Alexandros Kotsis

Adenosine Deaminase Activity and its Isoenzyme Pattern in Patients with Juvenile Rheumatoid Arthritis and Systemic Lupus Erythematosus

Abstract: Adenosine deaminase (ADA) is involved in purine metabolism and plays a significant role in the mechanisms of the immune system. The aim of this study was to investigate the activity of total ADA (tADA) and its isoenzymes ADA1 and ADA2 in serum and peripheral blood lymphocytes (PBLs) of children with juvenile rheumatoid arthritis (JRA) and systemic lupus erythematosus (SLE) in different phases of the diseases. The study comprised 34 patients with rheumatic disease, 24 with JRA and 10 with SLE, and 64 healthy controls. The tADA activity and its isoenzymes were measured in serum and PBLs of all patients by the method of Giusti and by the presence or absence of EHNA (erythro-9-(2-hydroxy-3-nonyl)adenine) during the active phase of the disease (before treatment), as well as during remission and relapse. Our data show that increased tADA activity in the serum and PBLs of patients with JRA and SLE is correlated mainly to increased levels of ADA2 activity in serum and ADA1 activity in PBLs. It also closely correlates with clinical disease activity and relapse. The cause of this increased tADA/ADA2 activity in serum and tADA/ADA1 activity in PBLs in JRA and SLE remains to be elucidated. Nevertheless, it may be noted that the measurement of tADA activity, together with ADA2 activity in serum and tADA with ADA1 activity in PBLs, could offer a biochemical approach to the assessment of the pathophysiology of JRA and SLE. Also, tADA and its isoenzymes could be used as alternative parameters representing disease activity.

Methylenetetrahydrofolate reductase polymorphism C677T is not associated to the risk of cervical dysplasia

The aim of the study was to explore a possible association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and cervical neoplasia. A total of 229 women were subjected to cytologic and colposcopic evaluation. Ninety-one of them were found to be normal, and served as the control group, while the other 138 of them had present or past histologically proven cervical pathology (patients group). All patients and controls were investigated for the MTHFR C677T polymorphism. Statistical analysis between the groups of cases with cervical intraepithelial neoplasia or invasive cervical cancer and the control group did not reveal any statistically significant difference in the frequency of the MTHFR C677T polymorphism.

Factor V Leiden and prothrombin G20210A mutations in pregnancies with adverse outcome

Background: Inherited thrombophilia has been associated with obstetric complications through mechanisms that are not yet fully elucidated. The aim of this study was to investigate the relationship between specific obstetric adverse outcomes and factor V Leiden and prothrombin G20210A mutations. Methods: Forty-five women with adverse pregnancy outcome defined as severe pre-eclampsia, abruptio placentae, intrauterine growth restriction and stillbirth, were tested for factor V Leiden and prothrombin G20210A mutations. The control group comprised 100 women with at least one normal pregnancy and no history of thrombosis. Results: Overall, 13 women with one or more of the above-mentioned pregnancy complications (28%) had either thrombophilic mutation, as compared with six in the control group (6%) (p < 0.001, odds ratio (OR) 6.1; 95% confidence interval (CI) 1.9-20). The factor V Leiden mutation was detected in ten of the women with complicated pregnancies (22%) and in four of the controls (4%) (p < 0.001, OR 6.6; 95% CI 1.7-27.2). The prothrombin G20210A mutation was detected in three women in the group with complications (6%) and in two of the controls (2%) (p = 0.17, OR 3.4; 95% CI 0.4-30.5). Compared to controls, the prevalence of the factor V Leiden mutation was significantly higher in the subgroups of severe pre-eclampsia, abruptio placentae and fetal growth restriction. The prevalence of the prothrombin G20210A mutation does not appear to be significantly different from that in the controls in any of the groups studied. Conclusions: Our data suggest that inherited thrombophilia, and specifically the factor V Leiden mutation, may be associated with adverse pregnancy outcome. The role of the prothrombin G20210A mutation remains to be elucidated.

An association study of a functional catalase gene polymorphism, −262C→T, and patients with Alzheimer's disease

According to the oxidative stress hypothesis which has been proposed as one of a number of possible mechanisms underlying pathogenesis of Alzheimers disease (AD), accumulation of hydrogen peroxide in the brain of affected individuals, due to overproduction and/or insufficient detoxification, can trigger a cascade of neurotoxic events, thus contributing to the neuronal damage characteristic of the disease. The upregulation of enzymes that are able to neutralize hydrogen peroxide (catalase, peroxidases) would then be conceivably able to offer at least some protection from the damaging effects of this agent. In this study we examined the distribution of a functional polymorphism in the gene for catalase, -262C-->T, in an independent population of 137 AD patients and 130 control individuals. The presence of the polymorphism, which results in the elimination of a SmaI restriction site, was tested with a PCR amplification/SmaI digestion-based assay. No significant difference has emerged from the comparison of either genotype or allele frequencies (P>0.5). We conclude that the catalase gene -262C-->T polymorphism does not confer a protective effect with respect to AD.

Association of the Tau haplotype with Parkinson's disease in the Greek population.

We compared the distribution of the Tau H1 haplotype and related subhaplotypes in a group of clinically diagnosed Parkinsons disease patients (n = 133) and in control individuals (n = 113) from northern Greece. We were able to detect a statistically significant overrepresentation of the H1H1 genotype in our patient group (OR for H1H1 vs. H1H2 and H2H2: 1.73; 95% CI: 1.03–2.90; P = 0.037). The H1 subhaplotype significantly associated with the disease in our population was different from the one previously reported for a Norwegian population, suggesting that the nature of the association of Tau with Parkinsons disease is influenced by ethnic variation.

Serum adenosine deaminase and procalcitonin concentrations in neutropenic febrile children with acute lymphoblastic leukaemia

Abstract Neutropenia as a state of immunosuppression is probably the major problem in patients suffering from acute lymphoblastic leukaemia undergoing intensive chemotherapy. Fever is frequent in neutropenic patients and often related to infection. Clinically, the presence of infection in patients with neutropenia may be difficult to establish, because there are usually few signs of infection. The aim of this work was to study sensitive markers for early diagnosis of microbial infection in neutropenic children undergoing intensive chemotherapy as a treatment for acute lymphoblastic leukaemia. The study included three groups (A, B and C) of children with acute lymphoblastic leukaemia and neutropenia. Group A consisted of 29 children with febrile neutropenia and microbial infection, aged 1–14 years (5.8±2.9), 11 boys and 18 girls; Group B of 38 children with febrile neutropenia without microbial infection, aged 2–14 years (6.8±3.1), 14 boys and 24 girls; and Group C of 53 children with neutropenia without fever and without infection, aged 1–14 years (5.9±2.1), 21 boys and 32 girls. Blood samples were collected upon admission and before the start of any antimicrobial treatment. The samples were used for blood culture, serological tests, leukocyte count and analysis of levels of C–reactive protein, procalcitonin, total adenosine deaminase (ADA) activity and its isoenzymes, ADA–1 and ADA–2. According to our results the procalcitonin levels and total ADA activity discriminated best between neutropenic febrile (Groups A and B) and neutropenic afebrile episodes (Group C). In conclusion, this study suggests procalcitonin and total ADA activity as two easily measurable and cost effective markers for the assessment of immune response in febrile neutropenic patients with acute lymphoblastic leukaemia.

An association study of the cholesteryl ester transfer protein TaqI B polymorphism with late onset Alzheimer's disease

Cholesteryl ester transfer protein (CETP) is reportedly able to affect the amount of cholesterol available for deposition and/or removal from peripheral tissues, in its capacity to mediate the transfer of cholesterol from high density lipoprotein (HDL) to very low density lipoprotein, in exchange for triacylglycerols from the latter. The TaqI B polymorphism of the human CETP gene has been associated with decreased CETP mass and an increase in HDL-cholesterol. While many studies have addressed the atherogenic or anti-atherogenic potential of this polymorphism, little is known about its effect on neurodegeneration, despite the fact that CETP is expressed in the brain and the disturbance of cholesterol homeostasis appears to be an important factor in the pathogenesis of Alzheimers disease (AD). In this report, we have compared the distribution of the TaqI B polymorphism in an independent population of 102 clinically diagnosed late onset AD patients and a spousal control group of 97 individuals. We have also examined the possible interaction between this polymorphism and two other polymorphisms suspected of affecting cholesterol flux, namely apolipoprotein E APOE epsilon4, and lipoprotein lipase LPLS447X. No statistically significant differences have emerged with respect to either genotype or allele frequencies between the AD and control populations. CETP TaqI B did not interact significantly with either APOE epsilon4 or LPLS447X, in this study.

GSK3β polymorphisms, MAPT H1 haplotype and Parkinson's disease in a Greek cohort

To determine whether polymorphisms in the microtubule-associated protein tau (MAPT) and/or glycogen synthase kinase-3β (GSK3β) genes underpin susceptibility to Parkinsons disease (PD), we conducted a case-control association study in a Greek cohort of 196 PD cases and 163 healthy controls. In our study, the MAPT H1 haplotype was found to be significantly associated with PD, no association was detected between the intronic rs6438552 (-157 T/C) GSK3β polymorphism and PD, whereas the C/C genotype of the promoter rs334558 (-50 T/C) GSK3β polymorphism was found to exert a protective role. The C/C genotype of the rs334558 GSK3β polymorphism was also found to have an additional protective role in our MAPT H1/H1 PD subgroup. Haplotype analysis revealed that, the T-T haplotype of both GSK3β polymorphisms was over-represented in PD patients compared to controls, and this association was independent of MAPT H1 haplotype.

Subspecies variation in Greek strains of Chlamydophila abortus.

The Greek chlamydial strains FAS, FAG, VPG and LLG, isolated from aborted sheep or goat foetuses, had been previously characterized as divergent on the basis of mouse cross-protection experiments, with LLG and its homologous POS significantly different from the rest in inclusion morphology, polypeptide profiles and reactivity with monoclonal antibodies. To determine the genetic basis of their divergence the 16S-23S ribosomal intergenic spacer was analysed by RFLP analysis of PCR 16SF2/23R amplicons. Using the restriction enzymes BfaI, SfcI, HpaI, BclI, DdeI and AclI, the strains were classified as Chlamydophila abortus. However, digestion with RsaI made it possible to differentiate strains FAS, FAG and VPG from strains LLG and POS, generating DNA fragments of 530/55 and 585bp, respectively. By subsequent sequence analysis of the 23S domain I rRNA gene only strain FAS was identical to reference strain A22 of C. abortus. Strains FAG and VPG presented an identical nucleotide deviation at position 593 of signature sequences. Strains LLG and POS presented three identical nucleotide deviations at positions 156, 186 and 307. Variation within the domain I signature sequences for the examined abortion strains was < or =0.69%. In conclusion, substantial genetic and biological diversity among strains of C. abortus was demonstrated, suggesting that subspecies variation status for certain strains may be applicable. Our findings suggest that differentiation may be possible at a subspecies level by RFLP analysis.

Factor V Leiden in Greek thrombophilic patients: relationship with activated protein C resistance test and levels of thrombin-antithrombin complex and prothrombin fragment 1 + 2.

We studied 172 Greek patients (72 men aged 44.0 × 16.7 years and 100 women aged 46.5 × 14.1 years) with an unexplained thrombophilic tendency. One hundred and four apparently healthy persons (63 men aged 34.2 × 10.0 years and 41 women aged 37.1 × 13.3 years) were included as a control group. We performed the activated protein C resistance (APC-r) test using a clotting test (Chromogenix kit), detection of factor V Leiden using polymerase chain reaction (PCR)-restriction fragment length polymorphisms and measurement of thrombin-antithrombin complexes (TAT) and prothrombin fragment 1+2 (F1+2) levels with an immunoenzymatic assay. The normal range for the APC-r test (> 2.12) was determined from the controls. The factor V Leiden mutation was found in 31.9% of all the patients tested, in 28.1% of the unrelated patients with documented thrombophilic tendency of unknown origin and in 4.8% of the healthy controls. The APC-r test had a sensitivity of 0.42 and a specificity of 0.91 for the detection of factor V Leiden. Furthermore, we found no significant difference in levels of TAT and F1+2 between patients with and without the mutation and there was no correlation between aPC-r values and levels of TAT and F1+2.