Serum β2-Microglobulin is Associated with Mortality in Hospitalized Patients with Exacerbated Chronic Obstructive Pulmonary Disease

Serum β2-microglobulin as an independent risk factor for mortality in patients with acute respiratory distress syndrome caused by bacterial infection

Acute respiratory distress syndrome (ARDS) is a heterogeneous disease with extremely high mortality. We hypothesized that the serum β2-microglobulin (β2MG) level would be elevated and be an independent risk factor for 28-day mortality in patients with ARDS caused by bacterial infection. We retrospectively enrolled 257 patients with ARDS caused by bacterial infection from January 1, 2015 to February 28, 2021. Patients were followed for up to 28 days and were divided into a survival group and non-survival group according to their clinical outcomes. The serum β2MG levels and other clinical data were collected. The relationship between β2MG levels and 28-day mortality was explored by performing a Cox regression analysis adjusted for age, updated Charlson comorbidity index, disorders of consciousness, septic shock, albumin level, cardiac troponin I level, procalcitonin level, lactic acid level, prothrombin time, partial pressure of arterial oxygen/fraction of inspired oxygen ratio, estimated glomerular filtration rate and Sequential Organ Failure Assessment. In this cohort, 96 patients died in 28 days, yielding a 28-day mortality of 37.4%. The median level of serum β2MG for all enrolled patients was 4.7 (interquartile range [IQR]: 2.9-8.5) mg/L. Higher β2MG levels were significantly associated with 28-day mortality when the β2MG level was analysed as a continuous variable (hazard ratio [HR]: 1.053; 95% confidence interval [CI] 1.004-1.104; P = 0.032) and when it was categorized into tertiles (HR: 3.241; 95% CI 1.180-8.905; P = 0.023). The β2MG level exhibited a high diagnostic accuracy for predicting 28-day mortality (area under the curve [AUC] = 0.732; 95% CI 0.673-0.785; sensitivity: 74.0%; specificity: 64.0%; P < 0.001). The level of serum β2MG is elevated and is an independent risk factor of 28-day mortality in patients with ARDS caused by bacterial infection.

Association of beta-2-microglobulin with cardiovascular and all-cause mortality in the general and non-CKD population

β-2 microglobulin, a light chain in the major histocompatibility complex Class 1 molecule, is associated with mortality in dialysis or uremic patients. Current evidence on the relationship between beta-2-microglobulin (B2M) and mortality in the general and non-chronic kidney disease (CKD) population are limited and controversial. Data from the nutrition and health examination survey database and the nutrition and health examination survey linked mortality file were used. In total, 10,388 adults who had complete data for B2M were included. Weighted multivariable Cox proportional hazards regression models and regression splines were employed to evaluate the relationship between B2M with mortality. Moreover, subgroup and sensitivity analyses were performed. During a median follow up of 17.9 years (interquartile range 15.2-18.7), 2780 people died, 902 (32%) from cardiovascular disease. Restricted cubic splines showed that B2M is J-shaped nonlinear positively associated with all-cause mortality and cardiovascular disease mortality in the non-CKD and general population. Based on the multivariable adjustment model, the adjusted hazard ratios comparing the highest versus lowest quartile of the distribution of B2M were 2.50 (95% confidence interval: 1.90, 3.28) for all-cause mortality in the general population, 2.58 (95% confidence interval: 1.52, 4.37) for cardiovascular disease mortality in the general population, 2.58 (1.91, 3.49) for all-cause mortality in the non-CKD population and 2.62 (1.52, 4.53) for cardiovascular disease mortality in the non-CKD population. The positive associations between B2M and outcomes remained broadly significant across subgroups and sensitivity analyses. Higher B2M levels were associated with cardiovascular and all-cause mortality in the general and non-CKD population.

Association of Beta-2 Microglobulin with Stroke and All-Cause Mortality in Adults Aged ≥40 in U.S.: NHANES III

Background

Stroke is the predominant cause of death worldwide. We aimed to investigate the association of serum beta-2 microglobulin ( β 2M) concentrations with risk of stroke and all-cause mortalities in a cohort study.

Methods

Overall, 4914 U.S. adults (mean age = 63.0 years, 44.3% male) were recruited from the National Health and Nutrition Examination Survey (NHANES Ⅲ). During a median follow-up of 19.4 years, 254 stroke deaths and 3415 all-cause deaths were identified by the National Center for Health Statistics. The associations of β 2M with stroke and all-cause mortalities were investigated by using weighted Cox proportional hazard regression models.

Results

β 2M was positively associated with stroke and all-cause mortality in unadjusted models and multivariable-adjusted models. The multivariable HR (95% CI) for stroke mortality in Q5 VS Q1 of serum β 2M concentrations was 3.45 (1.33-8.91; p for trend = 0.001) and that for all-cause mortality was 3.95 (3.05-5.12; p for trend < 0.001). In subgroup analyses, the association of β 2M and stroke mortality did not vary by different levels of sociodemographic and general stroke risk factors (p interaction > 0.05). In addition, the magnitude of positive association between β 2M with all-cause mortality did vary by age, ratio of family income to poverty, smoking status, and history of hypertensive (p interaction < 0.05).

Conclusions

Our findings suggest that support that β 2M may be a marker of stroke and all-cause mortality, which provides a new perspective for the study of cerebrovascular health and long-term survival in the future.

β2-Microglobulin is a Novel and Reliable Biomarker for Predicting Ischemic Stroke Recurrence: A Prospective Cohort Study

Immune and inflammatory mechanisms play key roles in the development and outcome of acute ischemic stroke (AIS). β2-Microglobulin (β2M) is the light chain of major histocompatibility complex-1 (MHC-1), which can directly and quickly reflect the immune and inflammatory state of the body. Previous studies have shown a close relationship between β2M and AIS, but its relationship with the recurrence of AIS has not been reported. This study attempted to explore the relationship between β2M and the recurrence of AIS. A single-center AIS cohort involving 135 patients was followed for approximately 26-46 months. Clinical and laboratory data from the patients were collected when hospitalized. The endpoint was the occurrence of recurrent AIS after patients were discharged. Propensity score matching was used to match cohort groups. Cox regression analysis was used to predict risk factors for recurrent AIS, and receiver operating characteristic curve (ROC) analysis was used to calculate the optimal cutoff value for discriminating recurrence in patients with AIS. The rate of recurrence was 29.6% [95% CI, 21.8%-37.3%] in the follow-up group. Patients with higher levels of serum β2M had a higher risk of AIS recurrence than patients with lower levels of β2M (adjusted hazard ratio, 3.214 [95% CI, 1.557-6.633]; adjusted hazard ratio after matching, 5.831, [95% CI, 2.052-16.572]). A β2M value of 2.31 mg/L was calculated by ROC analysis as the optimal cutoff value for AIS recurrence (area under the curve 0.770, [95% CI, 0.687-0.853]). As a quick responder to the body's immune and inflammatory states, β2M may be a novel and reliable biomarker in predicting AIS recurrence.

Association of Beta-2-Microglobulin With Coronary Heart Disease and All-Cause Mortality in the United States General Population

Few prospective studies explored the association of beta-2-microglobulin (B2M) with coronary heart disease (CHD) mortality. The primary objective of this study was to examine the association of serum B2M with CHD and all-cause mortality. This is a prospective cohort study of a nationally representative sample of 4,885 adults, aged 40–85 years, who participated in the National Health and Nutrition Examination Survey (NHANES III) from 1988 to 1994. The relationships between B2M and CHD and all-cause mortality were estimated using Cox proportional hazards regression models. During a median follow-up of 15.5 years, 845 CHD and 3,388 all-cause deaths occurred among 4,885 participants [2,568 women (55.7%); mean (S.D.) age, 66.4 (12.5) years], respectively. In the unadjusted model, B2M concentration was strongly linearly associated with CHD and all-cause mortality (p-trend < 0.001). After adjusting multivariable factors, a positive linear association between B2M and all-cause mortality was still observed (H.R. for Q4 vs. Q1 5.90; 95% CI: 5.31–6.57; p-trend < 0.001). In the multivariable adjustment model, B2M was significantly associated with an increased risk of CHD mortality (H.R. for Q4 vs. Q1 2.72; 95% CI: 2.07–3.57; p-trend < 0.001). In the stratified analyses, the associations of B2M with CHD and all-cause mortality varied by risk factors, such as age, smoking status, and history of hypertension. The findings suggest a significant relationship between the higher serum B2M concentration and increased risk for CHD and all-cause mortality. Further large-scale follow-up studies are also needed to validate this association.