The clinical application of leukocyte VCS parameters in the detection of blood bacterial infection

Abstract

Objective To investigate the clinical application of VCS parameters of leukocyte in the detection of blood bacterial infection, Methods The subjects consisted of 120 patients with blood bacterial infection,69 non-infectious fever patients and 67 health controls.The VCS parameters of neutrophil and lymphocyte were examined with Coulter LH 750 hematology analyzer.The parameters examined including mean channel of neutrophil volume(MNV),neutrophil volume distribution width (NDW) ,mean channel of neutrophil conductivity (MNC),mean channel of neutrophil scatter (MNS),mean channel of lymphocyte volme(MLV),lymphocyte volume distfibufion width (LDW),mean channel of lymphocyte conductivity (MLC) and mean channel of lymphocyte scatter (MLS).Additionally,120 blood bacterial infection patients were grouped according to WBC count(WBC≤10×109/L group and WBC＞10×109/L group),neutrophii rate(≥85%group and＜85%group)and bacterial stain(Gram positive bacteria group and Gram negative bacteria group).VCS parameters among these groups were compared.Results The results of blood infection group were as follows:MNV 156±15,NDW 23.31±3.72,MNS 137±7,MLV 87±12,LDW 17.50±3.38.MLC 110±5 and MLS 69±12.The results of non-infectious fever group were as follows:MNV 151±8,NDW 21.33 ±2.62,MNS 132±10,MLV 91±4.LDW 15.78±1.96.MLC 117±4 and MLS 62±6.The results of control group were as follows:MNV145 ±5.NDW 18.43±0.93.MNS 143 ±4,MLV 84±2,LDW 13.30±0.76.MLC 108±1 and MLS 62±2.There were significant diffierences among these three groups (F value were 19.295,26.272,32.767,6.226,31.016,23.739 and 12.662 respectively,P＜0.05 or P＜0.01).In the infection group.the MNV and NDW were 152 ±16 and 22.19±3.45 respectively for WBC≤10×109/L group.159±12 and 25.29±3.43 respectively for WBC＞10×109/L group.They were both significantly different compared with control group (F valRe were 21.575 and 40.856 respectively,P＜0.01).Also in the infection group.the MNV and NDW were 159±12 and 24.88 ±3.74 respectively for neutrophil rate≥85%group.151±16 and 21.68±2.29 respectively for neutrophil rate＜85%group.They were both significantly different compared with control group(F value were 23.76 and 43.22 respectively,P＜0.01).The MNV and NDW were 157±15 and 24.25±3.39 respectively in those cases with gram-negative bacteremia,153±14 and 21.51±3.78 respectively in those cases with gram-positive bacteremia.They were both signifieanfly difierent compared with control group (F value were 18.74 and 37.47 respectively,P＜0.01).With a cut-off value of 20.50 for the NDW,a sensitivity of 76.7%and specificity of 98.3% were achieyed in diagnosing blood hacterial infection.Conclusion The VCS parameters can reflect the morphologic change of leukocyte in blood bacterial infection.Additionally.the NDW can detect blood bacterial infection more sensitively and specifically. Key words: Bacterial infections; Leukocyte count