Nasal cavity inflammation in patients with primary ciliary dyskinesia (PCD) is associated with bacterial infection

Introduction: Patients with PCD typically suffer from rhinosinusitis. Despite the negative impact of nasal symptoms on quality of life there has been no nasal cavity inflammation research in this cohort. We aimed to identify whether PCD patients have increased levels of inflammatory cytokines in the nasal cavity compared to patients with cystic fibrosis (CF) and controls. Methods: Nasal mucosal lining fluid was collected (n= 50 PCD, 7 CF, 22 control) using nasosorption (NS) and analysed for inflammatory cytokines. Nasal swabs were performed for bacterial culture (n= 43 PCD). To assess ex vivo inflammatory response to controlled bacterial challenge, nasal brushings (n= 10 PCD, 10 CF, 18 control) were infected for 1 hour with Haemophilus influenzae, Pseudomonas aeruginosa or Staphylococcus aureus, the supernatant analysed for IL-8 at 1 and 24 hours post infection and compared with uninfected controls. Results: PCD patients had significantly higher NS levels of IL- 1β, IL-2, IL-6, IL-10, TNFα and IFNγ than patients with CF and significantly higher levels of IL-6, IL-8, IL- 1β and TNFα than controls. 50% of PCD patients had a positive bacterial culture. This was associated with significantly higher levels of IL-6, IL- 1β and TNFα, compared to patients with no growth who had similar levels to controls. Ex vivo PCD nasal cells produced higher baseline levels of IL-8 compared to control and CF cells but had a blunted response to infection at 24 hours. Conclusions: PCD patients have elevated levels of inflammatory cytokines in the nasal cavity, which are associated with bacterial infection. Further investigation is needed to determine the cause of a blunted IL-8 response ex vivo.