Fatal cytomegalovirus pneumonia after preemptive antiviral therapy in a renal transplant recipient

Cytomegalovirus (CMV) infections occur with an incidence of up to 70% in re nal transplant patients and mortality is low due to effective antiviral dru gs. We report here the case of a patient who suffered from an uncommonly se vere and therapy-resistant pulmonary CMV infection. During the disease cour se, CMV-PCR from alveolar cells and lung biopsy material was repeatedly neg ative despite high CMV pp65 antigenemia. CMV pneumonia was finally diagnose d from a biopsy obtained by open thoracotomy revealing positive CMV immunos taining of lung tissue. The patient died of respiratory failure though doub le-treatment using both ganciclovir and foscavir was administered. Post mor tem, the clinically suspected resistance to both antiviral drugs, but not t o cidofovir, could be proven by bioassay testing of in vitro growth respons es using viral cultures. CMV pneumonia may thus not be diagnosed by standar d PCR techniques-in rare cases and may be resistant to the available antivi ral therapy. Severe CMV pneumonia may benefit from novel antiviral drugs su ch as cidofovir, which is currently used in the treatment of CMV retinitis in HIV patients.