Anti-hapten antibodies and autoantibodies in Japanese patients with lepromatous leprosy.

In the sera of patients with lepromatous leprosy anti-DNP antibodies were detected in order to determine the mode of polyclonal B-cell activation. Anti-DNP antibodies were found in 30% of the patients with active lepromatous leprosy and in 8% of those with inactive lepromatous leprosy. The level of anti-DNP antibodies in active patients was significantly higher than the level in inactive patients and control. However, the presence of anti-DNP antibodies was unrelated to the production of circulating immune complexes and antinuclear antibodies. These results suggest that polyclonal B-cell activation might occur but that the B-cell clones stimulated by M. leprae are different from patient to patient.