Methylation of CYP1A1 and VKORC1 promoter associated with stable dosage of warfarin in Chinese patients

Objective To investigate the association between DNA methylation and the stable warfarin dose through genome-wide DNA methylation analysis and pyrosequencing assay. Method This study included 161 patients and genome-wide DNA methylation analysis was used to screen potential warfarin dose-associated CpGs through Illumina Infinium HumanMethylation 450 K BeadChip; then, the pyrosequencing assay was used to further validate the association between the stable warfarin dose and alterations in the methylation of the screened CpGs. GenomeStudio Software and R were used to analyze the differentially methylated CpGs. Results The methylation levels of CpGs surrounding the xenobiotic response element (XRE) within the CYP1A1 promoter, differed significantly between the different dose groups (P  0, P < 0.05) with an increase in the stable dose of warfarin. At the VKORC1 promoter, two CpGs methylation levels were significantly different between the differential dose groups (P < 0.05), and one CpG (Chr16: 31106793) presented a significant negative correlation (r <  0, P <  0.05) among different dose (low, medium, and high) groups. Conclusion This is a novel report of the methylation levels of six CpGs surrounding the XRE within the CYP1A1 promoter and one differential CpG at the VKORC1 promoter associated with stable warfarin dosage; these methylation levels might be applied as molecular signatures for warfarin

Diagnostic utility of the Elecsys anti-CCP assay in patients with rheumatoid arthritis

National Natural Science Foundation of China [8110331]Objective. The automatic anti-cyclic citrullinated peptide (anti-CCP) antibodies assay offered great advantages over traditional methods in terms of improved precision, reliability, technical simplicity, short turnaround time and high-speed throughput. In this study, we evaluated the main technical performance and diagnostic accuracy of the first automatic anti-CCP assay approved in China. Methods. The study comprised 106 rheumatoid arthritis (RA) patients, 203 non-RA rheumatic disease controls and 46 healthy persons. Anti-CCP, rheumatoid factor (RF), alpha(1)-acid glycoprotein, C-reactive protein and erythrocyte sedimentation rate were measured and compared. The precision, reference intervals for Chinese population and cut-off value for RA diagnosis, as well as the suitable diluent for anti-CCP were assessed. The positive rate and score of anti-CCP were compared with RF and acute-phase reactants, according to the new RA criteria. Results. Within-and between-run imprecision, expressed as the coefficient of variation, were 0.47-1.36% and 1.15-2.63%, respectively. Upper 95% reference limit of anti-CCP in healthy Chinese was 8.8 U/mL. The area under curve of the receiver operating characteristic (ROC) for anti-CCP and RF were 0.882 (95% CI 0.833-0.930) and 0.844 (95% CI 0.792-0.897), respectively. Based on the cut-off value set by ROC, compared to RF, anti-CCP had higher sensitivity (96.8% vs. 78.3%) and specificity (90.9% vs. 70.7%). With 17 U/mL set as the optimal cut-off for anti-CCP, the total positivity of anti-CCP was comparable to that of RF (76.4% vs. 75.5%), but the high-positivity rate of anti-CCP was significantly higher (74.5% vs. 62.3%, p < 0.005). Conclusions. Our results confirm anti-CCP as a more sensitive and specifi c marker than RF for the diagnosis of RA. The diagnostic performance of the Elecsys anti-CCP assay makes it a useful adjunct to clinical practice in the Chinese population