Krzystek-Korpacka Malgorzata, Neubauer Katarzyna, Matusiewicz Malgorzata
Department of Medical Biochemistry, Wroclaw Medical University, Wroclaw, Poland.
Clin Chem Lab Med. 2009;47(9):1085-90. doi: 10.1515/CCLM.2009.248.
Non-invasive biochemical markers are needed to support the diagnosis of ulcerative colitis (UC), an incurable disease of unknown pathology. Midkine is an angiogenic cytokine, chemotactic towards neutrophils and macrophages, and a T-regulatory cell suppressor.
Serum midkine was measured immunoenzymatically in 93 UC patients and 108 healthy subjects, and evaluated with respect to disease status, endoscopic, inflammatory and angiogenic activity. The diagnostic value of midkine was compared to C-reactive protein (CRP) using receiver operating characteristics (ROC) analysis.
Midkine was higher (p<0.0001) in inactive (199 ng/L) and active UC (351 ng/L) compared with controls (93 ng/L), and reflected disease activity (r=0.427, p<0.001). Midkine was correlated with CRP, erythrocyte sedimentation rate (ESR), leukocytes, platelets, interleukin-6, paraoxonase-1, albumin, transferrin, iron, hemoglobin, and hematocrit. Midkine correlated with angiogenic factors: vascular endothelial growth factor-A and platelet-derived growth factor-BB. As a marker of UC, midkine showed a diagnostic accuracy of 85%, sensitivity of 72%, specificity of 82%, whereas CRP showed 83%, 65% and 91%, respectively. As a marker of active UC, midkine showed a diagnostic accuracy of 87%, sensitivity of 84%, specificity of 75%, whereas CRP showed 75%, 63% and 83%, respectively. Combined assessment of midkine and CRP improved sensitivity but substantially decreased specificity.
UC is associated with increased circulating midkine, which corresponds with clinical, endoscopic, inflammatory and angiogenic activity, and anemia. Performance of midkine as a marker of UC or active UC was comparable to that of CRP.
溃疡性结肠炎（UC）是一种病因不明的无法治愈的疾病，需要非侵入性生化标志物来辅助诊断。中期因子是一种血管生成细胞因子，对中性粒细胞和巨噬细胞具有趋化作用，也是一种T调节细胞抑制因子。
采用免疫酶法检测93例UC患者和108例健康受试者血清中的中期因子，并根据疾病状态、内镜检查、炎症和血管生成活性进行评估。使用受试者工作特征（ROC）分析将中期因子的诊断价值与C反应蛋白（CRP）进行比较。
与对照组（93 ng/L）相比，静止期UC（199 ng/L）和活动期UC（351 ng/L）患者的中期因子水平更高（p<0.0001），且反映了疾病活动度（r=0.427，p<0.001）。中期因子与CRP、红细胞沉降率（ESR）、白细胞、血小板、白细胞介素-6、对氧磷酶-1、白蛋白、转铁蛋白、铁、血红蛋白和血细胞比容相关。中期因子与血管生成因子血管内皮生长因子-A和血小板衍生生长因子-BB相关。作为UC的标志物，中期因子的诊断准确率为85%，敏感性为72%，特异性为82%，而CRP的诊断准确率、敏感性和特异性分别为83%、65%和91%。作为活动期UC的标志物，中期因子的诊断准确率为87%，敏感性为84%，特异性为75%，而CRP的诊断准确率、敏感性和特异性分别为75%、63%和83%。中期因子和CRP联合评估可提高敏感性，但特异性大幅降低。
UC与循环中期因子水平升高有关，这与临床、内镜、炎症和血管生成活性以及贫血相关。中期因子作为UC或活动期UC标志物的性能与CRP相当。
