大约70%的再生障碍性贫血患者有PNH克隆细胞,但一般数量很少并很少引起症状。[10]Dunn DE, Tanawattanachareon P, Boccuni P, et al. Paroxysmal nocturnal hemoglobinuria cells in patients with bone marrow failure syndromes. Ann Intern Med. 1999;131:401-408.http://www.ncbi.nlm.nih.gov/pubmed/10498555?tool=bestpractice.com异常克隆会逐渐增多,多到足以表现出相关症状,大约15%再生障碍性贫血患者可以在不行干细胞移植基础上成功治疗。[11]Tichelli A, Gratwohl A, Wursch A, et al. Late haematological complications in severe aplastic anemia. Br J Haematol. 1988;69:413-418.http://www.ncbi.nlm.nih.gov/pubmed/3044440?tool=bestpractice.com这种克隆扩增的原因尚不清楚。
所有PNH患者都有一定程度骨髓发育不良,通常只能在骨髓检查时发现。[12]Young NS, Maciejewski JP, Sloand E. The enigma of the aplastic anemia/PNH syndrome. In: Omine M, Kinoshita T, eds. Paroxysmal nocturnal hemoglobinuria and related disorders: molecular aspects of pathogenesis. Tokyo, Japan: Springer; 2003:149.经典型PNH患者最终出现骨髓衰竭。[13]de Latour RP, Mary JY, Salanoubat C, et al. Paroxysmal nocturnal hemoglobinuria: natural history of disease subcategories. Blood. 2008;112:3099-3106.http://www.bloodjournal.org/content/112/8/3099.fullhttp://www.ncbi.nlm.nih.gov/pubmed/18535202?tool=bestpractice.com