Objectives: Recent studies have found cyclooxygenase-2 (COX-2) and its polymorphisms to be associated with sarcoidosis, being it significantly decreased in alveolar macrophages, with no information on the relationship between these polymorphisms and the rest of cells in bronchoalveolar layage (BAL). The present study aimed to investigate the potential association between COX-2 gene polymorphisms and the BAL cell profile including the CD4/CD8 ratio.
Material and methods: This observational cross-sectional study involved six hospitals in Spain. Patients diagnosed with sarcoidosis with a BAL performed were included. The following variables were recorded: age, gender, initial diagnostic methods, serum angiotensin-converting enzyme levels, pulmonary function tests, radiological stage, and the cellularity and CD4/CD8 ratio from BAL. Genotyping of four COX-2 polymorphisms (COX2.5909T>G, COX2.8473T>C, COX2.926G>C, and COX2.3050G>C) was undertaken on DNA extracted from peripheral blood lymphocytes using fluorescent hybridization probes. The relationship between the polymorphisms and the cellularity was done by means of a multiple linear regression, adjusting for gender.
Results: A total of 51 sarcoid patients (23 males, mean age: 45 +/- 15 years) were studied. CD4/CD8 ratio was significantly higher among homozygote allele C carriers of the polymorphism COX2.8473T>C (CC 11.2 +/- 5.5 vs. CT+TT 4.4 +/- 3.5; p = 0.022; beta = 7.43; 95% CI 1.38 - 13.48). Although several differences were observed in other cell groups, they did not reach the statistical significance level.
Conclusions: In patients diagnosed with sarcoidosis, there seems to be a relationship between COX2.8473 polymorphism and CD4/CD8 ratio from BAL.