Burroughs S F, Devine D V, Browne G, Kaplan M E
Section of Hematology/Oncology, Veterans Administration Medical Center, Minneapolis, MN 55417.
Blood. 1988 Apr;71(4):1086-9.
In patients with paroxysmal nocturnal hemoglobinuria (PNH) the RBCs, neutrophils (PMNs), monocytes, and platelets derived from the abnormal clone are deficient in the complement-regulatory protein decay-accelerating factor (DAF). RBC acetylcholinesterase (AChE) and leukocyte alkaline phosphatase (LAP) activities are also characteristically low. DAF, AChE, and LAP are known to be anchored within cell membranes to glycophospholipid-containing phosphatidylinositol (PI). Because PNH progenitors contain DAF that appears to be lost with maturation, it has been proposed that this disorder results from abnormal tethering of these and possibly other proteins to membrane PI. We were puzzled, therefore, that our two PNH patients consistently had normal LAP levels. Consequently, we studied their isolated PMNs to compare DAF and LAP activities in individual cells. PMNs were separated by flow cytometry into DAF-positive and -negative populations by using rabbit anti-DAF antiserum and fluorescein-conjugated goat antirabbit IgG. In both patients the majority of PMNs were DAF deficient, and these cells contained very little alkaline phosphatase activity. In contrast, the smaller, DAF-positive cell populations were phosphatase replete. This is the first demonstration that abnormalities in DAF and LAP activity occur in the same PNH PMN population and strengthens the hypothesis that defective anchoring of proteins to membrane glycophospholipid underlies the pathophysiology of this disorder.
在阵发性夜间血红蛋白尿（PNH）患者中，源自异常克隆的红细胞、中性粒细胞（PMN）、单核细胞和血小板缺乏补体调节蛋白衰变加速因子（DAF）。红细胞乙酰胆碱酯酶（AChE）和白细胞碱性磷酸酶（LAP）活性也有特征性降低。已知DAF、AChE和LAP通过含糖磷脂的磷脂酰肌醇（PI）锚定在细胞膜内。由于PNH祖细胞含有DAF，而DAF似乎会随着成熟而丢失，因此有人提出这种疾病是由于这些蛋白以及可能其他蛋白与膜PI的异常连接所致。因此，我们感到困惑的是，我们的两名PNH患者的LAP水平一直正常。因此，我们研究了他们分离出的PMN，以比较单个细胞中的DAF和LAP活性。通过流式细胞术，使用兔抗DAF抗血清和荧光素偶联的山羊抗兔IgG将PMN分离为DAF阳性和阴性群体。在两名患者中，大多数PMN缺乏DAF，这些细胞的碱性磷酸酶活性非常低。相反，较小的DAF阳性细胞群体则富含磷酸酶。这首次证明了DAF和LAP活性异常发生在同一PNH的PMN群体中，并强化了蛋白质与膜糖磷脂的锚定缺陷是该疾病病理生理学基础的假说。
