The relationships of HLA-antigens and Cluster Headache (C.H.) is described.

60 subjects (39 males and 21 females aged between 15 and 75 years - mean age 40.13 years) from Central Italy with Cluster Headache were examined. Three subgroups were identified, 29 Episodic Cluster Headache, 20 Hemicrania Cluster and 11 Chronic Paroxysmal Hemicrania. The 12 alleles of the Iocus-A and the 16 alleles of the Iocus-B were studied in the C.H. group and in 321 subjects, most of whom were blood donors, selected as a control group.

Typing was carried out with the microlymphocyto-toxicity technique used by N.I.H.

Genetic frequency, relative risk (R.R.) and “linkage disequilibrium” calculation were evaluated statistically. The statistical significance was corrected taking into consideration the number of observations carried out. The X2 test was used.

The data showed a decreased frequency of antigen HLA-B14 (1.66% vs 11.53% r<0.05) and HLA-Bw21 (5% vs 13.71%) in patients with C.H. compared to the group of controls. The R.R. was 0.19 and 0.33 respectively.