Serological profiles in Indian post kala-azar dermal leishmaniasis.

The sera of 20 Indian post kala-azar dermal leishmaniasis (PKADL) patients were analysed for immunoglobulin (IgG, IgM and IgA), third component of complement (C3) and specific antibody contents and the results compared with those of normal controls and kala-azar (KA) patients as obtained in an earlier study. Mean values of serum IgG and IgM in PKADL were found to be significantly higher than those of normal controls, although these values were substantially lower to those of KA patients. No significant difference, however, was noted in the mean levels of serum IgA and C3 between PKADL and control groups. Specific antibodies to Leishmania antigen could be demonstrated in PKADL sera by the indirect haemagglutination (IHA) and enzyme-linked immunosorbent assay (ELISA) methods. Most of these antibodies belonged to IgG class although some IgM antibodies were also demonstrable. Antibody titre ranges in PKADL sera were, however, definitely lower than those of KA sera. A reasonably good correlation between the severity of dermal lesions and IgG-ELISA titres was obtained. Of 12 chronic PKADL cases, only four and ten were found to be serologically positive by IHA and micro-ELISA methods respectively. All eight fresh cases were seropositive by both these tests. Analysis of the data suggests an over-all difference between the serological profiles of PKADL and KA patients.