McLean R H, Michael A F
J Clin Invest. 1973 Mar;52(3):634-44. doi: 10.1172/JCI107225.
Serological and immunopathological studies of human glomerulonephritis have suggested that alternate pathways of activation of the third component of complement may be important in some forms of glomerulonephritis. We have investigated the role of two alternate pathway proteins, properdin and C3 proactivator, in 22 patients with chronic membranoproliferative glomerulonephritis, 21 patients with systemic lupus erythematosus, 20 patients with acute poststreptococcal glomerulonephritis, and 19 patients with other forms of renal disease. C3 (measured at beta(1)A), properdin, and C3 proactivator were assayed by single radial immunodiffusion. In sera with low beta(1)A (< 2 SD), mean properdin was most significantly decreased in patients with acute poststreptococcal glomerulonephritis but was also significantly decreased in chronic membranoproliferative glomerulonephritis and in untreated systemic lupus erythematosus. Properdin levels in other renal disease, acute glomerulonephritis, and chronic membranoproliferative glomerulonephritis with normal beta(1)A levels were not significantly different from normal. A positive correlation between beta(1)A and properdin levels in individual sera was present in all diseases except systemic lupus erythematosus. Serum C3 proactivator was markedly decreased in active systemic lupus erythematosus and there was a positive correlation between beta(1)A and C3 proactivator levels in systemic lupus erythematosus and other renal diseases but not acute poststreptococcal glomerulonephritis. Properdin in fresh sera from four patients with systemic lupus erythematosus and five with chronic membranoproliferative glomerulonephritis showed increased migration toward the cathode on immunoelectrophoresis, suggesting in vivo change of the properdin molecule. The observation of reduced serum levels of properdin and C3 proactivator and altered electrophoretic migration of properdin in some patients with glomerulonephritis provide new evidence for participation of these alternate pathway proteins in glomerulonephritis.
人类肾小球肾炎的血清学和免疫病理学研究表明，补体第三成分的替代激活途径可能在某些形式的肾小球肾炎中起重要作用。我们研究了两种替代途径蛋白——备解素和C3前活化剂在22例慢性膜增生性肾小球肾炎患者、21例系统性红斑狼疮患者、20例急性链球菌感染后肾小球肾炎患者以及19例其他形式肾病患者中的作用。通过单向放射免疫扩散法检测C3（在β(1)A处测量）、备解素和C3前活化剂。在β(1)A水平较低（< 2个标准差）的血清中，急性链球菌感染后肾小球肾炎患者的平均备解素下降最为显著，但在慢性膜增生性肾小球肾炎和未经治疗的系统性红斑狼疮患者中也显著下降。β(1)A水平正常的其他肾病、急性肾小球肾炎和慢性膜增生性肾小球肾炎患者的备解素水平与正常水平无显著差异。除系统性红斑狼疮外，所有疾病的个体血清中β(1)A与备解素水平之间均存在正相关。活动性系统性红斑狼疮患者的血清C3前活化剂明显降低，在系统性红斑狼疮和其他肾病中β(1)A与C3前活化剂水平呈正相关，但在急性链球菌感染后肾小球肾炎中无此相关性。4例系统性红斑狼疮患者和5例慢性膜增生性肾小球肾炎患者新鲜血清中的备解素在免疫电泳中向阴极的迁移增加，提示备解素分子在体内发生了变化。肾小球肾炎患者血清中备解素和C3前活化剂水平降低以及备解素电泳迁移改变的观察结果为这些替代途径蛋白参与肾小球肾炎提供了新的证据。
