What immunological defects predispose to the non-tuberculosis mycobacterial infections?

Nontuberculous mycobacteria (NTM) are categorized as one of the large and diverse groups of environmental organisms which are abundant in water and soil. NTM cause a variety of diseases in human in which mainly lung is involved. A predisposition to pulmonary NTM is seen in patients with parenchymal structural diseases including bronchiectasis, emphysema, tuberculosis (TB), cystic fibrosis (CF), rheumatologic lung diseases, and other chronic diseases with pulmonary manifestations. Lung infections are not the only consequences of being infected by NTM as it can also infect skin and soft tissue and may also cause lymphadenitis (predominantly in young children) and disseminated disease in HIV-infected patients or those with severely compromised immune system. NTM is also reported in many subjects without any known risk factor. Although the recent advances in imaging and microbiologic techniques including gene sequencing has provided a better view of the problems caused by NTM and has enhanced our understanding of the disease, many uncertainties regarding the immunologic response to NTM still exist. There is also limited data on the immunogenetics of NTM infection. Here, the authors reviewed the main immunogenetic defects as well as other immunological conditions which are associated with an increased the risk of NTM infections