Mucins MUC5B and MUC5AC in Distal Airways and Honeycomb Spaces: Comparison among Idiopathic Pulmonary Fibrosis/Usual Interstitial Pneumonia, Fibrotic Nonspecific Interstitial Pneumonitis, and Control Lungs

Although the pathogenesis of idiopathic pulmonary fibrosis (IPF) remains elusive (1), one of the most intriguing aspects concerns the possible role of mucins. A strong association has been reported between the promoter polymorphism rs35705950 of MUC5B and the occurrence of familial/sporadic IPF (2–10), as well as with a more benign disease course (10, 11). Overexpression of MUC5B and of the other main airway mucin, MUC5AC, has been described in IPF lungs (12, 13), but the level of expression in other types of pulmonary fibrosis is unknown. In this study, we compare MUC5B and MUC5AC expression among IPF, idiopathic nonspecific interstitial pneumonitis (i-NSIP), systemic sclerosis–associated NSIP (SSc-NSIP), and control lungs. Some of the results of this study have been previously reported in the form of an abstract