Histopathologic and Clinical Characterization of Brentuximab Vedotin-associated Rash

Area of Science:

• Dermatology
• Oncology
• Immunology

Background:

• Brentuximab vedotin (BV) is a CD30-targeted antibody-drug conjugate for cutaneous T-cell lymphoma (CTCL).
• Rash is a common adverse event of BV, termed BV-associated rash (BVAR).
• Distinguishing BVAR from CTCL is clinically challenging, potentially disrupting treatment.

Purpose of the Study:

• To characterize the clinical and histopathologic features of BVAR.
• To identify features that differentiate BVAR from CTCL.
• To guide appropriate clinical management of BV-treated patients.

Main Methods:

• Retrospective analysis of 26 skin biopsy specimens from 14 patients with BVAR.
• Clinical data review for rash morphology, onset, and severity.
• Histopathologic examination, including immunohistochemistry, PCR, and TCR-HTS.

Main Results:

• BVAR typically presented as a morbilliform or maculopapular rash with delayed onset and moderate to severe classification.
• Spongiotic dermatitis was the primary histopathologic finding in most specimens.
• Immunohistochemistry showed a trend toward increased CD8+ cells in BVAR compared to CTCL.

Conclusions:

• BVAR exhibits specific clinical and histopathologic features, including spongiotic dermatitis and a distinct T-cell profile.
• These identified features can help distinguish BVAR from CTCL.
• Accurate differentiation facilitates optimized treatment strategies and avoids unnecessary therapy interruptions.