Solitary Functioning Kidney in Children - A Follow-Up Study

Background/Aims: This study aims to assess the cumulative incidence of elevated albuminuria, hypertension and decreased estimated glomerular filtration rate (eGFR) to identify possible renal injury in children with SFK. Methods: Forty-two children with SFK (23 boys; 27 congenital) were included in a prospective follow-up study. Blood pressure, albuminuria and eGFR were assessed repeatedly and the cumulative incidence rate of various forms of renal injury, overall and by type of etiology, were evaluated. Finally, renal injury-free survival was analyzed. Results: Mean follow-up was until age 11.3 years (SD 6.3 years). During follow-up, 16 (38.1%) patients met the criteria for renal injury, defined as hypertension (10; 23.8%), severely increased albuminuria (3; 7.1%) and a significantly impaired eGFR (2) (5; 11.9%) and/or use of antihypertensive or antiproteinuric medication (11; 26.2%). Children with CAKUT in SFK had a significantly higher incidence of renal injury. The median time to develop renal injury was 12.8 years. Conclusion: A substantial proportion of children with SFK develop renal injury during childhood, especially those with CAKUT in the SFK. Therefore, close follow-up of albuminuria, blood pressure and eGFR are warranted to identify chronic kidney disease in its early stages