新生儿败血症外周血中性粒细胞CD_(64)的表达及其意义

Expression of peripheral blood neutrophil CD_(64) in neonatal septicemia

目的探讨外周血中性粒细胞CD64表达在新生儿败血症早期诊断中的价值。方法89例疑似败血症患儿,通过临床表现、血培养及5项非特异性指标:白细胞、血小板、血浆C反应蛋白、微量血沉和未成熟中性粒细胞与中性粒细胞总数比值,分为败血症组39例和非败血症感染组50例。另设对照组19例。采用流式细胞仪检测外周血中性粒细胞CD64表达。结果败血症组患儿外周血中性粒细胞CD64表达率为(75.6±8.9)%,显著高于非败血症感染组(29.1±6.2)%和对照组(5.1±1.1)%(P均<0.05),非败血症感染组与对照组比较差异也有统计学意义(P<0.05);革兰阴性菌败血症患儿CD64表达率(79.5±3.5)%高于革兰阳性菌败血症(76.4±4.6)%,但二者差异无统计学意义(P>0.05);败血症组经抗感染治疗后CD64表达水平下降。中性粒细胞CD64对新生儿败血症诊断的敏感性97.4%,特异性84.0%,阳性预测值82.6%,阴性预测值分别为97.6%。CD64检测阳性率62.9%(56/89)高于血培养19.1%(17/89)和5项非特异性指标29.2%(26/89)(P均<0.05)。结论外周血中性粒细胞CD64测定可作为新生儿败血症早期诊断的指标,并可以判断疗效。

Objective Neonatal septicemia is a common and severe infection, which often results in death. Early diagnosis and treatment of neonatal septicemia may help decrease neonatal mortality. Recently, many studies sought to explore the possibility of early diagnosis of this disease. The high affinity Fcγ-receptor I (CD_(64)) was purposefully chosen as a potential marker for identifying neonatal septicemia. The present study was designed to evaluate neutrophil CD_(64) level for early diagnosis of neonatal septicemia. Methods(Eighty- nine) suspected neonatal septicemia cases were recruited into the study. Five non-specific indices, i.e., C-reactive protein (CRP), micro-erythrocyte sedimentation rate (mESR), white blood cell count, platelet count and the ratio of immature neutrophil count to total neutrophil count were measured for each patient.The patients were divided into septicemia group (n=39) and non-septisemic infection group (n=50) according to the diagnostic criteria for neonatal septicemia. Nineteen hospitalized neonates with non-infectious diseases were enrolled as controls (n=19). The levels of peripheral blood neutrophil CD_(64) were measured by using flow cytometry. The positive rate, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CD_(64) were calculated. Results The levels of peripheral blood neutrophil CD_(64) in septicemia patients were (75.6 ±8.9) % ,which were significantly higher than those of non-septisemic infection group (29.1±6.2) % and control group (5.1±1.1)% (P<0.05), respectively. There were no significant differenoes in the levels of CD_(64) expression between the patients with Gram-negative (79.5 ±3.5) % and Gram- positive (76.4 ±5.0) % (P>0.05) bacterial infection. The levels of CD_(64) of the cases with septicemia significantly decreased at day 10 of treatment with antibiotics. The detection of CD_(64) (cutoff value >30%) for suspected septicemia showed high sensitivity(97.4%), specificity (84.0%), PPV (82.6%), and NPV (97.6%). The positive rate of CD_(64) detection (62.9%) was much higher than that of the blood culture test (19.1%) and that of the five nonspecific indices (29.2%, P<0.05,respectively) . Conclusion The expression of CD_(64) increased in neonatal septicemia cases. The measurement of cell surface expression of CD_(64) on neutrophils may be helpful to early diagnosis, evaluation of severity of infection and observation of therapeutic effects for neonatal septicemia.