Using our C1-INH complex ELISA set, we successfully measured the concentration of total C1-INH, active C1-INH, and complexed C1-INH in six healthy controls, 5–5 C1-INH-HAE type I and type II patients in symptom-free periods, five patients during HAE attacks, as well as during a kinetic follow-up study of an HAE attack in one C1-INH-HAE patient from the beginning until the spontaneous termination of HAE symptoms. The gene discussed is SERPING1; the disease is hereditary angioedema.