TY - JOUR T1 - Relation between biomarkers and findings of low dose CT scans in hospitalized patients with AECOPD JF - ERJ Open Research JO - erjor DO - 10.1183/23120541.00054-2022 SP - 00054-2022 AU - Hendrik J. Prins AU - Ruud Duijkers AU - Gerdien Kramer AU - Els. Boerhout AU - Floris J. Rietema AU - Pim A. de Jong AU - Marianne I. Schoorl AU - Tjip S. van der Werf AU - Wim G. Boersma Y1 - 2022/01/01 UR - http://openres.ersjournals.com/content/early/2022/04/07/23120541.00054-2022.abstract N2 - Acute exacerbations of COPD (AECOPD) and community acquired pneumonia (CAP) often coexist. Although Chest X-rays may differentiate between both diagnoses, chest X-rays are known to underestimate the incidence of CAP in AECOPD. In this exploratory study, we prospectively investigated the incidence of infiltrative changes using low-dose CT-scan (LDCT). Additionally, we investigated whether clinical biomarkers of CAP differed between patients with and without infiltrative changes.Methods Patients with AECOPD in which pneumonia was excluded using chest X-ray underwent additional LDCT-thorax. The images were independently read by two radiologists, a third radiologist was consulted as adjudicator. C-reactive protein (CRP), procalcitonin (PCT), and serum Amyloid A (SAA) at admission were assessed.Results Of the 100 patients included, 24 patients had one or more radiographic abnormalities suggestive of pneumonia. The inter-observer agreement between two readers (Cohen's Kappa) was 0.562 (95%CI 0.371–0.752; p<0.001). Biomarkers were elevated in the group with radiological abnormalities compared to the group without abnormalities. Median CRP was 76 (IQR 21.5–148.0) mg·L−1 compared to 20.5 (IQR 8.8–81.5) mg·L −1 (p=0.018), median PCT was 0.09 (IQR 0.06–0.15) µg·L−1 compared to 0.06 (IQR 0.04–0.08) ug·L−1 (p=0.007), median SAA was 95 (7–160) µg·mL−1 compared to 16 (IQR 3–89) µg·mL−1 (p=0.019). Sensitivity and specificity for all three biomarkers were moderate for detecting radiographic abnormalities by LDCT in this population. The area under the ROC curve was 0.66 (95% CI: 0.52–0.80) for CRP, 0.66 (95%CI: 0.53–0.80) for PCT, and 0.69 (95%CI: 0.57–0.81) for SAA.Conclusion LDCT can detect additional radiological abnormalities which may indicate acute-phase lung involvement in patients with AECOPD without infiltrate(s) on the chest X-ray. Despite C-reactive protein, procalcitonin and serum amyloid A being significantly higher in the group with radiological abnormalities on LDCT, they proved unable to reliably detect or exclude CAP. Further research is warranted.FootnotesThis manuscript has recently been accepted for publication in the ERJ Open Research. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJOR online. Please open or download the PDF to view this article.Conflict of interest: All authors have completed and submitted the ICMJE form for disclosure of potential Conflicts of interest. No disclosures were reported.The authors have nothing to disclose. ER -