CYFRA 21-1 Predicts Progression in Idiopathic Pulmonary Fibrosis: A Prospective Longitudinal Analysis of the PROFILE Cohort

Age and Smoking Status Affect Serum Cytokeratin 19 Fragment Levels in Individuals Without Cancer

“…In chronic airway inflammatory disease, CYFRA 21-1 is released from an injured bronchial epithelium (25). Recently, CYFRA 21-1 has been highlighted as a potential biomarker of epithelial damage in patients with idiopathic pulmonary fibrosis (IPF) (26). In IPF, excessive apoptosis of epithelial cells and fibroblast resistance to apoptosis have been suggested to cause fibroproliferation (27,28).…”

The Need for a CYFRA 21-1 Cutoff Value to Predict Clinical Progression of IPF in Clinical Practice

“…We read with much interest the article by Molyneaux and colleagues on the concentrations of CYFRA 21–1 in patients with idiopathic pulmonary fibrosis published online in your prestigious journal ( 1 ). The authors found that the serum concentration of CYFRA 21–1 is significantly higher in patients with idiopathic pulmonary fibrosis than in a healthy population and that it can predict disease progression and overall mortality in idiopathic pulmonary fibrosis patients, suggesting the potential usefulness of serum CYFRA 21–1 as a diagnostic and prognostic biomarker ( 1 ). Unfortunately, a specific cutoff value of CYFRA 21–1 was not defined in the study to use as a reference in clinical practice.…”

“…Unfortunately, a specific cutoff value of CYFRA 21–1 was not defined in the study to use as a reference in clinical practice. Although the mean CYFRA 21–1 values were statistically different between healthy subjects and patients with idiopathic pulmonary fibrosis, most data from healthy subjects appear to overlap those from patients with idiopathic pulmonary fibrosis, making it difficult to determine a cutoff value for distinguishing both groups ( 1 ). The receiver operating characteristic curve analysis has been used in previous studies to define the most appropriate cutoff value of serum CYFRA 21–1 to differentiate benign from malignant disease, advanced from early cancer clinical stage, and squamous cell from small cell carcinoma ( 2 , 3 ).…”

Reply to Fujimoto et al.: The Need for a CYFRA 21-1 Cutoff Value to Predict Clinical Progression of IPF in Clinical Practice

“…We are grateful to Fujimoto and colleagues for their interest in our work ( 1 ). As they note, there remains an unmet need in clinical practice for biomarkers to aid in the diagnosis, prognostic assessment, and treatment of patients with idiopathic pulmonary fibrosis (IPF) and other forms of interstitial lung disease.…”

“…As they note, there remains an unmet need in clinical practice for biomarkers to aid in the diagnosis, prognostic assessment, and treatment of patients with idiopathic pulmonary fibrosis (IPF) and other forms of interstitial lung disease. We believe that CYFRA 21–1 has the potential to fulfill some of these roles ( 1 , 2 ).…”