Background: Distinguishing asthma from COPD can be problematic, particularly in smokers and old adults. Some patients may have clinical features of both asthma and COPD. Descriptive term asthma-COPD overlap (ACO) may be useful to maintain awareness by clinicians, researchers and regulators of the needs of these patients, since most guidelines and clinical trials are about asthma alone or COPD alone.
Objective: To guide better recognition of wide range criteria to identify asthma-COPD overlap and to encourage the development of specific interventions for clinical use.
Patients and methods: Our study was carried out on 85 Egyptian individuals, 10 healthy volunteers, 25 patients diagnosed as bronchial asthma, 25 patients diagnosed as COPD, and 25 patient diagnosed as asthma-COPD overlap in clinical and investigation base ground, collected from Aga General Hospital, between June 2019 and February 2020.
Results: Our results demonstrated that 300 cells/µL was the best cutoff value for blood esinophil counts in differentiating ACO from COPD. The sensitivity and specificity were 64% and 79%, respectively. At a cutoff value of 8.47 sputum esinophil percentage sensitivity and specificity were 72.3% and 52.4%, respectively. Also FeNO can be used to discriminate between ACO patients and COPD patients at a cutoff level of > 18.5, with 52% sensitivity and 88% specificity. Also, there was a significant difference between the four studied groups regarding HDL and pulmonary function tests. So, blood and sputum esinophil count, FeNO, HDL, FEV1 and FEV1/FVC can be used as significant predictors for ACO.
Conclusion: The inflammatory biomarkers FeNO, sputum esinophils and blood esinophils can support the diagnosis of ACO, which may help clinicians to choose individualized treatment plan.