血小板相关指标对慢性关节假体周围感染诊断价值的研究

Diagnostic value of platelet associated biomarkers in chronic periprosthetic joint infection

目的探讨血小板计数(PC)、血小板计数/平均血小板体积(PC/MPV)和血小板比容(PCT)对关节置换术后慢性假体周围感染(PJI)的诊断价值。方法回顾性分析2013年8月至2019年6月在青岛大学附属医院进行人工髋、膝关节翻修术的167例患者的临床资料。其中PJI组51例(膝26例,髋25例),男性28例,女性23例,年龄(68.0±11.8)岁(范围:32~84岁),体重指数(25.7±3.7)kg/m2。假体无菌性松动组116例(膝19例,髋97例),男性67例,女性49例,年龄(70.3±8.9)岁(范围:49~89岁),体重指数(25.0±3.6)kg/m2。收集两组患者翻修术前血浆C反应蛋白(CRP)、红细胞沉降率(ESR)、PC、平均血小板体积(MPV)、PC/MPV和PCT水平,以受试者工作特征曲线计算除MPV外每个指标的灵敏度与特异度,并根据曲线下面积(AUC)比较诊断价值。组间比较采用独立样本t检验或Mann-Whitney U检验。结果与无菌性松动组相比,PJI组的CRP、ESR、PC、PC/MPV和PCT升高(P值均<0.05),但MPV下降(P<0.05)。CRP、ESR、PC、PC/MPV和血小板比容的AUC分别为0.820、0.829、0.689、0.668、0.676。根据约登指数,C反应蛋白的最佳截点值为11.12 mg/L,灵敏度为74.4%,特异度为87.1%;ESR的最佳截点值为17.60 mm/1 h,灵敏度为81.4%,特异度为75.3%;PC的最佳截点值为243.00×10^(9)/L,灵敏度为60.5%,特异度为71.8%;PC/MPV的最佳截点值为24.95,灵敏度为58.1%,特异度为74.1%;血小板比容的最佳截点值为0.24%,灵敏度为69.8%,特异度为63.5%。结论PC、PC/MPV和PCT对PJI的诊断价值有限。

Objective To evaluate the diagnostic value of platelet count(PC),PC to mean platelet volume(MPV)ratio(PC/MPV)and plateletcrit(PCT)in chronic periprosthetic joint infection(PJI).Methods The medical records of 159 patients who underwent hip or knee revisions at Department of Joint Surgery,Affiliated Hospital of Qingdao University from August 2013 to June 2019 were retrospectively reviewed.There were 51 patients(26 knees and 25 hips)in the PJI group,which included 28 males and 23 females,aged(68.0±11.8)years(range:32 to 84 years)with a body mass index(BMI)of(26.1±3.6)kg/m².There were 116 patients(19 knees and 97 hips)in the aseptic loosening(AL)group,including 67 males and 49 females,aged(70.3±8.9)years(range:49 to 89 years)with a BMI of(25.0±3.6)kg/m².The plasma C-reactive protein(CRP),erythrocyte sedimentation rate(ESR),PC,MPV,PC/MPV and PCT levels of the two groups were recorded and analyzed.Receiver operating characteristic curve was used to calculate the sensitivity and specificity of each biomarker,expect for MPV,and the diagnostic value of each biomarker was compared according to the area under the curve(AUC).Independent-sample t test or Mann-Whitney U test were used for comparison between groups.Results Compared with AL group,AJI group had significantly higher levels of CRP,ESR,PC,PC/MPV and PCT(all P<0.05),but lower level of MPV(P<0.05).The AUCs for CRP,ESR,PC,PC/MPV and PCT were 0.820,0.829,0.689,0.668 and 0.676,respectively.Based on the Youden index,the optimal predictive cutoff for CRP was 11.12 mg/L,with a sensitivity of 74.4%and a specificity of 87.1%.The optimal predictive cutoff for ESR was 17.60 mm/1 h,with a sensitivity of 81.4%and a specificity of 75.3%.The optimal predictive cutoff for PC was 243.00×10^(9)/L,with a sensitivity of 60.6%and a specificity of 71.8%.The optimal predictive cutoff for PC/MPV was 24.95,the sensitivity was 58.1%and the specificity was 74.1%.And the optimal predictive cutoff for PCT was 0.24%,with a sensitivity of 69.8%and a specificity of 63.5%.Conclusion PC,PC to MPV ratio and PCT are of limited value to diagnose PJI.