Absence or mislocalization of DNAH5 is a characteristic marker for motile ciliary abnormality in nasal polyps.

OBJECTIVE

Motile cilia impairment is a common condition in patients with chronically inflamed airways, such as is seen in nasal polyps (NPs). The mechanism underlying this pathogenic condition is complex and not fully understood.

METHODS

We investigated the presence and localization of dynein axonemal heavy chain 5 (DNAH5) in motile cilia using immunofluorescence staining in paraffin-embedded nasal biopsies from NPs (n = 120) and inferior turbinate mucosa (n = 35) of healthy controls. We also performed single-cell staining on cytospin samples (NP = 5, control = 5). Three patterns of DNAH5 localization are defined, including pattern A (presence throughout the axoneme), pattern B (undetectable in the distal part of the axoneme), and pattern C (completely missing throughout the entire axoneme). We developed a semiquantitative scoring system for which 0 = (pattern A > 70%); 1 = (patterns A + B > 70%); and 2 = (pattern C ≥ 30%) in each high-power field (5 fields per sample).

RESULTS

Based on our DNAH5 scoring system, the median (1st and 3rd quartile) score was 0.3 (0.2 and 0.4) for samples from controls, and 1.1 (0.6 and 1.6) for samples from NPs in paraffin specimens (P < 0.001). The DNAH5 score had a significant positive relationship with the Lund-Mackay computed tomography score (r = 0.329, P = 0.005) and was higher in patients with eosinophilic NPs (P = 0.006). For cytospin samples, the mean percentage of patterns A, B, and C were 74%, 14%, and 12% in controls, and 48%, 20%, and 32% in NPs, respectively.

CONCLUSION

Our results suggest that the absence or mislocalization of DNAH5 from motile cilia is a common and potentially important pathological phenomenon in chronically inflamed airway epithelium.

LEVEL OF EVIDENCE: NA. Laryngoscope, 128:E97-E104, 2018.