Abstract: Objective To explore the clinical influencing factors and significance of plasma receptor interacting protein 3 (RIP3) level in preterm infants. Methods Plasma samples and clinical data of preterm infants admitted to the SuZhu Municipal Hospital from October 2019 and October 2021 were collected. Enzyme-linked immunoassay (ELISA) was used to detect plasma RIP3 level. Results A total of 92 preterm infants were included in the research project as infection group and non-infection group with 46 in each. Plasma samples were collected, including 46 from non-infection preterm infants, 46 from preterm infants at the onset of sepsis (before-treatment), and 32 from preterm infants 3 days after sepsis treatment (after-treatment). Comparing plasma RIP3 in different groups, it was found that the level of RIP3 in Post-treatment group (13.31±2.94)ng/mL and non-infection group (12.85±4.98)ng/mL were significantly lower than that in pre-treatment group(19.86±6.47)ng/mL (both P＜0.001), while there was no difference between after-treatment and non-infection.Multiple linear regression analysis found that infection was the main clinical factor affecting the plasma RIP3 level(β=0.571,95% CI:4 360.817-10 943.690,t=4.623,P＜0.01). The receiver operating characteristic(ROC) curve suggested that when the plasma RIP3 level reaches 15.16 ng/mL as a cut-off value, it has good predictive performance for sepsis [sensitivity=78.26%, specificity=73.91%, area under curve(AUC)=0.81]. Conclusions Plasma RIP3 level is closely related to infection in preterm infants and supports early diagnosis as well as treatment evaluation of sepsis.

Key words: preterm infant, receptor interacting protein 3(RIP3), influencing factor, sepsis