Hein Gert E, Meister Marit, Oelzner Peter, Franke Sybille
Department of Internal Medicine III, Section of Rheumatology and Osteology, Friedrich-Schiller University, Jena, Germany.
Rheumatol Int. 2008 Jun;28(8):765-9. doi: 10.1007/s00296-007-0514-3. Epub 2008 Jan 3.
The aim of this study was to investigate sRANKL and OPG levels in serum and synovial fluid (SF) and to evaluate their relations in patients with RA in comparison to those with non-erosive arthritis (NEA). The study included 45 unselected RA patients with knee joint effusions and 27 patients with knee joint effusions because of NEA. Serum and SF samples were investigated isochronously. OPG and sRANKL were measured by ELISA assays. In RA, sRANKL levels were higher in serum than in SF (P = 0.007). In contrast, the NEA revealed higher sRANKL in SF compared to the serum (P = 0.001). Though in RA the average levels of sRANKL(ser) were 5.6 times and of sRANKL(syn) 1.5 times higher than in NEA, the differences were not significant. The free (unbound) OPG in SF was not significantly different in RA compared to NEA. Also in serum, the measured free OPG was only slightly higher in RA. There were no significant differences between RA and NEA concerning ESR and CRP. Significant correlations could be found between sRANKL(syn )and CRP (r = 0.453; P = 0.005) as well as ESR (r = 0.362; P = 0.033) in RA. Nearly a positive correlation was evident also between sRANKL(syn) and CRP in NEA (r = 0.520; P = 0.08). RA and NEA differ in particular concerning their power and intensity to destruct the juxtaarticular bone. This is the most remarkable finding of this study, that in RA a high part of sRANKL seems to be OPG bound and cleared by the blood stream, but the sRANKL neutralizing capacity of produced OPG in opposite to NEA is not sufficient to prevent osteoclast activation and bone destruction in the RA joint.
本研究旨在调查血清和滑液（SF）中可溶性核因子κB受体活化因子配体（sRANKL）和骨保护素（OPG）水平，并评估类风湿关节炎（RA）患者与非侵蚀性关节炎（NEA）患者中它们之间的关系。该研究纳入了45例未经选择的有膝关节积液的RA患者和27例因NEA导致膝关节积液的患者。同步检测血清和SF样本。通过酶联免疫吸附测定（ELISA）法测量OPG和sRANKL。在RA中，血清中的sRANKL水平高于SF（P = 0.007）。相反，NEA患者的SF中的sRANKL水平高于血清（P = 0.001）。虽然在RA中，血清sRANKL平均水平比NEA高5.6倍，滑液sRANKL高1.5倍，但差异无统计学意义。与NEA相比，RA患者SF中游离（未结合）OPG无显著差异。血清中检测到的游离OPG在RA中也仅略高。RA和NEA在红细胞沉降率（ESR）和C反应蛋白（CRP）方面无显著差异。在RA中，sRANKL（滑液）与CRP（r = 0.453；P = 0.005）以及ESR（r = 0.362；P = 0.033）之间存在显著相关性。在NEA中，sRANKL（滑液）与CRP之间也几乎呈正相关（r = 0.520；P = 0.08）。RA和NEA在破坏关节周围骨骼的能力和强度方面存在差异。本研究最显著的发现是，在RA中，大部分sRANKL似乎与OPG结合并被血流清除，但与NEA相反，所产生的OPG的sRANKL中和能力不足以防止RA关节中的破骨细胞活化和骨破坏。
