IgG immune response to B19 parvovirus VP1 and VP2 linear epitopes by immunoblot assay

Human B19 parvovirus recombinant capsid proteins VP1 and VP2 were expressed in E. coli and purified. Recombinant proteins were used to detect a specif ic IgG immune response against VP1 and VP2 linear epitopes by immunoblot as say. A total of 222 serum samples from 218 apparently immunocompetent subje cts with different clinical conditions and laboratory evaluations with rega rds to B19 infection were analyzed. The sera had previously been tested for B19 DNA and for specific IgM and IgG against VP2 conformational antigens b y ELISA assay. The data show that, during the active or very recent phase o f infection, IgG anti-VP1 linear epitopes appear in concomitance and with t he same frequency as IgG anti-VP2 conformational antigens. IgG against conf ormational VP2 antigens and against linear VP1 epitopes seem to persist for months or years in the majority of individuals. IgG against VP2 linear epi topes are generally present during the active or very recent phase of infec tion and during the convalescent phase, while they are present only in abou t 20% of subjects with signs of a past B19 infection. (C) 1999 Wiley-Liss. Inc.