Occult hepatitis B in Cuban HIV patients.

INTRODUCTION Co-infections between hepatitis B and HIV viruses are frequent due to their similar epidemiological characteristics. Worldwide, hepatitis B infection is one of the main causes of hepatocellular carcinoma and cirrhosis. In Cuba as elsewhere, prevalences of hepatitis B and hepatitis C viral infections are higher in persons with HIV. These hepatitis viruses act as opportunistic infections in persons with HIV. In other contexts, persons with HIV have been found to be at higher risk for occult hepatitis B, defined as the presence in serum or plasma of hepatitis B virus DNA and antibodies to its core antigen, in the absence of hepatitis B surface antigen. OBJECTIVES Describe occult hepatitis B prevalence in Cuban HIV-positive patients and explore possible associations with their clinical characteristics. METHODS A total of 325 serum samples from patients positive for HIV and negative for hepatitis B surface antigen were studied, divided into two groups, Group 1, negative for hepatitis C virus; and Group 2, positive for hepatitis C virus. Exposure to hepatitis B was determined by testing for hepatitis B core antigen; samples positive for hepatitis B core antigen were then examined for presence of antibodies to hepatitis B surface antigen. Both determinations were done by ultramicroELISA. In samples positive for hepatitis B core antigen with levels of antibodies to hepatitis B surface antigen of <50 IU/L, real-time polymerase chain reaction was used to detect hepatitis B DNA and its presence examined in relation to several clinical variables. All data were obtained from patients' clinical records. RESULTS In the hepatitis-C-negative group, 27.9% (68/243) of serum samples tested were positive for hepatitis B core antigen. In the hepatitis-C-positive group, 37.8% (31/82) were positive for hepatitis B core antigen. Total hepatitis B virus exposure prevalence was 30.4% (99/325); 54.5% (54/99) showing low immunity (hepatitis B virus surface antigen <50 IU/L) and 24% of these (13/54), occult hepatitis. There was no statistically significant association between hepatitis B virus DNA and any of the clinical variables studied. CONCLUSIONS Low-immunity HIV-positive persons in our study were exposed to hepatitis B virus. Diagnosis of occult hepatitis B infection is frequent in these patients. This study suggests that diagnostic protocols for persons with HIV and without hepatitis B surface antigen should include testing for hepatitis B core antigen, with positive results followed by molecular techniques to detect occult hepatitis B. This study makes a useful contribution to prevention and control of hepatitis B in Cuba.