1. Department of Pediatric Hematology, Oncology and Transplantology; Medical University; Lublin Poland
2. Clinical Immunology; Polish-American Institute of Pediatrics; Jagiellonian University Medical College; Kracow Poland
3. Department of Transplantation; Children's University Hospital; Kracow Poland
4. Department of Pediatric Hematology and Oncology; Collegium Medicum; Nicolaus Copernicus University; University Hospital; Bydgoszcz Poland
5. Department of Pediatric Cardiology; Medical University; Lublin Poland