ELISA & lepromin skin tests in household contacts of leprosy patients.

A total of 438 household contacts of leprosy patients and 228 non-contacts were studied for anti-PGL-I antibodies and cell mediated immune response to Mycobacterium leprae using ELISA and lepromin tests. The contacts showed relatively higher positivity to ELISA (29.4%) and lepromin (70.5%) as compared to non-contacts who showed 9.6 and 57 per cent positivity. In contacts as well as non-contacts the seropositivity was not found to be influenced by age and sex. However, seropositivity was higher (39.7%) in the contacts of patients with multibacillary leprosy as compared to contacts (27.7%) of patients with paucibacillary leprosy.

Use of eluates of filter paper blood spots in ELISA for the serodiagnosis of leprosy.

Blood samples were collected from 59 leprosy patients and 35 normal healthy subjects by veni-puncture and finger prick methods to obtain serum samples and blood spots on filter paper respectively. The serum samples at 1:300 dilutions and the eluates of dried blood spots at 1:40, 1:80, 1:160 and 1:320 dilutions were applied in ELISA to measure the antibody levels (IgM) against synthetic ND-O-BSA antigen. The antibody levels were found to be high in the multibacillary leprosy patients than the pauci-bacillary patients irrespective of whether serum samples or eluates were used. The OD values obtained at 1:160 dilution of the eluates were equivalent to that of values obtained at 1:300 dilution of the serum samples. The positivities differ in different dilution of the eluates, showing the highest in the 1:40 dilution and the lowest in the 1:320 dilution.

Thyroglobulin autoantibodies in leprosy.

Two hundred and five sera from lepromatous leprosy patients were tested for the presence of thyroglobulin autoantibodies using tanned red cell haemagglutination technique. Six out of 182 sera from LL patients and 5 out of 23 sera from LL patients with ENL gave a positive reaction for thyroglobulin autoantibodies.