[The level and clinical significance of Toll-like receptor 4 in children with severe sepsis].

Objective To study the clinical significance of Toll-like receptor 4 (TLR4) in children with severe sepsis. Methods A prospective control study was performed. All cases were enrolled from pediatric department of the First Affiliated Hospital of Guangzhou Medical College, and they were divided into severe sepsis group (14 patients) who were diagnosed to have severe sepsis or septic shock in intensive care unit (ICU), pneumonia group (10 cases) with diagnosis of bronchial pneumonia, and healthy control group (10 healthy children). Venous blood samples of 2 ml were collected at admission, the level of TLR4 was detected by flow cytometry . At the same time, the changes in serum interleukin (IL-6, IL-10 ) and tumor necrosis factor-α (TNF-α) levels were determined by enzyme linked immunoadsorbent assay (ELISA).Results In severe sepsis group, the contents of TLR4[(71. 56±15.32)%], IL-6[(1. 98±1.55) ng/L],IL-10[(88. 20±61.23) ng/L]and TNF-α[(104. 08±85.36) ng/L]were significantly higher than those in pneumonia group[(50. 07 ± 26.36) %, (0. 93 ± 0. 16) ng/L, (41.42 ± 7.02) ng/L, (48. 96 ± 6. 40) ng/L]and healthy control group[(39. 43± 17.43)%, (0. 94± 0. 43) ng/L, (43.73 ± 22.68) ng/L, (49. 94±18. 47) ng/L, all P＜0. 05). But there was no significant difference in the contents of TLR4, IL-6, IL-10 and TNF-α between pneumonia group and healthy control group (all P＞0. 05). Conclusion This study suggests that TLR4 might be critically involved in the development of sepsis, and changes in TLR4 expression are parallel with levels of proinflammatory cytokines, including IL-6, TNF-α, and IL-10. The combination of TLR4 and proinflammatory cytokines would serve as the predictive parameters in early diagnosis and severity evaluation of sepsis in children. Key words: Toll-like receptor 4;  Cytokine;  Sepsis;  Children