Abstract: Objective To investigate the expression of forming enhancement rosette rate(FEER), neutrophil %(NEU%), interleukin-6(IL-6), and erythrocyte C3b receptor wreath rate(RBC-C3bR) in patients with Ⅲ and Ⅳ degree bedsore infection secondary to cerebral infarction and their predictive value in wound healing. 
Methods A total of 43 patients with Ⅲ degree bedsore infection secondary to cerebral infarction(Ⅲ degree group), 43 patients with Ⅳ degree bedsore infection secondary to cerebral infarction(Ⅳ degree group) and 43 healthy people(control group) were selected from Liangxiang Hospital of Fangshan District in Beijing. The general data, FEER, NEU%, IL-6, and RBC-C3bR levels of each group were compared, and Spearman correlation analysis was used to analyze the relationship between FEER, NEU%, IL-6, RBC-C3bR and the degree of bedsore. The FEER, NEU%, IL-6, RBC-C3bR levels and the Pressure Ulcer Scale for Healing(PUSH) scores of patients with healed and unhealed wound before treatment, at 10 d and 20 d after treatment were compared. Pearson analysis was used to analyze the correlation between FEER, NEU%, IL-6, RBC-C3bR and PUSH score, and receiver operating characteristic curve(ROC) and area under ROC(AUC) were used to analyze the value of each index in predicting wound healing. 
Results FEER and RBC-C3bR were the lowest in Ⅳ degree group, followed by Ⅲ degree group and control group, while NEU% and IL-6 were the highest in Ⅳ degree group, followed by Ⅲ degree group and control group, suggesting significant difference between groups(P＜0.05). FEER and RBC-C3bR were negatively correlated with the degree of bedsore, and NEU% and IL-6 were positively correlated with the degree of bedsore(P＜0.05). At 10 d after treatment, the FEER and RBC-C3bR of the patients with healed wound showed an increasing trend, and the NEU% and IL-6 showed a decreasing trend; there were statistically significant differences between the indicators at 20 d after treatment and those at 10 d after treatment(P＜0.05). The FEER and RBC-C3bR of patients with unhealed wounds at 10 d after treatment were higher than those before treatment, and NEU% and IL-6 were lower than those before treatment(P＜0.05). However, there was no statistically significant difference between the indexes at 20 d after treatment and those at 10 d after treatment(P＞0.05). The FEER and RBC-C3bR of patients with healed wound were higher than those of patients with unhealed wound at 10 d and 20 d after treatment, and the NEU% and IL-6 were lower than those of the unhealed(P＜0.05). FEER and RBC-C3bR at 10 d and 20 d after treatment were negatively correlated with PUSH score, while NEU% and IL-6 were positively correlated with PUSH score(P＜0.05), and the correlation at 10 d after treatment was stronger than that at 20 d after treatment. The AUC for predicting wound healing was the largest in IL-6(0.823), followed by NEU%(0.819), FEER(0.714) and RBC-C3bR(0.709), and the AUC of the combination of indicators was 0.896(P＜0.05). 
Conclusion The expressions of FEER and RBC-C3bR in patients with Ⅲ and Ⅳ degree bedsore infection secondary to cerebral infarction decreased significantly, and the expressions of NEU% and IL-6 increased significantly before treatment. After treatment, the increase of FEER, RBC-C3bR and the decrease of NEU% and IL-6 can indicate that the wound tends to heal. The detection of the level of each index at 10 d after treatment is expected to become a biomarker for predicting wound healing. 

Key words: brain infarction, pressure ulcer, interleukin-6