Potential PD-1 inhibitor immune dysregulation as a risk factor for Listeria monocytogenes bacteremia and meningitis

Abstract

As immune checkpoint inhibitor (ICI) therapy becomes increasingly popular for the treatment of cancer, there is a growing body of literature on opportunistic infections associated with ICI therapy. Pembrolizumab binds specifically to the PD-1 receptor on T cells, preventing PD-1’s interaction with PD-L1 and PD-L2. This blockade interrupts the inhibitory signal and restores a T cell’s ability to recognize and attack tumor cells. We present a case of invasive Listeria infection associated with ICI therapy. The case also suggests treating patients undergoing active ICI therapy as potential immunocompromised hosts due to possible immune dysregulation related to ICI therapy.