Nachman P H, Reisner H M, Yang J J, Jennette J C, Falk R J
Department of Medicine, University of North Carolina, Chapel Hill 27599-7155, USA.
Lab Invest. 1996 Feb;74(2):519-27.
Anti-neutrophil cytoplasmic autoantibodies (ANCA) have been hypothesized to participate in the pathogenesis of necrotizing vasculitis based on their association with small vessel vasculitides and the in vitro ability of such antibodies to activate cytokine-primed neutrophils. Much remains to be elucidated about the factors responsible for the generation and perpetuation of these autoantibodies and the shaping of the ANCA immune response. This study evaluated the clonal diversity of the ANCA immune response in patients with myeloperoxidase-ANCA associated disease. Isoelectric focusing was used to investigate the clonality of myeloperoxidase-ANCA from 34 patients with pauci-immune necrotizing glomerulonephritis. Sixty-nine percent of the patients had two or less clonotypes to myeloperoxidase, whereas 31% had more than two clonotypes. Clonality was stable over the course of the disease and shared among some unrelated patients. Shared idiotypy was specifically investigated using a murine monoclonal anti-idiotype (7F2C11) to the anti-myeloperoxidase antibodies of one patient with ANCA associated vasculitis. This monoclonal antibody was selected by demonstrating: (1) binding to the proband's affinity purified anti-myeloperoxidase antibodies; (2) an inhibitory effect on the binding of the proband's anti-myeloperoxidase to myeloperoxidase; and (3) lack of binding to control human antibody preparations, or to the proband's crude immunoglobulin preparation, thus excluding an anti-allotype antibody. Purified 7F2C11 was immobilized on Sepharose, and this monoclonal anti-idiotype affinity column was used to search for a shared anti-myeloperoxidase idiotype in the plasma of four other patients with myeloperoxidase-ANCA associated disease. Using this column, we were able to extract anti-myeloperoxidase antibodies from plasma of the other patients but not from control antibody preparations. We concluded that most myeloperoxidase-ANCA patients have a restricted response to myeloperoxidase and that some patients share a common idiotype. The demonstration of shared idiotypy suggests a restricted number of autoreactive epitopes of the myeloperoxidase molecule, or that some anti-myeloperoxidase autoantibodies are encoded by germ line genes, or both.
抗中性粒细胞胞浆自身抗体（ANCA）被认为参与了坏死性血管炎的发病机制，这是基于它们与小血管血管炎的关联以及此类抗体在体外激活细胞因子预致敏中性粒细胞的能力。关于这些自身抗体产生和持续存在的因素以及ANCA免疫反应的形成，仍有许多有待阐明之处。本研究评估了髓过氧化物酶-ANCA相关疾病患者中ANCA免疫反应的克隆多样性。采用等电聚焦法研究了34例寡免疫坏死性肾小球肾炎患者髓过氧化物酶-ANCA的克隆性。69%的患者对髓过氧化物酶有两种或更少的克隆型，而31%的患者有两种以上的克隆型。克隆性在疾病过程中是稳定的，并且在一些无亲缘关系的患者中存在。使用针对一名ANCA相关血管炎患者抗髓过氧化物酶抗体的鼠单克隆抗独特型抗体（7F2C11）专门研究了共享独特型。选择该单克隆抗体是通过证明：（1）与先证者亲和纯化的抗髓过氧化物酶抗体结合；（2）对先证者抗髓过氧化物酶与髓过氧化物酶结合的抑制作用；以及（3）不与对照人抗体制剂或先证者的粗免疫球蛋白制剂结合，从而排除抗同种异型抗体。将纯化的7F2C11固定在琼脂糖上，并用这种单克隆抗独特型亲和柱在另外四名髓过氧化物酶-ANCA相关疾病患者的血浆中寻找共享的抗髓过氧化物酶独特型。使用该柱，我们能够从其他患者的血浆中提取抗髓过氧化物酶抗体，但不能从对照抗体制剂中提取。我们得出结论，大多数髓过氧化物酶-ANCA患者对髓过氧化物酶的反应有限，并且一些患者共享一种共同的独特型。共享独特型的证明表明髓过氧化物酶分子的自身反应性表位数量有限，或者一些抗髓过氧化物酶自身抗体由种系基因编码，或者两者皆是。
