The goals of the present study were twofold: (i) to compare the repertoires of
antigens in culture filtrates of in vitro-grown Mycobacterium tuberculosis that are recognized by
antibodies from noncavitary and cavitary
tuberculosis (TB) patients and (ii) to determine the extent of variation that exists between the
antigen profiles recognized by individual TB patients.
Lipoarabinomannan-free culture filtrate
proteins of M.
tuberculosis were fractionated by one-dimensional (1-D) and 2-D
polyacrylamide gel electrophoresis, and the Western blots were probed with sera from non-human immunodeficiency virus (non-HIV)-infected cavitary and noncavitary TB patients and from HIV-infected, noncavitary TB patients. In contrast to earlier studies based on recombinant
antigens of M.
tuberculosis which suggested that antibody responses in TB patients were heterogeneous (K. Lyashchenko et al., 1998, Infect. Immun. 66:3936-3940, 1998), our studies with native culture filtrate
proteins show that the antibody responses in TB patients show significant homogeneity in being directed against a well-defined subset of
antigens. Thus, there is a well-defined subset of culture filtrate
antigens that elicits
antibodies during noncavitary and cavitary disease. In addition, another set of
antigens is recognized primarily by cavitary TB patients. The mapping with individual patient sera presented here suggests that serodiagnostic tests based on the subset of
antigens recognized during both noncavitary and cavitary TB will enhance the sensitivity of antibody detection in TB patients, especially in difficult-to-diagnose, smear-negative, noncavitary TB patients.