1. University of Nis, Faculty of Medicine, Department of Immunology + University Clinical Center Niš, Hematology, Allergology and Clinical Immunology Clinic, Niš
2. University of Nis, Faculty of Medicine, Department of Immunology
3. University of Nis, Faculty of Medicine, Department of Immunology + University Clinical Center Niš, Cardiovascular and Transplantation Surgery Clinic, Niš
4. University Clinic for Hematology, Skopje, Northern Macedonia + Ss. Cyril and Methodius University in Skopje, Faculty of Medicine, Northern Macedonia
5. University of Belgrade, Faculty of Medicine, Beograd + University Clinical Center of Serbia, Clinic of Allergology and Immunology