Anti-PD-1/PD-L1 Therapy associated Colitis is associated with Upregulation of Tight Junction Claudin-2

Cesar Mendoza, DePauw University
Ye Li PhD, University of Chicago
Le Shen MD, PhD, University of Chicago
Christopher R. Weber MD, PhD, University of Chicago

Chicago EYES on Cancer is funded by a grant to the University of Chicago Medicine Comprehensive Cancer Center from the National Cancer Institute (#R25 CA221767) and philanthropic support.


Anti-PD-1/PD-L1 therapy is an immunotherapy used to treat cancer. Patients can experience severe colitis and diarrhea as a result of this medication. We performed immunohistochemical staining on 20 colon biopsies from patients experiencing colitis from anti-PD-1/PD-L1 therapy and compared them to healthy aged matched controls. Our results showed that expression of claudin-2 in intestinal crypts was significantly higher in patients with anti-PD-1/PD-L1 colitis, which may contribute to increased paracellular water flux and diarrhea in these patients.