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IL1B polymorphisms modulate cystic fibrosis lung disease
Author(s) -
Levy Hara,
Murphy Amy,
Zou Fei,
Gerard Craig,
Klanderman Barbara,
Schuemann Brooke,
Lazarus Ross,
García K. Christopher,
Celedón Juan C.,
Drumm Mitch,
Dahmer Mary,
Quasney Michael,
Schneck Kaitlyn,
Reske Melissa,
Knowles Michael R.,
Pier Gerald B.,
Lange Christoph,
Weiss Scott T.
Publication year - 2009
Publication title -
pediatric pulmonology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.866
H-Index - 106
eISSN - 1099-0496
pISSN - 8755-6863
DOI - 10.1002/ppul.21026
Subject(s) - medicine , single nucleotide polymorphism , genotype , odds ratio , population , cystic fibrosis , immunology , gastroenterology , genetics , biology , gene , environmental health
Rationale Variability in pulmonary disease severity is found in patients with cystic fibrosis (CF) who have identical mutations in the CF transmembrane conductance regulator ( CFTR ) gene. We hypothesized that one factor accounting for heterogeneity in pulmonary disease severity is variation in the family of genes affecting the biology of interleukin‐1 ( IL‐1 ), which impacts acquisition and maintenance of Pseudomonas aeruginosa infection in animal models of chronic infection. Methods We genotyped 58 single nucleotide polymorphisms (SNPs) in the IL‐1 gene cluster in 808 CF subjects from the University of North Carolina and Case Western Reserve University (UNC/CWRU) joint cohort. All were homozygous for ΔF508, and categories of “severe” (cases) or “mild” (control subjects) lung disease were defined by the lowest or highest quartile of forced expired volume (FEV 1 ) for age in the CF population. After adjustment for age and gender, genotypic data were tested for association with lung disease severity. Odds ratios (ORs) comparing severe versus mild CF were also calculated for each genotype (with the homozygote major allele as the reference group) for all 58 SNPs. From these analyses, nine SNPs with a moderate effect size, OR ≤0.5 or >1.5, were selected for further testing. To replicate the case‐control study results, we genotyped the same nine SNPs in a second population of CF parent–offspring trios (recruited from Children's Hospital Boston), in which the offspring had similar pulmonary phenotypes. For the trio analysis, both family‐based and population‐based associations were performed. Results SNPs rs1143634 and rs1143639 in the IL1B gene demonstrated a consistent association with lung disease severity categories ( P < 0.10) and longitudinal analysis of lung disease severity ( P < 0.10) in CF in both the case‐control and family‐based studies. In females, there was a consistent association (false discovery rate adjusted joint P ‐value <0.06 for both SNPs) in both the analysis of lung disease severity in the UNC/CWRU cohort and the family‐based analysis of affection status. Conclusion Our findings suggest that IL1β is a clinically relevant modulator of CF lung disease. Pediatr Pulmonol. 2009; 44:580–593. © 2009 Wiley‐Liss, Inc.