Tanuma Y, Ohi H, Hatano M
Second Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan.
Clin Immunol Immunopathol. 1990 Aug;56(2):226-38. doi: 10.1016/0090-1229(90)90144-f.
The IgG fraction of serum from patients with membranoproliferative glomerulonephritis (MPGN) types I and II or partial lipodystrophy (PLD) was found to contain C3 nephritic factor (C3NeF) which reacts with the alternative pathway C3 convertase C3bBb and stabilizes it. Two types of C3NeF were detected, of which one was heat sensitive (56 degrees C for 30 min) and properdin dependent (C3NeF:P) but the other was heat stable and properdin independent (C3NeF:nP). C3NeF:P was found in sera from patients with MPGN types I and II and it displayed the properties of properdin and IgG. C3NeF:P was observed in patients with reduced serum concentrations of C3 and terminal complement components (TCC), and the generation of SC5b-9 complex was increased in mixtures with normal human serum. C3NeF:nP was found in sera from patients with MPGN type II and PLD, whose sera revealed a selective decrease in C3 concentrations.
研究发现，I型和II型膜增生性肾小球肾炎（MPGN）或部分脂肪营养不良（PLD）患者血清的IgG组分含有C3肾炎因子（C3NeF），该因子可与替代途径C3转化酶C3bBb发生反应并使其稳定。检测到两种类型的C3NeF，其中一种对热敏感（56℃，30分钟）且依赖备解素（C3NeF:P），而另一种对热稳定且不依赖备解素（C3NeF:nP）。C3NeF:P存在于I型和II型MPGN患者的血清中，具有备解素和IgG的特性。在血清C3和末端补体成分（TCC）浓度降低的患者中观察到C3NeF:P，且在与正常人血清混合时SC5b-9复合物的生成增加。C3NeF:nP存在于II型MPGN和PLD患者的血清中，这些患者的血清显示C3浓度选择性降低。
