Affiliation: | Milena Peruhova, Viktoriya Georgieva, Nonka Yurukova, Monika Sekulovska, Gabriela Panayotova, Department of Gastroenterology, University Hospital Lozenetz, Sofia 1407, BulgariaAntoaneta Mihova, Velislava Terzieva, Tsvetelina Veselinova Velikova, Department of Clinical Immunology, University Hospital Lozenetz, Sofia 1407, Bulgaria |