Utility of CD64 and TLR2 Assays to Diagnose Acute Pulmonary Exacerbations in Cystic Fibrosis

Cystic fibrosis (CF) is the most common inherited disease in the western world. On a yearly basis, 56% of CF patients, or nearly 17,000 individuals in the US, suffer from acute pulmonary exacerbations (APE). The purpose of this study is to test a candidate assay for its ability to diagnose APE, the most important disease event in CF. While previous studies have been able to identify biomarkers of CF prognosis and risk stratification, three markers have demonstrated characteristics ideal for APE diagnosis: CD64, TLR2, and GILT. CD64 is a cellular receptor, expressed on numerous cells of the immune system, whose role is to bind antibodies which are attached to infected cells or pathogens. TLR2 plays a major role in early host-microbial interactions. GILT has been shown to be more precise in targeting immune responses against antigens and influences T lymphocyte response. This study looks to identify the differences in the expression of neutrophil CD64 and CD4+ T cell TLR2 and GILT between acute illness and baseline health as a sensitive marker of acute pulmonary exacerbation so that it may facilitate rapid hematologic diagnosis of the condition. The study also looks to compare sensitivity and specificity of the assays above to standard measures, such as health related quality of life scores (CFQ-R), loss of lung function, white blood cell counts and CRP, for diagnosing acute exacerbations.