Several authors (Jeong et al., 2013; Qivst, 2015) have shown that this diagnosis is an alternative in the context of NTM infections in cystic fibrosis patients. Indeed, as mentioned above, the microbiological diagnosis is often faulted, due to the difficulty of culturing the samples and their low yield in the context of NTM infections. An indirect diagnostic approach can only reinforce the screening of cystic fibrosis patients who have had contact with a NTM. Any serological response, although unable to date an infection, is the result of a potentially protective response of the host undergoing infection, and evidence of antibodies directed against the agent's bacterial products pathogen in circulating blood. A simple colonization does not allow the appearance of antibodies. An infectious process, even inapparent, must have taken place.