Ocular Outcomes after Treatment of Cytomegalovirus Retinitis Using Adoptive Immunotherapy with Cytomegalovirus-Specific Cytotoxic T Lymphocytes

Abstract

Purpose: To describe ocular outcomes in eyes with cytomegalovirus (CMV) retinitis treated with adoptive immunotherapy using systemic administration of CMV-specific cytotoxic Tlymphocytes (CMV-specific CTLs).

Design: Retrospective cohort study.

Participants: Patients with active CMV retinitis evaluated at a tertiary care academic center.

Methods: Treatment of CMV retinitis with standard-of-care therapy (systemic or intravitreal antivirals) or CMV-specific CTLs (with or without concurrent standard-of-care therapies).

Main outcome measures: The electronic medical record was reviewed to determine baseline characteristics, treatment course, and ocular outcomes, including best-corrected visual acuity (BCVA), treatments administered (CMV-specific CTLs, systemic antivirals, intravitreal antivirals), resolution of CMV retinitis, any occurrence of immune recovery uveitis, cystoid macular edema, retinal detachment, or a combination thereof.

Results: Seven patients (3 of whom had bilateral disease [n = 10 eyes]) were treated with CMV-specific CTLs, whereas 20 patients (6 of whom had bilateral disease [n = 26 eyes]) received standard-of-care treatment. Indications for CMV-specific CTL therapy included persistent or progressive CMV retinitis (71.4% of patients); CMV UL54 or UL97 antiviral resistance mutations (42.9%); side effects or toxicity from antiviral agents (57.1%); patient intolerance to longstanding, frequent antiviral therapy for persistent retinitis (28.6%); or a combination thereof. Two patients (28.6%; 4 eyes [40%]) received CMV-specific CTL therapy without concurrent systemic or intravitreal antiviral therapy for active CMV retinitis, whereas 5 patients (71.4%; 6 eyes [60%]) continued to receive concurrent antiviral therapies. Resolution of CMV retinitis was achieved in 9 eyes (90%) treated with CMV-specific CTLs, with BCVA stabilizing (4 eyes [40%]) or improving (4 eyes [40%]) in 80% of eyes over an average follow-up of 33.4 months. Rates of immune recovery uveitis, new-onset cystoid macular edema, and retinal detachment were 0%, 10% (1 eye), and 20% (2 eyes), respectively. These outcomes compared favorably with a nonrandomized cohort of eyes treated with standard-of-care therapy alone, despite potentially worse baseline characteristics.

Conclusions: CMV-specific CTL therapy may represent a novel monotherapy or adjunctive therapy, or both, for CMV retinitis, especially in eyes that are resistant, refractory, or intolerant of standard-of-care antiviral therapies. More generally, adoptive cell transfer and adoptive immunotherapy may have a role in refractory CMV retinitis. Larger prospective, randomized trials are necessary.

Keywords: CMV retinitis; Cell therapy; T cells.