Evaluation of anti-cardiolipin antibody and its cross-reactivity in sera of patients with lepromatous leprosy.

Using a sensitive and modified solid-phase radioimmunoassay for detecting anti-cardiolipin antibodies, sera of 45 patients with lepromatous leprosy were examined. Nine of the 45 (20%) showed positive levels of anti-cardiolipin antibodies. Inhibition tests revealed that these antibodies significantly cross-reacted with double-stranded (ds) DNA, but not with single-stranded (ss) DNA or extractable nuclear antigens (ENA). We describe the unique pattern of antibody cross-reactivity with cardiolipin and dsDNA in sera of patients with lepromatous leprosy.