1. Department of Paediatrics, Pediatric Gastroenterology, Allergology and Nutrition, Medical University of Gdańsk, Nowe Ogrody 1-6, 80-803 Gdańsk, Poland
2. Department of Paediatrics, Hematology and Oncology, Medical University of Gdańsk, Dębinki 7, 80-211 Gdańsk, Poland
3. Department of Medical Immunology, Medical University of Gdańsk, Dębinki 7, 80-211 Gdańsk, Poland
4. Department of Surgery and Urology for Children and Adolescents, Medical University of Gdansk, Dębinki 7, 80-211 Gdańsk, Poland