Genetic analysis of the 2q33 region containing CD28-CTLA4-ICOS genes: association with non-Hodgkin's lymphoma

There is strong evidence that altered immunological function entails an increased risk of lymphoma, although the current knowledge of aetiological factors for lymphomas is limited. The CTLA4 gene encodes a receptor that provides a negative signal to the T-cell once an immune response is initiated and completed. We analysed the 2q33 chromosomal region harbouring CD28, CTLA4 and ICOS genes, which are closely linked and have related functions in immune regulation, for association in 100 non-Hodgkin's lymphoma (NHL) patients and in 128 healthy controls; both groups originated from Sardinia. There was a strong association of the CTLA4 49A and the 3'-untranslated region (AT)(82) alleles with NHL [odds ratio (OR) = 2, 95% confidence interval (CI) = 1.2-3.2, and OR = 1.6, 95% CI = 1.1-2.4 respectively]. CTLA4-318C:49A:(AT)(82) was the most represented haplotype in the studied population and was associated with NHL (P = 0.0029, OR = 1.76, 95% CI = 1.2-2.5). Strong linkage disequilibrium was detected between CD28, CTLA4 and ICOS and a 'common' haplotype was found very frequently among NHLs. However, no independent association between CD28, ICOS, D2S72 markers and NHL was observed. Our findings enable CTLA4 from adjacent functionally related genes as the true causative risk gene for NHL susceptibility at least in Sardinian patients.     

Association of polymorphic alleles of CTLA4 with inflammatory bowel disease in the Japanese

AM: To examine an association between the cytotoxic T-lymphocyte antigen 4 (CTLA4) gene that plays a role in downregulation of T-cell activation and inflammatory bowel disease consisting of ulcerative colitis (UC) and Crohn's disease (CD) in the Japanese. METHODS: We studied 108 patients with UC, 79 patients with CD, and 200 sex-matched healthy controls, with respect to three single nucleotide polymorphisms (SNPs) in CTLA4, such as C-318T in the promoter region, A+49G in exon 1 and G+6230A in the 3' untranslated region (3'-UTR) by a PCR-restriction fragment length polymorphism method, and to an (AT)n repeat polymorphism in 3'-UTR by fragment analysis with fluorescence-labeling on denaturing sequence gels. Frequency of alleles and genotypes and their distribution were compared statistically between patients and controls and among subgroups of patients, using X2 and Fisher exact tests. RESULTS: The frequency of "A/A" genotype at the G+6230A SNP site was statistically lower in UC patients than in controls (3.7% vs 11.0%, P= 0.047, odds ratio (OR) = 0.311). Moreover, the frequency of "G/G" genotype at the A+49G SNP site was significantly higher in CD patients with fistula (48.6%) than those without it (26.2%) (P = 0.0388, OR=2.67). CONCLUSION: The results suggest that CTLA4 located at 2q33 is a determinant of UC and responsible for fistula formation in CD in the Japanese.     

Influence of CTLA4 haplotypes on susceptibility and some extraglandular manifestations in primary Sjögren's syndrome

OBJECTIVE: Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) is a key negative regulator of the T cell immune response, and the CTLA4 gene is highly polymorphic. Many positive associations between CTLA4 single-nucleotide polymorphisms (SNPs) and various autoimmune diseases have been identified. Two CTLA4 SNPs that are important relative to genetic susceptibility in human autoimmune diseases are the +49GA polymorphism in exon 1 and the CT60A/G polymorphism in the 3'-untranslated region. Using these 2 polymorphisms as markers, we investigated possible genetic associations of CTLA4 in Australian patients with primary Sj?gren's syndrome. METHODS: One hundred eleven Australian Caucasian patients with primary SS and 156 population-based controls were genotyped for CTLA4 by polymerase chain reaction-restriction fragment length polymorphism methods, using the restriction enzymes BseXI (+49G/A) and HpyCh4 IV (CT60). RESULTS: The CT60 and +49G/A SNPs were in strong linkage disequilibrium, and only 3 haplotypes were observed. Significant differences in the haplotype frequencies between patients with primary SS and controls (P = 0.032) were observed, with susceptibility to primary SS associated with both the +49A;CT60A haplotype and the +49A;CT60G haplotype, whereas the +49G;CT60G haplotype was protective against primary SS. The +49A;CT60G haplotype association was predominantly with Ro/La autoantibody-positive primary SS, and the dose of this haplotype influenced the severity of daytime sleepiness (P = 0.036). The +49A;CT60A haplotype appeared to be protective against the development of Raynaud's phenomenon in patients with primary SS (odds ratio 0.49, 95% confidence interval 0.27-0.91). CONCLUSION: The CTLA4 +49G/A and CT60 haplotypes are associated with susceptibility to primary SS and with some extraglandular manifestations of the disease.     

Distinct tumour necrosis factor alpha, interferon gamma, interleukin 10, and cytotoxic T cell antigen 4 gene polymorphisms in disease occurrence and end stage renal disease in Wegener's granulomatosis

BACKGROUND: Cytokines and T cell regulatory proteins play an important role in the pathogenesis of Wegener's granulomatosis (WG). OBJECTIVE: To investigate cytokine and cytotoxic T cell antigen-4 (CTLA4) gene polymorphisms and HLA class II alleles in generalised WG. METHODS: The distribution of cytokine and cytotoxic T cell antigen 4 (CTLA4) gene polymorphisms and HLA class II alleles was analysed in 32 patients with generalised WG and 91 healthy controls. Genotyping was carried out for HLA-DRB1 and HLA-DQB1 and for polymorphism of the genes encoding TNF alpha (-238, -308, -376), TGF beta (codon 10 and 25), IFN gamma (+874), IL6 (-174), IL10 (-592, -819, -1082), CTLA4 (-318, +49), and the (AT)(n) repeats of the CTLA4 gene. In addition, stratification analysis was carried out according to the presence (n = 15) or absence (n = 17) of end stage renal disease. RESULTS: An increase in the IFN gamma +874 T/T (odds ratio (OR) = 3.14) and TNF alpha -238 G/A (OR = 5.01) genotypes was found in WG patients. When ESRD positive and negative patients were compared, the IFN gamma +874 A/A and the CTLA4 -318 C/C genotypes were found more often in the ESRD subgroup (OR = 10.6 and OR = 2.25). WG patients without ESRD had a higher frequency of the IL10 GCC/ACC promotor genotype (OR = 0.13) and long CTLA4 (AT)(n) repeats (OR = 0.4). No effect was seen for HLA-DR and -DQ markers. CONCLUSIONS: Disease susceptibility and clinical course in WG may be associated with distinct polymorphisms of cytokine and CTLA4 genes.     

Two single-nucleotide polymorphisms in the 5' and 3' ends of the osteopontin gene contribute to susceptibility to systemic lupus erythematosus

OBJECTIVE: To test the association of osteopontin (OPN) polymorphisms with systemic lupus erythematosus (SLE). METHODS: The coding 5' and 3' flanking regions of the OPN gene were scanned for polymorphisms by denaturing high-performance liquid chromatography. A case-control association study was performed in 394 Italian SLE patients and 479 matched controls. OPN serum levels were determined by enzyme-linked immunosorbent assay in 40 patients and 124 controls, and the mean levels were compared between the different OPN genotypes. RESULTS: Among the 13 detected single-nucleotide polymorphisms (SNPs), alleles -156G (frequency 0.714 versus 0.651; P = 0.006, corrected P [P(corr)] = 0.036) and +1239C (0.377 versus 0.297; P = 0.00094, P(corr) = 0.0056) were significantly increased in the SLE patients compared with the controls. The presence of the associated allele in single or double dose conferred an odds ratio (OR) of 2.35 (95% confidence interval [95% CI] 1.38-4.02) for SNP -156 and an OR of 1.57 (95% CI 1.16-2.13) for SNP +1239. These effects were independent of each other, i.e., not a consequence of linkage disequilibrium between the 2 alleles. The risk associated with a double dose of susceptibility alleles at both SNPs was 3.8-fold higher (95% CI 2.0-7.4) relative to the complete absence of susceptibility alleles. With regard to individual clinical and immunologic features, a significant association was seen between lymphadenopathy and -156 genotypes (overall P = 0.0011, P(corr) = 0.046). A significantly increased OPN serum level was detected in healthy individuals carrying +1239C (P = 0.002), which is indicative of an association between the SLE susceptibility allele and OPN levels. CONCLUSION: These data suggest the independent effect of a promoter (-156) and a 3'-untranslated region (+1239) SNP in SLE susceptibility. We can speculate that these sequence variants (or others in perfect linkage disequilibrium) create a predisposition to high production of OPN, and that this in turn may confer susceptibility to SLE.     

Association of CTLA-4 but not CD28 gene polymorphisms with systemic lupus erythematosus in the Japanese population.

OBJECTIVE: Systemic lupus erythematosus (SLE) in a multisystem autoimmune disorder characterized by multiorgan pathology and autoantibodies against a variety of autoantigens. The CD28 and CTLA-4 genes might be candidate genes for SLE, because costimulation signals from CD80/CD86 to CD28/CTLA-4 have been suggested to play an important role in the activation or inactivation of T lymphocytes. METHODS: We investigated three polymorphic regions within the CTLA-4 gene, a C/T base exchange in the promoter region -318 (CTLA-4 -318C/T), an A/G substitution in the exon 1 position 49 (CTLA-4 49A/G), an (AT)(n) repeat polymorphism in the 3' untranslated region of exon 4 [CTLA-4 3' (AT)(n)], and a CD28 gene polymorphism, a T/C substitution in the intron 3 position +17 (CD28 IVS3+17T/C), in SLE patients and controls. RESULTS: SLE patients had significantly higher frequencies of the CTLA-4 49G allele (P=0.003) and of the CTLA-4 (AT)(n) 106 bp allele (P=0.0008) than controls. We also found a strong linkage disequilibrium between the A allele of CTLA-4 49A/G and the 86 bp allele of CTLA-4 3' (AT)(n). On the contrary, no association was found between SLE and CTLA-4 -318C/T or CD28 IVS3 +17T/C. CONCLUSION: We conclude that the CTLA-4 gene appears to play a significant role in the development of SLE in the Japanese population.     

HO-1 promoter polymorphism associated with rheumatoid arthritis

OBJECTIVE: To investigate the role of the HO-1 gene as a novel functional candidate gene for rheumatoid arthritis (RA). METHODS: We performed a case-control study including 736 RA patients and 846 healthy controls of Spanish Caucasian origin. Two putative functional HO-1 promoter polymorphisms, a (GT)(n) microsatellite and a -413 A/T single-nucleotide polymorphism (SNP), were selected as genetic markers and genotyped using polymerase chain reaction-based methods. In addition, the intracellular expression of heme oxygenase 1 (HO-1) was determined in healthy individuals with different (GT)(n) genotypes. RESULTS: The distribution of HO-1 (GT)(n) short (S) alleles (< or =25 GT repeats) and long (L) alleles (>25 GT repeats) revealed a significant protective effect of S (GT)(n) alleles (P = 0.019) (odds ratio [OR] 0.8, 95% confidence interval [95% CI] 0.7-0.9) and the SS (GT)(n) genotype (P = 0.002) (OR 0.6, 95% CI 0.4-0.9). In contrast, the -413 HO-1 promoter SNP did not yield any statistically significant deviation between RA patients and controls, considering either allele or genotype frequencies. The haplotype analysis showed a strong protective effect of the S/A haplotype (P = 7 x 10(-7), corrected P [P(corr)] = 3 x 10(-6)) (OR 0.4, 95% CI 0.3-0.6), whereas the L/A haplotype showed the opposite tendency (P = 0.008, P(corr) = 0.03) (OR 1.2, 95% CI 1.0-1.4). In addition, we demonstrated that monocytes from individuals carrying the SS (GT)(n) genotype showed a significantly higher percentage of HO-1 expression than did cells from LL homozygous individuals (P = 0.0003). CONCLUSION: In this study, we identified the HO-1 (GT)(n) microsatellite as a new genetic marker involved in RA genetics in our population.     

+49A/G polymorphism of cytotoxic T‐lymphocyte antigen 4 gene in type 1 autoimmune hepatitis and primary biliary cirrhosis: A meta‐analysis

Aim: Recently, the associations of +49A/G polymorphisms of cytotoxic T‐lymphocyte antigen 4 (CTLA‐4) gene with the susceptibility to type 1 autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) have been reported; however these associations are yet to be fully elucidated. This study aimed to identify the associations of CTLA‐4 gene +49A/G polymorphisms with the susceptibility to type 1 AIH and PBC by using a meta‐analysis. Methods: PubMed was searched by using the following keywords: “autoimmune hepatitis AND (polymorphism OR polymorphisms)” or “primary biliary cirrhosis AND (polymorphism OR polymorphisms)”. Meta‐analyses of five studies including 526 patients with type 1 AIH and 631 controls and seven studies including 1500 patients with PBC and 2345 controls were performed. Results: For type 1 AIH, the odds ratio (OR) of G allele was 1.26 [95% confidence interval (CI) 1.06–1.51] although G/G homozygosity was not associated with the susceptibility to type 1 AIH. On the other hand, the OR of A/A homozygosity for type 1 AIH was 0.66 (95% CI 0.50–0.86). For PBC, the OR of G allele was 1.20 (95% CI 1.06–1.34). Furthermore, G/G homozygosity was significantly associated with the susceptibility to PBC (OR 1.29, 95% CI 1.01–1.66). The OR of A/A homozygosity for PBC was 0.81 (95% CI 0.70–0.94). Conclusions: This study suggests that CTLA‐4 gene +49A/G polymorphisms may be associated with the susceptibility to type 1 AIH and PBC. Especially, while G/G genotype may be associated with the susceptibility to PBC, A/A genotype may be protective against type 1 AIH and PBC.     

Variants in Intron 4 of PD-1 Gene are Associated with the Susceptibility to SLE in an Iranian Population

Background: Programmed cell death protein 1 (PD-1) is a negative costimulatory molecule with immunomodulatory properties. Recently, PD-1 gene defects have attracted attention in the pathogenesis of SLE. Objective: Here, we assessed the association of PD-1 gene polymorphisms in intron 4 and haplotypes with the susceptibility to SLE. Method: Seventy-six SLE patients and 159 healthy controls were included. We screened the polymorphisms by amplifying the intron 4 of the PD-1 gene with the specific primers followed by sequencing. Results: Two distinct SNPs were identified (rs6705653 and rs41386439) within the intron 4 of the PD-1 gene. The AA genotype of +7499 (G/A) SNP was associated with the higher risk of SLE [OR=3.31, 95% CI (1.25-8.76), p-value=0.045], while A allele was identified as a risk allele [OR=1.75, 95% CI (1.10-2.76), p-value=0.015]. However, no significant association was observed between the allele and the genotype frequencies of +7209 (C/T) polymorphic region of the PD-1 gene and susceptibility to SLE. Haplotype analysis showed the significantly higher presence of H2 haplotype (AC; +7499/+7209) [OR=1.70, 95% CI (1.24-2.33), p-value=0.0012] in SLE patients. Conclusion: To the best of our knowledge, this is the first report of the significant association of PD-1 +7499 (G/A) SNP with the SLE susceptibility and the first detection of both polymorphic loci in a population from Iran. However, more investigations are necessary to confirm these findings.     

No primary association of MICA polymorphism with systemic lupus erythematosus

OBJECTIVE: To replicate the described association between MHC class I chain-related A (MICA) gene polymorphism and susceptibility to systemic lupus erythematosus (SLE). METHODS: MICA transmembrane microsatellite polymorphism was genotyped using a polymerase chain reaction (PCR)-based method. Genotyping of HLA-B* and DRB1* was performed using PCR and detection with a reverse sequence-specific oligonucleotide (SSO) probe system. Combined data for these three loci (HLA-B*, DRB1* and MICA) were obtained from a total of 333 patients and 361 healthy controls. RESULTS: Significant association with B*08 [P < 10(-7), odds ratio (OR) 3.17, 95% confidence interval (CI) 2.02-5.00], DRB1*0301 (P < 10(-7), OR 2.07, 95% CI 1.59-2.68) and MICA5.1 (P = 0.01, OR 1.23, 95% CI 1.04-1.46) was observed. The combinations DRB1*0301-MICA5.1-B8 and HLA-DRB1*0301-B*08-positive and MICA5-1-negative were more frequent among SLE patients (11.4 vs 3.3% in healthy controls, P = 3.9 x 10(-5), OR 3.76, 95% CI 1.85-7.73, and 6.9 vs 1.7%, P = 0.0007, OR 4.32, 95% CI 1.68-13.10, respectively). Additionally, individuals who were HLA-DRB1*0301-B*08-negative and MICA5-1-positive were less frequent among patients (22.2 vs 31.3% in healthy controls, P = 0.007, OR 0.63, 95% CI 0.44-0.89) and the magnitude of the OR was similar to that obtained in individuals negative for all the three factors (OR 0.69, 95% CI 050-0.94). Further analysis performed to detect independent association strongly suggested that the association between MICA5.1 and SLE is secondary to the linkage disequilibrium of this allele with B*08. CONCLUSIONS: Our results do not support an independent association of MICA gene polymorphism with susceptibility to SLE.     

An association between the CTLA4 exon 1 polymorphism and early rheumatoid arthritis with autoimmune endocrinopathies

OBJECTIVE: To examine the allelic association of the single nucleotide polymorphism (CTLA4A/G) in exon 1 of the cytotoxic T lymphocyte antigen-4 (CTLA4) gene with early rheumatoid arthritis (RA). METHODS: One hundred and twenty-three unrelated white probands with early RA from the north-east of England and 349 local ethnically matched controls were studied. The CTLA4A/G polymorphism was genotyped with a polymerase chain reaction (PCR) method and digestion with the restriction enzyme Bst71I. Probands were also screened by allele-specific PCR for alleles HLA DRB1*01 and DRB1*04. RESULTS: The frequency of the G allele at CTLA4A/G was significantly increased in probands with early RA compared with controls [43 vs 36%; P=0.028, odds ratio (OR) 1.35, 95% confidence interval (CI) 1.01-1.82]. Most of this increased frequency was attributable to RA individuals with coexisting autoimmune thyroid disease or type 1 diabetes (58 vs 36% in controls; P=0.005, OR 2.50, CI 1.29-4.84). The frequency of the G allele in RA patients without autoimmune endocrinopathy was 40%, which was not significantly different from that in controls (P=0.140). CONCLUSION: The association between the CTLA4 G allele and early RA is largely explained by individuals with RA who have coexisting autoimmune endocrinopathies.     

CTLA4 gene and Graves' disease: association of Graves' disease with the CTLA4 exon 1 and intron 1 polymorphisms,but not with the promoter polymorphism

OBJECTIVE: Recent studies have shown that Graves' disease (GD) is linked to and associated with alleles of the cytotoxic T lymphocyte antigen-4 (CTLA4) locus. However, the true pathogenic polymorphism(s) at this locus remains uncertain. Moreover, the association studies of the promoter CTLA4(-318)C/T polymorphism in white GD populations have produced conflicting results. Therefore, we have analysed three CTLA4 single nucleotide polymorphisms, including promoter CTLA4(-318)C/T, exon 1 CTLA4(49)A/G and intron 1 CTLA4(1822)C/T in our GD cohort from the UK. PATIENTS AND METHODS: We studied 301 white patients with GD and 349 healthy ethnically matched local controls. Amongst GD probands, 129 had significant thyroid-associated orbitopathy (TAO; NOSPECS class III or worse). The CTLA4(-318)C/T, CTLA4(49)A/G and CTLA4(1822)C/T polymorphisms were genotyped by using the restriction enzymes MseI, Bst71I and HaeIII, respectively. RESULTS: We found no association between GD and alleles of CTLA4(-318)C/T. GD was found to be associated with the G allele of CTLA4(49)A/G[P = 5.9 x 10(-6), odds ratio (OR) 1.65] and the T allele of CTLA4(1822)C/T (P = 7.7 x 10(-6), OR 1.64). The frequencies of these alleles were significantly higher in GD probands with significant TAO than in those without TAO (G allele: P = 0.001, OR 1.68; T allele: P = 0.001, OR 1.70). CONCLUSIONS: The promoter CTLA4(-318)C/T polymorphism is not in linkage disequilibrium with the pathogenic polymorphism(s) at the CTLA4 locus. The alleles of both the exon 1 CTLA4(49)A/G and the intron 1 CTLA4(1822)C/T polymorphisms are associated with GD, which is stronger in patients with TAO.     

Association of autoimmune pancreatitis with cytotoxic T-lymphocyte antigen 4 gene polymorphisms in Japanese patients

OBJECTIVES: Autoimmune pancreatitis (AIP) is characterized by high serum IgG4 concentrations, lymphoplasmacytic inflammation, and a favorable response to corticosteroid treatment. Although the HLA DRB1*0405-DQB1*0401 haplotype and Fc receptor-like 3 polymorphisms have been associated with AIP, the role of other genetic factors is largely unknown. As cytotoxic T-lymphocyte antigen 4 (CTLA4) polymorphisms have recently been linked with several autoimmune diseases, we sought to determine if CTLA4 polymorphisms and serum sCTLA4 levels were associated with AIP as well. METHODS: Five CTLA4 polymorphisms, located at -1722, -658, and -318 in the promoter, +49 in exon 1, and +6230 in the 3' untranslated region, were genotyped in 59 patients with AIP and 102 healthy subjects. Serum sCTLA4 levels were also determined in cohorts of 52 patients and 32 controls. RESULTS: Compared with healthy subjects, we found a significant increase in the +6230 G/G genotype (64%vs 42%, odds ratio [OR] 2.48, P= 0.011) in AIP patients. Haplotype 2, which had the +6230A, was associated with AIP resistance (OR 0.49, P= 0.011). The +49A/A and +6230A/A genotypes were associated with an enhanced risk of relapse (OR 5.45, P= 0.038 and OR 12.66, P= 0.022). Additionally, median serum sCTLA4 levels were significantly higher in patients with AIP (8.9 ng/mL) compared with healthy subjects (2.9 ng/mL, P < 0.001). The +6230 G/A polymorphism did not influence sCTLA4 levels in AIP patients. CONCLUSIONS: Our findings suggest that AIP is associated with a genetic polymorphism in CTLA4 and is positively correlated with serum sCTLA4 levels.     

Chemokine receptor CCR2/CCR5 polymorphism in Spanish patients with systemic lupus erythematosus

OBJECTIVE: To investigate the possible association of CCR2 and CCR5 chemokine receptor gene polymorphisms with the susceptibility, clinical features, and the outcome of systemic lupus erythematosus (SLE). METHODS: We studied 276 patients with SLE and 194 ethnically matched healthy controls. Patients were stratified according to their clinical features and outcome. Genotyping of 190 (A/G) CCR2 and D32CCR5 was performed using polymerase chain reaction techniques. RESULTS: No association between the polymorphisms studied and susceptibility to SLE was found. However, when patients were stratified according to their clinical features, an increase in the frequency of individuals bearing D32CCR5 among patients with anti-dsDNA antibodies was found [15.1% vs 6.4% in negative patients (p = 0.03, pcorr > 0.05, OR 2.61, 95% CI 1.04-7.40) and 8% in controls (p = 0.04, pcorr > 0.05, OR 1.97, 95% CI 0.97-4.11)]. Moreover, a significant increase in the frequency of D32CCR5 individuals was observed among patients with biopsy-proven nephritis [20.5% vs 8.5% in patients without nephritis (p = 0.03, pcorr > 0.05, OR 2.79, 95% CI 0.93-7.70) and 8% in controls (pFisher = 0.04, pcorr > 0.05, OR 2.87, 95% CI 0.97-7.82)]. Regarding the outcome, a higher median severity index was found among patients bearing D32CCR5 (33.5 +/- 17.9 vs 26.6 +/- 17.1 in CCR5/CCR5 individuals; p = 0.04). CONCLUSION: Polymorphisms of CCR2 and CCR5 do not seem to be involved in susceptibility to SLE, although a slight contribution of the CCR5 polymorphism in the production of anti-dsDNA autoantibodies, in the development of lupus nephritis, and in the outcome of the disease could be postulated.     

HLA-DRB4 as a genetic risk factor for Churg-Strauss syndrome

OBJECTIVE: To explore the association between HLA alleles and Churg-Strauss syndrome (CSS), and to investigate the potential influence of HLA alleles on the clinical spectrum of the disease. METHODS: Low-resolution genotyping of HLA-A, HLA-B, and HLA-DR loci and genotyping of TNFA -238A/G and TNFA -308A/G single-nucleotide polymorphisms were performed in 48 consecutive CSS patients and 350 healthy controls. RESULTS: The frequency of the HLA-DRB1*07 allele was higher in the CSS patients than in controls (27.1% versus 13.3%; chi(2) = 12.64, P = 0.0003, corrected P [P(corr)] = 0.0042, odds ratio [OR] 2.42, 95% confidence interval [95% CI] 1.47-3.99). The HLA-DRB4 gene, present in subjects carrying either HLA-DRB1*04, HLA-DRB1*07, or HLA-DRB1*09 alleles, was also far more frequent in patients than in controls (38.5% versus 20.1%; chi(2) = 16.46, P = 0.000058, P(corr) = 0.000232, OR 2.49, 95% CI 1.58-3.09). Conversely, the frequency of the HLA-DRB3 gene was lower in patients than in controls (35.4% versus 50.4%; chi(2) = 7.62, P = 0.0057, P(corr) = 0.0228, OR 0.54, 95% CI 0.35-0.84). CSS has 2 major clinical subsets, antineutrophil cytoplasmic antibody (ANCA)-positive, with features of small-vessel vasculitis, and ANCA-negative, in which organ damage is mainly mediated by tissue eosinophilic infiltration; analysis of HLA-DRB4 in patients categorized by different numbers of vasculitic manifestations (purpura, alveolar hemorrhage, mononeuritis multiplex, rapidly progressive glomerulonephritis, and constitutional symptoms) showed that its frequency strongly correlated with the number of vasculitis symptoms (P for trend = 0.001). CONCLUSION: These findings indicate that HLA-DRB4 is a genetic risk factor for the development of CSS and increases the likelihood of development of vasculitic manifestations of the disease.     

CT60 single nucleotide polymorphisms of the cytotoxic T-lymphocyte-associated antigen-4 gene region is associated with Graves' disease in an Italian population.

Graves' disease (GD) is an autoimmune and polygenic disorder. Several studies have shown that human leukocyte antigen (HLA) class II and the cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) gene are involved in the genetic susceptibility. We performed a case control study on 150 patients with GD and 301 controls, matched for age and gender, to verify the association of three polymorphisms located in CTLA-4 region (A49G, [AT](n)-3'UTR, and CT60) and of HLA-DRB1 and DQB1 loci with the disease in an Italian population. The prevalence of patients with GD carrying the G allele of CT60 was significantly higher compared to control subjects (p = 0.02, odds ratio [OR] = 1.82). The allelic frequency of the G allele of CT60 was also significantly higher in patients with GD (p = 0.02). The G allele frequency of A49G in patients was significantly higher compared to control subjects (p = 0.04). The 280 allele phenotype frequency of (AT)(n)-3'UTR was also significantly higher in patients (p = 0.04). The G allele of A49G, the G allele of CT60, and the 280 allele of (AT)(n)-3'UTR microsatellite were significantly increased in patients with GD with thyroid-associated ophthalmopathy (TAO) compared to controls (p = 0.04, p = 0.03, and p = 0.02, respectively), however, we did not find any significant difference between TAO and non-TAO patients. We also found the HLA-DRB1*03 allele to be associated with GD; interestingly, the association of the CTLA-4 markers was independent from the HLA DRB1*03 status. These results highlight the role of the CTLA-4 locus, in addition to HLA, in the susceptibility to GD. Inside the CTLA-4 region, CT60 appears to be the most associated polymorphism to GD, however, further studies are needed to identify the etiologic variant.     

Cytotoxic T-lymphocyte antigen 4 gene +49A/G polymorphism significantly associated with susceptibility to primary biliary cirrhosis: a meta-analysis

OBJECTIVE: To evaluate comprehensively the association of cytotoxic T‐lymphocyte antigen 4 (CTLA‐4) +49A/G polymorphism with susceptibility to primary biliary cirrhosis (PBC). METHODS: PubMed was used to search for the relevant published articles. The risk of PBC association with the CTLA‐4+49A/G polymorphism was estimated for each study in a random‐effects model. Odds ratio (OR) and 95% confidence interval (CI) were estimated for each study. Risks to PBC were estimated by stratified analysis in patients with different ethnicity and antimitochondrial antibody (AMA) status, as well as histological stages. RESULTS: A total of 12 articles were included in the study. An association between PBC and CTLA‐4 G allele was found, overall OR = 1.20, 95% CI 1.03–1.41 (P = 0.02). However, stratification by ethnicity indicated a significant association between the G allele and PBC in Asians (OR = 1.36, 95% CI 1.12–1.65, P = 0.002), but not in Caucasians (OR = 1.15, 95% CI 0.95–1.39, P = 0.15). Moreover, AMA positive patients carrying G allele were more susceptible to PBC compared with AMA negative patients (OR = 1.23, 95% CI 1.06–1.43, P = 0.007; OR = 0.98, 95% CI 0.71–1.34, P = 0.88, respectively). CONCLUSIONS: Polymorphism in exon 1 of CTLA‐4 gene at position 49 may act as a candidate of susceptibility locus to PBC. However, larger studies with participants of varying ethnicity and stratified by clinical and laboratory characteristics are needed to validate our findings.     

CTLA-4 polymorphisms and clinical outcome after allogeneic stem cell transplantation from HLA-identical sibling donors

CTLA-4 is an inhibitory molecule that down-regulates T-cell activation. Although polymorphisms at CTLA-4 have been correlated with autoimmune diseases their association with clinical outcome after allogeneic hematopoietic stem cell transplantation (allo-HSCT) has yet to be explored. A total of 5 CTLA-4 single-nucleotide polymorphisms were genotyped on 536 HLA-identical sibling donors of allo-HSC transplants. Genotypes were tested for an association with patients' posttransplantation outcomes. The effect of the polymorphisms on cytotoxic T-lymphocyte antigen 4 (CTLA-4) mRNA and protein production were determined in 60 healthy control participants. We observed a reduction in the mRNA expression of the soluble CTLA-4 isoform in the presence of a G allele at CT60 and +49. Patients receiving stem cells from a donor with at least 1 G allele in position CT60 had worse overall survival (56.2% vs 69.8% at 5 years; P = .001; hazard ratio [HR], 3.80; 95% confidence interval [CI], 1.75-8.22), due to a higher risk of relapse (P = .049; HR, 1.71; 95% CI, 1.00-2.93). Acute graft-versus-host disease (aGVHD) was more frequent in patients receiving CT60 AA stem cells (P = .033; HR, 1.54; 95% CI, 1.03-2.29). This is the first study to report an association between polymorphisms at CTLA-4 and clinical outcome after allo-HSCT. The CT60 genotype influences relapse and aGVHD, probably due to its action on CTLA-4 alternative splicing.     

Increased frequency of the CTLA-4 49 A/G polymorphism in patients with acquired haemophilia A compared to healthy controls

Summary.  Acquired haemophilia (AH) is an autoimmune disorder characterized by autoantibodies against endogenous factor VIII (FVIII). Half of the patients present with an underlying disease known to cause the FVIII autoantibodies whereas in the other half the disease is of idiopathic nature. Recently, it has been shown that variants of the polymorphic cytotoxic T lymphocyte antigen-4 ( CTLA-4 ) gene are associated with autoimmune diseases and also represent a risk factor for inhibitor formation in inherited haemophilia A. In the present study, we investigated whether CTLA-4 variants also play a role in the pathogenesis of AH. Therefore, we analyzed three single nucleotide polymorphisms (SNPs) of the CTLA-4 gene (-318 C/T, +49 A/G and CT60 A/G) in 57 AH patients and 98 controls. The CTLA-4  +   49 G allele occurred with a significantly higher frequency in patients with AH compared with controls [odds ratio (OR) = 2.17, 95% confidence interval (CI): 1.36–3.48, P  = 0.001]. This effect was mainly caused by a higher frequency of the 49 G allele in female patients (OR = 5.1, 95% CI: 1.76–15.02, P = 0.002 ), whereas in males the frequencies were not significantly different (OR = 1.4, P  = 0.5). A higher frequency of the G allele was also observed in the subcohort with AH and underlying autoimmune disease (OR = 3.1, P  = 0.04). Our observations of a higher frequency of the CTLA-4  +   49 A/G SNP in AH patients are in concordance with findings in other autoimmune disorders. In conclusion, on the background of the CTLA-4 gene polymorphism, further genetic and/or environmental factors might contribute to and finally trigger the clinical manifestation of AH.     

Association of CTLA4 polymorphisms with sustained response to interferon and ribavirin therapy for chronic hepatitis C virus infection

Cytotoxic T lymphocyte antigen-4 (CTLA4) suppresses cytotoxic T lymphocyte activity. We examined the associations of CTLA4 single-nucleotide polymorphisms (SNPs) at promoter site -318 and exon-1 site 49 with clearance of hepatitis C virus (HCV) after treatment with combination interferon-alpha plus ribavirin (IFN-alpha+R) therapy in 79 white sustained responders (SRs) and 79 nonresponders (NRs). SRs had higher frequencies of 49G, alone (odds ratio [OR], 2.3; P=.042) and tightly linked with -318C in a haplotype (OR, 2.4; P=.030). Homozygosity for the -318C-49G haplotype was even more frequent among SRs (OR, 5.2; P=.049). Comparably strong associations persisted after multivariable analysis. Relationships were not seen with non-1 genotype viruses (OR, 0.93-1.25; P>.25). Virus load also declined more rapidly in carriers of both 49G (P=.0095) and the -318C-49G haplotype. CTLA4 49G in exon 1 alone and in a haplotype with -318C promoter is associated with sustained IFNalpha+R response in white patients with HCV genotype 1 infection.