Rolovic, Z. (7006321033)Z. (7006321033)RolovicElezovic, I. (12782840600)I. (12782840600)ElezovicObrenovic, B. (6506095227)B. (6506095227)ObrenovicRizza, C. (58439940000)C. (58439940000)Rizza2025-06-122025-06-121982https://doi.org/10.1111/j.1365-2141.1982.tb02830.xhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-0020322312&doi=10.1111%2fj.1365-2141.1982.tb02830.x&partnerID=40&md5=fc5f2f3a0fb862f93d6139665d3b9666https://remedy.med.bg.ac.rs/handle/123456789/2145Five instances of inhibitor to factor XII-XI have been reported so far. These have arisen in two women suffering from systemic lupus erythematosus and in three patients with Waldenstrom macroglobulinaemia. None of these patients had a bleeding tendency. The authors believe that it is of interest to report a 45-year-old female with an 18 years history of a bleeding tendency, who developed life-threatening vaginal bleeding following total hysterectomy for rupture of an ovarian cyst. Coagulation studies revealed a prolonged whole blood clotting time of 19 min and an activated partial thromboplastin time of 199 s (control 40 s). Further experiments showed that the patient's plasma at the dilution of 1:32 inhibited a contact product preparation thus indicating an inhibitor to factor XII-XI. The patient was treated with a variety of blood products without success but the administration of FEIBA 60 units/kg/d for 4 d was followed by the arrest of bleeding. The patient recovered completely. She had no evidence of an associated systemic disease but the inhibitor is still present in the plasma.