RECOMBINANT IMMUNOBLOT IN THE SERODIAGNOSIS OF LYME BORRELIOSIS - COMPARISON WITH INDIRECT IMMUNOFLUORESCENCE AND ENZYME-LINKED-IMMUNOSORBENT-ASSAY

A recombinant immunoblot was developed for detection of IgM and IgG an tibodies in patients with Lyme borreliosis. The recombinant antigens w ere the chromosomal-encoded Borrelia burgdorferi proteins p100, the fl agellin and an internal flagellin fragment thereof as well as the plas mid-encoded outer surface proteins A (OspA) and C (OspC). A panel of 1 44 sera from patients with Lyme borreliosis (erythema migrans, n = 31; neuroborreliosis state 11, n = 60; Lyme arthritis, n = 24 and acroder matitis chronica atrophicans, n = 19) have been investigated and the r esults have been compared to the immunofluorescence absorption test (I FA-ABS) and to two different enzyme-linked immunosorbent assays [the f lagellin ELISA and a newly developed ELISA (OGP-ELISA)]. The two ELISA s were comparable in sensitivity, whereas the IFA-ABS was less sensiti ve for IgM antibody but equally sensitive for IgG antibody detection. Immunoblot analysis revealed that IgG antibodies are mainly reactive w ith p100 and the internal flagellin fragment (sensitivity 51% and 32%, respectively) and rarely with OspC (14%). All patients with late Lyme borreliosis had IgG antibodies against the p100. IgM antibodies were predominantly directed against OspC (43%) and in a lower extent agains t the internal flagellin fragment and p 100 (15% and 13%, respectively ). The complete flagellin was not useful due to a high number of unspe cific reactions with control sera and the OspA was only exceptionally reactive in Lyme borreliosis patients. The sensitivity of IgM antibody detection could be increased in cases with early Lyme borreliosis fro m 46% to 65% when the OspC blot was performed in addition to the flage llin ELISA, or from 56% to 65% when performed in addition to the OGP-E LISA. The recombinant blot is, therefore, a valuable diagnostic test t o increase sensitivity of early antibody detection and is regarded as a valuable confirmatory test also in late disease.