USE OF RECOMBINANT OSPC FROM BORRELIA-BURGDORFERI FOR SERODIAGNOSIS OF EARLY LYME-DISEASE

Infection with Borrelia burgdorferi, the etiologic agent of Lyme disea se, is associated with an early and dominant humoral response to the s pirochete's 23-kDa outer surface protein C (OspC). We have cloned and expressed OspC as a fusion protein in Escherichia coli and have shown that patient serum samples react with it in an enzyme-linked immunosor bent assay (ELISA) (S. J. Padula, A. Sampieri, F. Bias, A. Szczepanski , and R. W. Ryan, Infect. Immun. 61:5097-5105, 1993). Now we have comp ared the detection of B. burgdorferi-specific immunoglobulin M antibod ies in 74 individuals with culture-positive erythema migrans by a whol e-cell ELISA, immunoblot, and the recombinant OspC (rOspC) ELISA. Seve nty-six negative controls were also studied. With all of the tests, th ere was a statistically significant association between the duration o f disease and the frequency of a positive result. With the rOspC ELISA , the predictive value of a positive test was 100% and the predictive value of a negative test was 74%. Similar results were obtained with t he whole-cell ELISA and with the immunoblot using as the source of tes t antigen a strain ofB. burgdorferi which expresses abundant levels of OspC. We conclude that the use of rOspC in an ELISA is a convenient, readily automated, and easily standardized test for the serodiagnosis of early Lyme disease.