Circulating and tissue immune complexes in leprosy.

Various immunological studies were conducted in lepromatous leprosy patients. There was a polyclonal rise of all the three major immunoglobulins. Serum IgD levels remained unaltered. Positive latex agglutination reactions (RA) and parietal cell antibodies were distinctly more frequent in patients. Eighty-five percent of patients showed a strongly positive complement deviation test, and the mean platelet aggregation titer was 1 in 81 in the patients compared to 1 in 3 in the controls, thus indicating the presence of circulating immune complexes in a large percentage of cases. Immunoglobulins and complement were observed in the dermal capillaries and small arterioles, but not in larger vessels, in 6 of 17 cases. Only one case showed staining of the dermoepidermal junction. Antinuclear antibodies (ANA) were detected in a single patient, and this patient also showed ANA in vivo.