IMMUNOGLOBULIN-M CAPTURE ASSAY FOR SEROLOGIC CONFIRMATION OF EARLY LYME-DISEASE - ANALYSIS OF IMMUNE-COMPLEXES WITH BIOTINYLATED BORRELIA-BURGDORFERI SONICATE ENHANCED WITH FLAGELLIN PEPTIDE EPITOPE

We previously reported on the efficacy of the enzyme-linked immunoglob ulin M capture immune complex (IC) biotinylated antigen assay (EMIBA) for the seroconfirmation of early Lyme disease and active infection wi th Borrelia burgdorferi. In earlier work we identified non-cross-react ing epitopes of a number of B. burgdorferi proteins, including flagell in, We now report on an improvement in the performance of EMIBA with t he addition of a biotinylated form of a synthetic non-cross-reacting i mmunodominant flagellin peptide to the biotinylated B. burgdorferi B31 sonicate antigen source with the avidin-biotinylated peroxidase compl ex: detection system used in our recently developed indirect IgM-captu re immune complex-based assay (EMIBA). As in our previous studies, the enzyme-linked immunosorbent assay (ELISA) reactivities of antibodies liberated from circulating ICs (by EMIBA) were compared with those of antibodies in unprocessed serum (antibodies found free in the serum, t hus as an IgM-capture ELISA, but not EMIBA, because the antibodies wer e not liberated from ICs), the sample usually used in standard ELISAs and Western blot assays, The addition of the flagellin epitope enhance d the ELISA signal obtained with untreated sera from many Lyme disease patients but not from healthy controls, In tests with both free antib odies and ICs, with or without the addition of the flagellin epitope t o the sonicate, we found the most advantageous combination was IC as t he source of antibodies and sonicate plus the flagellin epitope as the antigen, In a blinded study of sera obtained from patients with early and later-phase Lyme disease, EMIBA with the enhanced antigenic prepa ration compared favorably with other serologic assays, especially for the confirmation of early disease.