Predictive Value of Serum β2-Microglobulin for 28-Day Mortality in Sepsis Patients in the Emergency Department.

Background: Sepsis is an infection-induced systemic inflammatory response syndrome with high morbidity and mortality. β2-microglobulin (β2-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 β2-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 β2-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 β2-MG was compared to SOFA scores and Lac levels. Results: β2-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 β2-MG was 94%, and its specificity was 77% for predicting 28-day mortality. Combining β2-MG with SOFA scores increased sensitivity to 94%, while combining it with Lac improved specificity to 88.9%. ROC analysis showed that β2-MG's predictive accuracy improved significantly when combined with these indicators. Conclusion: The serum level of β2-MG is an independent predictor of 28-day mortality in sepsis patients. While less sensitive and specific than SOFA scores and lactate, combining β2-MG with these markers improves predictive accuracy, offering complementary prognostic value.