[Distribution of HB s Ag subtypes in a sample of acute viral hepatitis of type B in Northern Italy].

82 HBsAg from acute hepatitis B patients living in Northern Italy were subtyped. HBsAg has been detected by immunodiffusion (ID), electrosyneresis (ES), complement fixation (CF) and radioimmunoassay (RIA, Kit Ausria I and II, Abbott). Subtyping was performed by ES in 50 and by ID in 30 of the 82 assayed sera. An higher frequency of ayw subtype (83,1%) in comparison with adw subtype (16,9%) has been observed. No difference was found between adw and ayw subtypes analyzed as far as geographic-ethnic characters, incubation time, course and prognosis of the disease or the biohumoral indices. No patient was found to have both y and d specificities and so r determinant was never found.