Hematin, an oxidative metabolite of heme, suppresses porphyrin biosynthesis and is shown to be effective therapy for acute intermittent porphyria. In vitro, hematin activates platelets and inhibits thrombin and plasmin. These effects are caused by a hematin degradation product termed hematin derived anticoagulant (HDA) generated by prolonged aging of aqueous solutions of hematin (Jones RL. J Exp Med 1986; 163: 724-39). HDA activity is inhibited by antioxidants such as sorbitol and 2-mercaptoethanol. There is evidence that HDA is also generated in vivo but the mechanism is unclear. A single case of hematin induced coagulopathy has been reported in the past (Morris et al. Ann Intern Med 1981; 95(6): 700-1). We report the case of a 27 year old Caucasian female who developed coagulopathy following administration of hematin. The patient had recurrent episodes of abdominal crises due to acute intermittent porphyria and was maintained on home intravenous hematin t.i.w. She was admitted for an elective bilateral laparoscopic oophorectomy and tolerated the procedure well. On the second post operative day, she developed abdominal discomfort and was treated with narcotics. Over the next five days, she had significant abdominal pain consistent with porphyria and was managed with iv dextrose and narcotics. On day 8, she had persistent pain and a single dose (4 mg/kg) of hematin/sorbitol (panhematin) was administered via intravenous infusion over 10 minutes. The drug was administered 35 minutes after it was reconstituted in the pharmacy. Over the next twelve hours the patient's hematocrit declined from 34.8% to 24.9% and she developed a clinically overt coagulopathy as shown in the Table. The fibrinogen was within normal limits but the fibrin split products were moderately elevated. She was found to have a reclus sheath hematoma that required surgical evacuation. She was managed with fresh frozen plasma, 2 units of packed red blood cells and platelet transfusions. The coagulopathy resolved over next 72 hours and subsequently, the patient recovered. Hematin can cause life-threatening coagulopathy. A high index of suspicion can prompt early diagnosis and supportive measures to prevent morbidity. Hematin should be administered immediately after reconstitution and not be allowed to degrade prior to use to minimize the risk of coagulopathy. Platelets/ ram3 aPTT (sec) FT (sec) INR TT (sec) [8h] Pre Hematin 129,000 35.6 15.5 1.19 18.9 [5h] Post Hematin 72,000 58.2 18.9 1.52 25.6.
|Original language||English (US)|
|Issue number||11 PART II|
|State||Published - 2000|
ASJC Scopus subject areas
- Cell Biology