Abstract
Background: The BTNL2 A allele is associated with increased risk of sarcoidosis. The aim was to evaluate the influence of the BTNL2 genotype profile on the course of disease in sarcoidosis patients.
Subjects and methods: BTNL2 genotype was performed in 133 ethnic Danish patients with biopsy-verified sarcoidosis (80 men). Age at diagnosis: median 38±1.8 years. Follow-up period: median 48 months (range 0-373).
Results:Distribution of BTNL2 genotypes was in Hardy-Weinberg equilibrium in patients and 113 controls. A allele frequency was increased in sarcoidosis patients (A=73.9%, G=26.1%) vs. controls (A=55.8%, G=44.2%) (p<0.03); 5.7% were GG homozygous and 54.0% were AA homozygous vs. 16% and 27.4% in controls. AA genotype was associated with an increased risk of sarcoidosis in a dominant OR 3.1 (95%CI 1.11–8.74), p<0.03 and a recessive model OR 3.1 (95%CI 1.72–5.61), p<0.001). All patients with end-stage pulmonary sarcoidosis had the AA genotype. In the entire series, we could not demonstrate an association between BTNL2 genotype and an acute or chronic course of disease. There was no association between degree of lung involvement and BTNL2 genotype. Analyses of clinical parameters and lung function at latest follow-up showed no association between BTNL2 genotype and outcome.
Conclusions: BTNL2 AA genotype is prevalent in patients with sarcoidosis and may be of use to help establish a diagnosis. There appeared to be no association between BTNL2 genotype and outcome of disease.
- © 2014 ERS