CD4 and hereditary angioedema: Comparison of lymphocytes subpopulations distribution between examined groups showed significantly increased subpopulation of CD4+ in HAE patients during the attack (65.8%; 51.9–76.8%, p = 0.013) and in remission (66.1%; 48.4–84.2%, p = 0.027) in comparison to healthy subjects (58.8%; 44.0–70.4%).