Affiliation: Experimental Pathology, National Institute of Medical Sciences and Nutrition “Salvador Zubirán”, Calle Vasco de, Quiroga 15, Tlalpan, CP 14000, Mexico D.F. Mexico.
Tuberculosis (TB) has been a widespread infectious disease since ancient times and remains a worldwide major health problem. TB morbidity with 8 to 9 million active cases per year and 1.3 deaths annually represent the largest number of incidences and of human deaths attributable to a single bacterial agent. Its causal agent Mycobacterium tuberculosis is able to survive in a latent state in infected individuals, thereby serving as a reservoir, waiting for the reactivation that usually occurs in immune-suppressed individuals, such as HIV patients. According to World Health Organization estimation, 2 billion people, almost one-third of the world’s population, are believed to be latently infected. An additional significant factor is the continued emergence of new multidrug resistant strains often associated to poor compliance due to the long, complex, toxic and expensive treatment. Thus, new anti-TB drugs and better therapeutic strategies are urgently needed. New drug candidates should short the standard regimens and being effective against drug resistant strains. In recent years, an emphasized research activity in the development of new TB drugs has being produced. Some compounds are presently in clinical development, while others are being investigated pre-clinically. The immune system is a critical factor for containment and cure of mycobacterial infection. Augmentation of protective immunity or decreasing the immune modulatory responses during late disease can be of value in the TB treatment. Thus, the use of immunotherapy with cytokines or bacterial derivatives as an adjunct to drug treatment may improve success rates for treatment of MDR-TB and shorten treatment time for drug-sensitive TB.
The present review concentrates to describe the most promising new drugs against TB which are now in clinical trials, as well as the immunotherapeutic assays performed in humans.