Association study of the IL18RAP locus in three European populations with coeliac disease.

Coeliac disease is caused by dietary gluten, triggering a chronic inflammation of the small intestine in genetically predisposed individuals. Recently, a risk locus on chromosome 2q11-q12, harbouring interleukin 18 receptor accessory protein (IL18RAP) and three other genes, was suggested for coeliac disease. IL18 has been shown to play an important role in T helper type 1 activity in coeliac disease, making this locus a highly interesting candidate. In this study, two previously indicated risk variants at the IL18RAP locus (rs13015714 and rs917997) were tested for genetic association in 1638 cases with coeliac disease and 1385 control individuals from the Finnish, Hungarian and Italian populations. The protein expression level of IL18RAP was also compared between risk allele carriers and non-carriers by Western blotting. Furthermore, immunohistochemical analysis was performed to study IL18RAP protein expression in small intestinal biopsies of untreated and treated coeliac patients and controls. We confirmed genetic association and dose effects of variants at the 2q12.1 locus with coeliac disease in the Hungarian population. The GA haplotype of the markers rs13015714 and rs917997 showed the strongest association (P = 0.0001, odds ratio = 1.475, 95% confidence interval 1.21-1.80). Two putative isoforms of IL18RAP were detected and the ratios and total levels of these isoforms may contribute to the aetiology of coeliac disease. Our study supports IL18RAP as a novel predisposing gene for coeliac disease and highlights the need for further functional studies on this relatively unknown gene in coeliac disease pathogenesis.

Cost-effective HLA typing with tagging SNPs predicts celiac disease risk haplotypes in the Finnish, Hungarian, and Italian populations.

Human leukocyte antigen (HLA) genes, located on chromosome 6p21.3, have a crucial role in susceptibility to various autoimmune and inflammatory diseases, such as celiac disease and type 1 diabetes. Certain HLA heterodimers, namely DQ2 (encoded by the DQA1*05 and DQB1*02 alleles) and DQ8 (DQA1*03 and DQB1*0302), are necessary for the development of celiac disease. Traditional genotyping of HLA genes is laborious, time-consuming, and expensive. A novel HLA-genotyping method, using six HLA-tagging single-nucleotide polymorphisms (SNPs) and suitable for high-throughput approaches, was described recently. Our aim was to validate this method in the Finnish, Hungarian, and Italian populations. The six previously reported HLA-tagging SNPs were genotyped in patients with celiac disease and in healthy individuals from Finland, Hungary, and two distinct regions of Italy. The potential of this method was evaluated in analyzing how well the tag SNP results correlate with the HLA genotypes previously determined using traditional HLA-typing methods. Using the tagging SNP method, it is possible to determine the celiac disease risk haplotypes accurately in Finnish, Hungarian, and Italian populations, with specificity and sensitivity ranging from 95% to 100%. In addition, it predicts homozygosity and heterozygosity for a risk haplotype, allowing studies on genotypic risk effects. The method is transferable between populations and therefore suited for large-scale research studies and screening of celiac disease among high-risk individuals or at the population level.

IL23R in the Swedish, Finnish, Hungarian and Italian populations: association with IBD and psoriasis, and linkage to celiac disease.

BACKGROUND: Association of the interleukin-23 receptor (IL23R) with inflammatory bowel disease (IBD) has been confirmed in several populations. IL23R also associates with psoriasis, suggesting that the gene may be an important candidate for many chronic inflammatory diseases. METHODS: We studied association of single-nucleotide variants in IL23R with IBD in Swedish patients, in both Crohn's disease (CD) and ulcerative colitis (UC) subsets. The same genetic variants were also studied in Finnish patients with psoriasis or celiac disease, and in Hungarian and Italian patients with celiac disease. RESULTS: Association of IL23R with IBD was replicated in our Swedish patients, and linkage and association of the IL23R region with psoriasis was found in the Finnish population. The IL23R region was also linked to celiac disease in Finnish families, but no association of IL23R variants with celiac disease was found in the Finnish, Hungarian or Italian samples. CONCLUSION: Our study is the first to demonstrate association of IL23R with CD and UC in Swedish patients with IBD. It is also the first study to report linkage and association of the IL23R region with psoriasis in the Finnish population. Importantly, this is the first report of linkage of the IL23R region to celiac disease, a chronic inflammatory condition in which IL23R has not been previously implicated.

Discordance in human paraoxonase-1 gene between phenotypes and genotypes in chronic kidney disease.

BACKGROUND: Human serum paraoxonase-1 (PON1) is a high-density lipoprotein-associated ester hydrolase which can inhibit low-density lipoprotein oxidation and has an antiatherogenic effect. Two common polymorphisms are known in the PON1 gene in humans (at positions 55 and 192), from which the latter gene alteration has been mainly attributed to alter the activity of the protein. Moreover, significantly reduced PON1 activity was found in chronic kidney disease (CKD) and renal transplant patients. METHODS: The aim of the present study was to investigate the genotype and phenotype distribution of the PON1 gene as well as its end product activity in patients with CKD (n = 117), in renal transplant recipients (n = 146) and in reference subjects (n = 1,180). RESULTS: Unexpectedly high discordances between phenotype and genotype assessments were observed in all studied groups (28.2% in the CKD, 20.55% in the transplant and 30.9% in the reference group). Arylesterase activity was significantly lower in the CKD group compared to the reference sample. There were no significant differences between patients and the reference group in the frequencies of polymorphisms PON1-55 and PON1-192. PON1 activity did not differ in patients compared to the reference group. CONCLUSIONS: Both PON1 phenotype and genotype determinations are necessary to estimate PON1 status.

Polymorphisms of TNF-alpha and LT-alpha genes in multiple myeloma.

Allelic distribution of -308 G>A (TNF 1/2) polymorphism of the TNF-alpha, and the +252 A>G promoter polymorphism of the LT-alpha gene, the 1267 A>G polymorphism of the HSP70-2 gene as well as the -429 T>C promoter polymorphism of the RAGE gene were tested in 94 MM cases and 141 controls. Significantly less MM patients than controls carried the TNF2 allele (p=0.018) and the TNF2-LTA 252G haplotype (p=0.025). The difference was, however, restricted to the females, as well as the relatively young (<69 years) subjects. By contrast, we did not find differences with the other SNPs tested.

Modulation of the risk of coronary sclerosis/myocardial infarction by the interaction between factor XIII subunit A Val34Leu polymorphism and fibrinogen concentration in the high risk Hungarian population.

INTRODUCTION: The results on the association of factor XIII (FXIII) A subunit (FXIII-A) Val34Leu polymorphism with the risk of myocardial infarction (MI) are rather inconclusive. The original paper and confirmatory reports demonstrated a protective effect of the mutation, but results demonstrating the lack of protection have also been published. Gene-gene and gene-environmental interactions have been proposed to be responsible for the opposing results. As the rate of change in fibrin clot permeability with increasing fibrinogen concentrations decreased stepwise with increasing number of Leu34 alleles it was proposed that the protection by Val34Leu polymorphism become effective only at higher fibrinogen concentrations. However, this hypothesis has not been tested on patients with coronary artery disease. PATIENTS AND METHODS: 955 consecutive patients admitted for coronary angiography were categorized according to the presence or absence of significant coronary sclerosis (CS) and according to positive or negative history of MI. The frequency of FXIII-A Val34Leu polymorphism, and a number of risk factors, including fibrinogen were determined in the patients. FXIII-A Val34Leu polymorphism was also investigated in a population control group of 1146 subjects. RESULTS: The presence of FXIII-A Leu34 allele or homozygous Leu34 genotype did not change the risk of CS or MI in the general Hungarian population. However, when patients with fibrinogen level in the upper quartile were separately investigated, the Leu34 allele provided a statistically significant protection against MI. CONCLUSIONS: Fibrinogen concentration modulates the effect of Leu34 allele on the risk of MI; its protective effect emerges at increasing fibrinogen concentration.

Rapid genotyping of paraoxonase 55 and 192 mutations by melting point analysis using real time PCR technology.

BACKGROUND: Paraoxonase (PON1) enzyme was identified as one of the components of HDL responsible for prevention of lipid peroxides accumulation in low-density lipoprotein (LDL). A triphasic phenotypic frequency distribution of PON1 activity was shown in the human population resulted by two nucleotide interchanges at residues 55 and 192. The paraoxonase isoforms have different effectiveness in hydrolysing lipid peroxides. METHODS: To date, genotyping for PON1 is mainly performed by PCR RFLP technique, that is time consuming and sensitive to contamination. We developed highly reliable single-step methods for genotyping both PON1 55 and 192 polymorphisms using LightCycler real time PCR technology based on fluorescence resonance energy transfer. After the ultrafast PCR, melting point analysis was performed and fluorescence intensity was monitored simultaneously with slow heating. RESULTS AND CONCLUSIONS: The observed melting temperatures in the PON1 55 and 192 melting point analyses characteristic to the oligonucleotides hybridised to the mutant and wild-type DNA were 57 degrees C, 61 degrees C and 51.5 degrees C, 57.5 degrees C, respectively. The temperature differences in melting points (4 degrees C and 6 degrees C, respectively) offer a powerful tool for rapid, reliable mutation detection for 55 and 192 polymorphisms even in routine diagnostic laboratories or large epidemiological studies.

ADH1B*2 allele is protective against alcoholism but not chronic liver disease in the Hungarian population.

BACKGROUND: Standardized death rates from chronic liver diseases (CLDs) in Hungary are much higher than the European Union average. Carrying the alcohol dehydrogenase 1B 48His allele (rs1229984 or ADH1B*2) could decrease the risk of alcoholism, but with persistent drinking may confer a greater risk of CLDs. The aim of this study was to assess the prevalence of this polymorphism in the Hungarian population and its association with alcohol consumption and with CLDs. METHODS AND RESULTS: A total of 278 cases with diagnosed CLDs and 752 controls without any alterations in liver function, all males aged 45-64, were screened for ADH1B Arg48His polymorphism. ADH1B*2 allele frequencies in controls and cases were 8.31% and 4.50%, respectively (chi(2) = 9.2; P = 0.01). Carrying the ADH1B*2 allele was associated with significantly lower odds ratio (OR) for drinking frequency (OR = 0.63; P = 0.003), the number of positive answers on CAGE (Cut-down, Annoyed, Guilt, Eye-opener) assessment (OR = 0.58; P = 0.005) and a positive CAGE status (OR = 0.55; P = 0.007). There was a significant association between ADH1B*2 and CLDs (OR = 0.50; P = 0.003), but it disappeared after adjusting for CAGE status and scores (OR = 0.67 P = 0.134; OR = 0.67 P = 0.148, respectively) and weakened after adjusting for drinking frequency (OR = 0.61; P = 0.045). Among heavy drinkers the presence of ADH1B*2 did not increase the risk of cirrhosis but there was a significant interaction between genotype and CAGE status (P = 0.003, P = 0.042), with ADH1B*2 conferring reduced risk of CLDs in CAGE negatives. CONCLUSION: In Hungarians, the ADH1B 48His allele reduces the risk of alcoholism, but not the risk of chronic liver disease among heavy drinkers.

The 8.1 ancestral MHC haplotype is strongly associated with colorectal cancer risk.

Many recent data indicate that some alleles encoded in the central major histocompatibility complex (MHC) region (Class III) of short arm of chromosome 6 may modify the risk of cancer development. Therefore we determined 4 single nucleotide polymorphisms (SNPs) of this region (TNF-alpha -308 G > A, RAGE -429 T > C, HSP70-2 -1267 A > G, LTA 252 A > G) in genomic DNA samples from 183 Hungarian patients with colorectal cancer and 141 age matched control subjects representing the Hungarian population of the same age and gender. No significant differences were found in either SNP tested. When, however, three- or four-locus haplotypes consisting of known constituents of the so-called 8.1 ancestral haplotype (8.1AH) were considered, marked differences were observed. Frequency of TNF-alpha -308A, RAGE -429C, HSP70-2 -1267G, LTA 252G (8.1AH) haplotype was significantly (p = 0.006) more frequent (19.1%) among patients than in the controls (7.7%). Age- and gender-adjusted ratio of the 8.1AH carriers vs. non-carriers to have colorectal cancer was 2.514 (1.130-5.594). This risk was higher in

A preliminary evaluation of a health monitoring programme in Hungary.

BACKGROUND: In 1998 a joint initiative of the Hungarian School of Public Health and the National Public Health Service created a network of sentinel stations based in primary care facilities in four Hungarian counties. The aim was to establish a system that will provide valid data on morbidity of selected diseases in Hungary. METHODS: Based on standardized protocols, the participating centres have continuously reported data on the prevalence of cardiovascular diseases, diabetes mellitus, liver cirrhosis, and some malignant diseases, as well as supplying denominator data. The four counties represent both eastern and western parts of Hungary, reflecting the known geographical disparities in health. Each county office enrolled general practitioners maintaining representation in terms of both geography and distribution of settlement size. RESULTS: A total of 73 general practitioners agreed to participate, providing care for 15.6% (138,088 people) of the population in the counties. The population registered with the practices were representative in terms of age and sex of both the participating counties and the entire country. The prevalence of hypertension, diabetes mellitus and liver cirrhosis is high in each county but varies considerably, with higher levels in the western counties, especially among older age groups of both sexes. CONCLUSIONS: The establishment of sentinel stations to collect morbidity data is feasible and sustainable in Hungarian primary care. The data that have been generated provide a valid and comprehensive picture of important aspects of the Hungarian population's health, with important implications for health policy and health service planning. In regions where low prevalence rates of diseases and high mortality rates simultaneously exist special attention is required to explore the background of this caveat. KEY POINTS: Till the end of 1998 no program operated in Hungary engaged with non-communicable disease morbidity data collection, except some hospital-based registries, which failed to produce reliable information. The establishment of sentinel stations to collect morbidity data is feasible and sustainable in Hungarian primary care, the valid morbidity data can be built into the decision making process in health service planning. Regular training, quality control and feedback are important contributors to the success of the program. The prevalence of hypertension, diabetes mellitus and liver cirrhosis is high in each county but varies considerably, with higher levels in the western counties, especially among older age groups of both sexes. More research needed to determine the possible contribution of unknown morbidity and health service utilisation to the different prevalence values in the two parts of Hungary.