RESUMEN
BACKGROUND: DNA methylation, one of the most stable forms of epigenetic modification is associated with the development and progression of coronary artery disease (CAD). Our previously reported study on epigenome-wide microarray analysis showed significantly methylated CpG sites. Top 5 significant CpGs from HLA gene were selected and analysed by Pyrosequencing (PSQ) to determine their association with severity of CAD. METHODS: Blood samples of 50-age matched angiographically CAD positive male cases with 50 angiographically CAD negative male controls were subjected to lipid profile estimation and PSQ for methylation level analysis. Findings and subgroup analysis were evaluated by Mann-Whitney U; Kruskal-Wallis' rank test and two-way ANOVA by MedCalc (v19.6). RESULTS: Methylation levels in HLA-DQA1 for cg10217052 was 78.5 (37-85) and 76.5 (24-84); cg09411910 was 81 (72.0 to 93.0) and 81.5 (50.0 to 89.0) in cases and controls respectively. Levels in HLA-DQB1-cg03344051, were 28.88 + 9.41 for cases and 30.36 + 9.37 in controls. For HLA-DRB1-cg07889003, levels in cases and controls were 15.5 (5.00-39.00) and 10.5 (5.00-29.0); while in cg08269402 were 52 (16-65) and 42.5 (17-61) respectively. No association was observed between methylation levels and lipid profile. cg03344051, cg07889003 and cg08269402 were significantly differentiated in double or triple vessel disease (DVD or TVD) as compared to single vessel disease (SVD) suggesting an increase in the extent of methylation with the increase in CAD severity. CONCLUSION: The present study shows significant increase in the extent of methylation in 3 CpG sites in DVD/TVD cases as compared to SVD cases. Additionally, a novel site, cg07889003 identified in our discovery phase has shown association with the severity of CAD.
Asunto(s)
Enfermedad de la Arteria Coronaria , Enfermedades Vasculares , Humanos , Masculino , Enfermedad de la Arteria Coronaria/genética , Metilación de ADN/genética , Epigénesis Genética/genética , LípidosRESUMEN
BACKGROUND: Thiopurine methyltransferase (TPMT) gene variants have achieved limited success in predicting the outcome of thiopurine therapy, which shows wide inter-individual variations. The literature indicates a strong association between the NUDT15 gene variant and thiopurine-induced toxicity in Asian patients. The present study intends to explore the role of the NUDT15 variant (C415T) in Indian patients on thiopurine therapy. METHODS: NUDT15 and TPMT genotyping were performed using amplification-refractory mutation system-polymerase chain reaction (ARMS-PCR) and the restriction fragment length polymorphism (RFLP) technique. RESULTS: Of 370 samples received for TPMT testing, 206 samples were available for NUDT15 genotyping. The NUDT15 risk allele frequency was 10.7%, with the frequency of wild, heterozygous and mutant genotypes being 80.6%, 17.5% and 1.9%, respectively. TPMT variants were seen in 13 of 370 (3.5%) patients, whereas the NUDT15 variant was seen in 40 of 206 (19.4%) patients. Thiopurine-induced toxicity information was available for 101 patients, among whom 10 developed leukopenia and all harbored the NUDT15 variant (p<0.0001). NUDT15 was clinically more relevant than TPMT in terms of sensitivity and specificity, as well as with a statistically significant difference in thiopurine dose requirement for patients with the NUDT15 variant. CONCLUSIONS: A preemptive NUDT15 genotyping approach can therefore help identify high-risk patients (NUDT15 C415T positive) who could benefit from thiopurine dose reduction, thereby preventing fatal thiopurine-induced toxicity.