SIMULTANEOUS EXPRESSION OF BORRELIA OSPA AND OSPC AND IGM RESPONSE INCEREBROSPINAL-FLUID IN EARLY NEUROLOGIC LYME-DISEASE

Lyme disease is the major tick-borne disease, caused by Borrelia burgd orferi (Bb). Neurological involvement is common in all stages. In vivo expression of Bb antigens (Ags) and the immune response to them has n ot been well investigated in the cerebrospinal fluid (CSF). Upregulati on of outer surface protein (Osp) C and concomitant downregulation of OspA before tick inoculation of the spirochete has been reported in sk in and blood in animals. CSF OspA Ag in early disease suggests otherwi se in CSF. Early Ag expression and IgM response in human CSF was inves tigated here. Paired CSF and serum was collected from 16 early, predom inantly erythema migrans Lyme disease patients with neurologic problem s, 13 late Lyme disease patients, and 19 other neurologic disease (OND ) controls. Samples were examined for IgM reactivity to recombinant Bb -specific Osps using ELISA and immunoblot. Of 12 early Lyme disease pa tients with neurologic involvement with both CSF and serum IgM against OspC, 7 (58%) had IgM to OspA (n = 5) or OspB (n = 2) that was restri cted to the CSF, not serum. Overall, 12 of 16 (75%) of these early Lym e disease patients with neurologic involvement had CSF and serum IgM a gainst OspC. Only 3 of 13 (23%) late Lyme disease patients and none of 19 OND controls had CSF IgM directed against OspC. In conclusion, in CSF, OspC and OspA can be coexpressed, and IgM response to them occurs in early Lyme disease patients with neurologic involvement. This biol ogic finding may also provide a discriminating marker for CNS infectio n in Lyme disease.