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Biomedical subjects

M Sanak

Publications and source records attributed to M Sanak.

At least 19 recordsLinked to original sources

Familial aggregation of aspirin-induced urticaria and leukotriene C synthase allelic variant.

BACKGROUND: We have reported that in patients with chronic idiopathic urticaria (CIU) who reacted adversely to aspirin, the frequency of the (-444)C allele of the leukotriene C(4) synthase gene (LTC4S) was higher than in patients who tolerated aspirin well. OBJECTIVES: To study the pattern of aspirin-induced urticaria (AIU) in two families, with special interest on the polymorphisms of LTC4S (AA, AC, CC) and the glutathione S-transferase M1 and P1 genes (GSTM1 and GSTP1). METHODS: Of 74 patients with CIU and a history of aspirin hypersensitivity studied by us, two patients (probands) gave a family history of aspirin intolerance. Oral challenge tests with aspirin were carried out in members of these families. Genomic DNA samples were obtained from peripheral blood to study the polymorphisms of LTC4S, GSTM1 and GSTP1. RESULTS: In family 1 the aspirin challenge test confirmed AIU in three of five (60%) individuals, but in family 2 only in two of seven (29%). In both families, the variant genotypes of LTC4S (AC or CC) were present in the parents, but only one of them had CIU. In family 1, with both parents healthy, the three children had AIU; in two it was associated with variant LTC4S genotype. In family 2, urticaria following aspirin ingestion was present only with variant LTC4S genotype. In patients of both families with positive aspirin challenge test, deletion of the GSTM1 gene was present. CONCLUSIONS: AIU aggregates in families inheriting the LTC4S(-444)C allele. Segregation of aspirin sensitivity in these families does not follow a clear Mendelian pattern. A common deletion of GSTM1, one of several enzymes involved in conjugation of a wide range of electrophilic substances with glutathione, was present in all individuals ascertained to have AIU.

Adult↗

The alpha-chain of high-affinity receptor for IgE (FcepsilonRIalpha) gene polymorphisms and serum IgE levels.

BACKGROUND: The high-affinity receptor for immunoglobulin-E (IgE) (FcepsilonRI) plays a major role in the pathogenesis of allergy, but there are only two published studies on its alpha subunit (FcepsilonRIalpha) genetic variability in allergic diseases. AIMS OF THE STUDY: Mutational screening in the region of the FcepsilonRIalpha gene promoter and the first exon with subsequent genetic variability assessment in allergic patients and a random population sample. METHODS: Allergic subjects were individuals with asthma or urticaria. Age- and sex-matched controls were randomly selected from a large population sample. Mutational screening was performed using a single-stranded conformational polymorphism and subsequent sequencing. Detected polymorphisms were genotyped by restriction fragment length polymorphism. Total serum IgE was measured in allergic subjects and controls. Skin prick tests, blood eosinophil count and aspirin challenge test were performed only in the subjects. A subgroup of the subjects was further characterized by autologous serum skin test, histamine release test, Phadiatop and IgE antibodies against staphylococcal enterotoxins. RESULTS: Two linked polymorphisms -344 C>T and -95 T>C were found within the FcepsilonRIalpha gene. The allele -344 T frequency was 0.45 vs 0.37 (P = 0.33), and the allele -95 C frequency was 0.26 in subjects vs 0.30 in controls (P = 0.62). Serum IgE was significantly higher in subjects homozygous for the -344T allele (TT genotype) than in those carrying the -344 C allele (CT or CC genotype; P = 0.003), but this association was not detectable in controls. CONCLUSIONS: Our findings of genotype-related differences in IgE levels in allergic patients suggest an impact of -344 C>T but not -95 T>C gene polymorphism of FcepsilonRIalpha on total levels of IgE. The genetic variability in FcepsilonRIalpha at the -344 nucleotide of its regulatory sequence, though not related to atopy, predicts higher levels of the immunoglobulin.

Adult↗

Valine/Leucine247 polymorphism of beta2-glycoprotein I in patients with antiphospholipid syndrome: lack of association with anti-beta2-glycoprotein I antibodies.

In antiphospholipid syndrome (APS) the presence of anti-beta2-glycoprotein I (beta2GPI) antibodies is strongly associated with thromboembolic complications. It has been suggested that the common beta2GPI Valine/Leucine247 (Val/Leu247) polymorphism could be found more commonly in APS and might influence the generation of anti-beta2GPI antibodies. Therefore we studied beta2GPI Val/Leu247 single-nucleotide polymorphism (SNP) by PCR in 338 patients with various autoimmune diseases (46 with secondary and 84 with primary APS) and 147 sex and age-matched healthy controls. In all patients lupus anticoagulant, anticardiolipin and anti-beta2GPI antibodies (both IgG and IgM) were also determined. All patients and controls were Caucasians. Frequencies of the SNP genotypes in patients did not depart from genetic equilibrum and did not differ from those found in controls. There was also no association between the presence of beta2GPI Val/Leu247genotypes and the presence or absence of lupus anticoagulant, anticardiolipin antibodies, anti-beta2GPI antibodies or clinical APS symptoms in all patients studied. In conclusion, among the exclusively Caucasian, Polish population of autoimmune patients beta2GPI Val/Leu247SNP has the same distribution as in healthy subjects and does not influence the production of anti-beta2GPI antibodies.

Adult↗

Prediction of the excessive perioperative bleeding in patients undergoing coronary artery bypass grafting: role of aspirin and platelet glycoprotein IIIa polymorphism.

OBJECTIVE: The presence of the glycoprotein IIIa allele PlA2 is associated with enhanced thrombin formation and an impaired antithrombotic action of aspirin, which could favor coronary thrombosis. We wondered whether PlA1/A2 genetic polymorphism could affect the postoperative bleeding in patients undergoing coronary artery bypass grafting. We also aimed to assess the effects of aspirin pretreatment and to ascertain the value of platelet function studies as predictors of postoperative bleeding. METHODS: In a randomized, double-blind study, patients undergoing coronary artery bypass grafting were pretreated with a 150-mg dose of aspirin orally 12 and 3 hours before surgery (n = 51, 41 elective) or with placebo (n = 51, 43 elective). The hemostasis was monitored by Simplate (bioMérieux, Inc, Durham, NC) bleeding time and capillary closure time (platelet function analyzer PFA 100; Sysmex UK Ltd, Milton Keynes, United Kingdom). Postoperative bleeding and blood products transfusions were recorded. The glycoprotein IIIa polymorphism was analyzed. RESULTS: Bleeding was significantly greater in PlA1 homozygotes from control group. Blood loss was significantly greater (by 25%) in aspirin group. The volume of blood products transfusions in aspirin patients was significantly larger (by 137%). When subjects were stratified accordingly to blood platelet glycoprotein IIb/IIIa genotype, in the aspirin group PlA2 carriers had greater blood loss than PlA1 homozygotes (1858 +/- 932 mL vs 1216 +/- 525 mL, P < .05). CONCLUSION: PlA1 homozygotes normally had a greater risk of perioperative bleeding. Capillary closure time had no advantage relative to Simplate bleeding time in predicting postoperative blood loss. Aspirin pretreatment revealed no beneficial effects and resulted in increased postoperative bleeding and requirement for blood product transfusions after coronary artery bypass grafting in patients with stable angina. It was most unfavorable for PlA2 carriers.

Alleles↗

Aspirin resistance.

Treatment failures occur with any drug and aspirin is no exception. Evidence is growing to indicate that there are subpopulations that do not respond to antithrombotic action of aspirin. The term 'aspirin resistance' has been used to describe a number of different phenomena, including inability of aspirin to: (i) protect against cardiovascular events despite its regular intake; (ii) to affect various laboratory tests, reflecting platelet activity. Research on aspirin resistance yielded interesting results in clinical pharmacology and pharmacogenetics. Future studies will show whether genotyping for polymorphisms might be of value in everyday clinical use of aspirin. Present data indicate that in survivors of recent myocardial infarction or unstable angina, patients receiving coronary artery bypass grafts, as well as in subjects with hypercholesterolemia, aspirin resistance has to be considered when implementing antithrombotic therapy. However, in individual patients the available laboratory tests are of no particular use to predict reliably the clinical outcome or to guide in making therapeutic decision. Prospective clinical trials seem necessary to reach such conclusions.

Anti-Inflammatory Agents, Non-Steroidal↗

Exhaled eicosanoids following oral aspirin challenge in asthmatic patients.

BACKGROUND: Biochemical analysis of expiratory breath condensate is an emerging non-invasive technique for assessment of airway inflammation. OBJECTIVE: We wondered whether application of expiratory breath condensate could facilitate diagnosis of aspirin-intolerant asthma and reproduce eicosanoids mediators' abnormalities described in this disease. METHODS: We measured prostaglandins (PGs) E(2), F(2 alpha), 9 alpha 11 beta F(2) and iso-F(2) by gas-chromatography/mass-spectrometry and cysteinyl leukotrienes (cys-LTs) by radioimmunoassay in breath condensates of asthmatic patients undergoing oral aspirin challenge. Fourteen patients with aspirin-induced asthma and 20 aspirin-tolerating asthmatics, most of them on chronic inhaled corticotherapy, were studied and compared with 10 healthy subjects. Additionally, plasma 9 alpha 11 beta PGF(2), the metabolite of PGD(2) and urinary leukotriene (LT) E(4) were measured before and following the challenge. RESULTS: At baseline, PG did not differ between the groups, except for lower 9 alpha 11 beta PGF(2) in aspirin-intolerant asthma. Their concentrations were not changed by the challenge. Breath condensate cys-LTs were similar in the groups studied at base, and after aspirin challenge increased only in aspirin-intolerant patients. Elevated baseline urinary LTE(4) and its further increase following aspirin challenge was highly diagnostic for aspirin-intolerant asthma. The discriminatory value of cys-LTs increase in breath condensates was lower (72.8%) than either basal (99%) or post-challenge increase (94%) of urinary LTE(4). CONCLUSIONS: In asthmatic patients on chronic corticotherapy measurement of urinary LTE(4) excretion rather than cys-LTs in breath condensate is of greater value for diagnosis of aspirin hypersensitivity.

Adult↗

Genetic polymorphisms associated with acute pulmonary embolism and deep venous thrombosis.

Frequently an inherited predisposition to thrombosis remains clinically silent until an additional environmental factor intervenes. The present study aimed to assess distribution of inherited risk factors of venous thrombosis in patients with venous thromboembolism (VTE). The prevalences of factor V Leiden (FV Leiden), prothrombin factor II G20210A (FII G20210A), C677T and A1298C of methylenetetrahydrofolate reductase (MTHFR) mutations were studied in 149 VTE patients and 100 controls. The following key risks were established: previous deep venous thrombosis or pulmonary embolism (23.5%), bed rest (34.2%), immobilisation of lower limb (10.1%), hospitalisation (30.9%) and obesity (28.9%). In 29 (19%) patients and in three (3%) controls FV Leiden was found. A significant association between VTE and FV Leiden was established. There were six (4%) carriers of the FII G20210A among VTE patients and one in the controls. No associations between VTE and MTHFR polymorphisms (C677T, A1298C) were found. In three of 149 patients both FV Leiden and FII G20210A polymorphisms were observed. The mean protein C activity was slightly, though nonsignificantly, smaller in VTE patients. In conclusion, there was a positive association between venous thromboembolism and factor V Leiden. Only a weak trend favouring a relationship between prothrombin factor II G20210A and venous thrombolism was present. No associations between common polymorphisms of methylenetetrahydrofolate reductase and venous thromboembolism were found.

Case-Control Studies↗

Clinical and genetic features underlying the response of patients with bronchial asthma to treatment with a leukotriene receptor antagonist.

BACKGROUND: Treatment with antileukotriene drugs results in clinical improvement in many, though not all, patients with asthma. It can be hypothesized that the subpopulation of asthmatic patients, characterized by aspirin intolerance and cysteinyl-leukotriene overproduction, might profit most from antileukotriene treatment. MATERIALS AND METHODS: We compared the clinical response to montelukast in two well-matched groups of patients with mild asthma: 26 aspirin-intolerant asthmatics (AIAs) and 33 aspirin-tolerant asthmatics (ATAs). We also searched for possible predictors of the clinical response among the parameters reflecting the expression and production of cysteinyl-leukotrienes (cys-LTs). This was an 8-week, single-blind, placebo-controlled trial. RESULTS: Following a 3-week montelukast 10 mg day-1 treatment compared with placebo, there was a statistically significant reduction in the mean daytime and nocturnal asthma symptoms and beta 2-agonist use, as well as a significant improvement in the morning and evening peak expiratory flows and quality of life. Both groups showed a similar significant improvement in the parameters studied. Clinical response did not correlate with the baseline urinary LTE4 excretion level. Improvement of asthma was observed mostly in patients with a low baseline and non-IL-5 inducible expression of LTC4 synthase (LTC4S) mRNA in eosinophils. There was a trend toward a better response in carriers of LTC4S allele C, but no relationship to the CC10 genetic polymorphism. CONCLUSIONS: No difference in the clinical response to the montelukast treatment was observed between the AIAs and the ATAs.

Acetates↗

Mutations C677T and A1298C of the 5,10-methylenetetrahydrofolate reductase gene and fasting plasma homocysteine levels are not associated with the increased risk of venous thromboembolic disease.

Mild hyperhomocysteinemia is associated with homozygosity for the thermolabile variant of 5,10-methylenetetrahydrofolate reductase (MTHFR) and could increase the risk of venous thromboembolic disease (VTD). Recently, the second A1298C mutation of the MTHFR gene was described. The present study aimed to analyze both mutations of the MTHFR gene and plasma homocysteine levels in subjects with VTD. The study groups comprised 146 patients with VTD and 100 healthy subjects. There were no statistical differences in carrier frequency and allelic frequency for both A1298C and C677T mutations, nor were there any differences encountered between subjects with VTD and controls in either plasma homocysteine levels or according to C677T or A1298C genotypes of MTHFR. In our VTD patients and controls, neither MTHFR 677CT/1298CC nor MTHFR 677TT/1298CC combined genotypes were observed; double heterozygotes (A1298C/C677T) were represented only in 11% of VTD patients, and in 15% of the controls. In conclusion, the polymorphisms C677T and A1298C of MTHFR and fasting plasma homocysteine levels do not seem to be significant risk factors for venous thromboembolic disease.

3' Untranslated Regions↗

DOI, an agonist of 5-HT2A/2C serotonin receptor, alters the expression of cyclooxygenase-2 in the rat parietal cortex.

The hallucinogenic effect of DOI, serotonin 5-HT2A/2C receptor agonist, is known to be associated with the activation of cortical 5-HT2 receptors. However, the effect of DOI on excitability of cortical neurons and their subsequent function is still not quite understood. Previous immunohistochemical studies using Fos proteins expression as a marker of neuronal activity showed the involvement of arachidonic acid cascade, particularly cyclooxygenase metabolic pathway, in DOI-induced Fos proteins expression in the rat parietal cortex. DOI increases arachidonic acid release which is transformed itself via acceleration of cyclooxygenase metabolic pathway to biologically active metabolites, such as prostaglandins and thromboxanes. Since cyclooxygenase-2 (COX-2) expression correlates with neuronal activity, it was of interest to investigate whether DOI is capable of influencing the level of COX-2 protein and mRNA expression in the rat parietal cortex. It was observed that neurons which were positive for 5-HT2A receptors showed constitutive COX-2 immunoreactivity. It was found further, that COX-2 protein level was increased at 1 h, and returned to the control level at 3 and 6 h after DOI (5 mg/kg) administration. In contrast, DOI decreased the COX-2 mRNA expression at all tested time points (1 h, 3h and 6h after DOI treatment). The obtained results further support the suggestion that COX-2 activation and possibly arachidonic acid metabolites generated by COX-2 may be considered as important mediators of functional responses generated by activation of cortical 5-HT2A/2C receptors.

Animals↗

Mutation A1298C of methylenetetrahydrofolate reductase: risk for early coronary disease not associated with hyperhomocysteinemia.

Diminished activity of 5,10 methylenetetrahydrofolate reductase (MTHFR), a regulatory enzyme of homocysteine metabolism, may predispose to coronary artery disease (CAD). In a case-control study we determined the prevalence of two common MTHFR polymorphisms, C677T and A1298C, in 161 male patients under the age of 50 years with angiographically documented CAD and compared it to that in 211 healthy controls. Genotyping was also performed in a random population sample, consisting of 149 men and 121 women at an average age of 40 years. The studied group had classic risk factors of atherosclerosis but did not differ in fasting plasma homocysteine, folic acid, and vitamin B12 levels in either the control group or population sample. The frequency of the 1298C allele was significantly higher in CAD (0.304) than in controls (0.199) or the population sample (0.235). Allele 1298C showed a significant association with early-onset CAD both in homozygotes and in heterozygous carriers. These findings were further supported by comparisons with the population sample. Homozygosity for allele 677T showed a tendency to associate with CAD. Allele 1298C of MTHFR is associated with early-onset CAD (carriers- RR = 1.71, 95% CI: 1.13-2.59; homozygotes- RR = 3.09, 95% CI: 1.36-7.02), even when blood homocysteine levels are not elevated.

Adolescent↗

Serum interleukin-5 in aspirin-induced asthma.

BACKGROUND: Eosinophilopoetic cytokine IL-5 enhances cysteinyl-leukotriene (cys-LT) synthesis in eosinophils in vitro. In patients with aspirin-induced asthma (AIA) bronchial biopsies revealed eosinophil infiltration and a marked increase in IL-5 positive cells. OBJECTIVE: We wondered whether in AIA patients the bronchial IL-5 increase is reflected in peripheral blood, and if so, whether it is related to overproduction of cys-LT. METHODS: In 11 stable patients with AIA, 32 with ATA (aspirin-tolerant asthma) and in 16 controls we measured serum IL-5 concentrations and urinary LTE4, believed to reflect global cys-LT production. RESULTS: Serum IL-5 was detectable in 12 of 43 asthmatics, but in none of the control subjects. It was highest in the ATA group and differed significantly from the controls. There was no significant difference in IL-5 levels between: (i) the asthmatic groups studied, and (ii) AIA patients and controls. No relationship was found between serum IL-5 and urinary cys-LT. CONCLUSION: Overexpression of IL-5 reported in the airways of aspirin-sensitive patients with asthma was not reflected in their blood. If IL-5 affects cys-LT production, it is rather in the bronchi of the patients than in the blood.

Adult↗

Aspirin-induced rhinitis and asthma.

Interesting findings relating to aspirin-induced asthma recently emerged. In this distinct clinical syndrome, aspirin and most other nonsteroidal anti-inflammatory drugs that inhibit cyclooxygenase precipitate rhinitis and asthma attacks. Aspirin-induced asthma affects 5-10% of adult asthmatics, but remains largely underdiagnosed. The natural history of aspirin-induced asthma has been described, based on an extensive pan-European survey. All over Europe the disease develops according to a pattern in a similar, characteristic way, which might suggest a common underlying principle. Aspirin provocation tests with improved diagnostic accuracy have been developed, although no in-vitro test has been found to be of diagnostic value. At the biochemical level, aspirin-induced asthma is characterized by a chronic overproduction of cysteinyl leukotrienes. The key enzyme, LTC4 synthase, is overexpressed in bronchi and its mRNA is upregulated in peripheral blood eosinophils. The gene coding for LTC4 synthase exists in two common alleles, one of which appears to be associated with a severe, steroid-dependent type of aspirin-induced asthma. Preliminary observations indicate that new, highly specific cyclooxygenase-2 inhibitors may soon become a safe alternative for aspirin-intolerant patients with asthma.

Aspirin↗