Epidemiology

Standard tests for hepatitis B often miss infection in dialysis patients

Last Updated: 2004-11-11 12:37:31 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Monoclonal antibody testing for hepatitis B virus (HBV) surface antigen (HbsAg) underestimates the true prevalence of the infection among patients attending hemodialysis clinics, results of a Canadian study suggest.

Dr. Gerald Y. Minuk, at the University of Manitoba in Winnipeg, and colleagues tested patients for occult HBV (serum HbsAg negative but HBV DNA positive) in the summer of 2003. The 241 patients were attending two main hemodialysis units in Winnipeg. HBV vaccination had been administered to 211, of whom 202 had completed four vaccinations.

As the authors report in the November issue of Hepatology, only two patients were positive for HbsAg. However, nine of the remaining patients were HBV DNA positive, according to screening by real-time polymerase chain reaction testing with two independent sets of primers.

Viral loads were low, the authors note, ranging from 650 to 25,000 viral copies/mL. Liver enzyme and function tests were normal. Those positive for occult HBV did not differ from their counterparts in terms of demographics, biochemistry, or results of serological testing. All but one had been vaccinated against HBV.

"Until data exist indicating whether nosocomial transmission of occult HBV can occur in susceptible dialysis patients and/or staff, screening with sensitive PCR-based assays of all dialysis patients for HBV DNA regardless of demographic, biochemical, or serological findings seems prudent," Dr. Minuk and his associates conclude.

Hepatology 2004;40:1072-1077.