B lymphocyte population and immunoglobulins in Indian kala-azar in response to chemotherapy.

The levels of immunoglobulin classes (IgG, IgM and IgA) along with B lymphocyte population size were estimated in 24 kala-azar (KA) patients and results were compared with those obtained from 30 controls. A marked increase in the level of IgG and to a lesser extent in that of IgM was noted in the sera of KA patients. But, no such difference could be noted in serum IgA level. Along with the increased levels of immunoglobulins the elevation of B lymphocyte population size was also observed. Follow-up studies during and after chemotherapy for the period of 8 months showed that clinical improvement in KA patients resulting from treatment had a positive correlation with the progressive decline in the B lymphocyte population and in the level of immunoglobulin though the latter, particularly IgG, took a longer time to return to normal.