The Role of Adjunctive Mycobacterium w Immunotherapy for Tuberculosis

Mycobacterium w (Mw) is a potent immunomodulator based on saprophytic cultivable autoclaved atypical Mycobacterium (M.), and shares T cell and B cell antigenic determinants with M. tuberculosis and M. leprae. Mw enhances T-helper 1 response, resulting in the release of type-1 cytokines, predominantly interferon-γ, and thereby propagates cell-mediated immune responses. In experimental models, Mw has shown a protective effect against tuberculosis in mice and guinea pigs challenged with live M. tuberculosis H37Rv. Clinical trials have shown significant clinical benefits of Mw in leprosy and tuberculosis. Used as an adjuvant to multidrug therapy in multibacillary leprosy, Mw resulted in expedited and distinct clinical improvement, a decline in the bacterial index, and enhanced the immunologic recovery of patients. In tuberculosis, Mw has resulted in higher curative rates and a significant reduction in the time to sputum conversion in patients with a high bacterial load. In addition, Mw has shown potential for tuberculin conversion and increased CD4+ cell count in human immunodeficiency virus (HIV)-infected people. With the increasing incidence of multidrug resistant tuberculosis and the high burden of HIV infection, there is a need to evaluate the role of Mw as an adjunctive treatment in tuberculosis, and to examine its immunomodulatory effects in large, well-designed, randomized, controlled clinical trials. An effective immunotherapeutic vaccine, particularly for HIV-positive patients, would greatly affect the profile of tuberculosis at the population level.