Modulation of tuberculosis-related immune responses by helminths.

Tuberculosis (TB) continues to be a major worldwide health problem, with 9.4 million newly emerging active tuberculosis cases and causes nearly 2 million deaths annually. Currently, experimental evidence for an strong association between helminths and diminished T helper (Th)1 immunity against Mycobacterium tuberculosis infection is based on studies which show that helminth-induced Th2, T regulatory (Treg) responses and alternatively activated macrophages contribute to enhanced susceptibility to TB. In this context, it has been shown that Th1 response is reduced in helminth coinfected TB patients. This article discusses what is presently known about the types of immune responses modulated by helminths to diminish the protective immune response to TB.