Serum Amyloid A in Stable COPD Patients is Associated with the Frequent Exacerbator Phenotype
Open Access
- 1 September 2020
- journal article
- research article
- Published by Taylor & Francis Ltd in International Journal of Chronic Obstructive Pulmonary Disease
- Vol. ume 15, 2379-2388
- https://doi.org/10.2147/copd.s266844
Abstract
Background: We sought to determine whether circulating inflammatory biomarkers were associated with the frequent exacerbator phenotype in stable COPD patients ie, those with two or more exacerbations in the previous year. Methods: Eighty-eight stable, severe, COPD patients (4 females) were assessed for exacerbation frequency, pulmonary function, fraction of expired nitric oxide (FENO); inflammatory variables were measured in venous blood. Logistic regression assessed associations between the frequent exacerbator phenotype and systemic inflammation. Results: Compared with infrequent exacerbators, frequent exacerbators (n=10; 11.4%) had greater serum concentration (median (25th-75th quartile)) of serum amyloid A (SAA; 134 (84– 178) vs 71 (38– 116) ng/mL; P=0.024), surfactant protein D (SP-D; 15.6 (9.0– 19.3) vs 8.5 (3.6– 14.9) ng/mL; P=0.049) and interleukin-4 (IL-4; 0.12 (0.08– 1.44) vs 0.03 (0.01– 0.10) pg/mL; P=0.001). SAA, SP-D and IL-4 were not significantly correlated with FEV1%predicted or FVC %predicted. After adjusting for sex, age, BMI, FEV1/FVC and smoking pack-years, only SAA remained independently associated with the frequent exacerbator phenotype (OR 1.49[1.09– 2.04]; P=0.012). The odds of being a frequent exacerbator was 18-times greater in the highest SAA quartile (≥ 124.1 ng/mL) than the lowest SAA quartile (≤ 44.1 ng/mL) (OR 18.34[1.30– 258.81]; P=0.031), and there was a significant positive trend of increasing OR with increasing SAA quartile (P=0.008). For SAA, the area under the receiver operating characteristic curve was 0.721 for identification of frequent exacerbators; an SAA cut-off of 87.0 ng/mL yielded an 80% sensitivity and 61.5% specificity. Conclusion: In stable COPD patients, SAA was independently associated with the frequent exacerbator phenotype, suggesting that SAA may be a useful serum biomarker to inform progression or management in COPD.This publication has 47 references indexed in Scilit:
- Serum Amyloid A Activates the NLRP3 Inflammasome and Promotes Th17 Allergic Asthma in MiceThe Journal of Immunology, 2011
- Susceptibility to Exacerbation in Chronic Obstructive Pulmonary DiseaseThe New England Journal of Medicine, 2010
- Review: Surfactant protein D: A lung specific biomarker in COPD?Therapeutic Advances in Respiratory Disease, 2008
- Exacerbations of chronic obstructive pulmonary diseaseEuropean Respiratory Journal, 2007
- Inflammatory changes, recovery and recurrence at COPD exacerbationEuropean Respiratory Journal, 2007
- Is this the beginning of unravelling the puzzle of COPD exacerbations?European Respiratory Journal, 2005
- Th1/Th2 paradigm: not seeing the forest for the trees?European Respiratory Journal, 2005
- Immunoregulatory functions of surfactant proteinsNature Reviews Immunology, 2005
- Serum Amyloid A as a Predictor of Coronary Artery Disease and Cardiovascular Outcome in WomenCirculation, 2004
- Immunocytochemical localization of surfactant protein D (SP-D) in type II cells, Clara cells, and alveolar macrophages of rat lung.Journal of Histochemistry & Cytochemistry, 1992