597 EGFR monoclonal antibodies and EGFR tyrosine kinase inhibitors have distinct effects on the keratinocyte innate immune response

Reduced induction of human β‐defensins is involved in the pathological mechanism of cutaneous adverse effects caused by epidermal growth factor receptor monoclonal antibodies

“…We previously reported that EGFR mAbs suppressed the production of hBDs induced by staphylococci in vitro 4,7 . In accordance with our previous in vitro findings, we found significant decreases in hBD1 and hBD3 production in patients with papulopustular eruptions after therapy in the present study.…”

“…In addition, hBDs have multiple immunomodulatory functions such as inducing proinflammatory response by recruiting dendritic cells, T cells, mast cells and neutrophils, and inhibiting proinflammatory action by bacterial component and alarmins 3 . We previously reported that EGFRIs suppress the expression of all hBD types (hBD1–3) induced by staphylococci in cultured keratinocytes 4,5 . However, it is still unclear whether these in vitro data are relevant to clinical settings or whether they are correlated with cutaneous AEs.…”

“…3 We previously reported that EGFRIs suppress the expression of all hBD types (hBD1-3) induced by staphylococci in cultured keratinocytes. 4,5 However, it is still unclear whether these in vitro data are relevant to clinical settings or whether they are correlated with cutaneous AEs. In the present study, using skin samples to validate in vitro findings, we examined whether patients receiving EGFR mAb therapy exhibit inhibition of hBD induction.…”