Early changes of chemotactic function of peripheral blood neutrophil of patients with severe burns and the influence factor

Objective To observe the early changes of chemotactic function of peripheral blood neutrophil of patients with severe burns and the influence factor. Methods Seven severe burn patients who met the inclusion criteria and were admitted to Suzhou Hospital Affiliated to Nanjing Medical University in 6 hours post burns from January to May 2019 were selected and included in burn group (4 males and 3 females, aged (36±10) years). Seven healthy volunteers with normal physical examination results in the Physical Examination Center of the same hospital in the same period of time were included in healthy control group (5 males and 2 females, aged (35±8) years). A prospective and controlled study was performed. (1) The venous blood of 2 mL was taken from each patient in burn group on post admission day (PAD) 1, 3, 5 and venous blood of 2 mL was taken from each volunteer in healthy control group for routine detection of white blood cell count, platelet count, neutrophil count, serum procalcitonin level, and C-reactive protein level. (2) The venous blood of patients and healthy volunteers was taken as before for measuring interleukin-6 (IL-6), IL-10, and tumor necrosis factor α (TNF-α) by enzyme-linked immunosorbent assay. (3) The venous blood of patients and healthy volunteers was taken as before, and peripheral blood neutrophils were isolated by Ficoll density gradient centrifugation. The chemotactic distance of neutrophil was detected by agarose chemotaxis test, and the positive expression rates of chemokine receptor CXCR1 and CXCR2 of patients in burn group on PAD 3 and volunteers in healthy control group were detected by flow cytometer. Data were statistically analysed with analysis of variance for repeated measurement, t test, and Bonferroni correction. Results (1) The platelet count of patients in burn group on PAD 1, 3, 5 was close to that of volunteers in healthy control group respectively (t=0.55, 0.44, 0.12, P>0.05). The counts of neutrophil and white blood cell and the expression levels of serum procalcitonin and C-reactive protein of patients in burn group on PAD 1, 3, 5 were significantly higher than those of volunteers in healthy control group (t=196.96, 273.31, 45.22, 3.46, 4.18, 5.55, 4.36, 5.26, 11.13, 64.94, 89.97, 84.31, P<0.01). (2) The level of IL-6 of patients in burn group on PAD 1, 3, 5 was significantly higher than that of volunteers in healthy control group respectively (t=187.43, 213.54, 195.74, P<0.01), the level of IL-10 of patients in burn group on PAD 1, 3, 5 was significantly higher than that of volunteers in healthy control group respectively (t=21.47, 11.13, 6.23, P<0.01), and the level of TNF-α of patients in burn group on PAD 1, 3, 5 was significantly higher than that of volunteers in healthy control group respectively (t=5.27, 7.89, 15.58, P<0.01). (3) The chemotactic distances of neutrophil of patients in burn group were (1 479±102), (1 395±82), and (1 017±91) μm respectively on PAD 1, 3, 5, which were significantly shorter than (1 902±120) μm of volunteers in healthy control group (t=7.11, 9.23, 15.55, P<0.01). (4) The CXCR1 and CXCR2 positive expression rates of neutrophil of patients in burn group on PAD 3 were (48.3±1.6)% and (79.0±1.8)%, respectively, which were significantly lower than (95.4±4.5)% and (97.8±2.1)% of volunteers in healthy control group (t=27.13, 23.10, P<0.01). Conclusions The chemotactic dysfunction of peripheral blood neutrophil was detected in the early stage of severe burn patients, which may be related to the decreases of CXCR1 and CXCR2.