Investigation of the correlation of C1 esterase inhibitor levels and functions with attack severity and frequency in hereditary angioedema - Fatma Arzu Akkuş; Fatih Çölkesen; Mehmet Emin Gerek; Ümmügülsüm Yılmaz Ergün; Tuğba Önalan; Recep Evcen; Filiz Sadi Aykan; Mehmet Kılınç; Selim Kahraman; Şevket Arslan (Alergologia Polska)