ABSTRACT BACKGROUND: Mannose-binding lectin (MBL) deficiency is associated with susceptibility to respiratory infections. We investigated the impact of MBL2 gene polymorphisms and MBL deficiency on the recurrence of infective exacerbation in patients with chronic obstructive pulmonary disease (COPD). METHODS: A prospective study was conducted among 215 COPD individuals and 137 healthy subjects. MBL deficiency was determined by the MBL2 gene polymorphisms and serum levels of MBL. RESULTS: The average frequency of infective exacerbations over three years in the 215 COPD patients was 2.5 +/- 1.3 episodes. The COPD group with >/= 3 episodes of infective exacerbation (recurrent exacerbators) included 96 patients. The other 119 COPD patients had </= 2 episodes of exacerbation (less frequent exacerbators). Among the 96 recurrent exacerbators, 12 (12.50%) had the MBL deficiency genotype, compared with 5 (4.20%) among the less frequent exacerbators (OR 3.25, 95% CI 1.01 to 11.07, p = 0.0253). In recurrent exacerbators, the frequency of infective exacerbation was significantly higher in patients with MBL-deficient genotypes than in those with non-MBL-deficient genotypes (4.75 +/- 1.22 vs. 3.52 +/- 0.78, p < 0.0001). In addition, the mortality was significantly increased in recurrent exacerbators with MBL-deficient genotypes compared with those with non-MBL-deficient genotypes (66.7% vs. 31.0%, p = 0.0153). CONCLUSIONS: MBL deficiency due to MBL2 polymorphisms increases the risk of recurrent infective exacerbation and worsens its outcome in COPD patients.
