Immunoglobulin deposits in lepromatous leprosy skin. Presence of deposits in apparently uninvolved skin and occurrence of serum antiepithelial antibodies.

Immunoglobulin deposits were detected in ten of 13 biopsy specimens from apparently uninvolved skin of patients with lepromatous leprosy. There were deposits of IgM at the dermoepidermal junction in the skin of five patients, and deposits of IgM along the dermal collagen and elastic fibers in the skin of the other five. The deposits were eluted with acid buffers and high molarity salt solution. Circulating IgG antibodies to intercellular substance of epithelial cells, similar to those present in pemphigus vulgaris, were found in 25% of patients with lepromatous leprosy who were studied. These antibodies appeared to be different from the skin-bound immunoglobulin deposits.