TARGET IMBALANCE - DISPARITY OF BORRELIA-BURGDORFERI GENETIC MATERIALIN SYNOVIAL-FLUID FROM LYME ARTHRITIS PATIENTS

Lyme arthritis is a late manifestation of Lyme disease that results in episodic synovial inflammation and swelling. Although this process is thought to be driven directly by the spirochetal etiologic agent, Bor relia burgdorferi, the organism itself has been recovered by culture o nly twice. In contrast, polymerase chain reaction (PCR) studies are us ually positive. This apparent discrepancy in 19 culture-negative synov ial fluid specimens from 18 patients with Lyme arthritis was investiga ted. In all 19, DNA sequences characteristic of plasmid-encoded genes OspA and OspB were easily detected. However, despite equivalent or eve n superior analytic sensitivity for detection of cultured organisms, t he reactivity of two genomic DNA targets was often weak or absent alto gether in the clinical specimens. This apparent overrepresentation of B. burgdorferi plasmid sequences was found exclusively in clinical spe cimens and not in cultured organisms. The physiologic imbalance of gen omic and plasmid DNA reactivity in B. burgdorferi infection may signal an underlying pathogenetic mechanism.