Csilla Sipeky

Functional variants of interleukin-23 receptor gene confer risk for rheumatoid arthritis but not for systemic sclerosis

Objectives: Recently, an association was found between Crohn’s disease and the interleukin-23 receptor (IL-23R) gene. Since the IL-23/IL-17 pathway is known to associate with other autoimmune diseases, including rheumatoid arthritis (RA) and systemic sclerosis (SSc), we hypothesised that IL-23R could be a shared susceptibility gene. Methods: Groups of patients with rheumatoid arthritis (n = 412), systemic sclerosis (n = 224), Crohn’s disease (n = 190) and healthy controls (n = 220) were genotyped for rs10889677 (exon-3’UTR C2370A), rs2201841, and rs1884444 variants; the first two have been shown to confer risk for Crohn’s disease. Results: We observed an increased prevalence of the homozygous rs10889677 AA and homozygous rs2201841 CC genotypes both in the Crohn’s disease and in the RA groups as compared to the controls (12.1%, 11.9% vs 5.91%, p<0.05; and 13.2%, 13.1% vs 5.91%, p<0.05), but not in the SSc patients. Logistic regression analysis revealed that bearing these alleles represent risk for the development of rheumatoid arthritis (χ2 = 5.58, p = 0.018, OR = 2.15, 95% CI 1.14–4.06 for rs10889677; and χ2 = 7.45, p = 0.006, OR = 2.40, 95% CI 1.28–4.51 for rs2201841). The rs1884444 allele, which has been previously reported as neutral for development of Crohn’s disease, was also found neutral for all studied groups in the present study. Conclusions: The data reported here provide direct evidence that some allelic variants or haplogroups of IL-23R represent independent risk factors for rheumatoid arthritis as well as Crohn’s disease, but not for scleroderma.

Variants of the IL23R Gene are Associated with Ankylosing Spondylitis but not with Sjögren Syndrome in Hungarian Population Samples

Recently, associations were found between several autoimmune diseases and functional variants of interleukin‐23 receptor (IL23R) gene; here, we studied the possible association of nine polymorphisms of IL23R with ankylosing spondylitis (AS) and with Sjögren syndrome (SS). In our study, we genotyped groups of patients with AS (n = 206), SS (n = 156) and healthy controls (n = 235) for rs11805303, rs10889677, rs1004819, rs2201841, rs11209032, rs11209026, rs10489629, rs7517847 and rs7530511 variants using PCR‐RFLP methods. We observed significant increase in the carriage of the T allele of rs11805303 and the A allele of rs1004189 in the AS group compared with the controls. For the rs10889677 variant, the prevalence of the AA genotype and for the rs2201841, the CC genotype showed a more than two‐fold increase in the AS group compared with the controls. By contrast, the GA heterozygous genotype of rs11209026 variant showed a significant decrease in AS patients compared with controls. Haplotype analysis revealed association of four IL23R haplotypes with AS. There was no difference in the distribution of any of the examined IL23R variants between controls and SS patients. In conclusion, we confirmed the susceptibility or protective associations of IL23R polymorphisms with AS in a Hungarian population and first demonstrated the involvement of the rs11805303 intronic single nucleotide polymorphisms, which was tested so far only for other autoimmune diseases.

Apolipoprotein A5 T-1131C Variant Confers Risk for Metabolic Syndrome

The −1131C is a naturally occurring variant of the apolipoprotein A5 (ApoA5) gene, which has been shown to associate with increased triglyceride levels. This variant has also been shown to confer risk for development of ischemic heart disease and stroke. The gene is in linkage disequilibrium with factors known to correlate with impaired glucose homeostasis. These observations prompted us to study the prevalence of the ApoA5 –1131C allele in patients with metabolic syndrome. A total of 201 metabolic syndrome patients and 210 controls were studied. In both groups the triglyceride levels of patients with −1131C allele were significantly increased compared to the subjects with −1131T allele (3.22 ±0.43 mmol/1 vs. 2.24 ±0.12 mmol/1, p<0.01 in the metabolic syndrome patients; 2.10 ±0.19 mmol/1 vs. 1.22 ±0.05 mmol/1, p<0.01 in the controls). In metabolic syndrome patients the prevalence of the ApoA5 –1131C variant was increased compared to the healthy controls (11% vs. 6.20%). Multiplex regression analysis model adjusted for age, gender, serum total cholesterol levels, acute myocardial infarction and stroke events revealed that the examined ApoA5 variant confers risk for the development of metabolic syndrome: the odds ratio at 95% confidence interval was 3.622 (1.200–10.936), p=0.02. Our findings strongly suggest that this variant is a risk factor for the development of hypertriglyceridemia and metabolic syndrome.

Interethnic differences of CYP2C9 alleles in healthy Hungarian and Roma population samples: Relationship to worldwide allelic frequencies

CYP2C9 gene polymorphisms are widely studied in several ethnic groups, however they are less known in the Roma population. The aim of this work was to study the ethnic differences of the CYP2C9 allele distribution in a healthy Roma population in order to compare them with a healthy Hungarian population. A total of 535 Hungarian and 465 Roma volunteers were genotyped for the CYP2C9*2 (Arg144Cys) and CYP2C9*3 (Ile359Leu) allelic variants by PCR-RFLP assay. The frequencies of the CYP2C9*1, *2 and *3 alleles in the Hungarian population were 0.787, 0.125, and 0.088 and in Roma 0.727, 0.118, and 0.155, respectively. We found a significant difference in CYP2C9*3 prevalence between the Hungarian and Roma populations, which have therapeutic consequences (p<0.005). The distribution of *1/*1, *1/*2, *1/*3, *2/*2, *2/*3, and *3/*3 genotypes in Hungarians were 0.620, 0.195, 0.139, 0.021, 0.015, and 0.011, while in Roma were 0.533, 0.168, 0.219, 0.011, 0.047, and 0.022, respectively. A significant difference was found between the Hungarian and Roma populations regarding the *1/*1, *1/*3 and the *2/*3 (p<0.005) genotypes. This is the first study to investigate the polymorphisms of CYP2C9 gene in the two largest populations in Hungary, healthy Hungarians and Roma. The prevalence of variant CYP2C9 alleles in the Hungarian population is similar to that observed in other European populations. In contrast, the Roma population differs from Hungarians, from most of other Caucasian groups, and from Indians in the incidence of CYP2C9 common variants. The difference in allele distribution patterns between the two populations studied has therapeutic implications as it influences the optimization of therapies.

Polymorphisms of the IL23R Gene Are Associated with Psoriasis but not with Immunoglobulin A Nephropathy in a Hungarian Population

Recently, associations were found between autoimmune diseases and variants of interleukin-23 receptor (IL23R) gene; here, we analyzed the association of nine IL23R polymorphisms with psoriasis and with immunoglobulin A nephropathy (IgAN). Groups of patients with psoriasis, IgAN, and controls were genotyped using polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) methods. We observed a significant increase in the carriage of the minor allele of rs11805303 in psoriasis patients compared to controls. Similarly, for rs2201841 prevalence of the CC genotype and for rs10889677, the AA genotype showed a more than two- and threefold increase, respectively in patients compared to controls. There was no difference in the distribution of IL23R variants between controls and IgAN patients. We confirmed the association of IL23R with psoriasis in a Hungarian population and demonstrated the effect of the rs11805303 SNP, which was tested so far only for other autoimmune diseases. We could not detect any association between the IL23R variants and IgAN.

Functional Variants of Glucokinase Regulatory Protein and Apolipoprotein A5 Genes in Ischemic Stroke

Both the natural variants of the apolipoprotein A5 (APOA5) and the glucokinase regulatory protein gene (GCKR) have been shown to associate with increased fasting triglyceride levels. Here, we investigated the possible association of the functional variants of these two genes with non-fasting triglyceride levels and their susceptibility nature in ischemic stroke. A total of 513 stroke patients and 172 healthy controls were genotyped. All the APOA5 variants (T-1131C, IVS3 + G476A, C56G, and T1259C) were associated with increased triglyceride levels in all stroke patients and controls; except for T1259C, they all conferred risk for the disease. No such association was found for the examined GCKR rs1260326 (C1337T) variant. Furthermore, we examined the effects of specific combinations of the GCKR rs1260326 and APOA5 polymorphisms. Our findings confirmed the previous results regarding the association of APOA5 variants with triglyceride-level increase and stroke susceptibility of these alleles. By contrast, we could not detect any association of the studied GCKR allele with triglyceride levels or with the susceptibility of stroke in the same cohort of patients. In addition, the effect of APOA5 did not change significantly when specific combinations of the two genes were present.

Interleukin-23 receptor gene variants in Hungarian systemic lupus erythematosus patients.

ObjectiveWe investigated the association between systemic lupus erythematosus (SLE) and polymorphisms of interleukin-23 receptor (IL23R) gene, which was recently found to be associated with autoimmune diseases, including Crohn’s disease, rheumatoid arthritis, psoriasis and ankylosing spondylitis.SubjectsWe analysed 383 SLE patients and 253 controls for rs11805303, rs10889677, rs1004819, rs2201841, rs11209032, 11209026, rs10489629, rs7517847 and rs7530511 variants.MethodsThe analysis was carried out using PCR–RFLP methods. Logistic regression analysis was used to compare the genotype distributions of the polymorphisms and haplotypes between the SLE patients and healthy controls.ResultsWe observed no significant difference of the examined variants between the patient and control groups.ConclusionsOur results suggest that neither single nucleotide variants nor haplotypes of IL23R indicate susceptibility to developing SLE in the Hungarian population.

Vitamin K epoxide reductase complex 1 (VKORC1) haplotypes in healthy Hungarian and Roma population samples

The aim of this work was to determine the VKORC1 haplotype profile in healthy Hungarian and Roma population samples, and to compare our data with other selected populations. Using haplotype tagging SNPs (G-1639A, G9041A and C6009T), we characterized Hungarian (n = 510) and Roma (n = 451) population samples with regard to VKORC1*1, *2, *3 and *4 haplotypes. In the Hungarian samples, the VKORC1*1, *2, *3 and *4 haplotypes accounted for 3, 39, 37 and 21%, respectively and by contrast, in the Roma population samples the VKORC1 variants were 5, 30, 46 and 19%, respectively. Comparing the genotypes of Roma and Hungarian populations, difference was found in the *2/*2 (6.87 vs 13.5%), *2/*4 (13.9 vs 19.2%) and *3*3 (21.9 vs 13.7%) VKORC1 haplotype combinations. Comparing each group with the others, and our data with findings published previously by other groups, the VKORC1 genetic profile in Hungarians was more similar to European Caucasians and Americans with European descent than to Roma samples. Clear differences could be detected between Roma versus Hungarians and European or American Caucasians; the Roma population had only minor similarities with data from India.

Triglyceride level modifying functional variants of GALTN2 and MLXIPL in patients with ischaemic stroke

Background:  Recent genome‐wide studies identified several genetic variants associated with blood lipid level alterations. Because affected lipid metabolism can confer risk to the development of ischaemic stroke, we studied three polymorphisms reportedly associated with triglyceride‐level changes, rs17145738 and rs3812316 of the MLXIPL locus, and rs4846914 variant of GALNT2 gene in biobanked samples of patients with stroke. This pool of samples was previously investigated for haplotype tagging minor alleles of apolipoprotein A5 gene (T‐1131C, T1259C, IVS3+G476A and C56G), and an association was found between the minor allele carriage and the triglyceride levels, and also these variants were found to confer risk to the development of stroke.

Prevalence of SLC22A4 1672T and SLC22A5 −207C combination defined TC haplotype in Hungarian ulcerative colitis patients

Ulcerative colitis (UC) is a chronic inflammatory disease of the gastrointestinal tract. The aim of this study was to verify the prevalence rate of the haplotype called TC, determined by combination of two functional alleles of OCTN cation transporter genes (SLC22A4 1672T and SLC22A5 /t-207C combination variants) in ulcerative colitis patients and unrelated healthy controls. The “TC haplotype” has recently been suggested to confer risk for UC. A total of 121 unrelated Hungarian subjects with UC and 110 matched controls were genotyped for the two single nucleotide polymorphisms. The genotypes were determined by using PCR/RFLP assay and direct sequencing. The SLC22A4 1672T allele frequency was 46.7% in the patients with UC and 46.4% in the controls, whereas the SLC22A5 −207C allele occurred in 48.8% of the patients and 51.4% of the controls. The prevalence of the TC haplotype was 19% in the patient group and 22.7% in controls. Since there was no accumulation of the TC haplotype in the patient group, our observation suggests that carrying the TC haplotype is not associated with a higher risk for UC in the Hungarian population.