Juraj Javor

Genetic variations of interleukin‐8, CXCR1 and CXCR2 genes and risk of acute pyelonephritis in children

Acute pyelonephritis (APN) is the most severe form of urinary tract infection, the etiopathogenesis of which is still not well understood. Previous studies demonstrated that chemotaxis of neutrophils into the tissue and across the infected epithelial layer is a key step in rapid bacterial clearance. Variations within genes encoding the major chemokine interleukin‐8 and its receptors CXCR1 and CXCR2 are therefore attractive candidates for participation in genetic predisposition to APN. The aim of our study was to evaluate the association of single nucleotide polymorphisms (SNPs) −251 T/A, +781 C/T, +1633 C/T and +2767 A/T in the IL‐8 gene, +2608 G/C in the CXCR1 gene and +1208 C/T in the CXCR2 gene with susceptibility to APN in the Slovak population. PCR–SSP and PCR–RFLP were used to genotype SNPs in 147 children with APN (62 with recurrent and 85 with episodic form) and 215 healthy individuals. Statistical analysis revealed significantly increased frequency of CXCR1 +2608 C allele (P = 0.0238, OR = 2.452, 95% CI = 1.147–5.243) and GC genotype (P = 0.0201, OR = 2.627, 95% CI = 1.188–5.810) and lower frequency of CXCR2 +1208 T allele (P = 0.0408, OR = 0.645, 95% CI = 0.429–0.972) and TT+TC genotypes (P = 0.0497, OR = 0.5273, 95% CI = 0.288–0.964) in patients with recurrent APN compared with healthy controls. Furthermore, the A allele of IL‐8 −251 T/A SNP was also significantly overrepresented in patients with recurrent APN when compared with those with only single episode of APN (P = 0.0439, OR = 1.627, 95% CI = 1.019–2.599). Our results indicate that the minor CXCR1 +2608 C allele is associated with significantly increased susceptibility to APN in childhood, while the CXCR2 +1208 T allele confers protection from recurrent APN. Moreover, allele A of the IL‐8 −251 T/A may also increase the risk of developing recurrent attacks after the first‐time APN.

Single nucleotide polymorphisms of cytokine genes in the healthy Slovak population

Cytokines are molecules that control and modulate the activities of numerous target cells via binding to specific receptors. The observed differences in the cytokine production among individuals can be, at least partially, explained by gene polymorphisms. Several cytokine gene polymorphisms have been identified to play a role in susceptibility to various diseases, including autoimmune, infectious, allergic or cardiovascular diseases.

Inflammatory marker sTREM-1 reflects the clinical stage and respiratory tract obstruction in allergic asthma bronchiale patients and correlates with number of neutrophils.

The knowledge that asthma is an inflammatory disorder has prompted us to investigate the plasma levels of a new inflammatory marker sTREM-1 that is released from the surfaces of activated neutrophils and monocytes. The plasma levels of sTREM-1 were analysed by a sandwich ELISA test in the cohort of 76 patients with allergic asthma bronchiale and 39 healthy controls. Our results revealed more than 3.5 times higher levels of sTREM-1 in AB patients (92.3 pg/mL ± 125.6) compared with healthy subjects (25.7 pg/mL ± 9.2; P = 0.0001). Higher levels of sTREM-1 were found also in patients with exacerbated AB (170.5 pg/mL ± 78.2) compared with nonexacerbated AB patients (59.1 ± 78.2; P < 0.0001), patients with respiratory tract obstruction (176.4 pg/mL ± 177.8), than those without obstruction (51.99 pg/mL ± 64.0; P < 0.0001) and patients with anti-IgE therapy (P < 0.0001). Levels of sTREM-1 correlated with number of leucocytes (P = 0.002), and absolute number of neutrophils (P = 0.001). Elevated plasma levels of sTREM-1 reflect the severity, state of exacerbation, presence of respiratory tract obstruction in AB patients and together with increased number of neutrophils point to the role of neutrophils in inflammation accompanying AB.

TNF-α and IL-10 gene polymorphisms show a weak association with pemphigus vulgaris in the Slovak population.

Backround  Pemphigus vulgaris is a rare chronic autoimmune disease of skin and mucous membranes, with several cytokines participating in its development. The role of their gene polymorphisms in susceptibility to the disease is, however, not fully understood.

High susceptibility to pemphigus vulgaris due to HLA-DRB1*14:54 in the Slovak population

The current work describes an association between pemphigus vulgaris (PV) and class II HLA alleles in the Slovak population, the first such study in Slovakia on the ‘high‐resolution level’. This work takes into account the new HLA allele nomenclature, officially adopted in 2010. In particular, we have focused on the associations between PV and DRB1*14:54 and DRB1*14:01. This case–control study was performed in a cohort of 43 PV Caucasian patients and 113 Caucasian control subjects from Slovakia. HLA typing was performed using PCR‐SSP (polymerase chain reaction with sequence‐specific primers). We found significantly positive associations between PV and the HLA alleles DRB1*04:02, DRB1*04:04, DRB1*14:54, DRB1*14:04, DRB1*14:05, DQB1*03:02 and DQB1*05:03. In contrast, HLA‐DQB1*06, DRB1*07 and DRB1*13 were negatively associated with PV. Importantly, 93% of PV patients possessed at least one of two HLA haplotypes, DRB1*04–DQB1*03 or HLA‐DRB1*14–DQB1*05. We confirmed the previously reported associations between HLA class II alleles and PV and described a new association between PV and DRB1*14:54. This allele was first described in 2005, and there has been only one report of its association with PV to date.

ApaI, BsmI and TaqI VDR gene polymorphisms in association with multiple sclerosis in Slovaks

Objective: Vitamin D acts through vitamin D receptor (VDR) and has promising beneficial effects in the development and progression of multiple sclerosis (MS). The purpose of our study was to investigate the possible association of the VDR gene polymorphisms ApaI, BsmI and TaqI with the MS susceptibility and with the rate of disease disability progression in the Central European Slovak population. Methods: The allele and genotype variants of ApaI, TaqI and BsmI VDR gene polymorphisms were analysed in 270 clinically diagnosed MS patients and 303 healthy controls. Genotyping was performed by polymerase chain reaction and restriction analysis. Patients were stratified by the rate of disease disability progression using MSSS scores. Results: By logistic regression analysis, we revealed that genotype BB (AA) of BsmI VDR gene polymorphism is decreasing the risk of MS (BB (AA) vs Bb (AG) + bb (GG); OR = 0.59, 95% CI = 0.39–0.90, plog = 0.014). We did not identify any association of ApaI and TaqI polymorphisms neither with MS development nor with the disease progression. Discussion: We showed for the first time that BsmI genotype BB (AA) is associated with the decreased susceptibility to MS in Slovak population. We propose the BsmI gene polymorphism to be one of the important genetic markers in evaluation of the risk of MS. However, our data suggest that VDR gene polymorphisms ApaI, BsmI and TaqI are not useful in the prediction of disease disability progression rate in MS in Slovaks.

Linkage disequilibrium with HLA-DRB1-DQB1 haplotypes explains the association of TNF-308G>A variant with type 1 diabetes in a Brazilian cohort

BACKGROUND A functional variant in the promoter region of the gene encoding tumor necrosis factor (TNF; rs1800629, -308G>A) showed to confer susceptibility to T1D. However, TNF rs1800629 was found, in several populations, to be in linkage disequilibrium with HLA susceptibility haplotypes to T1D. We evaluated the association of TNF rs1800629 with T1D in a cohort of Brazilian subjects, and assessed the impact of HLA susceptibility haplotypes in this association. METHODS 659 subjects with T1D and 539 control subjects were genotyped for TNF-308G>A variant. HLA-DRB1 and HLA-DQB1 genes were genotyped in a subset of 313 subjects with T1D and 139 control subjects. RESULTS Associations with T1D were observed for the A-allele of rs1800629 (OR 1.69, 95% CI 1.33-2.15, p<0.0001, in a codominant model) and for 3 HLA haplotypes: DRB1*03:01-DQB1*02:01 (OR 5.37, 95% CI 3.23-8.59, p<0.0001), DRB1*04:01-DQB1*03:02 (OR 2.95, 95% CI 1.21-7.21, p=0.01) and DRB1*04:02-DQB1*03:02 (OR 2.14, 95% CI 1.02-4.50, p=0.04). Linkage disequilibrium was observed between TNF rs1800629 and HLA-DRB1 and HLA-DQB1 alleles. In a stepwise regression analysis HLA haplotypes, but not TNF rs1800629, remained independently associated with T1D. CONCLUSION Our results do not support an independent effect of allelic variations of TNF in the genetic susceptibility to T1D.

The +190 G/A (rs1799864) polymorphism in the C-C chemokine receptor 2 (CCR2) gene is associated with susceptibility to multiple sclerosis in HLA-DRB1*15:01-negative individuals.

C-C chemokine receptor 2 (CCR2) is one of the key players involved in the transmigration of mononuclear cells into the central nervous system (CNS) and subsequent development of multiple sclerosis (MS). The aim of the current study was to analyse the association of CCR2 +190 G/A (rs1799864) polymorphism with susceptibility to MS and its influence on the age at onset, severity and neurological disability in MS. CCR2 genotyping was carried out by a polymerase chain reaction with restriction fragment length polymorphism (PCR-RFLP) in 301 MS patients and 342 healthy controls. Logistic regression analysis suggested a marginally significant association between MS and rs1799864 A allele (AA+GA vs. GG, P=0.047, OR=1.50, 95% CI=1.00-2.25), however, after stratification of study groups for the presence of HLA-DRB1*15:01 risk allele, this association could be found in HLA-DRB1*15:01-negative individuals only (AA+GA vs. GG, P=0.014, OR=1.84, 95% CI=1.13-2.98). Furthermore, there was no association between CCR2 polymorphism and clinical features of MS. In conclusion, our results suggest that CCR2 +190 G/A polymorphism may increase the susceptibility to MS, but its action seems to be restricted to individuals who do not possess the major risk allele HLA-DRB1*15:01.

The HLA-DRB1 and HLA-DQB1 alleles are associated with multiple sclerosis disability progression in Slovak population

Abstract Objective: The aim of our present study was to analyse the association of HLA-DRB1 and -DQB1 alleles and genotypes with Multiple Sclerosis (MS) disability progression in a cohort of Central European Slovak population. Methods: The allele and genotype variants were analyzed in 282 non-related MS patients. Rate of disease disability progression was evaluated using EDSS score in the 5th, 7th, 10th, and 15th year of disease duration, time to reach EDSS score 3 and 5, and MSSS score. Genotyping was performed by polymerase chain reaction with sequence-specific primers. Results: We found that carriers of homozygous genotype for alleles DRB1*15 and DQB1*03 reached EDSS score 3 significantly earlier than non-carriers of these alleles (p = 0.0172; p = 0.00183, respectively). Genotype DQB1*03/03 carriage was also associated with significantly reduced time to reach EDSS score 5 (p = 0.00316). Lower EDSS score in the 5th year of disease duration was found in carriers of DRB1*07 allele (p cor = 0.028). When MSSS score was used, genotype DRB1*15/15 was found to be less frequent in slow progressing MS patients, when compared to MS patients with mid-rate and rapid disease disability progression (p cor = 0.0305). Discussion: We showed for the first time that HLA-DRB1 and -DQB1 genotypes are genetic markers associated with disability progression in Slovak MS patients. Genotypes DRB1*15/15 and DQB1*03/*03 were identified as short-term clinical negative prognostic factors, while allele DRB1*07 carriage appeared to be a positive prognostic marker of better MS outcome.

A Novel Association of Polymorphism in the ITGA4 Gene Encoding the VLA-4 α4 Subunit with Increased Risk of Alzheimer’s Disease

Alzheimers disease (AD) is the most prevalent cause of dementia in elderly people worldwide. Many studies support the hypothesis that the inflammation of the CNS contributes to the neurodegeneration and disease progression. The integrin molecule α4β1, also known as very late antigen 4 (VLA-4), belongs to adhesion molecules that activate the inflammatory process through the migration of immune cells into the CNS. Therefore, the objective of our study was to analyze the association between two polymorphisms located in the ITGA4 gene encoding the α4 subunit of VLA-4 and the risk of AD. 104 late-onset AD patients and 206 control subjects from Slovakia were genotyped for ITGA4 gene SNP polymorphism rs113276800 (−269C/A) and rs1143676 (+3061A/G). The same study cohorts were also genotyped for the APOE-ε4, which is a known genetic factor associated with increased risk of AD developing. ITGA4 polymorphism analysis revealed significantly higher frequency of the +3061AG carriers in AD group compared to the controls (P ≤ 0.05). Following the APOE-ε4 stratification of study groups, the association remained significant only in APOE-ε4 noncarriers. Our study suggests a novel association of ITGA4 +3061A/G polymorphism with AD and its possible contribution to the disease pathology.