Enhancement of Circulating Immune Complexes in Episodic Cluster Headache

Abstract

Abnormalities have already been reported in the phenotypic frequency of the major histocompatibility complex antigens and in the relative proportions of the leukocyte subsets in patients affected by episodic cluster headache (ECH). Circulating immune complexes (CIC) and leukocyte subsets have been studied in 19 patients affected by episodic cluster headache during and in the absence of periods of crisis. The presence of CIC was determined in another five patients outside periods of crisis. CIC were evaluated using two techniques based on different principles revealing different types of CIC: the solid phase Clq method, and the conglutinin radioimmune assay. Monoclonal antibodies have been used to phenotype total T, helper/suppressor, K and NK leukocyte subsets, and monocytes. The findings demonstrate an increased incidence of CIC in the 19 ECH patients followed with time (37%) with respect to control subjects (10%), and an increase in Leu7-positive cells (K and NK cells) and in LeuM3-positive cells (monocytes). Interestingly, when patients were grouped according to the presence of CIC, only CIC-positive patients showed the previously described abnormalities. This would suggest that the cell-mediated immune alterations present in these patients may interact with the presence of CIC.