Induction of experimental allergic arthritis with outer surface proteins of borrelia burgdorferi

Objective. The arthritogenic potential of the cationic outer surface proteins (Osp) from Borrelia burgdorferi was tested in rats. Methods. Water‐soluble Osps were prepared by butanol extraction and were administered by intraarticular injection. Tissue injury was assessed by scintigraphy and histology. Results. A mild arthritis was seen in naive rats. Preimmunized animals had more severe, longer lasting bouts of inflammation. Conclusion. The Osps of Borrelia burgdorferi are potent arthritogens in rats. These immunodominant antigens may play a role in the development of Lyme arthritis in humans.