Tuberculosis following PD-1 blockade for cancer immunotherapy.

Because of the well-established therapeutic benefit of boosting antitumor responses through blockade of the T cell inhibitory receptor PD-1, it has been proposed that PD-1 blockade could also be useful in infectious disease settings, including (Mtb) infection. However, in preclinical models, Mtb-infected PD-1 mice mount exaggerated T1 responses that drive lethal immunopathology. Multiple cases of tuberculosis during PD-1 blockade have been observed in patients with cancer, but in humans little is understood about Mtb-specific immune responses during checkpoint blockade-associated tuberculosis.