Cancer immunotherapy utilizing immune checkpoint inhibitors (ICIs) has revolutionized the treatment of numerous cancer types. As the underlying mechanism of these treatments lies in the interference with inhibitory signals that usually impair potent antitumor immunity, for example, cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and the programmed cell death protein 1 (PD-1):programmed death-ligand 1/2 (PD-L1/2) pathway, it is not surprising that this could also promote exaggerated adaptive immune responses to unrelated antigen specificities. One of the side effects of ICI-based cancer immunotherapy that is increasingly observed in the clinic is immune-related adverse events (irAEs), including various types of autoimmunity. However, the precise etiology is incompletely understood. T follicular helper (Tfh) cells provide essential help to B cells for potent antibody responses and their tumor tissue presence is often correlated with a better outcome in several solid tumor entities. Importantly, these CD4
© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY. Published by BMJ.
Competing interests: DB reports grants and personal fees from Sanofi, and grants from Novartis, outside the submitted work; PB reports grants and personal fees from BMS, and personal fees from AstraZe
