Relationship between myeloperoxidase promotor polymorphism and disease severity in sarcoidosis

Background: Previously, we demonstrated that the number of polymorphonuclear neutrophils (PMNs) in bronchoalveolar lavage fluid (BALF) is useful in distinguishing sarcoidosis patients with a favorable outcome from those having a more severe course of disease. Neutrophils contain the oxidant-generating enzyme myeloperoxidase (MPO). Cellular levels of MPO can be influenced by functional promotor polymorphisms, −463G/A and −129G/A, which may modify disease severity. Methods: In the present study, we investigated two MPO promotor polymorphisms in 110 sarcoidosis patients and in 191 ethnically matched controls. Pulmonary disease severity was evaluated by means of radiographic staging, HRCT scoring, lung function, and exercise capacity testing. Results: No significant differences were found between sarcoidosis patients and healthy controls with regard to either polymorphism. Nor was any association observed between −463 G/A and −129 G/A polymorphism and the severity of sarcoidosis. Conclusions: The functional MPO promotor polymorphisms −463G/A and −129G/A did not explain disease severity in the sarcoidosis population studied. Future studies are needed to identify predictive features useful in guiding therapeutic strategies and to determine difficult-to-treat cases.