1. Department of Pediatric Laboratory Diagnostics, Medical University of Bialystok, 15-274 Bialystok, Poland
2. Department of Biochemistry and Molecular Biology, Centre of Postgraduate Medical Education, 01-813 Warsaw, Poland
3. Department of Biochemical Diagnostics, Medical University of Bialystok, 15-269 Bialystok, Poland
4. Department of Internal Diseases and Gastroenterology, Provincial Welded Hospital, 15-278 Bialystok, Poland