Cytomegalovirus infection can mimic genetic nephrotic syndrome: a case report

BACKGROUND Nephrotic syndrome is a relatively rare but serious condition in children. Infantile nephrotic syndrome often has a genetic origin; the treatment is then symptomatic, with a poor prognosis, and a rapid evolution to chronic kidney disease. However, non-genetic infantile nephrotic syndrome has been identified. Here we report for the first time in a child a nephrotic syndrome as the sole clinical expression of a cytomegalovirus infection. CASE PRESENTATION The patient was 5 months old when he presented with a nephrotic syndrome. An exhaustive genetic testing was conducted and came back negative. A viral work-up only showed a positive cytomegalovirus PCR. Antiviral treatment lead to a complete remission of the nephrotic syndrome, with no requirement for steroid therapy. Renal function remained normal throughout follow-up. CONCLUSION Nephrotic syndrome should always be carefully investigated in children. This observation reinforces the connection between viral infections and pediatric nephrotic syndrome, sparking more controversy about an infectious origin to childhood nephrotic disease.