1. Department of Cardiac Surgery and General Pediatric Surgery, Warsaw
2. Department of Pediatrics and Nephrology, Medical University of Warsaw, Warsaw
3. Department of Nephrology and Kidney Transplantation, Children's Memorial Health Institute, Warsaw
4. Department of Nephrology and Dialysis, District Children's Hospital, Szczecin
5. Department of Pediatric Nephrology, Karol Marcinkowski University of Medical Sciences, Poznan, Poland