Alteration of cytolytic and proliferative responsiveness of peripheral blood mononuclear cells from cluster headache patients to interleukin-2

Cluster headache (CH) is a primary headache of unknown etiology and various immunological abnormalities have been found in these patients. In a previous paper a reduced activity of Natural Killer (NK) cells have been demonstrated in these patents. This study describes the effects of Interleukin-2 (IL-2) on the NK cell activity, on the IL-2 receptor (CD25) expression, and on the proliferative ability by peripheral blood mononuclear cells (PBMC) collected from CH patients. We found that IL-2 was highly effective in the restoration of the low NK activity found in CH patients; that IL-2 stimulated PBMC from patients evidenced a proportion of CD25 positive cells lower than that found in PBMC from control subjects and finally, that IL-2 was not able to increase the low proliferative ability of PBMC from CH patients. These results provide an additional evidence of the alteration of immunological status in patients affected by CH.