Circulating antibody to Nocardia in the serum of patients with Parkinson's disease.

Nocardia is a genus of aerobic Gram-positive bacteria which forms filamentous cells that fragmented into rod-shaped or coccoid elements or L-forms. According to the literature N. asteroides causes encephalitis with parkinsonian features, and it may be an unknown etiologic agent causing encephalitis with a parkinsonian syndrome. Because there are no reliable immunologic tests routinely used for diagnosing nocardial infection, less severe CNS infections with nocardiae may not be recognized or may be attributed to unknown or incorrect etiologic agents. Recently, it was shown that sublethal doses of N. asteroides causes an L-DOPA-responsive movement disorder with Lewy-like bodies in mice. In this study, we detected antibodies to nocardia in the serum of patients with Parkinson's disease (PD). Sera was diluted in PBS and added in two-fold dilutions to coccoid and rod-shaped cells of nocardia attached to nonfluorescence slides. IF test demonstrated antibodies to coccoid and rod-shaped cells of nocardia in the serum from 20/20 patients with PD at a titer greater than 1:10, and 14 controls showed 10 positively. The results suggested that not only PD patients but also age-matched healthy volunteers are routinely exposed to and naturally infected with nocardia-related microorganisms. A further reliable immunologic test will be required.