[Levels of complement and its various fractions in the blood of patients with Horton's headache. Preliminary report].

The pathogenesis of cluster headache remains unexplained and the immunological mechanisms have not been studied in this disease. Suspecting a possible allergic character of headache attacks it was decided to determine the haemolytic activity of the complement system and the levels of its C3 and C4 components. The investigations were carried out in 11 patients with cluster headache and in 10 patients with neurotic symptoms who served as controls. It was found that the levels of complement and its C4 fraction were not different in both groups but the level of C3 fraction showed a statistically significant difference. The authors discuss the obtained results and postulate continuation of investigations.