Immune reconstitution complicated by CMV retinitis in a pediatric patient who underwent haploidentical CD34+-selected hematopoietic stem cell transplant for acute lymphoblastic leukemia.

We describe two episodes of CMV retinitis in a pediatric patient who underwent a CD34+ selected graft from his haploidentical father. Both recipient and donorwere cytomegalovirus (CMV) seropositive. Both episodes occurred latepost-grafting during a phase of complete immunological recovery with sufficientnumbers of circulating CMV-specific clones. Antiviral treatment with foscarnetand ganciclovir was successful but prolonged treatment was required to preventrelapses. We hypothesize that this complication was more related to an immunereconstitution process than to an immune-deficient state post-grafting. Weconclude that CMV retinitis is a late complication of HSCT that can occur despitesatisfactory immune reconstitution. Usually, it is responsive to antiviraltherapy. Dilated fundoscopic examination is essential both for examining patientswith reduced visual acuity and for screening asymptomatic patients.