Cytomegalovirus nephritis in a lung transplant recipient: A case report

Introduction Cytomegalovirus (CMV) infections are frequent in solid organ transplant recipients and associated with increased allograft dysfunction.Clinical story We report the case of a 58-year-old lung transplant recipient (CMV mismatched) who presented with severe acute kidney injury (AKI) without any other organ involvement. Urinalysis showed moderate proteinuria, leukocyturia, and hematuria suggestive of interstitial nephritis, while renal/urinary tract ultrasound was normal. Anamnesis excluded iatrogenic AKI causes including contrast- and non-steroidal anti-inflammatory drugs-induced AKI, while dedicated blood tests excluded other AKI causes such as vasculitis, hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infection, thrombotic microangiopathy, tacrolimus overdosage, rhabdomyolysis. Urine and serum CMV polymerase chain reaction (PCR) were strongly positive, while urine BK virus was negative. A renal biopsy could not be performed due to anticoagulation and logistic reasons.Diagnosis Based on the existing literature, we made a presumptive diagnosis of CMV nephritis and initiated intravenous antiviral therapy with ganciclovir. Within a few weeks, renal function improved but did not fully recover.Conclusion CMV nephritis is very rare in nonkidney solid organ transplant recipient but should be investigated in case of acute kidney injury as it may lead to chronic renal impairment.