Acquired C1-inhibitor deficiency in a patient with systemic lupus erythematosus: a case report and review of the literature

The C1-inhibitor (C1-INH) is an important member of the serpin family which inhibits the first component of the human complement system and controls contact activation of the coagulation and kinin system. An acquired form of C1-INH deficiency was recognized and classified as type I, which is characterized by accelerated catabolism of C1-INH, whereas type II is defined by the presence of an autoantibody directed against the C1 inhibitor molecule. This study reports the case of a 32-year-old woman with systemic lupus erythematosus (SLE) who experienced recurrent angioedema because of an acquired C1-INH deficiency. The relevant literature is reviewed.