SERODIAGNOSIS IN EARLY LYME-DISEASE

Using a commercially available enzyme-linked immunosorbent assay (ELIS A) and an immunoblot assay (IB), we tested sera from 100 patients with erythema migrans (EM) seen in 1991 at the Westchester County Medical Center Lyme Disease Diagnostic Center. Convalescent-phase sera were av ailable from 59 patients. Fifty-five patients had EM of < 7 days' dura tion, 31 had EM of 7 to 14 days' duration, and 14 had EM of > 14 days' duration. During the acute phase of infection, 35 patients had a posi tive ELISA result and 43 had a positive IB result by the recently publ ished criteria of Dressler et al. (F. Dressler, J. A. Whalen, B. N. Re inhardt, and A. C. Steere, J. Infect. Dis. 167:392-400, 1993) for inte rpretation of IB in patients with Lyme disease. A greater sensitivity of IB was observed in patients with EM of <7 days' duration, as follow s: 14 of 55 (25%) for IB versus 7 of 55 (13%) for ELISA (P = 0.144). S era of all 14 patients with EM of > 14 days' duration were reactive by both tests, as follows: 13 positive and 1 equivocal by ELISA and 12 p ositive and 2 indeterminate by the IB. The band reactivity most freque ntly observed in the IB was to the 41- and 25-kDa antigens, the latter being the most frequent band observed in immunoglobulin M blots. Sero conversion was observed in 74 and 64% of evaluable patients by ELISA a nd IB, respectively, despite the use of antibiotic therapy.