Pagano Monica B, Hobbs William, Linenberger Michael, Delaney Meghan
Department of Pathology, Transfusion Medicine Division, Johns Hopkins Medical Institutions, Balimore, Maryland, USA.
J Clin Apher. 2012;27(6):336-41. doi: 10.1002/jca.21249. Epub 2012 Sep 21.
Erythropoietic protoporphyria (EPP) is a rare and usually autosomal dominant disorder characterized by ferrochelatase deficiency and accumulation of protoporphyrin in red blood cells (RBCs), skin, and liver. A small minority of patients develop severe liver dysfunction for which optimum treatment is lacking. Therapeutic plasma exchange (TPE) and RBC exchange (RCE) have been anecdotally reported to benefit patients with EPP and liver failure. A 50-year-old female with EPP developed severe liver dysfunction after knee replacement surgery and high-dose acetaminophen use. Liver biopsy showed cholestatic liver injury without fibrosis. A total of 20 TPE procedures, six RCE procedures, and then 14 more TPE procedures were performed as adjunctive therapy with the purpose of preventing progression to end-stage liver failure. After initial TPE, the plasma and RBC protoporphyrin levels decreased from 834.9 to 180.4 μg/dL (normal, ≤1 μg/dL), and from 3,905 to 2,879 μg/dL (normal, ≤80 μg/dL), respectively, without liver function improvement. RCE decreased RBC protoporphyrin levels from 2,879 to 1,225 μg/dL but plasma protoporphyrin increased from 180.4 to 1,044.1 μg/dL, and liver function failed to improve. Additional TPE again stabilized plasma protoporphyrin and improved RBC protoporphyrin levels but the patient ultimately died owing to end-stage liver disease complications. This case illustrates that TPE and RCE may improve the plasma and RBC biochemical markers of EPP activity but liver function abnormalities may persist and patients may still progress to liver failure either because of irreversible liver injury or independent pathobiological factors unrelated to EPP-induced hepatotoxicity.
红细胞生成性原卟啉病(EPP)是一种罕见的常染色体显性遗传病,其特征为亚铁螯合酶缺乏以及原卟啉在红细胞、皮肤和肝脏中蓄积。少数患者会出现严重肝功能障碍,目前缺乏最佳治疗方法。据报道,治疗性血浆置换(TPE)和红细胞置换(RCE)对EPP合并肝衰竭患者有益。一名50岁EPP女性患者在膝关节置换手术及使用高剂量对乙酰氨基酚后出现严重肝功能障碍。肝活检显示胆汁淤积性肝损伤,无纤维化。总共进行了20次TPE、6次RCE,之后又进行了14次TPE作为辅助治疗,目的是防止进展为终末期肝衰竭。初次TPE后,血浆和红细胞原卟啉水平分别从834.9降至180.4μg/dL(正常,≤1μg/dL),以及从3905降至2879μg/dL(正常,≤80μg/dL),但肝功能未改善。RCE使红细胞原卟啉水平从2879降至1225μg/dL,但血浆原卟啉从180.4升至1044.1μg/dL,且肝功能未改善。再次进行TPE使血浆原卟啉稳定,红细胞原卟啉水平改善,但患者最终因终末期肝病并发症死亡。该病例表明,TPE和RCE可能改善EPP活动的血浆和红细胞生化指标,但肝功能异常可能持续存在,患者可能仍会因不可逆肝损伤或与EPP诱导的肝毒性无关的独立病理生物学因素而进展为肝衰竭。