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Updated: Feb 17, 2026
Monitoring PD-1-Blocking Antibodies Bound to T Cells Derived from a Drop of Peripheral Blood
Published on: February 5, 2020
[Two cases of granuloma annulare under anti-PD1 therapy]
R Charollais1, F Aubin1, B Roche-Kubler1
1EA3181, service de dermatologie, université de Bourgogne-Franche-Comté, CHU, 3, boulevard Fleming, 25030 Besançon, France.
Background:
Granuloma annulare as a granulomatous cutaneous reaction may be drug-induced. Immune checkpoint inhibitors including programmed death-1 (PD-1) inhibitors show remarkable antitumor activity and are approved for melanoma and other cancers. Different immune-related adverse effects have been described. We report herein a rare adverse effect of anti-PD1 therapy given for metastatic melanoma : granuloma annulare.
Patients And Methods:
Two women receiving pembrolizumab metastatic melanoma presented with granuloma annulare. The therapy was continued in both cases. In the first patient, granuloma annulare appeared and then subsided; in the second patient, the lesion resolved completely with topical corticosteroids.
Discussion:
While there have been reported cases of sarcoidosis induced by immunotherapies, immunotherapy-induced granuloma annulare has not been described. The pathogenesis of drug-induced granulomatous reactions is thought to involve autoimmune dysregulation affecting T cells, especially Th1 cells, which lead to granuloma formation. Granuloma annulare should thus be considered a cutaneous adverse effect of anti-PD1 immunotherapy.
