联合检测关节液中白细胞介素6和C-反应蛋白对早期诊断兔人工股骨头置换术后感染的研究

Combined Detection of Interleukin-6 and C-reactive Protein in Synovial Fluid on Early Diagnosis of Post-operative Infection of Artificial Femoral Head in Rabbits

目的通过比较兔人工股骨头置换术后感染与未感染兔关节液中白细胞介素6(interleukin-6,IL-6)和C-反应蛋白(C-reactive protein,CRP)的差异,探讨联合检测兔关节液中IL-6和CRP在兔人工股骨头置换术后感染早期诊断中的价值。方法选取64只健康新西兰大白兔,随机分为实验组和对照组,各32只,均行右侧人工兔股骨头置换术。实验组所有兔子在人工股骨头置换术后即刻将金黄色葡萄球菌液注入右侧髋关节内,对照组则注入等量生理盐水。检测所有兔子关节液中IL-6和CRP含量变化。术后2周取关节液和关节滑膜3块进行细菌培养。结果实验组细菌培养均可见金黄色葡萄球菌阳性,对照组则为阴性;术后1 d,实验组与对照组的关节液IL-6和CRP水平均较术前明显升高(P<0.01),但两组间相比无统计学差异(P>0.05);术后3、6、9、14 d,实验组关节液IL-6和CRP水平均明显高于同时期对照组(P<0.01);实验组术后关节液中IL-6和CRP含量持续升高(P<0.01),对照组于术后6 d关节液中IL-6和CRP含量开始回落(P<0.01),其中CRP、IL-6分别于术后9 d、14 d下降至术前水平(P>0.05);联合检测关节液中IL-6和CRP的灵敏性为87.50%,特异性为93.70%,高于单独检测关节液中IL-6或CRP的灵敏性及特异性。结论在早期诊断兔人工股骨头置换术后感染时,联合检测兔关节液中IL-6和CRP具有较高的特异性和敏感性,该研究为临床诊断假体周围感染(periprosthetic joint infection,PJI)提供了新思路和新方法。

Objective To compare the differences of interleukin-6（IL-6）and C-reactive protein（CRP）in synovial fluid between infected and non-infected rabbits after artificial femoral head replacement,and to discuss the early diagnosis value of joint detection of IL-6 and CRP in rabbit synovial fluid for rabbit artificial femoral head replacement.Methods Sixty-four healthy New Zealand white rabbits were selected and randomly divided into experimental group and control group,each with 32 rabbits.All rabbits in experimental group were injected with staphylococcus aureus immediately after artificial femoral head replacement in the right hip joint,the control group was injected with the same amount of saline.The IL-6 and CRP levels of all rabbits synovial fluid were measured.Synovial fluid and 3 joint synoviums were taken after surgery two weeks for bacterial culture.Results The bacterial culture was positive in experimental group,and negative in control group.The levels of IL-6 and CRP in synovial fluid of two groups after operation were significantly higher than those before operation at the first day（P0.01）,but there was no significant difference between two groups（P0.05）.The levels of IL-6 and CRP in synovial fluid of experimental group at the 3 rd,6 th,9 th and 14 th day after operation were significantly higher than those of control group（P0.01）.The levels of IL-6 and CRP in synovial fluid of experimental group continued to increase after operation（P0.01）,while control group began to drop from the6 th day（P0.01）.The levels of IL-6 and CRP decreased to preoperative level on the 9 th,14 th day after operation（P0.05）.The sensitivity and specificity of combined detection of IL-6 and CRP in synovial fluid were 87.50%and 93.70%,respectively,which were higher than those of IL-6 or CRP in synovial fluid alone.Conclusion For early diagnosis of rabbit femoral head replacement infection,the combined detection of IL-6 and CRP of rabbit joint fluid has a high specificity and sensitivity,it provides a new idea and method for clinic diagnosis of PJI.