OBJECTIVETo explore the change in the expression of extracellular heat shock protein 70 (eHSP70) and interleukin 2 (IL-2) and their correlation in intestine of rats with severe scald injury, and to observe the effects of eHSP70 on CD3(+) T lymphocytes in Peyer's patch of intestine in rats with severe scald injury in vitro.

METHODS(1) Sixty male SD rats were divided into normal control group (NC, n=10, only anesthetized) and scald group (S, n=50) according to the random number table. Rats in scald group were inflicted with 30% total body surface area full-thickness scald on the back. Ten rats from group NC immediately after anesthetization and 10 rats from group S at post injury hour (PIH) 3, 6, 12, 24, 48 were sacrificed to harvest their small intestines. The expressions of eHSP70 and IL-2 were determined with enzyme-linked immunosorbent assay (ELISA), and their correlation was analyzed. (2) Another 2 male SD rats were inflicted with the same injury as above. At PIH 12, CD3(+) T lymphocytes in Peyer's patch of small intestine were isolated and cultured with RPMI 1640 nutrient solution containing 10% fetal bovine serum. Cells were divided into blank control group (BC) and 5, 10, 20 μg/mL eHSP70 groups according to the random number table, with 6 wells in each group. Cells in group BC didn't receive any other treatment, while cells in the latter three groups were treated with corresponding mass concentration of recombinant rat eHSP70. After being cultured for 48 hours, the proportions of Th1 and Th2 in CD3(+) T lymphocytes, and the apoptosis rate of CD3(+) T lymphocytes were detected with flow cytometer, while the expressions of IL-2 and IL-10 in culture supernatant of cells were determined with ELISA. The cell experiments were repeated for 10 times. Data were processed with one-way analysis of variance, Kruskal-Wallis rank sum test, SNK-q test, and Pearson correlation analysis.

RESULTS(1) Compared with those in group NC [(1 278±135) and (48.6±4.9) ng/mg], the levels of eHSP70 [(728±93), (412±31), (314±21), (528±40), (1 028±97) ng/mg] and IL-2 [(38.6±2.3), (32.3±1.0), (25.3±3.6), (33.9±4.1), (44.3±2.6) ng/mg] in intestine of rats in group S obviously decreased at PIH 3, 6, 12, 24, 48 (with q values from 3.48 to 5.32, P values below 0.05), reaching the nadir both at PIH 12, with a significantly positive correlation between the level of IL-2 and the level of eHSP70 (r=0.920, P<0.01). (2) Compared with those in group BC [(8.6±1.1)% and (3.75±0.45)%], the proportion of Th1 obviously increased [(11.3±2.1)%, (15.7±1.8)%, (10.8±1.5)%, with q values from 2.97 to 4.57, P values below 0.05], while the proportion of Th2 obviously decreased [(2.39±0.38)%, (1.05±0.23)%, (2.67±0.26)%, with q values from 2.48 to 4.32, P values below 0.05] in CD3(+) T lymphocytes of rats in 5, 10, 20 μg/mL eHSP70 groups. Compared with those in group BC [(34.3±2.2)% and (254±16) pg/mL], the apoptosis rate of CD3(+) T lymphocytes obviously decreased [(26.1±2.6)%, (20.7±1.5)%, (31.5±2.4)%, with q values from 3.47 to 4.95, P values below 0.05], while the level of IL-2 obviously increased [(417±22), (587±19), (307±27) pg/mL, with q values from 3.02 to 4.98, P values below 0.05] in culture supernatant of CD3(+) T lymphocytes of rats in 5, 10, 20 μg/mL eHSP70 groups. There was no significant difference in the level of IL-10 in culture supernatant of CD3(+) T lymphocytes of rats among the four groups (F=2.12, P>0.05).

CONCLUSIONSThe expressions of eHSP70 and IL-2 in intestine of rats are decreased after severe scald, with a obviously positive correlation between them. eHSP70 can promote the differentiation of CD3(+) T lymphocytes in Th1 orientation, decrease the apoptosis rate of the cells, and promote the release of IL-2 of cells in Peyer's patch of intestine in rats with severe scald injury in vitro.

Animals ; Burns ; metabolism ; CD3 Complex ; metabolism ; Enzyme-Linked Immunosorbent Assay ; HSP70 Heat-Shock Proteins ; metabolism ; Interleukin-10 ; metabolism ; Interleukin-2 ; metabolism ; Intestine, Small ; metabolism ; Male ; Peyer's Patches ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Th1 Cells ; cytology

Objective:To retrospect the blood transfusion status of patients with extensive burns in multiple centers and analyze its influencing factors.Methods:A retrospective case series study was conducted. Clinical data of 455 patients with extensive burns who met the inclusion criteria and were admitted to the burn centers of 3 hospitals from January 2016 to June 2022 were collected, including 202 patients from the First Affiliated Hospital of Nanchang University, 179 patients from the Second Affiliated Hospital of Zhejiang University School of Medicine, and 74 patients from the First Affiliated Hospital of Anhui Medical University. The following data were collected from patients during their hospitalization, including infusion of red blood cells, plasma, and platelets during hospitalization; age, gender, body mass index, combined underlying diseases, cause of injury, time of admission after injury, type of admission, total burn area, full-thickness burn area, combination of inhalation injury, combination of other trauma, and combination of pulmonary edema; the blood lactic acid, serum creatinine, total bilirubin, and albumin values within 24 h of admission; combination of bloodstream, wound, lung, and urinary tract infection, and combination of sepsis; the number of escharectomy or tangential excision and skin grafting surgery (hereinafter referred to as surgery) and total surgical blood loss volume; occurrence of hemoglobin<70 g/L, admission to intensive care unit (ICU), conduction of mechanical ventilation and continuous renal replacement therapy (CRRT), length of hospital stay, and prognosis were recorded. In 602 surgeries of patients within 14 days after injury, data including area of escharectomy or tangential excision and skin graft harvesting, duration of operation, and surgical blood loss volume per surgery, operation site, and use of tourniquet and wound graft were collected. Data were statistically analyzed with Mann-Whitney U test, Kruskal-Wallis H test, and Spearman correlation analysis. Combined with the results of single factor analysis and clinical significance, multiple linear regression analysis was performed to screen the independent influencing factors of red blood cell infusion volume and plasma infusion volume, as well as blood loss volume per surgery. Results:During the whole hospitalization period, 437 (96.0%) patients received blood transfusion therapy, including 435 (95.6%) patients, 410 (90.1%) patients, and 73 (16.0%) patients who received transfusion of plasma, red blood cells, and platelets, respectively. The patients were mainly male, aged 18 to 92 years. There were statistically significant differences in the plasma infusion volume among patients with different combination of underlying disease, combination of inhalation injury, combination of other trauma, combination of pulmonary edema, combination of bloodstream infection, combination of wound infection, combination of lung infection, combination of urinary tract infection, combination of sepsis, occurrence of hemoglobin value <70 g/L, admission to ICU, conduction of mechanical ventilation, and conduction of CRRT (with Z values of -2.06, -4.67, -2.11, -6.13, -9.56, -4.93, -8.08, -4.78, -9.12, -6.55, -9.37, -11.46, and -7.17, respectively, P<0.05). The total burn area, full-thickness burn area, blood lactic acid value within 24 h of admission, serum creatinine value within 24 h of admission, albumin value within 24 h of admission, number of surgeries, and total surgical blood loss volume were correlated with the plasma infusion volume of patients (with r values of 0.39, 0.51, 0.14, 0.28, -0.13, 0.47, and 0.56, respectively, P<0.05).There were statistically significant differences in the red blood cell infusion volume among patients with different gender, combination of inhalation injury, combination of other trauma, combination of pulmonary edema, combination of bloodstream infection, combination of wound infection, combination of lung infection, combination of urinary tract infection, combination of sepsis, occurrence of hemoglobin value <70 g/L, admission to ICU, conduction of mechanical ventilation, and conduction of CRRT (with Z values of -2.00, -4.34, -3.10, -4.22, -8.24, -7.66, -8.62, -4.75, -7.42, -9.36, -6.12, and -8.31, -6.64, respectively, P<0.05). The age, total burn area, full-thickness burn area, blood lactic acid value within 24 h of admission, serum creatinine value within 24 h of admission, total bilirubin value within 24 h of admission, number of surgeries, and total surgical blood loss volume were correlated with the red blood cell infusion volume of patients (with r values of 0.12, 0.22, 0.49, 0.09, 0.18, 0.13, -0.15, 0.69, and 0.77, respectively, P<0.05). Combined underlying diseases, full-thickness burn area, combined pulmonary edema, serum creatinine value within 24 h of admission, combined sepsis, conduction of CRRT, number of surgeries, and total surgical blood loss volume were the independent influencing factors for plasma infusion volume during hospitalization in patients with extensive burns (with standardized regression coefficients of 0.09, 0.16, 0.12, 0.07, 0.11, 0.15, 0.31, and 0.26, respectively, P<0.05). Female, full-thickness burn area, serum creatinine value within 24 h of admission, combined sepsis, occurrence of hemoglobin value <70 g/L, conduction of CRRT, and total surgical blood loss volume were the independent influencing factors for red blood cell infusion volume during hospitalization in patients with extensive burns (with standardized regression coefficients of 0.10, 0.12, 0.10, 0.11, 0.05, 0.19, and 0.54, respectively, P<0.05). There were statistically significant differences in blood loss volume per surgery of patients with different surgical site and wound graft (with Z values of -2.54 and -2.27, respectively, P<0.05). The area of escharectomy or tangential excision and skin graft harvesting and duration of operation were correlated with the blood loss volume per surgery of patients (with r values of 0.40 and 0.21, respectively, P<0.05). The area of escharectomy or tangential excision and skin graft harvesting, duration of operation, and active wound grafts were the independent influencing factors for blood loss volume per surgery of patients with extensive burns (with standardized regression coefficients of 0.41, 0.16, and 0.12, respectively, P<0.05). Conclusions:The major factors influencing blood transfusion status in patients with extensive burns are female, combined underlying diseases, full-thickness burn area, serum creatinine value within 24 h of admission, combined pulmonary edema, occurrence of hemoglobin value <70 g/L, combined sepsis, conduction of CRRT, number of surgery, and total surgical blood loss volume. In addition, the area of escharectomy or tangential excision and skin graft harvesting, duration of operation, and active wound grafts indirectly affect the patient's blood transfusion status by affecting the blood loss volume per surgery.