Seyed Moayed Alavian1. 1. Baqiyatallah Research Center for Gastroenterology and Liver Diseases, Baqiyatallah University of Medical Sciences, Tehran, IR Iran.
Sir,I read with interest the published article by Kalantari et al.[1] in your journal recently. The authors presented the zero prevalence for occult hepatitis B virus (HBV) in patients on hemodialysis in Isfahan. However, I would like to highlight some points about occult HBV among them. Occult HBVpatients may be seronegative (both hepatitis B core antibody [anti-HBcAb] and hepatitis B surface [anti-HBs] antibody are negative) or seropositive (anti-HBc is positive with or without anti-HBs positivity).[2] Occult HBV is predominantly detected in patients with isolated anti-HBc (hepatitis B surface antigen [HBsAg] negative, anti-HBs negative and anti-HBc positive). Ramezani et al. showed that 1% of patients on hemodialysis with HBsAg-negative had occult HBV with positive HBV DNA in their serum without considering their HBcAb status.[3] It seems that if the authors would done in all hemodialysis HBsAg-negative group, the result would be clearer and it seems that the occult HBV had underestimated in their study group. However, currently available evidence suggests a relatively high prevalence of occult hepatitis B in hemodialysis patients. Conventional serologic testing used in most hemodialysis centers is not able to identify the occult infection.[4]