Background: Hepatitis B virus (HBV) infections are a matter of concern in hemodialysis units; occult HBV infections (serum HBsAg negative but HBV DNA positive) were demonstrated in this setting, and this involves further concerns regarding possible transmission and pathogenic consequences. This study aimed to investigate the prevalence and correlates of occult HBV infection in a group of patients with reference to a single hemodialysis unit in southeastern Italy.
Methods: We analyzed HBV serology and DNA (using a qualitative nested PCR) in 128 HBsAg-negative hemodialysis patients, and correlated the results obtained, with sex, age, hemodialysis duration and HCV seropositivity.
Results: As a whole, occult HBV infection was demonstrated in 34/128 patients (26.6%); HBV DNA detection was more frequent when anti-HBcAg antibodies were detected in isolation (72%) than when associated with anti-HBsAg antibodies (31%). Among HCV-seropositive patients, occult HBV infection was observed in 66%, and among these as many as 14/15 patients (93%) who were HCV+/anti-HBcAg+ had serum HBV DNA detectable. On multivariate analysis, HCV seropositivity and the presence of anti-HBs were still respectively correlated to the presence and absence of occult HBV infection.
Conclusions: Occult HBV infection is frequent among hemodialysis patients in our geographical area, particularly correlated to the presence of isolated anti-HBcAg and anti-HCV antibodies. Thus, the presence of isolated anti-HBcAg should prompt the clinician to evaluate a possible occult HBV infection especially if anti-HCV antibodies are also detectable; this condition, in fact, seems to strongly predict the detection of HBV DNA.