Carpenter A B, Huczko E, Eisenbeis C H, Kelly R H
Division of Clinical Immunopathology, University of Pittsburgh School of Medicine, PA.
Clin Chim Acta. 1990 Dec 13;193(1-2):1-12. doi: 10.1016/0009-8981(90)90002-a.
In this study, we examined the immunoglobulin (Ig) present in synovial fluid (SF) from patients with rheumatoid arthritis (RA) to determine if it was locally produced and to assess the presence of clonally restricted (oligoclonal) immunoglobulin. We studied SF/serum pairs from 55 RA patients and 23 patients with degenerative joint disease (DJD). We found increases in total protein, IgG, IgA, and IgM in RA vs DJD SF (P less than 0.01). The immunoglobulin present in RA appeared to be locally produced as evidenced by significant increases (P less than 0.01) in the immunoglobulin indices. Regression analysis among the levels of IgG, IgA, and IgM RF and the Ig indices suggested that only a minority of the locally synthesized Ig present was specific for RF. To provide evidence of clonal restriction, we further analyzed the SF specimens by isoelectric focusing and assessed the presence of oligoclonal bands present only in RA SF. In 7/55 RA specimens (13%) we found unique SF IgG bands. All bands were of similar isoelectric point (pI), being quite cathodic with pI greater than 7.5. Our evidence supports synthesis of Ig within RA synovium, with a minority of patients showing prominent and unique SF Ig bands. This suggests an oligoclonal response in SF of some patients, but polyclonal Ig synthesis in most.
在本研究中，我们检测了类风湿关节炎（RA）患者滑液（SF）中的免疫球蛋白（Ig），以确定其是否在局部产生，并评估克隆限制性（寡克隆）免疫球蛋白的存在情况。我们研究了55例RA患者和23例退行性关节病（DJD）患者的滑液/血清对。我们发现，与DJD滑液相比，RA滑液中的总蛋白、IgG、IgA和IgM增加（P<0.01）。RA中存在的免疫球蛋白似乎是在局部产生的，免疫球蛋白指数显著增加（P<0.01）证明了这一点。IgG、IgA、IgM RF水平与Ig指数之间的回归分析表明，局部合成的Ig中只有少数对RF具有特异性。为了提供克隆限制性的证据，我们通过等电聚焦进一步分析了滑液标本，并评估了仅在RA滑液中存在的寡克隆带的情况。在55例RA标本中的7例（13%）中，我们发现了独特的滑液IgG带。所有条带的等电点（pI）相似，相当偏阴极，pI大于7.5。我们的证据支持RA滑膜内Ig的合成，少数患者表现出突出且独特的滑液Ig条带。这表明一些患者的滑液中存在寡克隆反应，但大多数患者为多克隆Ig合成。
