Antigenicity of borrelial protein BBK32 fragments in early Lyme borreliosis.

Recombinantly produced borrelial BBK32 protein fragments originating from Borrelia burgdorferi sensu stricto, Borrelia garinii and Borrelia afzelii were evaluated as antigens in the serology of Lyme borreliosis (LB). In ELISA, a mid-portion hydrophilic fragment reacted with LB patient sera. Of the 23 patients with culture- or PCR-positive erythema migrans (EM), 43 % at diagnosis and 52 % at convalescence were positive for at least one Borrelia species-specific variant BBK32 fragment antigen. In parallel ELISAs with BBK32 whole proteins from the three borrelial subspecies as antigens, 17 % at diagnosis and 26 % at convalescence were positive. These results suggest that BBK32 protein fragments may improve the early IgG serology of LB compared to the BBK32 whole protein.