Recurrent CMV retinitis in a non-HIV patient with drug-resistant CMV

Background: We report a case of recurrent cytomegalovirus (CMV) retinitis in an HIV-negative patient with CD4+ T lymphocytopenia. Methods: Case report. Results: A 41-year-old HIV-negative woman with a history of systemic lupus erythematosus, idiopathic thrombocytopenic purpura requiring splenectomy, and diabetes presented with primary CMV infection, high-grade viremia, CMV pneumonia followed by CMV retinitis (CMVR) and a CD4+ T lymphocyte (CD4) count of 12 cells/mm³ after therapy with rituximab, prednisone, and methotrexate. Persistent CMV viremia led to genotypic analysis of the circulating virus, which revealed UL97 and UL54 mutations known to be associated with resistance to ganciclovir (GCV) and cidofovir. CMV clearance from the bloodstream followed systemic antiviral therapy and recovery of CD4 cell count. However, CMVR recurred multiple times despite GCV implants, systemic valganciclovir, intravitreal GCV injections, and persistent CD4 counts greater than 100 cells/mm³. Recurrent episodes of CMVR responded to multiple high dose intravitreal GCV injections (5000-6000 micrograms) and recovery of CD4 cell counts to greater than 200 cells/mm³. Conclusion: This case demonstrates that recurrent CMVR occurs in HIV-negative patients at CD4 cell counts thought to be protective in HIV patients, and suggests that an ineffective local immune response to retinal infection combined with CMV drug resistance may have been important factors leading to recurrent disease in this patient. Treatment producing high local concentrations of GCV may be effective therapy for CMV retinitis due to GCV-resistant virus.