Serum interleukin-1 beta is increased in cluster headache

We measured serum interleukin-l beta (IL-1 beta) in 24 episodic cluster headache (CH) patients and 45 normal controls using a specific ELISA method. There was an increase in IL-1 beta in all CH patients compared to controls. IL-1 beta was further increased during the ictal phase of CH compared to patients between attacks and normal individuals. Between attacks, IL-1 beta was also significantly increased compared to controls. We suggest that these results represent an activation of the immune system in CH.