BACKGROUND: In renal transplant patients, pneumonitis may be caused by cytomegalovirus (CMV pneumonitis). This condition is usually accompanied by CMV viremia. However, CMV may also reactivate locally in the lungs of renal transplant patients with pneumonitis due to other pathogens. The impact of local CMV replication/reactivation in the lungs is unknown.

MATERIAL AND METHODS: All renal transplant patients at the Duesseldorf transplant center in the time from 01/2004 to 1/2008 were analyzed concerning pulmonary CMV replication in the setting of pneumonitis.

RESULTS: Of 434 renal transplant recipients, 25 patients were diagnosed with pneumonitis. From these 25 patients with pneumonitis, 7 presented with isolated pulmonary CMV replication but without relevant CMV viremia 8±4.2 months after renal transplantation. Three of the 7 patients needed long-term respiratory support by invasive mechanical ventilation. Pulmonary opportunistic infections were diagnosed in 6 of the 7 patients. Therapy consisted of a reduction in immunosuppression, ganciclovir, and antibiotics.

CONCLUSIONS: Our findings suggest that pulmonary CMV replication occurs in renal transplant patients with pneumonitis even at later phases after renal transplantation. This finding seems to be a frequent complication (7/25 patients). Clinicians should be aware of this condition because blood-based screening assays for CMV will remain negative.

Keywords: Kidney Transplantation, Lung Diseases, Interstitial