Abstract: Objective  To investigate the prognostic role of serum beta 2-microglobulin (β2M) as a systemic inflammatory biomarker in 
hospitalized patients with exacerbation of COPD, compared with other inflammatory biomarkers. Methods  We retrospectively analyzed hospitalized patients with exacerbated COPD as the first diagnosis at Beijing Chao-Yang hospital, P. R. China,  from December 31, 2012 to December 28, 2017. Serum β2M levels, laboratory and clinical indexes were measured or collected on admission, and all patients were followed up for 90 days. The prognostic performance of β2M was compared with the neutrophils-lymphocytes ratio (NLR), C-reactive protein values (CRP) and white blood cell (WBC) using MedCalc. Results  For 30-day mortality, β2M, NLR, and CRP showed significant predictive value (all P<0.001) and were better than WBC (P=0.044, 0.003 and 0.030, respectively) in hospitalized patients with exacerbated COPD , while WBC had no predictive significance. For 90-day mortality, β2M, NLR, CRP, and WBC were all statistically significant, but only NLR outperformed WBC (P=0.004). No significant differences were observed among β2M, NLR, and CRP. Conclusion  As a systemic inflammatory biomarker, serum β2M was a useful prognostic biomarker for short-term death in hospitalized patients with COPD exacerbations. It performed slightly better than NLR and CRP for 30-day mortality prediction and slightly superior to CRP and slightly inferior to NLR for 90-day mortality prediction. 

Key words: β2-microglobulin, COPD, prognosis, C-reactive protein, neutrophils-lymphocytes ratio