Two-dimensional electrophoretic analysis of humoral responses to culture filtrate of Mycobacterium bovis BCG in patients with leprosy and tuberculosis.

Sera from 3 lepromatous (LL), 3 borderline lepromatous (BL), 3 mid-borderline (BB), 3 borderline tuberculoid (BT), 2 tuberculoid (TT) and 4 tuberculosis (TB) patients and 3 healthy individuals were examined for their reactivities against the proteins in the culture filtrate of BCG separated by two-dimensional electrophoresis (2-DE). The sera were obtained from patients who were untreated. Sera from LL and BL patients reacted strongly with the antigen 85 (Ag85) complex and MPB51. Sera from LL and BL patients also weakly reacted with the newly identified 29-, 24- and 23-kDa spots. Sera from the other patients reacted similarly, but the levels of reaction were remarkably lower than those form LL and BL patients. Mycobacterium leprae antigens that are analogous to BCG AG85 and MPB51 are suggested as the main targets for the humoral immunity of untreated patients. The reactivities of sera with newly identified antigens may provide the potential for predicting the severity and prognosis of diseases.