Polymorphisms in the lectin pathway genes as a possible cause of early chronic Pseudomonas aeruginosa colonization in cystic fibrosis patients.

Genes of innate immunity may be involved in early onset of chronic Pa (Pseudomonas aeruginosa) colonization (cPaC) in cystic fibrosis (CF) patients. We studied 19 single nucleotide polymorphisms (SNPs) in 5 genes coding for proteins of the lectin complement pathway: MBL2 (Mannose binding lectin 2), MASP 1, 2, 3 (MBL-associated serine Protease) and FCN 1, 2 (Ficolin) gene in 96 CF patients. Association survival analysis using different genetic models was performed looking for an association between SNPs and age at onset of cPaC. CF patients who are MBL deficient are earlier chronic Pa colonized compared to MBL sufficient patients. Also patients with MBL2 genotype YO/YO, YO/XA, XA/XA, YA/YO and YA/XA are earlier chronic Pa colonized. CF patients heterozygous or homozygous for mutant alleles of two linked SNPs in the FCN1 gene (rs2989727 and rs1071583) are earlier colonized with Pa. Similarly, earlier onset of Pa colonization is seen in CF patients heterozygous for linked SNPs of FCN2 gene (rs7865453 and rs7851696) and MASP3 gene (rs7851696). Variants in MBL2, FCN1, FCN2 and MASP3 genes are significantly associated with earlier onset of chronic P. aeruginosa colonization.