SPECIFIC AND NONSPECIFIC ASPECTS OF HUMORAL IMMUNE-RESPONSE IN LEPROSY

1. We have studied some generic and specific aspects of the humoral im mune response in 96 patients with leprosy (29 paucibacillary and 67 mu ltibacillary individuals). We determined serum immunoglobulins (IgM, I gG and IgA), CH50, Clq, C3 and C4, circulating immune complexes (CIC), C-reactive protein (CRP), rheumatoid factor (RF) and antinuclear anti bodies. No specific pattern of general humoral immune changes could be observed. 2. The specific immune response was studied by the detectio n of specific IgM anti-M. leprae antibodies. An immunoradiometric assa y (IRMA) and an ELISA were compared for clinical effectiveness. IRMA s howed greater sensitivity for the serodiagnosis of leprosy as compared to ELISA (88.1% vs 58.2% for multibacillary patients and 20.7% vs 10. 3% for paucibacillary leprosy patients). Specificity was 96% for IRMA and 97% for ELISA. 3. Our results indicate that nonspecific changes in the humoral immune response are of little value in assessing leprosy patients and that immune assays for the detection of specific anti-M. leprae antibodies may be of value in the diagnosis, study and follow-u p of these patients.