Evidence for eosinophil activation in bronchiectasis unrelated to cystic fibrosis and bronchopulmonary aspergillosis: discrepancy between blood eosinophil counts and serum eosinophil cationic protein levels

Abstract

Background-There is increasing interest in the use of non-invasive nocturnal intermittent positive pressure ventilation (NIPPV) in the management of patients with chronic hypercapnoeic (type II) respiratory failure. Although this treatment enables patients requiring mechanical ventilatory support to be treated more readily at home, few studies have been done to demonstrate its long term benefits in chronic obstructive pulmonary disease (COPD) and the application of NIPPV in these circumstances remains controversial. Methods-Eleven patients in severe stable chronic type II respiratory failure due to COPD who were unresponsive to conventional treatments experienced symptomatic hypercapnia when receiving suYcient supplementary oxygen to result in an arterial oxygen saturation (SaO 2 ) of >90%. They were assessed for treatment with NIPPV, and its eVects were observed for over two years using arterial blood gas tensions, spirometric parameters and body mass index (BMI), survival, hospital admissions, use of general practitioner resources, and patient satisfaction. Results-Hospital admissions and GP consultations were halved after one year compared with the year before NIPPV and there was a sustained improvement in arterial blood gas tensions at 12 and 24 months when breathing air, despite progressive deterioration in ventilatory function. BMI did not change during the period of observation. The median survival was 920 days, with no patient dying within the first 500 days. Conclusions-Domiciliary NIPPV results in improvements in arterial blood gas tensions which are sustained after two years of treatment and reduces both hospital admissions and general practitioner visits by patients with severe COPD in hypercapnoeic respiratory failure. It is well tolerated and, although there was no control group, survival appears to be prolonged when these results are compared with those of the NOTT and MRC (LTOT) trials. (Thorax 1998;53:495-498) Keywords: home ventilation; chronic obstructive pulmonary disease; outcome measures Non-invasive positive pressure ventilation (NIPPV) is a well established form of treatment for chronic hypercapnoeic (type II) respiratory failure in patients with neuromuscular disease or skeletal deformity. Although there has been increasing interest in its use for patients in chronic type II respiratory failure due to chronic obstructive pulmonary disease (COPD), its use remains controversial in this group of patients with conflicting reports of its eYcacy and acceptability. MethodsEleven patients, all ex-smokers in severe type II respiratory failure, were electively admitted between 1991 and 1995. All were diagnosed as having COPD and were receiving maximal drug therapy. Long term oxygen therapy (LTOT) suYcient to correct hypoxaemia (SaO 2 >90%) resulted in symptomatic hypercapnia, especially morning headaches and excessive diurnal somnolence. Sleep apnoea syndrome was excluded (apnoea/hypnoea index <10) but patients 1, 3, 7, 8, 9, and 10 (table 1) experienced severe sleep hypoventilation....

Mucosal inflammation in idiopathic bronchiectasis: cellular and molecular mechanisms

“…In contrast, blood eosinophil counts were not increased compared with normal controls or patients with COPD [128].…”

Pathogenesis, imaging and clinical characteristics of CF and non-CF bronchiectasis

“…Eosinophils contribute to tissue injury in CF and the presence of eosinophil cationic protein (ECP) heralds the cell activation state. ECP levels are elevated both in the airway and systemically in bronchiectasis [84][85][86]. Other eosinophilic markers including eosinophil protein X and peroxidase follow a similar pattern and like ECP contribute to poorer pulmonary function [87].…”

Pediatric bronchiectasis: No longer an orphan disease

“…Increased numbers of activated eosinophils are reported in bronchial biopsies and sputum of adult patients with bronchiectasis . An adult study found poor correlation between serum eosinophil cationic protein levels and peripheral blood eosinophil counts in patients with bronchiectasis, possibly indicating the localized nature of eosinophilia in bronchiectasis compared with its more generalized nature in asthma . Similarly, raised eosinophils were reported in the BAL fluid of 34% of indigenous children with a recent diagnosis of bronchiectasis .…”

“…32,70 An adult study found poor correlation between serum eosinophil cationic protein levels and peripheral blood eosinophil counts in patients with bronchiectasis, possibly indicating the localized nature of eosinophilia in bronchiectasis compared with its more generalized nature in asthma. 71 Similarly, raised eosinophils were reported in the BAL fluid of 34% of -Conflicting evidence, where a prospective study showed that MBL deficient genotype was associated with more bronchiectasis, whereas a retrospective study found no difference in severity.…”