TY - JOUR T1 - Effect of season and sunlight on viral kinetics during hepatitis C virus therapy JF - BMJ Open Gastroenterology DO - 10.1136/bmjgast-2016-000115 VL - 4 IS - 1 SP - e000115 AU - Noemi Hernández-Alvarez AU - Juan Manuel Pascasio Acevedo AU - Enrique Quintero AU - Inmaculada Fernández Vázquez AU - María García-Eliz AU - Juan de la Revilla Negro AU - Javier Crespo García AU - Manuel Hernández-Guerra Y1 - 2017/03/01 UR - http://bmjopengastro.bmj.com//content/4/1/e000115.abstract N2 - Background and aims Rapid viral response (RVR) during antiviral treatment for hepatitis C virus (HCV) predicts sustained viral response (SVR). Recently, vitamin D levels have been associated with SVR. As sunlight is the most important source of vitamin D and shows seasonal variation, we evaluated the effect of season on viral kinetics during peginterferon/ribavirin-based therapy for HCV.Methods Consecutive HCV patients treated with peginterferon/ribavirin and boceprevir/ telaprevir (June 2011–July 2014) were included. Patients were grouped according to season when therapy was initiated (Season A: May–October and Season B: November–April) depending on hours of daily sunlight. Multiple logistic regression analysis included factors known to influence SVR to treatment. The dependent variables were undetectable viral load (VL) or VL ≤15 UI/mL (VL ≤15) at weeks 4, 8 and 12, end of treatment and SVR.Results The study included 930 patients (66.8% men; median 54 years) treated with telaprevir (n=537) or boceprevir, without (n=481) or with lead-in therapy of peginterferon/ribavirin. Baseline characteristics of patients in Season A (45.3%, n=421) and Season B groups were similar. Overall, a higher rate of RVR (23.5% vs 16.1%, p=0.005) and VL ≤15 (51.0% vs 38.6%, p≤0.001) was observed in patients starting treatment during Season A versus Season B. By logistic regression analysis, initiating treatment in Season A proved to be an independent predictor of RVR and VL ≤15.Conclusions In our setting, seasonality affects viral kinetics in HCV genotype 1 patients treated with peginterferon/ribavirin-based therapy. Our findings support the hypothesis that vitamin D influences viral response to peginterferon/ribavirin-based therapy. ER -