Mannose binding lectin deficiency is associated with disease severity in patients with non-cystic fibrosis bronchiectasis

Background: Mannose binding lectin (MBL) is a serum protein involved in phagocytic clearance of bacteria, viruses and apoptotic cells. Deficiency of mannose binding lectin is associated with disease severity in cystic fibrosis bronchiectasis but has not been studied in adult non-cystic fibrosis bronchiectasis. Methods: 470 patients with adult non-cystic fibrosis bronchiectasis (confirmed by HCRT) and matched controls were recruited. MBL serum levels were measured by ELISA. MBL deficiency was defined as a serum level 10 colony forming units/ml (cfu/ml). Results: MBL deficiency was not more frequent in bronchiectasis patients than controls (27.2% vs. 29.6%, p=0.4). MBL deficient patients had more severe disease as defined by radiology (39.8% vs. 19.3%, p Pseudomonas aeruginosa (22.7% vs. 12.3%, p=0.005). Conclusion: Mannose binding lectin deficiency is associated with more severe disease in patients with non-cystic fibrosis bronchiectasis.