Background:

There exists a clinical and radiological spectrum of sarcoidosis which significantly impacts the approach to patient management. The role of immune dysregulation in different phenotypes remains unclear. We evaluated if mucosal lining fluid (MLF) biomarkers were distinct in parenchymal (PS or stage 2/3) versus nodal sarcoidosis (NS or stage 1).

Methods:    

Three groups of patients underwent a bronchoscopy; 1. PS 2. NS 3. Healthy individuals. MLF was collected by placing a synthetic absorptive matrix  on the bronchial mucosa "bronchosorption". Clinical and radiological data were collected along with samples for inflammatory mediators using an immunoassay platform.

Results:

In 40 patients, 6 bronchosorption mediators of importance were identified (figure 1).  We found higher levels in PS (n=13) compared to NS (n=9) and healthy (n=18) groups in the following mediators: IFN-?, IP-10, MCP-4, IL-15, IL12-p40, IL-12p70. IL-12p70 was significantly higher in PS than NS, while a similar trend was seen for IL-12p40.

 Conclusion:

This exploratory study found that PS patients had elevated levels of some inflammatory mediators in bronchosorption samples.  As IL-12 is a key trigger of type 1 immune responses, These findings might suggest the role of type 1 inflammation in sarcoidosis progression.