SERUM ANTIBODIES AGAINST PERIPHERAL NERVOUS-SYSTEM ANTIGENS IN LEPROSY

Since antibodies against peripheral nervous system (PNS) antigens may play a pathogenetic role in the mechanism of nerve damage in leprosy, sera from leprosy patients and contacts were investigated for anti-PNS antibodies by ELISA and immunoblot. In ELISA, elevated anti-PNS antib ody levels were detected in 4 of 98 (4.1%) leprosy patients (4 of 52, 7.7%, lepromatous leprosy patients), in 1 of 28 (3.6%) contacts, and i n 1 of 18 (5.6%) normal controls. There was no correlation between ant i-PNS antibody levels and the bacterial index or neuropathy in leprosy . Immunoblot with a sample of six leprosy and five control sera showed that the antigenic binding pattern (mainly within the 100-200-kDa reg ion) was very similar in patients and controls. Staining intensity, ho wever, appeared to be higher with the leprosy sera than with the contr ol sera. IgM and IgG were found to contribute to the staining pattern: IgM in the 150-200-kDa range, IgG with multiple bands between 25 kDa and 200 kDa. Thus, the presence and levels of serum anti-PNS antibodie s in leprosy appear to be unrelated to parameters of disease activity, neuropathy in particular, and do not seem to be critically involved i n the pathogenesis of nerve damage.