Immune response to Mycobacterium tuberculosis culture filtrate antigen in cured spinal tuberculosis patients and their spouses

Humoral and cell mediated immune responses were studied in cured spinal tuberculosis patients and their spouses to \nunderstand immunit to tuberculosis in cured patients. Antibody litre and immune complex levels were measured and lymphocyte \nresponse to Mycobaclerinm tuberculosis culture filtrate antigen was observed in cured spinal tuberculosis patients ( n = 3 0 ) and their \nspouses (n =27). A trend towards increased antibody litre was seen in cured patients as compared to their spouses. Significantly \nincreased circulating immune complex levels, as measured by PEG OD280 (polyethylene glycol optical density 280) were seen in the \ncontacts compared to cured patients. And a trend towards increased lymphocyte response to Mtuberculosis culture filtrate antigen \nwas seen with different antigen concentrations (0.1,1 and 10 μg /ml). Moreover, the effect of active-pulmonary-Tuberculosis (AT B) \nplasma taken from 1ILA-DR2 positive and DR2 negative patients on lymphocyte response of the cured patients showed no dramatic \nimmunomodulatory effect in the lymphocyte response when treated with DR2 positive or DR2 negative plasma. The study suggests \nthat the memory response lo Mtuberculosis is well maintained even after 10-15 years of treatment.