POLYMERASE CHAIN-REACTION DETECTION OF THE HEMAGGLUTININ GENE FROM ANATTENUATED MEASLES-VACCINE STRAIN IN THE PERIPHERAL MONONUCLEAR-CELLSOF CHILDREN WITH AUTOIMMUNE HEPATITIS

We examined the measles H gene using reverse transcriptase-polymerase chain reaction in peripheral mononuclear cells obtained from 4 pediatr ic and 2 adult patients with autoimmune hepatitis and 12 healthy child ren who had been infected with measles or vaccinated with an attenuate d measles vaccine in the past. All patients were positive for the pres ence of the gene. Only one healthy control, who had been vaccinated tw o weeks before the study, was positive, while the other 11 controls we re negative for the presence of the gene. The restriction enzyme patte rns of the products in the pediatric patients were different from thos e observed in adults. The sequences of amplified products from pediatr ic patients coincided with the vaccine strain, whereas those from adul ts were different from the vaccine strain. The sequence of those from one of two adult patients was similar to those of the isolates in 1990 and later. Our results demonstrated that children with autoimmune hep atitis can have persistence of the vaccine strain in vivo for many yea rs after vaccination.