Xiangqun Zhang,1,2 Long Yang,1 Yu Gu,1 Junyuan Wu,1,2 Xue Mei,1,2,* Shubin Guo1,2,* 

1Emergency Medicine Clinical Research Center, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People’s Republic of China; 2Clinical Center for Medicine in Acute Infection, Capital Medical University, Beijing, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Xue Mei, Email meixue91@yeah.net Shubin Guo, Email shubin007@yeah.net

Background: Sepsis is an infection-induced systemic inflammatory response syndrome with high morbidity and mortality. β 2-microglobulin (β 2-MG), a low-molecular-weight protein involved in immune processes, shows potential for predicting the prognosis of various diseases. However, its role in sepsis prognosis remains unclear, necessitating further exploration.
Objective: This study aimed to evaluate the predictive value of serum β 2-MG for 28-day mortality in sepsis patients and compare it with traditional indicators such as sequential organ failure assessment (SOFA) scores and lactate (Lac) levels.
Methods: A total of 346 sepsis patients were included in this single-center retrospective study conducted at the emergency department of Beijing Chao-Yang Hospital. Clinical and biochemical indicators, including β 2-MG, SOFA scores, and Lac levels, were collected. Predictive ability was assessed using receiver operating characteristic (ROC) curve analysis and binary logistic regression models, and β 2-MG was compared to SOFA scores and Lac levels.
Results: β 2-MG was significantly correlated with 28-day mortality and identified as an independent risk factor (P< 0.001, OR=1.142, 95% CI: 1.083– 1.204). The sensitivity of β 2-MG was 94%, and its specificity was 77% for predicting 28-day mortality. Combining β 2-MG with SOFA scores increased sensitivity to 94%, while combining it with Lac improved specificity to 88.9%. ROC analysis showed that β 2-MG’s predictive accuracy improved significantly when combined with these indicators.
Conclusion: The serum level of β 2-MG is an independent predictor of 28-day mortality in sepsis patients. While less sensitive and specific than SOFA scores and lactate, combining β 2-MG with these markers improves predictive accuracy, offering complementary prognostic value.

Keywords: 28-day mortality, β 2-microglobulin, lactate level, sepsis, sequential organ failure assessment score