Nissen C, Tichelli A, Gratwohl A, Warthmann C, Moser Y, dalle Carbonare V, Sendelov S, Chklovskaia E, Jansen W, Wodnar-Filipowicz A, Sadallah S, Speck B
Departments of Research and Internal Medicine, Division of Hematology, University Hospital, Basel, Switzerland.
Acta Haematol. 1999;101(4):165-72. doi: 10.1159/000040948.
In a prospective long-term study on the incidence of paroxysmal nocturnal hemoglobinuria (PNH), 115 consecutive patients with severe aplastic anemia (SAA), 97 treated with antilymphocyte globulin (ALG) and 18 with bone marrow transplantation (BMT), were observed over a period of 4-18 years and tested for the presence of complement-sensitive hematopoietic precursor cells with the bone marrow (BM) sucrose test. Sixteen (14%) of the ALG-treated patients developed clinical signs of PNH between 0.5 and 8 years after treatment. Complement-sensitive BM precursors were found in 89% of the SAA patients at some time during their disease, but in none of 18 normal donors. At diagnosis, their proportion was significantly higher in patients who later developed PNH than in patients who later achieved disease-free complete remission (CR). After ALG, the abnormal population was found in both groups, but it was gradually replaced by normal precursors in remission patients. After BMT, the complement-sensitive population decreased to very low numbers in patients with a stable graft, but increased again in 3 patients upon graft rejection. Mimicking the PNH defect by enzymatic removal of glycosyl-phosphatidylinositol (GPI)-linked proteins from CD34+ cells resulted in their complement sensitivity, suggesting that the BM sucrose test identifies precursor cells carrying the PNH defect. In 66 patients, white blood cells (WBC) in peripheral blood (PB) were examined for GPI-deficient populations by flow cytometry (FACS). Ten patients with signs of clinical or laboratory PNH had over 25% complement-sensitive precursor cells in the BM and a GPI-deficient WBC population in the PB. Of 56 SAA patients without PNH, 8 had an abnormal population detectable with both tests, 26 only with the BM sucrose test, 4 only with PB FACS analysis, and in 18, no abnormal cells were detected with either test. In search for parameters which might explain why in some patients the abnormal population expands, while it regresses or disappears in others, we tested the release of IL-2 as a parameter of immune competence. At diagnosis, IL-2 release was approximately 50% of normal in patients who later developed PNH, while it was double the normal value in patients who later achieved CR. We conclude that the majority of SAA patients transiently harbor complement-sensitive precursor cells in the BM. Patients with more than 25% abnormal BM precursors and low endogenous IL-2 release are at risk of progression to clinical PNH.
在一项关于阵发性夜间血红蛋白尿（PNH）发病率的前瞻性长期研究中，对115例连续的重型再生障碍性贫血（SAA）患者进行了为期4至18年的观察，其中97例接受抗淋巴细胞球蛋白（ALG）治疗，18例接受骨髓移植（BMT），并通过骨髓（BM）蔗糖试验检测补体敏感的造血前体细胞的存在情况。16例（14%）接受ALG治疗的患者在治疗后0.5至8年出现了PNH的临床症状。在89%的SAA患者病程中的某个时间发现了补体敏感的BM前体细胞，但18例正常供者中均未发现。在诊断时，后来发生PNH的患者中其比例显著高于后来实现无病完全缓解（CR）的患者。ALG治疗后，两组均发现了异常群体，但在缓解患者中异常群体逐渐被正常前体细胞取代。BMT后，移植稳定的患者中补体敏感群体数量降至极低水平，但3例患者在移植排斥时该群体数量再次增加。通过酶法去除CD34+细胞上糖基磷脂酰肌醇（GPI）连接蛋白来模拟PNH缺陷，导致这些细胞具有补体敏感性，这表明BM蔗糖试验可识别携带PNH缺陷的前体细胞。对66例患者的外周血（PB）白细胞（WBC）进行流式细胞术（FACS）检测GPI缺陷群体。1０例有临床或实验室PNH迹象的患者，其BM中补体敏感前体细胞超过25%，PB中存在GPI缺陷的WBC群体。在56例无PNH的SAA患者中，8例两种检测均能检测到异常群体，26例仅通过BM蔗糖试验检测到异常，4例仅通过PB FACS分析检测到异常，18例两种检测均未检测到异常细胞。为了寻找可能解释为什么在一些患者中异常群体扩大，而在另一些患者中则消退或消失的参数，我们检测了IL-2的释放作为免疫能力的一个参数。在诊断时，后来发生PNH的患者IL-2释放约为正常水平的50%，而后来实现CR的患者其IL-2释放是正常水平的两倍。我们得出结论，大多数SAA患者的BM中短暂存在补体敏感的前体细胞。BM前体细胞异常比例超过25%且内源性IL-2释放低 的患者有进展为临床PNH的风险。
