The Study Of Expression And Clinical Significance Of Soluble Triggering Receptor Expressed On Myeloid Cells-1 In Pneumonia

Objective:Comparing the levels of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) in pneumonia patients caused by different pathogens (including bacteria, viruses, mycoplasma and mixed infection) and the changes of sTREM-1 before and after the treatment, to discuss the application of sTREM-1 in the diagnosis,differential diagnosis and prognosis assessment of bacterial pneumonia and its clinical significance. To understand the clinical effect of triggering receptors expressed on myeloid cells-1 (TREM-1) in early judgment of pneumonia and the relationship with cytokine TNF alpha(TNF-a) and IL-8.Methods:A total of 400 hospitalized children with Bronchial pneumonia were observed from May 2010 to Dec 2010. All children were taken etiology detectation with 24 hours after admission.2 ml venous blood were got from 400 cases of pneumonia patients and 30 healthy children and anticoagulanted with heparin respectively, centrifuge 10 minutes in 3000r/min, take the upper plasma and preserved in low temperature refrigerator. In the seventh day after admission, plasma samples were got again from 33 cases of pneumonia children caused by simple bacterial infections. Above all,214 cases were positive in etiology detectation. Applying solid-phase enzyme-linked immunosorbent adsorption method to detect the levels of sTREM-1 in plasma of 214 positive cases,30 healthy cases and 33 pneumonia cases in recovery phase, meanwhile to detect the count of white blood cell(WBC) and the level of c-reactive protein (CRP). There were 29 cases with severe pneumonia,35 cases with non severe pneumonia and 30 normal controls. The expressions of TREM-1 which expressed in the surface of WBC were tested by reverse-transcription polymerse chian reaction (RT-PCR) and the levels of TNF-a and IL-8 were tested by solid-phase enzyme-linked immunosorbent adsorption method.Results:1. Compared with the normal control group, simple virus group, simple mycoplasma group and virus merger mycoplasma group, the levels of sTREM-1 in simple bacterial group and the mixed infection group combined with bacterium increased significantly, the difference had statistical significance(P<0.05). There was no significant difference of the levels of sTREM-1 between the simple bacterial group and the mixed infection group combined with bacterium(P> 0.05). There was also no significant difference between other groups(P> 0.05).2. The levels of CRP in simple bacterial group, simple mycoplasma group and the mixed infection group was high, compared with that of the normal group, the difference was significant(P< 0.05). There was no difference between other groups and the normal group(P> 0.05).3. Compared with the normal group, the count of WBC in simple bacterial group, bacteria merger mycoplasma group, virus merger mycoplasma group and the mixed infection group rised significantly, the difference had statistical significance(P< 0.05). But between different groups of mixed infection group, the difference was not significant(P> 0.05).4. According to the ROC curve, the area of sTREM-1 under the ROC curve in the simple bacterial group was 0.868, sTREM-1 and CRP had the same degree of diagnostic efficiency, but better than that of WBC (P< 0.05). A sTREM-1 cutoff value of 18.39 ng/ml correlated with sensitivity and specificity values of 81.0% and 94.1%, respectively. In the mixed bacterial infection group, the area of sTREM-1 under the ROC curve was 0.928, the degree of diagnostic efficiency of sTREM-1 was better than that of CRP and WBC(P< 0.05), the sTREM-1 cutoff value of 18.42 ng/ml yielded sensitivity and specificity values of 85.2% and 94.1%, respectively.5. In the group of 33 cases of pneumonia children caused by simple bacterial infections, the levels of sTREM-1 and CRP were lower than those before treatment, the difference wes significant(P< 0.05), but there was no significant difference of the count of WBC before and after treatment(P> 0.05).6. The levels of TREM-1, TNF-a and IL-8 in the severe pneumonia group were higher than those of the non-severe pneumonia group, and both groups were higher than those of the normal group, the difference were significant(P< 0.05). But in the severe pneumonia group and non-severe pneumonia group, there were no correlation between TREM-1, TNF-a and IL-8.Conclusions:1. sTREM-1 is a specificity index which reflects the bacterial infection. Clinical suspicion of bacterial infection but have no evidence, high levels of sTREM-1 can be used as evidence.2. sTREM-1 can be regarded as one indexes which can reflect the illness and prognosis, and it can survey the development of illness.3.The level of TREM-1 which expressed in the surface of white cell membrane is closely related with the severity of pneumonia. It can be used to judge the severity of infection.4. The levels of TREM-1 have no correlation with inflammation factors TNF-a and IL-8. At present, the role of TREM-1 in the inflammatory response is not clear.