T), rs2227310 (C/G) and rs2227309 (G/A) was performed in a total of 906 RA patients and 528 matched healthy controls using TaqMan assays. All the subjects were of Spanish Caucasian origin. A relative quantification of mRNA encoding the non-functional variant of procaspase 7 (isoform beta) vs functional isoforms was performed in total RNA from 32 healthy individuals using real-time PCR. RESULTS: Only the rs2227309 SNP was found to be associated with susceptibility to RA. Frequency of the G allele was significantly higher among RA patients [overall frequency of the G allele 74.0% in cases vs 68.4% in controls, P = 0.001, Odds ratio (OR) = 1.32, 95% Confidence intervals (95% CI) 1.11-1.56] and a higher frequency of GG homozygous individuals was found in the RA patient group (overall frequency of GG genotype 56.0% in cases and 46.4% in controls, P = 0.0005, OR = 1.47, 95%CI 1.18-1.83). A statistically significant deviation was observed to compare the relative expression of the procaspase 7 isoform beta in samples from individuals stratified according their rs2227309 genotypes (AA + AG: 1.36 +/- 0.55, n = 19, vs GG: 2.35 +/- 0.74, n = 13; P = 0.0002). CONCLUSION: 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.

CCL2-2518 A/G and CCR2 190 A/G do not influence the outcome of hepatitis C virus infection in the Spanish population.

AIM: To assess whether CCL2 or interactions between this chemokine and its receptor (CCR2) are associated with outcomes of chronic hepatitis C and with responses to antiviral therapy. METHODS: Two hundred and eighty-four patients with chronic hepatitis C and 193 non-infected matched controls were included in this study. Patients were categorized according to their Scheuer score of hepatic fibrosis as F0-F2 (n = 202) or F3-F4 (n = 82) and according to their response to anti-Hepatitis C virus (HCV) therapy as sustained response (SR, n = 101) or non-sustained response (NSR, n = 98). Genotyping of the -2518 (A/G) CCL2 was performed using PCR-RFLP, genotyping of the 190 (A/G) CCR2 using a PCR-ARMS system, and genotyping of the rs3138042 (G/A) CCR2 using Taqman probes. RESULTS: Univariate analyses identified 4 parameters (infection duration time, viral genotype, gender and AST levels) that tended to influence fibrosis and 7 parameters (CCL2G, CCL2ACCR2A, viremia levels, fibrosis stage, viral genotype, infection duration time and AST levels) that significantly influenced or tended to influence response to treatment. Multivariate analysis identified gender and AST levels as parameters that independently influenced fibrosis stage and viral genotype and infection duration time were the two parameters that independently influenced response to treatment. CONCLUSION: Our results indicate that the mutations studied in the gene pair CCL2/CCR2 do not play a major role in the outcome and response to treatment for HCV infection in the Spanish population.

Contribution of MHC class I region to genetic susceptibility for giant cell arteritis.

OBJECTIVE: The aim of this study was to assess the potential contribution of HLA-class I MICA and HLA-B gene polymorphisms towards the pathogenesis of giant cell arteritis (GCA). METHODS: Ninety-eight biopsy-proven GCA patients and 225 ethnically matched controls from Lugo, Northwest Spain, were genotyped for the MICA-TM microsatellite polymorphism using a polymerase chain reaction (PCR)-based method. Genotyping of HLA-B was performed using PCR and detection with a reverse sequence-specific oligonucleotide (SSO) probes system. RESULTS: A significant difference in the distribution of the alleles of MICA between patient and control groups (P = 0.005) was found. This was due to an increased frequency of the MICA A5 allele in GCA patients compared with controls (26 vs 13.6%; P = 0.0001; P(C) = 0.0005; OR 2.2, 95% CI 1.4-3.4). In addition, the HLA-B*15 allele showed a higher frequency in GCA patients compared with controls (P = 0.004; P(C) = 0.04; OR 2.7, 95% CI 1.3-5.7). Interestingly, the association observed with the MICA A5 allele seems to be independent of linkage disequilibrium with HLA-B, as well as independent of that previously described with HLA-DRB1*04. Remarkably, simultaneous presence of MICA A5 and HLA-B*15 or HLA-DRB1*04 genetic markers leads to an increase in the OR obtained for each individual genetic marker (MICA A5 + B*15 OR 3.2; MICA A5 + DRB1*04 OR 5.8). CONCLUSIONS: Our results provide the first evidence that the MICA and HLA-B genes are independently associated with the genetic susceptibility to GCA, and suggest that several genes within the MHC might have independent effects in the susceptibility to this systemic vasculitis.