Unrelated immunodeficiency states may impact outcomes and immune checkpoint molecule expression in patients with mycosis fungoides: A clinicopathologic case-control study.

Abstract

Immunodeficiency (ID) correlates with worse outcomes and decreased immune checkpoint molecule expression in melanoma. The impact of ID in mycosis fungoides (MF) is unknown. Our goal was to evaluate the impact of ID in MF. We conducted a case-control study of 17 patients with MF and ID versus age-, stage-, and race-matched controls as a subset of a comparative analysis of 23 patients with MF with ID (prior lymphoma, recent/current pregnancy, HIV, hypogammaglobulinemia, and prior chemotherapy) versus without ID. Programmed cell death 1 (PD1), programmed death ligand 1 (PDL1), forkhead box p3, and interleukin 17 immunohistochemistry was performed on 12 patients with ID and 10 controls. Patients with ID had more treatment failure (14 of 23 vs 5 of 17 [P = .028]), more treatment failure within 3 years of diagnosis (12 of 23 vs 4 of 17 [P = .050]), more angiocentrism (6 of 12 vs 0 of 10 [P = .005]), larger cells (1.92 ± 0.51 out of 3 vs 1.30 ± 0.48 out of 3 [P = .009]), more cases with at least 10% PD1 positivity (9 of 11 vs 4 of 10 [P = .031]) and at least 10% PDL1 positivity (7 of 12 vs 2 of 10 [P = .042]), and a higher average percentage of PD1⁺ cells (43.27 ± 40.22 vs 11.2 ± 13.62 [P = .028]). No differences in survival, forkhead box p3 expression, interleukin 17 expression, histologic depth, ulceration, granulomatous changes, or syringotropism were seen. This was a small single-center study with heterogeneous immunodeficiencies. ID correlated with worse outcomes and increased PD1 and PDL1 expression in MF. Patients with MF and ID may be candidates for immune checkpoint inhibitor therapy, pending further investigation.