Methods for diagnosing early Lyme disease

DETAILED DESCRIPTION This invention is based upon the discovery that sera from patients with early Lyme disease contain predominant IgM reactivity to a major 23 kDa protein (p23; also referred to herein as OspC) from Borrelia burgdorferi strain 2591, an isolate found in Connecticut.
This strain was found to abundantly produce OspC.
The p23 gene from strain 2591 was cloned and sequenced.
The protein deduced therefrom contained 212 amino acids and had a molecular weight of 22,250 kDa.
Purified and recombinant forms of OspC protein were produced as a target antigen and tested in Enzyme Linked Immunosorbant Assay (ELISA) and Western Blot assays.
Detection of B.
burgdorferi-specific IgM antibodies in 74 individuals with culture positive erythema migrans and 76 controls without Lyme disease were determined using a whole cell (WC) ELISA, immunoblot and recombinant OspC (rOspC) ELISA.
With all test results there was a statistically significant association between the duration of disease and the frequency of a positive result.
The rOspC ELISA had a positive predictive value of 100% and a negative predictive value of 74%.
Simlar results were obtained with the whole cell ELISA and immunoblot.
Based upon these results, recombinant p23 can be used in diagnostic assays (serological and cellular) to detect early stages of Lyme disease.
Methods for detecting early Lyme disease, diagnostic reagents therefor, kits containing the reagents, and method for preventing Lyme borreliosis are described.
The invention provides the advantages of immunoassay standardization due to use of recombinant forms of OspC; early detection of the humoral response in infected individuals; and antigen uniformity due to phenotype stability of strain 2591.
The rOspC ELISA is equally or more sensitive and specific than currently used diagnostic tests for early Lyme disease.