title: High eosinophil blood counts are associated with a shorter length of hospital stay in exacerbated COPD patients – a retrospective analysis
title: Hohe Werte von Bluteosinophilen unter exazerbierten COPD Patienten sind assoziiert mit einer kürzeren Krankenhausverweildauer - eine retrospektive Datenanalyse
titleType: AlternativeTitle
Creators: name: Tüffers, Julia
Publisher: name: Philipps-Universität Marburg
Year: 2023
Subjects: Eosinophilie
Verweildauer
Exazerbation
eosinohil blood counts
COPD
exacerbation
Medical sciences Medicine
Medizin

description: Morbidity and mortality of chronic obstructive pulmonary disease is associated with severe exacerbations. In severely exacerbated patients, the courses of disease are strongly varying. This might be due to the existence of different exacerbation phenotypes and their respective respond to the chosen treatment. As a marker for the responsiveness to inhaled corticosteroids, current recommendations emphasize blood eosinophil cell counts. For the treatment of moderate to severe exacerbations, the administration of systemic steroids is recommended. Analyses from randomized clinical trials indicate a favorable response to systemic corticosteroids in exacerbated patients with blood eosinophils &gt;2%, however data outside clinical trials are scarce. We retrospectively evaluated the association between baseline eosinophil blood count and both short- and long-term clinical outcomes, as well as different inflammatory parameters and markers of disease severity in patients hospitalized due to an exacerbation of their underlying chronic obstructive pulmonary disease. We evaluated data from 1007 cases of patients who were admitted to the University Medical Center Marburg between 01/2013 and 12/2018. All patients had been diagnosed with an acute exacerbation of chronic obstructive pulmonary disease. Patients were predominantly male (65%), had a median age of 74 years and a median forced expiratory volume in one second of 1.03l (42.6% predicted). Our analysis was based on a subgroup of 417 patients in whom a full blood cell count was obtained at the day of admission. We compared the hospital length of stay, inflammatory parameters and long-term outcome using established thresholds for the eosinophil blood cell count (100 and 300/μl and 2%). For patients that were re-hospitalized or died in our hospital during the observational time period, Kaplan-Meier curves were used to evaluate the long-term outcome. Patients with low eosinophils (&lt; 2%, &lt; 100/μl) had a longer median time in hospital (length of hospital stay) as compared to patients with high eosinophils (&lt; 2%: 9.31 vs. ≥ 2%: 7 days, and &lt; 100/μl: 10 vs. 100-300/μl: 8 vs. &gt; 300/μl: 7 days). The median C-reactive protein and more inflammatory markers (Procalcitonin, Neutrophil-to-lymphocyte ratio, neutrophils, leucocytes and fibrinogen) were higher in patients with low eosinophils as compared to the other groups (&lt; 2%: 22.7 vs. ≥ 2%: 9 mg/dl and &lt; 100/μl: 25 vs. 100-300/μl: 13.5 vs. &gt; 300/μl: 7.1 mg/dl). Time to re-hospitalization or time to death did not differ between the strata of eosinophils. To further reinforce the generalizability of our results and to prevent avoidable influences, we did three subgroup analyses, excluding a) patients that had received systemic steroids before blood collection, b) patients with radiological signs of pneumonia and c) patients who did not receive any systemic steroids either before their hospital stay and/or during admission. These restricted analyses did not alter the results significantly. In an additional subgroup analysis, we compared both short- and long-term outcome between patients with low eosinophil blood counts and high parameters of inflammation (demonstrated by C-reactive protein and Neutrophil-to-lymphocyte ratio) and those with high eosinophils and low parameters of inflammation. Hospital length of stay was significantly higher in patients with low eosinophils and high C-reactive protein/ Neutrophil-to-lymphocyte ratio. Time to re-hospitalization and time to death did not differ significantly among the groups. The shorter length of hospital stay and the lower levels of inflammation in eosinophilic patients can be interpreted as an indication for the existence of different exacerbation phenotypes. This could be an explanation for the better responsiveness to steroid treatment in eosinophilic patients and the notion that a more non-eosinophilic phenotype (which may include bacterial or viral infections) may need a longer time to clinical improvement. Our data confirms the results of other clinical studies and add to the growing body of evidence that blood eosinophils may serve as a biomarker not only for inhaled corticosteroid-responsiveness with regard to the prevention of exacerbations but also for responsiveness towards systemic steroids during an acute exacerbation of chronic obstructive pulmonary disease.