Background/Aims: Thiopurines are key drugs for inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn’s disease (CD). Recently, NUDT15 polymorphism (R139C, c.415C > T) has been shown to be associated with thiopurineinduced adverse events in Asian populations. In patients with the C/T genotype, low-dose thiopurine treatment is recommended, but its long-term efficacy and tolerability remain unclear. This study aimed to uncover the long-term efficacy and appropriate dosage of thiopurine for IBD patients with the C/T genotype. Methods: A total of 210 patients with IBD (103 UC and 107 CD) determined to have NUDT15 R139C variants were enrolled. Clinical data were retrospectively reviewed from medical records. Results: Of 46 patients (21.9%) with the C/T genotype, 30 patients (65.2%) were treated with thiopurines. Three of whom (10.0%) discontinued thiopurine treatment due to adverse events and 27 of whom continued. The median maintenance dosage of 6-mercaptopurine was 0.25 mg/kg/day (range, 0.19–0.36 mg/kg/day), and 6-thioguanine nucleotides level was 230 (104–298) pmol/8 × 108 red blood cells. Cumulative thiopurine continuation rates for 120 months for patients with the C/C and C/T genotypes were not significantly different (P= 0.895). Cumulative non-relapse rates in the patients with UC treated with thiopurine monotherapy and surgery-free rates in CD patients treated with combination therapy (thiopurines and anti-tumor necrosis factor-α agents) for maintenance remission were not significantly different at 60 months (C/C vs. C/T, P= 0.339 and P= 0.422, respectively). Conclusions Low-dose thiopurine treatment is an effective and acceptable treatment for patients with C/T genotype.

Purpose: To investigate the association between skin advanced glycation end-products (AGEs) levels, blood antioxidative vitamin and carotenoid concentrations, and severe erectile dysfunction (ED) in community-dwelling men. Materials and Methods: This cross-sectional study used the 5-Item International Index of Erectile Function to identify 335 community-dwelling men with ED. The accumulation of skin AGEs was assessed noninvasively by measuring skin autofluorescence. Background-adjusted multivariable logistic regression analyses using the inverse probability of treatment weighting method were performed to evaluate the effects of AGEs, vitamins, and carotenoids on severe ED. Moreover, multiple linear regression analyses were performed to assess the association between skin AGEs levels and serum carotenoid concentrations. Results: The median age of study participants was 57 years. Of the 335 men, 289 (86.3%) and 46 (13.7%) were classified into the mild/moderate and severe ED groups, respectively. Multivariable analyses revealed that skin AGEs levels, blood vitamins C and E, lutein, zeaxanthin, β-cryptoxanthin, α-carotene, β-carotene, total lycopene, and cis-lycopenes concentrations were significantly associated with severe ED, whereas all-trans lycopene concentrations were not. In the multiple linear regression analyses, serum zeaxanthin concentrations were negatively and significantly correlated with skin AGEs levels. Conclusions Higher skin AGEs levels and lower blood antioxidative vitamin and carotenoid concentrations were significantly associated with severe ED. Serum zeaxanthin levels were negatively and significantly correlated with skin AGEs levels, suggesting the possible effects of zeaxanthin on ED by decreasing tissue AGEs levels.