Immunotherapy for tuberculosis: what's the better choice?

A Th1/Th2 imbalance in tuberculosis (TB) patients caused by a decreased Th1 response and an increased Th2 response is a significant factor in the pathogenesis and development of TB. Protective immune responses to TB include bacteriostatic and bactericidal responses. Unfortunately, however, immunoprotection and immune pathology co-exist in TB patients. Immunotherapy for TB principally aims to restore the Th1/Th2 balance by enhancing the Th1 response and suppressing the excessive Th2 response. Immunotherapy for TB can be classified into three categories: immune-enhancing therapy using cytokines, immunosuppressive therapy, and immunomodulatory therapy. Immunomodulatory therapy targets the Th1/Th2 imbalance and includes cytokine regulation therapy, antibody regulation therapy, a multi-dose heat-inactivated Mycobacterium vaccae vaccine, thymosin hormones and a DNA vaccine. A new approach in supplementary TB immunotherapy is to simultaneously up-regulate the Th1 response and down-regulate the Th2 response. While immunotherapy can contribute to TB treatment, it may also cause immunopathological injury. Therefore, immunotherapy needs to be improved and further studied to maximize its potential.