Cathelicidin, kallikrein 5, and serine protease activity is inhibited during treatment of rosacea with azelaic acid 15% gel.

Background: Excess cathelicidin and kallikrein 5 (KLK5) have been hypothesized to play a role in the pathophysiology of rosacea.

Objective: We sought to evaluate the effects of azelaic acid (AzA) on these elements of the innate immune system.

Methods: Gene expression and protease activity were measured in laboratory models and patients with rosacea during a 16-week multicenter, prospective, open-label study of 15% AzA gel.

NLRP3/cryopyrin is necessary for interleukin-1beta (IL-1beta) release in response to hyaluronan, an endogenous trigger of inflammation in response to injury.

Inflammation under sterile conditions is a key event in autoimmunity and following trauma. Hyaluronan, a glycosaminoglycan released from the extracellular matrix after injury, acts as an endogenous signal of trauma and can trigger chemokine release in injured tissue. Here, we investigated whether NLRP3/cryopyrin, a component of the inflammasome, participates in the inflammatory response to injury or the cytokine response to hyaluronan.