L-ficolin (ficolin-2) insufficiency is associated with combined allergic and infectious respiratory disease in children

Mol Immunol. 2009 Dec;47(2-3):415-9. doi: 10.1016/j.molimm.2009.08.028. Epub 2009 Sep 19.

Abstract

We previously reported an association between relative L-ficolin deficiency and recurrent respiratory infections co-existing with allergic disorders in children. To confirm and extend this preliminary finding, we performed a prospective study on children of a similar age (mean 8.9 years) designed to establish whether the principal relationship was with infection or allergy. Serum L-ficolin values in healthy children were normally distributed with a mean value of 3838 ng/ml. L-ficolin concentrations were generally lower in patients with asthma and/or allergic rhinitis with (mean 3413 ng/ml; p=0.02) or without (3512 ng/ml; p<0.07) respiratory infections, but not in patients with respiratory infections without allergic disease (3623 ng/ml; p=0.2). The lower average values in the group comprised of children with respiratory allergy and infections were largely due to a high proportion of very low values: 18.3% had values below 2150 ng/ml compared to only 5.5% of healthy controls (OR=3.9; p=0.01). This relationship was not apparent in the groups characterized by allergy without infection or infections without allergy. An association between mannan-binding lectin (MBL) insufficiency and recurrent respiratory infections was also confirmed. One of the patients was MASP-2 deficient, evidenced both by MASP2 genotyping and by lectin pathway activity measurement. In conclusion, L-ficolin may confer some protection from microorganisms that exacerbate allergic inflammation in the lung and its relative deficiency may contribute to enhanced susceptibility to respiratory infections. MBL insufficiency and MASP-2 deficiency are risk factors for recurrence of infections independently of allergic disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Case-Control Studies
  • Child
  • Ficolins
  • Genotype
  • Humans
  • Infant
  • Lectins / blood
  • Lectins / deficiency*
  • Mannose-Binding Lectin / blood
  • Mannose-Binding Lectin / genetics
  • Mannose-Binding Lectin / immunology
  • Mannose-Binding Protein-Associated Serine Proteases / genetics
  • Mutation / genetics
  • Reference Values
  • Respiratory Hypersensitivity / blood
  • Respiratory Hypersensitivity / complications*
  • Respiratory Tract Infections / blood
  • Respiratory Tract Infections / complications*

Substances

  • Lectins
  • MBL2 protein, human
  • Mannose-Binding Lectin
  • MASP2 protein, human
  • Mannose-Binding Protein-Associated Serine Proteases