The refined ABCD assessment and non-costly laboratory parameters are outcome predictors in acute exacerbation of COPD

Association of Blood Inflammatory Biomarkers with Clinical Outcomes in Patients with AECOPD: An 8-Year Retrospective Study in Beijing

Purpose

To discover potential inflammatory biomarkers, which can compare favorably with traditional biomarkers, and their best cut-offs at first admission to predict clinical outcomes (short-term and long-term) and the risk of readmission among acute exacerbations of chronic obstructive pulmonary disease (AECOPD) patients.

Patients and Methods

Novel inflammatory biomarkers (such as the neutrophil-lymphocyte ratio [NLR], platelet-lymphocyte ratio [PLR], etc.) were compared with traditional biomarkers by Pearson's correlation test. Logistic regression analysis and receiver operating characteristic (ROC) curves were applied to judge the accuracy of these novel biomarkers to predict in-hospital mortality.

Results

Surviving AECOPD patients had lower NLR, PLR, and lymphocyte-to-monocyte ratios than non-survival patients (all P < 0.001). According to Pearson's correlation test, there was a linear correlation between novel and traditional biomarkers (all P < 0.05). In terms of a single biomarker, the AUC value of NLR was the largest, which was not inferior to C-reactive protein (Z-P = 0.064), and superior to erythrocyte sedimentation rate (Z-P = 0.002) and other novel single inflammatory biomarkers (all Z-P < 0.05). The mortality of patients with NLR ≥ 4.43 was 2.308-fold higher than that of patients with NLR < 4.43. After dividing patients into a higher or lower NLR group, pooled results showed that patients with NLR ≥ 4.43 had a higher rate of treatment failure, intensive care unit admission, longer hospital length of stay, one-year mortality after the index hospitalization, and overall mortality than patients with NLR < 4.43 (all P < 0.001). Patients with NLR ≥ 4.43 were associated with higher and earlier first readmission due to AECOPD than patients with lower NLR.

Conclusion

NLR was the best to forecast the clinical prognosis and readmission risk among AECOPD patients, which was not inferior to CRP, and the best cut-off value of NLR was 4.43.

Hematological Parameters for Predicting Mortality in Acute Exacerbation of Chronic Obstructive Pulmonary Disease

(1) Introduction: COPD is a common and serious condition affecting a significant proportion of the population globally. Patients often suffer from exacerbations which lead to the worsening of their health status and respiratory function, and can often lead to death. Quick and cheap investigations are required that are capable of predicting mortality in patients with acute exacerbations that can be applied in low resource settings. (2) Materials and methods: This was a retrospective study carried out using hospital records of patients admitted for AECOPD from 1 January 2017 to 30 November 2022. Chi-square test (for sex) and Student's t-test were used to look for significant associations. Receiver Operating Characteristics (ROC) curves were plotted and Area Under Curve (AUC) values were calculated for various hematological parameters. Youden's J was used to identify the ideal cut-off with optimal sensitivity and specificity. Multivariate Cox regression was used to identify independent hematological predictors of mortality. Kaplan-Meir survival plots for neutrophil lymphocyte ratio (NLR) with the optimal cut-off were plotted. (3) Results: Amongst the 500 patients, 42 died while 458 survived, giving a mortality rate of 8.4%. NLR had the strongest association with mortality. The cut-off for various parameters were: NLR 14.83 (AUC 0.73), total leukocyte count (TLC) 13,640 cells/mm³ (AUC 0.60), absolute neutrophil count (ANC) 12,556 cells/mm³ (AUC 0.62), derived NLR (dNLR) 9.989 (AUC 0.73), hemoglobin 11.8 mg/dL (AUC 0.59), packed cell volume (PCV) 36.6% (AUC 0.60), and platelet lymphocyte ratio (PLR) 451.32 (AUC 0.55). (4) Conclusions: In patients with acute exacerbation of COPD, NLR was strongly associated with mortality, followed by dNLR. Cox regression identified NLR as an independent predictor of mortality.

Clinical significance of the neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio in acute exacerbations of COPD: present and future

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are a leading cause of hospitalisation and death in COPD patients. In addition to the identification of better strategies to prevent AECOPD, there is an intense focus on discovering novel markers of disease severity that enhance risk stratification on hospital admission for the targeted institution of aggressiveversussupportive treatments. In the quest for such biomarkers, an increasing body of evidence suggests that specific indexes derived from routine complete blood counts,i.e.the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR), can significantly predict adverse outcomes in AECOPD. This narrative review discusses the current evidence regarding the association between the NLR and the PLR on admission and several clinical end-points (need for invasive ventilation, noninvasive mechanical ventilation failure, admission to an intensive care unit, pulmonary hypertension, length of hospitalisation, and mortality) in AECOPD. Future research directions and potential clinical applications of these haematological indexes in this patient group are also discussed.

A Comprehensive Systematic Review and Meta-Analysis of the Association between the Neutrophil-to-Lymphocyte Ratio and Adverse Outcomes in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

The neutrophil-to-lymphocyte ratio (NLR) predicts adverse outcomes in stable chronic obstructive pulmonary disease (COPD); however, its prognostic role in acute exacerbations (AECOPD) is less clear. We conducted a systematic review and meta-analysis of the association between the NLR on admission and adverse outcomes (mortality, need for mechanical ventilation, transfer to the intensive care unit, length of stay, pulmonary hypertension, or their combination) in AECOPD by searching PubMed, Web of Science, and Scopus from inception to April 2022. Risk of bias and certainty of evidence were assessed using the Joanna Briggs Institute Critical Appraisal Checklist and the Grades of Recommendation, Assessment, Development, and Evaluation, respectively. In 15 studies (n = 10,038 patients), the NLR was significantly associated with the risk of adverse outcomes (odds ratio = 1.054, 95% CI 1.016 to 1.093, p = 0.005; low certainty of evidence; standard mean difference = 0.82, 95% CI 0.57 to 1.06, p < 0.001; high certainty of evidence). Pooled sensitivity, specificity, and area under the curve were 0.71 (95% CI 0.64 to 0.77), 0.73 (95% CI 0.65 to 0.80), and 0.78 (95% CI 0.74 to 0.81), respectively. In our study, the NLR on admission was significantly associated with adverse outcomes in AECOPD patients, suggesting the potential utility of this biomarker for early risk stratification and management in this group.