Use of the anti-PGL-I antibody ELISA and the Mitsuda reaction in early diagnosis of leprosy.

Cutaneous reaction to the Mitsuda antigen and anti-PGL-I IgM antibodies (ELISA) were determined in 134 leprosy patients, 290 household contacts, 52 healthy controls and 43 tuberculous individuals. The multibacillary patients did not develop cell-mediated immunity (CMI), although they presented high levels of IgM (absorbance at 492 nm greater than 0.5). The paucibacillary patients presented CMI, although in varying degrees, and IgM levels did not exceed 0.5 absorbance units. Most of the contacts (107) showed a Mitsuda-positive test, and 25 of them were anti-PGL-I IgM seropositive (absorbance less than 0.5 but greater than 0.22), although none became ill during the two-year follow-up. Of the 17 Mitsuda-negative contacts, two exhibited an immunological status of lepromatous leprosy (negative Mitsuda test and positive serology; absorbance greater than 0.5) and became ill (one borderline lepromatous and one indeterminate leprosy). These results show that the immunological status of lepromatous leprosy can appear prior to clinical symptoms, and thus serology for anti-PGL-I IgM together with the Mitsuda test can be useful in an active search for new preclinical cases among high risk populations.

The dot-ELISA test for the detection of anti-PGL-1 IgM in leprosy patients and their contacts.

1. Since dot-ELISA has recently been reported to be a sensitive, simple and fast method, we have compared it with the conventional microplate ELISA method. Sera of 124 leprosy patients, 136 household and professional contacts, and 92 controls were tested for antibodies against a Mycobacterium leprae antigen using dot-ELISA on nitrocellulose membrane filters and microplate ELISA. 2. The sensitivity of the two techniques was similar for multibacillary patients, but dot-ELISA was less sensitive for paucibacillary patients although it was more specific (100%) than ELISA (93.4%). 3. Of 21 household contacts that gave a response by ELISA, 3 were also positive by dot-ELISA; one of these 3 developed indeterminate leprosy 12 months later and the other was diagnosed as borderline lepromatous after 28 months. 4. These data indicate that dot-ELISA has a high specificity and can be a useful tool in field evaluation.

The dot-ELISA test for the detection of anti-PGL-1 IgM in leprosy patients and their contacts

Since dot-ELISA has recently been reported to be a sensitive, simple and method, we have compared it with the conventional microplate ELISA method. Sera of 124 leprosy patients, 136 household and professional contacts, and 92 controls were tested for a antibodies against a Mycobacterium leprae antigen using dot-ELISA on nitrocellulose membrane filters and microplate ELISA. The sensitive of the techniques was similar for multibacillary patients, but dot-ELISA was less sensitive for paucibacillary patients although it was more specific (100%) than ELISA (93,4%). Of 21 household contacts that gave a response by ELISA, 3 were also positive by dot-ELISA; one of these 3 developed indeterminate leprosy 12 months later and the other was diagnosed as borderline lepromatous after 28 months. These data indicate that dot-ELISA has a high spedificity and can be a useful tool in field evaluation

Use of the anti-PGL-I antibody ELISA and the Mitsuda reaction in early diagnosis of leprosy

Cutaneous reaction to the Mitsuda antigen and anti-PGL-I IgM antibodies (ELISA) were determined in 134 leprosy patients, 290 household contacts, 52 healthy controls and 43 tuberculous individuals. The multibacillary patients did nort developed cell-mediated immunity (CMI), although they presented high levels of IgM (absorbance at 492 m > 0.5). The paucibacillatry patients presented CMI, although in varying degrees, and IgM levels did not exceed 0.5 absorbance units. Most of the contacts (107) showed a Mitsuda-postive test, and 25 of then were anti-PGL-I IgM seropositive (absorbance < 0.5 but > 0.22), although none became ill during the twoyear follow-up. Of the 17 Mitsuda-negative contacts, two wxhibited an immunological status of lepromatous leprosy (negative Mitsuda test and positive serology; absorvance > 0.05) and became ill (one borderline lepromatous and one indeterminate leprosy). These results show that the immunological status of lepromatous leprosy can appear prior to clinical symptoms, and thus serology for anti-PGL-I IgM together with the Mitsuda test can be useful in an activbe search for new preclinical cases among high risk populations

IgM immunoglobulins reacting with the phenolic glycolipid-1 antigen from Mycobacterium leprae in sera of leprosy patients and their contacts

For the first time in Brazil it was investigated the occurrence of IgM anti-PGL-1 in the sera of household contacts of leprozy patients using the ELISA methodology. The sera of the multipatients. It was observed a high subclinical infection incidence among household contacts (19.4%). The percentage of leprosy development was 5% (1/21) among the seropositive contact group. This finding suggests that serology could be useful as prognostic test, but for better definition is necessary to tet a population from endemic area for long period time

IgM immunoglobulins reacting with the phenolic glycolipid-1 antigen from Mycobacterium leprae in sera of leprosy patients and their contacts.

For the first time in Brazil it was investigated the occurrence of IgM anti-PGL-1 in the sera of household contacts of leprosy patients using the ELISA methodology. The sera of the multibacillary patients showed significantly more immuno-reactivity than from the paucibacillary patients. It was observed a high subclinical infection incidence among household contacts (19.4%). The percentage of leprosy development was 5% (1/21) among the seropositive contact group. This finding suggests that serology could be useful as prognostic test, but for better definition is necessary to test a population from endemic area for long period time.