Eckle I, Kolb G, Neurath F, Havemann K
Division of Hematology/Oncology, Marburg, F.R.Germany.
Adv Exp Med Biol. 1988;240:531-4. doi: 10.1007/978-1-4613-1057-0_68.
In vitro granulocyte elastase is known to cleave a large number of substrates e.g. complement components, fibrinogen, collagen and IgG. In vivo the enzyme is rapidly complexed by the plasma inhibitors a1proteinase inhibitor (a1PI) and a2macroglobulin. Therefore in biological fluids elastase is measured as the inactive a1PI-complex. We present a radioimmunoassay for elastase specific IgG split products as marker for the elastase activity in vivo. Elastase splits human IgG1 in Fab and Fc fragments and low molecular weight peptides. We produced specific antibodies against the elastase induced Fc fragment by immunization with an elastase generated peptide. After purification of the antibodies there is no crossreactivity with native IgG nor with similar Fc fragments produced by plasmin or papain. The elastase specific IgG split products are detected in synovial fluid samples of patients with rheumatoid arthritis. The measured concentrations are higher in the RA group than in control groups of patients with other inflammatory joint diseases.
已知体外的粒细胞弹性蛋白酶可裂解大量底物，例如补体成分、纤维蛋白原、胶原蛋白和免疫球蛋白G（IgG）。在体内，该酶会迅速与血浆抑制剂α1蛋白酶抑制剂（α1PI）和α2巨球蛋白形成复合物。因此，在生物体液中，弹性蛋白酶是以无活性的α1PI复合物形式进行测定的。我们提出了一种针对弹性蛋白酶特异性IgG裂解产物的放射免疫测定法，作为体内弹性蛋白酶活性的标志物。弹性蛋白酶可将人IgG1裂解为Fab和Fc片段以及低分子量肽段。我们通过用弹性蛋白酶生成的肽段进行免疫，制备了针对弹性蛋白酶诱导的Fc片段的特异性抗体。抗体纯化后，与天然IgG以及纤溶酶或木瓜蛋白酶产生的类似Fc片段均无交叉反应。在类风湿性关节炎患者的滑液样本中检测到了弹性蛋白酶特异性IgG裂解产物。类风湿性关节炎（RA）组中测得的浓度高于其他炎性关节疾病患者的对照组。
