PT  - JOURNAL ARTICLE
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
TI  - Effect of season and sunlight on viral kinetics during hepatitis C virus therapy
AID  - 10.1136/bmjgast-2016-000115
DP  - 2017 Mar 01
TA  - BMJ Open Gastroenterology
PG  - e000115
VI  - 4
IP  - 1
4099  - http://bmjopengastro.bmj.com//content/4/1/e000115.short
4100  - http://bmjopengastro.bmj.com//content/4/1/e000115.full
AB  - 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.