CMV-Related Hemorrhagic Retinal Vasculitis in a Multiple Myeloma Patient on Daratumumab Therapy: A Case Report

PURPOSE: To report a case of cytomegalovirus (CMV)-related hemorrhagic retinal vasculitis in a patient with multiple myeloma (MM) on daratumumab, a trial cereblon E3 ligase modulatory drug (CELMoD), dexamethasone, and acyclovir, and discuss clinical implications for CMV prophylaxis. METHODS: Case report, narrative review of CMV reactivation risk in MM patients on daratumumab and antiviral agent efficacy for CMV prophylaxis. RESULTS: A 63-year-old female presented with 3 days of progressive unilateral vision loss in the right eye to the level of counting fingers. She had a history of relapsed and refractory MM and autologous stem cell transplant (ASCT). At the time of presentation, she was receiving daratumumab, a trial CELMoD, dexamethasone, and acyclovir. Posterior segment exam demonstrated trace vitreous cells (0.5+ vitritis as per SUN criteria) and scattered hemorrhages with multifocal intraluminal vascular whitening, aligned with infectious posterior uveitis and suggestive of panretinal occlusive vasculitis. Optical coherence tomography showed inner macular edema and epiretinal membrane formation. CMV reactivation was confirmed with PCR of anterior chamber fluid and blood. CONCLUSION: Patients with MM on daratumumab are at increased risk of opportunistic reactivations including CMV, potentially due to daratumumab's immunomodulatory side effects. Our patient developed CMV-related hemorrhagic retinal vasculitis despite low-dose acyclovir, which provides limited protection against CMV reactivation in CMV seropositive individuals. This case report therefore offers casuistic support for ophthalmic screening for CMV reactivation or CMV prophylaxis with letermovir in this patient population.