Shichishima T
Department of Internal Medicine I, Fukushima Medical College, Japan.
Fukushima J Med Sci. 1995 Jun;41(1):1-13.
Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hemolytic anemia in which abnormal red blood cells with enhanced susceptibility to complement undergo intravascular hemolysis when complement is activated in vivo, resulting in hemoglobinuria. This enhancement of complement susceptibility appears to involve multipotent stem cells and, in this respect, is thought to closely resemble myelodysplastic syndrome. Recently, it has been reported that the increased susceptibility of PNH cells to complement-mediated lysis is related to a deficiency of complement regulatory membrane proteins, especially CD55 and CD59. Both proteins are glycosylphosphatidylinositol (GPI)-anchored membrane proteins. It was found that a deficiency of GPI-anchored membrane proteins in PNH cells is due to the faulty synthesis of the GPI-anchor which may occur during early synthesis. Moreover, it is suggested that an abnormality of the PIG-A (phosphatidylinositol glycan-class A) gene, which is related to the early stage of GPI-anchor synthesis, is responsible for the pathogenesis of PNH. In conclusion, the clinical expression of PNH is dependent on two factors, complement susceptibility of PNH blood cells and changes in bone marrow function. The search for the ideal treatment of this disease may be aided by resolving the relationship between the two.
阵发性睡眠性血红蛋白尿（PNH）是一种获得性溶血性贫血，其中对补体敏感性增强的异常红细胞在体内补体激活时会发生血管内溶血，导致血红蛋白尿。补体敏感性的这种增强似乎涉及多能干细胞，在这方面，被认为与骨髓增生异常综合征密切相似。最近，有报道称PNH细胞对补体介导的溶解敏感性增加与补体调节膜蛋白，尤其是CD55和CD59的缺乏有关。这两种蛋白都是糖基磷脂酰肌醇（GPI）锚定的膜蛋白。研究发现，PNH细胞中GPI锚定膜蛋白的缺乏是由于GPI锚在早期合成过程中可能出现的合成错误。此外，有人提出，与GPI锚合成早期阶段相关的PIG-A（磷脂酰肌醇聚糖A类）基因异常是PNH发病机制的原因。总之，PNH的临床表型取决于两个因素，即PNH血细胞的补体敏感性和骨髓功能的变化。解决两者之间的关系可能有助于寻找这种疾病的理想治疗方法。
