INTRODUCTION Complex regional pain syndrome (CRPS) is a complication following trauma or surgery and may be difficult to diagnose since biomarkers are lacking. Using protein array technology, we found antibodies binding to p29ING4, which we further characterized using ELISA. METHODS Thirty-six sera of early-stage type 1 CRPS, 66 sera of rheumatoid arthritis (RA), 53 sera of axial spondyloarthritis (axSpA), 29 sera of psoriatic arthritis (PsA), 22 sera of patients after radial fractures (trauma control), and 100 sera of blood donors (BD) were analyzed for anti-p29ING4. We established ELISAs with 7 different antigens and using different secondary antibodies binding to IgG, IgG1, IgG2, IgG3, IgG4, IgA, and IgM, and 2 different tests to detect immune complexes (IC) of p29ING4 and IgG or IgG1. RESULTS The highest likelihood ratios versus CRPS and trauma control were observed considering the A1-23 (sensitivity 19%, specificity 100%, LR > 19) using IgG as a secondary antibody, the A120-165 (sensitivity 17%, specificity 100%, LR = 17) using IgG as a secondary antibody and the A120-165 (sensitivity 31%, specificity 95%, LR = 6.2) using IgA as a secondary antibody. IC of p29ING4 and IgG were present in 11/36 (31%) CRPS sera, 17/64 (27%) RA sera, 13/53 (25%) SpA sera, 5/29 (17%) PsA sera, 1/22 (5%) trauma control sera, and 4/100 (4%) sera of BD. IC of p29ING4 and IgG1 were present in 14/36 (39%) CRPS sera, 19/64 (30%) RA sera, 13/53 (25%) SpA, 1/29 (3%) PsA, 2/22 (9%) trauma control, and 4/100 (4%) of the BD sera. CONCLUSION Due to the lack of other biomarkers of type 1 CRPS, P29ING4 autoantibodies could be helpful in its diagnostic work-up.

中文翻译：

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针对P29ING4的自身抗体与复杂的区域性疼痛综合征相关。

简介复杂的局部疼痛综合征（CRPS）是外伤或手术后的并发症，由于缺乏生物标志物，可能难以诊断。使用蛋白质阵列技术，我们发现了与p29ING4结合的抗体，我们使用ELISA对其进行了进一步表征。方法早期1型CRPS的36血清，类风湿性关节炎（RA）的66血清，轴突性脊柱关节炎（axSpA）的53血清，银屑病关节炎（PsA）的29血清，radial骨骨折后患者的22血清（创伤控制） ），并分析了100个献血者血清（BD）中的抗p29ING4抗体。我们建立了具有7种不同抗原并使用与IgG，IgG1，IgG2，IgG3，IgG4，IgA和IgM结合的不同二抗的ELISA，以及2种不同的检测方法来检测p29ING4和IgG或IgG1的免疫复合物（IC）。结果考虑到使用IgG作为第二抗体的A1-23（敏感性19％，特异性100％，LR> 19），A120-165（敏感性17％，特异性100％，使用IgG作为第二抗体的LR = 17）和使用IgA作为第二抗体的A120-165（敏感性31％，特异性95％，LR = 6.2）。p29ING4和IgG的IC分别存在于11/36（31％）CRPS血清，17/64（27％）RA血清，13/53（25％）SpA血清，5/29（17％）PsA血清，1 /创伤控制血清为22（5％），BD血清为4/100（4％）。p29ING4和IgG1的IC分别存在于14/36（39％）CRPS血清，19/64（30％）RA血清，13/53（25％）SpA，1/29（3％）PsA，2/22（ 9％）的创伤控制和BD血清的4/100（4％）。结论由于缺乏其他1型CRPS生物标志物，