Imai H, Hamai K, Komatsuda A, Ohtani H, Miura A B
Third Department of Internal Medicine, Akita University School of Medicine, Japan.
Kidney Int. 1997 Jan;51(1):270-6. doi: 10.1038/ki.1997.32.
Primary glomerulopathy can be classified into seven essential patterns based on histopathological studies. The pathogenesis of membranoproliferative glomerulonephritis (MPGN), and membranous nephropathy (MN), which show glomerular IgG deposition and induce mainly nephrotic syndrome, is not known. To clarify the role of IgG subclass in glomerulonephritis, we compared serum concentrations of IgG subclasses, the ratio of serum IgG subclasses to total IgG (%IgG subclass), and glomerular deposition of IgG subclasses between 7 MPGN patients, 21 MN patients, and 9 lupus nephritis (LN) patients. Serum IgG subclasses and %IgG in all groups were almost within normal range based on the values in Japanese healthy adults. In the MPGN and MN groups, the IgG1 concentration was significant lower than that of the LN group (P < 0.001, P < 0.0001, respectively). The IgG2 concentration in the MPGN group decreased significantly compared with that in the LN group (P < 0.05). The %IgG2 of the LN group decreased significantly compared with that of the MN group (P < 0.05). The %IgG3 of the MPGN group was significantly higher that that of the MN group (P < 0.05). The glomerular immunofluorescent intensity of IgG1 and IgG2 were significantly stronger in the LN group than in the MPGN and MN groups (IgG1, P < 0.001, P < 0.01, respectively; IgG2, P < 0.0001, P < 0.0001, respectively). IgG3 in the MPGN and LN groups deposited significantly compared with that in the MN group (P < 0.0001, P < 0.01, respectively). The intensity of IgG4 in the MN group showed a significant difference compared with that in the MPGN and LN groups (P < 0.0001, P < 0.01, respectively). IgG3 is an important factor in the pathogenesis of primary MPGN, while IgG4 relates to glomerular IgG deposition in MN.
根据组织病理学研究，原发性肾小球病可分为七种基本类型。膜增生性肾小球肾炎（MPGN）和膜性肾病（MN）的发病机制尚不清楚，它们表现为肾小球IgG沉积，主要诱发肾病综合征。为了阐明IgG亚类在肾小球肾炎中的作用，我们比较了7例MPGN患者、21例MN患者和9例狼疮性肾炎（LN）患者的血清IgG亚类浓度、血清IgG亚类与总IgG的比例（%IgG亚类）以及IgG亚类的肾小球沉积情况。根据日本健康成年人的值，所有组的血清IgG亚类和%IgG几乎都在正常范围内。在MPGN组和MN组中，IgG1浓度显著低于LN组（分别为P < 0.001，P < 0.0001）。MPGN组的IgG2浓度与LN组相比显著降低（P < 0.05）。LN组的%IgG2与MN组相比显著降低（P < 0.05）。MPGN组的%IgG3显著高于MN组（P < 0.05）。LN组中IgG1和IgG2的肾小球免疫荧光强度显著强于MPGN组和MN组（IgG1分别为P < 0.001，P < 0.01；IgG2分别为P < 0.0001，P < 0.0001）。与MN组相比，MPGN组和LN组中的IgG3沉积显著（分别为P < 0.0001，P < 0.01）。MN组中IgG4的强度与MPGN组和LN组相比有显著差异（分别为P < 0.0001，P < 0.01）。IgG3是原发性MPGN发病机制中的一个重要因素，而IgG4与MN中的肾小球IgG沉积有关。
