Detection of antibodies to human nerve antigens in sera from leprosy patients by ELISA

Anti‐neural antibodies have been implicated to play a role in the pathogenesis of nerve damage in leprosy patients. To find the relationship between anti‐neural antibodies and clinical findings, we attempted to detect antibodies against neurofilament‐enriched proteins by ELISA in sera from leprosy patients. Of 289 sera from leprosy patients, 74(25–6%) had significant anti‐neural antibodies: in contrast, 1 (5–0%) of 20 tuberculosis patients and 11 (7–1%) of 154 controls were seroreactive to nerve antigen. When clinical types were considered, a significant level of anti‐neural IgG antibodies was detectable in 53 (30–1%) of 176 sera from lepromatous patients compared with 21(18–6%) of 113 sera from tuberculoid patients, indicating that lepromatous patients were more likely to be seropositive to nerve antigens in ELISA. Some of the ELISA‐reactive sera showed antibody reactivity with 38‐kD, 40‐kD and 43‐kD nerve antigens in Western blotting analysis. There was no apparent correlation between seroreactivity to nerve antigens and bacterial load in leprosy patients. Although there was no statistical significance, anti‐neural antibodies were detectable more often among the patients on chemotherapy than the untreated and among the patients with erythema nodosum leprosum than without. The results, therefore, suggest that anti‐neural antibodies arc elicited during the course of leprosy and may be associated with the extensiveness of nerve involvement in the patients.