Elevated Serum C1q Levels in Children With Sepsis

Abstract

Objective: To analyze the serum complement C1q levels in children with sepsis, and explore the suggestive effect of serum C1q levels on the condition of children with sepsis.Methods: The clinical and laboratory data of children with sepsis (n = 95) and healthy children (n = 71) in Renmin Hospital of Wuhan University from January 2019 to October 2019 were collected, and each index of the two groups was compared. Then we divided children with sepsis into three subgroups based on the Pediatric Critical Illness Score (PCIS): non-critical group, critical group, and extremely critical group. The serum C1q and PCT levels of the three subgroups were analyzed, and the correlation analysis was carried out between the levels of serum C1q and PCT levels as well as PCIS among children with sepsis. Finally, we analyzed the serum C1q levels of septic children infected by different pathogens.Results: The serum C1q levels of children with sepsis were significantly higher than those of healthy children (median 198.4 vs. 186.2 mg/L, P < 0.001). In the analysis of subgroups, the serum C1q levels of non-critical group, critical group, and extremely critical group septic children were 182.80 (166.75, 195.85) mg/L, 219.90 (209.10, 246.40) mg/L and 249.95 (239.10, 272.25) mg/L, respectively, which were correlated with the severity of the disease. At the same time, we also found that serum C1q in children with sepsis was positively correlated with PCT levels (r = 0.5982, P < 0.001), and negatively correlated with PCIS score (r = −0.6607, P < 0.001). The serum C1q levels of septic children with bacterial infections, mycoplasma infections, viral infections, and co-infection were higher than those of the control group (P < 0.05).Conclusion: The serum levels of C1q in children with sepsis were increased and related to the severity of sepsis, suggesting that C1q may be involved in the occurrence and development of sepsis, which had reference value for the preliminary diagnosis and severity classification of sepsis.

Serum C1q Levels Have Prognostic Value for Sepsis and are Related to the Severity of Sepsis and Organ Damage

“…In a previous study, nevertheless, an increase of serum C1q in children with sepsis was observed. 13 We believed that there were several reasons: Firstly, the immune system of children was very different from that of adults, which would cause the response and regulation of inflammation to be different; Secondly, we observed that the main pathogen of infection in children with sepsis was mycoplasma in previous studies, and there were reports in the literature indicated that children with mycoplasma infection had elevated other complement components, 23 we guessed that C1q was also be elevated. The main pathogens in adult patients with sepsis in this study were bacteria and fungi.…”

“…12 Although there are many studies on the role of complement system in sepsis in recent years, there is only one simple report on the role of C1q in children with sepsis. 13 C1q is also an important component of complement system, unlike most other complement proteins derived mainly from liver, C1q is mainly synthesized by macrophages. 14 It can regulate a variety of immune cells and plays an important role in maintaining autoimmune tolerance and regulating inflammatory response.…”