The change in nasal inflammatory markers after intranasal challenges with particulate chitin and lipopolysaccharide: a randomized, double-blind, placebo-controlled, crossover study with a positive control.

BACKGROUND

We investigated the effect of chitin on the inflammation and immune modulation of the nasal mucosa. This compound was compared to placebo and as a positive control we used lipopolysaccharide (LPS).

METHODS

Fourteen healthy nonsmoking volunteers 22 to 28 years of age were included. All persons underwent exposure to chitin microparticles (CP) and placebo in a randomized double-blinded fashion. In a last session we used LPS from Enterobacter agglomerans in a single-blinded fashion. There were 2 weeks between each session. The outcome measures were Total Nasal Symptom Score (TNSS) and nasal lavage for cytokines and cells at 0, 3, 4, 8 hours.

RESULTS

We showed that CP was only weakly inflammatory compared to LPS. In contrast to the LPS response, we did however show an immune-regulatory effect of CP on enhanced interleukin (IL)-4 and IL-6 responses known to downregulate T helper 2 (Th2) responses, indicating a potential beneficial effect of CP for the regulation of the allergic Th2 immune response.

CONCLUSION

This study also shows that CP is well tolerated in healthy volunteers, and that does not induce significantly more symptoms compared to placebo. In fact there is a tendency for CP instillation to induce less rhinorrhoea compared to placebo.