Lymphoid reactions possible with dupilumab treatment for atopic dermatitis

Key takeaways:

• Some patients with atopic dermatitis using dupilumab experienced lymphoid reactions that mimic cutaneous T-cell lymphomas.
• Dupilumab discontinuation is recommended in these patients.

In patients with atopic dermatitis treated with dupilumab, a reversible and most likely benign lymphoid reaction could occur, according to a study.

“Dupilumab, a monoclonal antibody that blocks the interleukin (IL)-4 receptor alpha, and thereby inhibits IL-4/13 signaling, is a new targeted AD treatment. It has proven to be effective and overall safe for the treatment of moderate to severe AD,” Celeste M. Boesjes, MD, of the department of dermatology and allergology and National Expertise Center for Atopic Dermatitis at University Medical Center of Utrecht, and colleagues wrote. “However, since the increased use of dupilumab in daily practice, several cases have been published on cutaneous adverse effects, such as the development of (atypical) lymphoid infiltrates and cutaneous T-cell lymphomas (CTCL).”

A retrospective observational case series study, using data from the BioDay Registry, evaluated adult patients with AD who were suspected of having CTCL during dupilumab treatment at one treatment center between October 2017 and July 2022.

Of 530 patients, 14 (2.6%) were suspected to have CTCL, of which three (0.6%) were diagnosed with mycosis fungoides (MF). Biopsies from before dupilumab treatment was available for each of these patients, and they were all evaluated to find misdiagnosis of AD.

Lymphoid infiltrates different from MF’s histopathologic characteristics were found in 11 (2.1%) of patients. Six of these individuals (54.5%) had pre-AD diagnosis biopsies available which were used to confirm AD diagnosis.

All biopsies found a lymphoid infiltrate with lichenoid or perivascular distribution and intraepithelial T-cell lymphocytes; however, those with MF had atypical hyperconvoluted and cerebriform lymphocytes along the basal layer of the epidermis.

In the patients with lymphoid reactions (LR), similar hyperchromatic and cerebriform lymphocytes were found, but sprinkled in the upper epidermal section.

Additionally, dysregulated CD4:CD8 ratio and CD30 overexpression without loss of CD2/CD3/CD5 was also found in the LR patients.

All 14 patients discontinued dupilumab treatment. Posttreatment biopsies found the LR cleared. However, AD lesions and itching emerged, which were treated with other systemic therapies.

“Dupilumab treatment may cause a reversible and most likely benign LR in patients with AD that mimics CTCL, though it has distinctive histopathologic features,” the authors wrote. “Clinical and histopathologic recognition of LR is important and treatment discontinuation is recommended in these patients.”