Introduction: The Diagnostic Dilemma of Chronic Bronchitis
Chronic bronchitis (CB) has traditionally been defined by clinical symptoms—specifically, a productive cough for at least three months in two consecutive years. While this definition has served clinicians for decades, it is inherently subjective and often fails to capture the underlying biological reality of muco-obstructive lung disease. Recent advances in respiratory medicine have focused on identifying objective biomarkers that can quantify airway mucus pathology. Previous research established that total sputum mucin concentration is a reliable marker for CB. However, a new study published in NEJM Evidence introduces a more sophisticated metric: the Mucin Quantitative Score (MUCQ). This score integrates both the quantity and the specific molecular composition of mucus, providing a superior diagnostic tool for clinicians and researchers alike.
