Futó Gábor, Somogyi Attila, Szekanecz Zoltán
Department of Rheumatology, Institute of Medicine, University of Debrecen Medical and Health Science Center, Nagyerdei str 98, Debrecen, 4032, Hungary.
Clin Rheumatol. 2014 May;33(5):623-9. doi: 10.1007/s10067-014-2559-5. Epub 2014 Mar 6.
There has been continuous debate regarding the applicability of various composite measures for the assessment of disease activity in rheumatoid arthritis (RA). In order to further dissect this issue, we numerically and graphically modeled 28-joint disease activity scale (DAS28), simplified disease activity index (SDAI), and clinical disease activity index (CDAI) by three-dimensional (3D) plotting. We wished to graphically visualize the relative contribution of various elements in the three activity indices to each other. We calculated DAS28 (3 variables), SDAI, and CDAI by the standard equations. We plotted 3D "carpets" showing all combinations of the corresponding variables yielding to DAS28 = 5.1, DAS28 = 3.2, DAS28 = 2.6, SDAI = 26, SDAI = 11, and SDAI = 3.3. We also plotted the 3D carpet for CDAI. In patients with high or moderate disease activity, erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) was not a major confounding factor when calculating DAS28 and SDAI, respectively. In contrast, ESR and CRP highly overshadowed changes in joint counts and global assessments in patients with low disease activity (LDA) or those in remission. No reliable assessment of LDA can be performed in cases where ESR >54 mm/h or CRP >20 mg/dl. Similarly, remission cannot be determined if ESR >19 mm/h or CRP >5 mg/dl. As CDAI does not include acute phase reactants, CDAI may be a useful tool even in states of remission or LDA. Our results suggest that acute phase reactants are indeed major confounding factors and should be omitted when assessing RA disease activity at least in special cases.
关于各种综合指标在类风湿关节炎（RA）疾病活动度评估中的适用性一直存在持续的争论。为了进一步剖析这个问题，我们通过三维（3D）绘图对28关节疾病活动度量表（DAS28）、简化疾病活动指数（SDAI）和临床疾病活动指数（CDAI）进行了数值和图形建模。我们希望以图形方式直观呈现这三个活动指数中各要素之间的相对贡献。我们根据标准方程计算DAS28（3个变量）、SDAI和CDAI。我们绘制了3D“地毯图”，展示了对应变量的所有组合，这些组合分别得出DAS28 = 5.1、DAS28 = 3.2、DAS28 = 2.6、SDAI = 26、SDAI = 11和SDAI = 3.3。我们还绘制了CDAI的3D地毯图。在疾病活动度高或中度的患者中，计算DAS28和SDAI时，红细胞沉降率（ESR）或C反应蛋白（CRP）分别不是主要的混杂因素。相比之下，在疾病活动度低（LDA）或缓解期的患者中，ESR和CRP极大地掩盖了关节计数和整体评估的变化。当ESR > 54 mm/h或CRP > 20 mg/dl时，无法对LDA进行可靠评估。同样，如果ESR > 19 mm/h或CRP > 5 mg/dl，则无法确定缓解状态。由于CDAI不包括急性期反应物，即使在缓解期或LDA状态下，CDAI也可能是一个有用的工具。我们的结果表明，急性期反应物确实是主要的混杂因素，至少在特殊情况下评估RA疾病活动度时应予以忽略。
