PD-1 monoclonal antibody (Tislelizumab)-induced DRESS syndrome in an intrahepatic cholangiocarcinoma patient with FGFR3 mutation and elevated IgG4:A case report.

BACKGROUND

Immune-related adverse events (irAEs) include a rare, idiosyncratic but potentially life-threatening drug reaction with eosinophilia and systemic symptoms (DRESS), characterized by exanthem, fever, as well as hematologic and visceral organ involvement.

CASE PRESENTATION: We describe a 54-year-old man under the novel sequential treatment including all-trans retinoic acid (ATRA) and programmed death protein 1(PD-1) antibody (Tislelizumab) for advanced intrahepatic cholangiocarcinoma (iCCA). He was found to have Tislelizumab-induced DRESS syndrome during adjuvant therapy, and also showed the evidence of IgG4-related lymphadenopathy (IgG4-RLAD) as well as Epstein-Barr virus (EBV) infection in the absence of hemophagocytic lymphohistiocytosis (HLH) and T cell lymphoma. The patient's clinical status was successfully ameliorated through the administration of corticosteroids, intravenous immunoglobulin (IVIG), and antiviral agents, demonstrating a positive response to the treatment protocol. He was the first-ever case report of Tislelizumab-induced DRESS syndrome in the context of IgG4-RLAD with an exploration of potential mechanisms. Furthermore, we found that a somatic fibroblast growth factor receptor (FGFR) 3 p.P774L mutation at the frequency of 1.96 % was detected in his iCCA tissue.

CONCLUSION

These findings indicated that this novel therapy, based on ARTA and PD-1 antibody, is more effective and could guide the clinical application of PD-1 antibody in the iCCA patients with elevated IgG4. Human leukocyte antigen (HLA) typing assay might help to screen the potential susceptible individuals to avoid immune checkpoint inhibitors (ICIs)-induced DRESS syndrome.