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Chemokine receptor CCR2 and CCR5 polymorphisms in children with insulin- dependent diabetes mellitus

Studies have shown the important roles of several regulatory and proinflammatory cytokines in insulin-dependent diabetes mellitus (IDDM). CC-chemokine receptors CCR2 and CCR5 bind chemokines that are involved in the trafficking of leukocytes in both basal and inflammatory states. A common 32-bp deletion mutation in the CCR5 gene (CCR5Δ32) and a G-to-A nucleotide substitution in the CCR2 at position 190 (CCR2-64I) have recently been described. In the present study, we have determined the frequency of the CCR5Δ32 and CCR2-64I alleles in children with IDDM [n = 115; age 1-14 (9.3 ± 4.3) y] and in nondiabetic subjects [n = 280; age 1-14 (8.5 ± 4.5) y]. The CCR5Δ32 allele frequencies were 0.117 in children with IDDM and 0.111 in nondiabetic subjects, indicating that the deletion allele has no association with IDDM. The CCR2-64I allele frequency in children with IDDM was 0.226, which differed significantly from the allele frequency in controls (0.114, p = 0.001). The role of this mutation in IDDM cannot be explained yet, but, because CCR2 mediates the chemotaxis of CD4+ and CD8+ T cells to areas of inflammation and because these cells play important roles in insulitis, a mutation in the CCR2 gene may contribute to the susceptibility to the disease. Alternatively, the 64I allele could be a marker of a linked mutation through linkage disequilibrium. According to these results, the CCR2 gene may be a new candidate for the susceptibility locus of IDDM. However, because no IDDM locus has been identified near 3p21 until now, further investigations are needed to confirm this statement.

The type 2 diabetes-associated variant in TCF7L2 is associated with latent autoimmune diabetes in adult Europeans and the gene effect is modified by obesity: a meta-analysis and an individual study

Aims/hypothesisThe variants of transcription factor 7-like 2 (TCF7L2) gene have been proposed to be associated with latent autoimmune diabetes in adults (LADA). We sought to confirm the possible association in Europeans and to examine the interaction between one gene variant and clinical data.MethodsThe TCF7L2 rs7903146 C-to-T polymorphism was genotyped in 211 LADA, 1,297 type 2 diabetic, 545 type 1 diabetic and 1,497 control individuals from Hungary. A meta-analysis of our and previously published studies was performed to evaluate the size and the heterogeneity of the gene effect.ResultsThe meta-analysis yielded a significant effect of TCF7L2 T allele (OR 1.28; p < 0.0001) on LADA risk without heterogeneity among Europeans. The T allele conferred equally strong susceptibility to LADA and type 2 diabetes. In the Hungarian dataset, the T allele was associated with LADA and type 2 diabetes, but not with type 1 diabetes. T allele carriers had significantly lower BMI than patients with the CC genotype in the LADA and type 2 diabetes groups (p = 0.0021 and p = 0.0013, respectively). In both diseases, the diabetes risk was significantly higher in the non-overweight than in the overweight BMI category (p = 0.0013 and p < 0.0001, respectively); susceptibility to LADA was increased by 2.84-fold in non-overweight individuals compared with overweight ones.Conclusions/interpretationThe meta-analysis demonstrates that TCF7L2 rs7903146 polymorphism is a population-independent susceptibility locus for LADA in Europeans. The effect size is similar for LADA and type 2 diabetes. The gene effect on diabetes risk may be modulated by BMI, such that the lower the BMI, the higher the gene effect.

Antibodies against different epitopes of heat-shock protein 60 in children with type 1 diabetes mellitus

The aim of this study was to investigate the amounts and epitope specificity of antibodies against heat shock protein 60 (hsp60) in the sera of type 1 diabetic and healthy children. Antibodies specific for peptide p277 of human hsp60 and of M. bovis as well as for human hsp60, M. bovis hsp65 proteins were measured by ELISA. Other autoantibodies (islet cell antibodies, glutamate decarboxylase antibodies and IA-2 antibodies) were also determined. A total number of 83 serum samples from children with type 1 diabetes mellitus and 81 samples of control children were investigated. Epitope scanning of the hsp60 for linear antibody epitopes was carried out using synthetic peptides attached to pins. The antibody levels specific for peptide p277 of human- and of M. bovis origin were significantly (human: P=0.0002, M. bovis: P=0.0044) higher in the diabetic children group than in the healthy children. We could not find significant difference in the antibody levels to whole, recombinant hsp proteins among the examined groups of children. Antibodies to two epitope regions on hsp60 (AA394-413 and AA435-454) were detected in high titres in sera of children with diabetes mellitus. The first region similar to the sequence found in glutamate decarboxylase, whereas the second one overlaps with p277 epitope to a large extent. Presence of antibodies to certain epitopes of hsp60 (AA394-413-glutamic acid decarboxylase-like epitope; AA435-454-p277-like epitope) in diabetic children may reflect their possible role in the autoimmune diabetogenic process of the early diabetes.

Differences in the genetic background of latent autoimmune diabetes in adults (LADA) and type 1 diabetes mellitus

OBJECTIVES According to the recent classification of diabetes mellitus the Latent Autoimmune Diabetes in Adults (LADA) belongs to the group of type 1 autoimmune diabetes, as a slowly progressive form. Our aim was to determine (i) the prevalence of HLA-DRB1 and DQB1 genotypes, and (ii) to determine the tumor necrosis factor (TNF) alpha promoter polymorphism at position -308 (the G-->A substitution, designated the TNF2 allele) in patients with type 1 diabetes and with LADA compared with the healthy population. METHODS The major histocompatibility complex (MHC) II genotypes and the TNF alpha promoter polymorphism were determined by PCR method. We examined 69 type 1 diabetic and 42 LADA patients. As control samples of 336 cadaver kidney donors and 138 volunteers were used. RESULTS Both type 1 diabetes mellitus and LADA were positively associated with the DRB1*04-DQB1*0302 (DR4/DQ8) haplotype (P=0.00001, and P=0.0005, respectively), and negatively associated with the DRB1*11-DQB1*0301 (DR11/DQ7) haplotype (P=0.00006, and P=0.007, respectively) compared with control population. There were differences between the two disease entities in the frequency of the DRB1*03-DQB1*02 (DR3/DQ2) haplotype (P=0.00008 vs. P=0.177) compared with control group. The presence of the TNF2 allele was significantly lower in LADA than type I diabetes (P=0.022) or control group (P=0.017). CONCLUSION Our findings indicate that there are marked differences in the genetic background of type 1 diabetes and LADA. The low presence of TNF2 allele (known to be associated with high amount of TNF alpha production) in LADA could be one of the factors responsible for the relatively slow progression.

Lymphocyte activation in type 1 diabetes mellitus: the increased significance of Kv1.3 potassium channels.

Kv1.3 and IKCa1 potassium channels participate in the maintenance of calcium-influx during lymphocyte activation. Kv1.3 channels have a prominent role in specific T cell subsets, presenting a possible target for selective immunomodulation. We investigated the impact of Kv1.3 and IKCa1 channel inhibitors on calcium-influx characteristics in human T cells in type 1 diabetes mellitus. We isolated lymphocytes from 9 healthy and 9 type 1 diabetic individuals and measured the alteration of calcium-influx with flow cytometry in the Th1, Th2, CD4 and CD8 subsets after treatment of samples with specific channel inhibitors. Our results indicate an increased reactivity of type 1 diabetes lymphocytes, which is correlated to their increased sensitivity to Kv1.3 channel inhibition. However, the contribution of Kv1.3 channels to calcium flux is not exclusive for a specific lymphocyte subset as previous reports suggest, but is characteristic for each subset investigated. Therefore, the proposed inhibition of Kv1.3 channels as a novel therapeutic approach for the treatment of type 1 diabetes mellitus may have a major effect on overall lymphocyte function in this disease.

A detailed investigation of maternally inherited diabetes and deafness (MIDD) including clinical characteristics, C-peptide secretion, HLA-DR and -DQ status and autoantibody pattern.

Background This article presents a clinically characterization of the mitochondrial DNA mutation (A3243G) associated with maternally inherited diabetes and deafness (MIDD) syndrome in two families.

Glutathione S-Transferase Enzyme Polymorphisms in a Hungarian Myelodysplasia Study Population

GSTM1, GSTT1 and GSTP1 Ile105Val that are members of the GST gene family encode for Phase II drug/xenobiotic metabolizing enzymes, primarily with detoxifying function, and are polymorphic in humans. GSTM1 and GSTT1 homozygous deletion genotypes do not express the enzymes. It has been hypothesised that individuals with homozygous deletion of the GSTM1 and/or GSTT1 gene may have lower detoxification capacity towards genotoxic agents therefore those individuals may be at increased risk of myelodysplastic syndrome which is a preleukemic condition. Genetic polymorphism of GSTM1, GSTT1 and GSTP1 Ile105Val was investigated in a case–control study in a Hungarian patient population comprising 86 patients with myelodysplastic syndrome and 99 hospital-based controls. There were no statistically significant differences between cases and controls for the GSTM1, GSTT1 and GSTP1 Ile105Val genotype frequencies for any of the three genes separately and in various combinations. This suggests that these genetic polymorphisms may not be strong risk factors, if any, for myelodysplastic syndrome.

A kardiometabolikus kockázati ténycz″ok kezelésének eredményessége 1-es típusú diabetesben szenved″ok körében

UNLABELLED The attainment and maintenance of therapeutic goal of cardiovascular risk factors are of great clinical importance. The effectiveness of cardiovascular risk management is not well characterized during regular care of patients with type 1 diabetes mellitus. AIM The aim of the study was to estimate the effectiveness of cardiovascular risk management in type 1 diabetic patients. METHODS Adult patients with type 1 diabetes mellitus (n = 533; 256 men, 277 women; age: 35.6 +/- 11.6 years; duration of diabetes: 18.0 +/- 11.1 years; x +/- SD) were consecutively enrolled from 11 diabetes outpatient departments. Data on medical history, actual treatment, anthropometric and laboratory parameters as well as actual blood pressure were registered, while eating and smoking habits, education level and physical activity were evaluated by standardized questionnaires. The treating goal was set according to the national guideline which corresponds to the current international task force. RESULTS Of 533 patients, the body mass index target level (< 25 kg/m 2 ) was achieved by 295 (55.5%) patients. Ideal waist circumference (< 80 cm for women and < 94 cm for men) was measured in 140 (50.5%) and in 165 (63.7%) patients, respectively. Optimal glycaemic control (HbA 1c level < 6.5%) was documented in 45 (8.4%) patients. Lipid lowering drugs (statins, fibrates or ezetimibe) were used by 130 patients, among which 53.1% reached the target triglyceride level, 71.5% the target HDL-cholesterol and 27.8% the target LDL-cholesterol levels. Taking the lipid target values together, only 23 (17.7%) patients were at goal. Antihypertensive drugs were used by 173 patients among which 29.5% reached the systolic and 34.8% the diastolic target values (< 130/80 mmHg). Regarding smoking habits, 94 (17.7%) patients were current smokers and 102 (19.2%) ex-smokers. CONCLUSIONS The attainment of therapeutic goal of cardiovascular risk factors proved to be difficult in a substantial part of patients. Further efforts are needed for attaining and maintaining the established goal of cardiovascular risk management during regular care of adult patients with type 1 diabetes mellitus.A kardiometabolikus kockazati tenyezők csokkentesevel visszaszorithatok a cardiovascularis esemenyek. A kardiometabolikus kockazati tenyezők befolyasolasanak eredmenyessegeről 1-es tipusu diabetes mellitusban szenvedő felnőtt cukorbetegek koreben csak keves adat all rendelkezesre. Celkitűzes: Diabetes-szakrendelesen ellenőrzes celjabol megjelenő, 1-es tipusu diabetes mellitusban szenvedő felnőtt (eletkor ≥ 18 ev) cukorbetegek koreben adatokat gyűjtottunk a kardiometabolikus kockazati tenyezők előfordulasarol es kezelesuk eredmenyessegeről. Modszerek: Fel ev alatt az orszag 11 diabetescentrumaban egymast kovetően megjelent 1-es tipusu cukorbetegsegben szenvedők (n = 533; 256 ferfi, 277 nő; eletkor 35,6 ± 11,6 ev; diabetestartam 18,0 ± 11,1 ev; x ± SD) ellenőrzesekor, az előzmenyi adatok felvetelen tul, antropometriai es laboratoriumi adatokat regisztraltunk. A kardiometabolikus kockazati tenyezők kezelesi celertekekent a III. Magyar Cardiovascularis Konszenzuskonferencia ajanlasaban szereplő adatokat tekin...

Az 1-es típusú diabetes genetikája: jelen és jövő

Over the past decades the majority of genetic research focused on common diseases, and remarkable results were obtained for exploring the genetic background of type 1 diabetes. The classic linkage analyses and the modern genome-wide association studies demonstrated that the genetic background is the primary risk factor for beta-cell autoimmunity while the progression to clinical onset could be triggered by the genetic factors, epigenetic modifications of gene expression and environmental factors together. The new system biology concept can help to understand the mechanisms underlying the immune-mediated beta-cell destruction by generating networks based on data from whole genome scans, fine mapping and gene expression studies to develop targeted prevention and therapeutic strategies. In this paper, we discuss the present understanding of genetic factors which could initiate beta-cell autoimmunity (i.e. define the aetiology) and the genetic and epigenetic factors which might contribute to the progression to clinical disease in individuals with autoantibodies (i.e. define the pathogenesis). Orv Hetil. 2017; 158(44): 1731-1740.Absztrakt: Az elmult evtizedek genetikai kutatasanak nagy resze a gyakori betegsegekre iranyult, igy jelentős eredmenyek szulettek az 1-es tipusu diabetes genetikai hatterenek felterkepezeseben is. A klasszikus kapcsoltsagi vizsgalatok es a modern, genomszintű asszociacios vizsgalatok felhasznalasaval igazoltak, hogy a genetikai faktorok jelentik a beta-sejt elleni autoimmunitas primer kockazati tenyezőit, mig a betegsegiranyu progressziot feltehetőleg a genetikai tenyezők, az epigenetikai modosulasok genexpressziora gyakorolt hatasa es a kornyezeti hatasok egyuttesen valtjak ki. Az uj rendszerbiologiai koncepcio pedig a teljes genomszűres, a finom terkepezes es a genexpresszios vizsgalatok adatai alapjan alkotott biologiai halozatok reven segithet az immunmedialt beta-sejt-pusztulas alapjaul szolgalo mechanizmusokat megerteni, es ezaltal celzott prevencios es terapias strategiakat kifejleszteni. Ebben a cikkben osszefoglaljuk a beta-sejt elleni autoimmunitast elindito (azaz az etiologiat meghatarozo) gen...

Coexistent systemic mastocytosis and essential thrombocythemia complicated with monoclonal gammopathy and hypocomplementaemia

Hematological neoplasms associated with systemic mast cell disease are most frequently of myeloid origin. There are a few reports, however, of systemic mastocytosis (SM) cases associated with lymphoid or plasma cell neoplasms as well. In this report, the authors present a case of SM (with D816V mutation in the c-KIT gene) associated with JAK2 V617F mutation negative essential thrombocythemia. The leading symptom of the 78-year-old female was recurring hydrothorax that responded only to interferon alpha therapy. During the first year of therapy, the patient developed insulin-dependent diabetes and hypothyroidism. The hematological workup also revealed IgG kappa monoclonal gammopathy that was non-progressive in the following next three years. Low levels of complements without known clinical significance accompanied the entire picture.