Original Open Access Vitamin D levels in patients with chronic hepatitis B virus infection and naturally immunized individuals Canan Demir 1* and Mehmet Demir 2 *Correspondence: drcananmd@gmail.com 1 Bursa Şevket Yılmaz Education and Research Hospital Infectious Disease Department, Bursa/Turkey. 2 Bursa Yüksek İhtisas Education and Research Hospital Cardiology Department, Bursa/Turkey. Abstract Vitamin D deiciency is associated with several adverse health outcomes, and vitamin D appears to have systemic antimicrobial efects that may be crucial in a variety of both acute and chronic illnesses. In the present study, 25-hydroxyvitamin D (25-OHD) levels were compared among patients with chronic hepatitis B virus infection, naturally immunized individuals and control individuals. hirty-ive patients with chronic hepatitis B virus infection (group I), 30 naturally immunized individuals (group II) and 30 healthy adults were included in the present study. Markers of hepatitis were measured using commercially available kits based on chemiluminescence assays. Routine biochemical parameters, hepatitis B virus serology, hepatitis B virus DNA, 25-OHD and parathyroid hormone levels were measured. Baseline characteristics of the study groups were comparable. Patients in group I had a lower 25-OHD level compared with group II and the control group (7.65±4.19 ng/mL versus 12.1±7.13 ng/mL and 14.17±9.18 ng/mL, respectively; P<0.001). In addition, patients in group I had a higher parathyroid hormone level compared with group II and the control group (88.21±34.2 ng/mL versus 75.14±23.4 ng/mL and 74.16±20.15 ng/mL, respectively; P=0.001). 25-OHD levels were correlated with hepatitis B virus DNA levels. In patients infected with hepatitis B virus, diminished 25-OHD levels may be an indicator of the status of viral replication and portends a poor prognosis. Keywords: Hepatitis B, immune system, vitamin D, chronic © 2013 Demir et al; licensee Herbert Publications Ltd. his is an Open Access article distributed under the terms of Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0). his permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Introduction Hepatitis B virus (HBV) infection is a major public health problem worldwide. Hepatitis B is an infectious disease, affecting an estimated 350 million chronically infected patients [ 1, 2]. HBV is a 42 nm DNA virus belonging to the family Hepadnaviridae. The virus has a partially double-stranded DNA genome and contains a core antigen (HBcAg) surrounded by a shell containing surface antigen (HBsAg). The immune response to HBsAg provides immunity against HBV. Antibodies to HBcAg (anti-HBc) indicate infection; immunoglobulin (Ig) M anti-HBc indicates recent infection and usually disappears within six months, while IgG anti- HBc persists for life and indicates past infection. Antibodies to HBsAg (anti-HBs) appear after clearance of HBsAg or after immunization. The presence of HBsAg for longer than six months is defined as chronic HBV infection [3]. The clinical course of hepatitis B is determined by the interaction between viral replication and the host immune response. HBV infection is generally asymptomatic; however, HBV is the most common and important cause of cirrhosis and hepatocellular carcinoma worldwide [ 2,4]. Vitamin D deficiency is associated with several adverse health outcomes. A plethora of health benefits associated with vitamin D supplementation, including a boost in longevity, are evident. Vitamin D has an emerging role in regulating inflammation as well as an important role in immunomodulation. Vitamin D may also improve survival in acute illness by boosting innate immunity, and appears to exhibit systemic antimicrobial effects that may be crucial in a variety of both acute and chronic illness [5- 8]. Given this information, we hypothesized that vitamin D deficiency is related to HBV infection status and is a prognostic marker. To our knowledge, the present study was the first to assess the relationship between vitamin D deficiency in patients with HBV infection and immune response. The aim of the present study was to define the pattern of vitamin D levels in patients with chronic HBV infection compared with naturally immunized individuals. Materials and methods Patient selection Thirty-five patients who had been followed in the outpatient clinic of the infection diseases department due to chronic hepatitis B (HBsAg positive, anti-HBs negative for at least six months), who had normal liver enzyme levels and had not received antiviral treatment (group I; mean (± SD) age 32.5±9.8 years; 22 men), and 30 naturally immunized individuals (HBsAg negative, anti-HBs and anti-HBc-IgG positive) (group II; mean age 31.1±5.5 years; 18 men) were included in the present study. Thirty age- matched healthy adult subjects were also included as a control group (mean age 32.4±8.4 years; 17 men). Because the level of 25-hydroxyvitamin D (25-OHD) fluctuates according to seasonal changes (effects of sunlight), the study was initiated in the winter season and continued to the end of March. Internal Medicine Inside ISSN 2052-6954