SUMMARY Macrolides have diverse biological activities and an ability to modulate inflammation and immunity in eukaryotes without affecting homeostatic immunity. These properties have led to their long-term use in treating neutrophil-dominated inflammation in diffuse panbronchiolitis, bronchiectasis, rhinosinusitis, and cystic fibrosis. These immunomodulatory activities appear to be polymodal, but evidence suggests that many of these effects are due to inhibition of extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and nuclear factor kappa B (NF-κB) activation. Macrolides accumulate within cells, suggesting that they may associate with receptors or carriers responsible for the regulation of cell cycle and immunity. A concern is that long-term use of macrolides increases the emergence of antimicrobial resistance. Nonantimicrobial macrolides are now in development as potential immunomodulatory therapies.

Dex at therapeutic concentrations did not inhibit the effects of IL-13 on goblet cell differentiation, characteristic of severe asthma. Paradoxically, MUC5AC production was increased with lower dose IL-13 exposure. This may lead to airway mucus obstruction commonly seen in life-threatening asthma.

IL-13 is a T-helper class 2 cytokine that induces goblet cell hyperplasia and mucus production in airway epithelial cells. Because macrolide antibiotics are known to have immunomodulatory and mucoregulatory properties, the aim of this study was to examine the effect of clarithromycin on IL-13-induced goblet cell hyperplasia and mucin hypersecretion in normal human bronchial epithelial (NHBE) cells. NHBE cells were cultured to differentiation at an air-liquid interface with IL-13 plus clarithromycin or vehicle. Histochemical analysis was performed using H&E staining, periodic acid-Schiff (PAS) staining, and MUC5AC immunostaining. MUC5AC synthesis was assayed using RT-PCR and ELISA. Western blotting was used to evaluate signaling pathways. IL-13 significantly increased the number of PAS-positive, MUC5AC-positive goblet cells, and this was significantly attenuated by clarithromycin at concentrations greater than 8 μg/ml (P < 0.01). Clarithromycin also dose-dependently decreased MUC5AC mRNA expression induced by IL-13 (P < 0.001), and, at 24 μg/ml, clarithromycin significantly attenuated the amount of MUC5AC protein in cell supernatants (P < 0.01). Western blotting showed that clarithromycin affected IL-13 receptor janus kinase signal transducers, activators of transcription6 (STAT6), and epidermal growth factor receptor mitogen-activated protein kinase signaling and that inhibition of these pathways by clarithromycin decreased goblet cell hyperplasia via nuclear factor-κB inactivation. We conclude that clarithromycin inhibits goblet cell hyperplasia and may directly regulate mucus secretion by IL-13 in NHBE cells.

We report herein high-resolution computed tomography findings from a patient with IgG4-related pulmonary disease for the first time. The 61-year-old male patient complained of low-grade fever, dry mouth, and night sweats. He was diagnosed as having autoimmune pancreatitis, Sjögren syndrome, and elevated serum IgG4. High-resolution computed tomography of the lungs showed dense alveolar consolidation and air bronchograms in bilateral perihilar regions. IgG4-positive lymphoplasmacytes were detected in pulmonary lesions by immunostaining of biopsy samples. IgG4-related pulmonary disease can be associated with various radiologic findings.