Headache and complement C'1-esterase inhibitor deficiency in Vietnamese immigrants living in southern California.

The objective was to measure complement C'1-esterase inhibitor (C1INH) in a group of Vietnamese outpatients with headache. All 51 patients (7 males and 44 females), with either migraine or chronic tension-type headache, were evaluated during 1994 and 1995. Their ages ranged from 15 to 69 years old (mean age, 37.5 years). They were found to have low levels of C1INH (mean, 11 +/- 2 mg/dL versus control subjects, 15 +/- 2 mg/dL with p < 0.0001). Twenty patients (5 males and 15 females) were treated with a low dose of danazol, 200 mg daily for 1-2 months. The improvement of the headache coincided with the return to normal levels of C1INH in all of our patients (pretreatment, 11 +/- 2 mg/dL versus post-treatment, 16 +/- 2 mg/dL with p < 0.001). The levels of C1q and C4d/C4 ratios did not change as a result of treatment with danazol. Our patients may represent a form of androgen-responsive headache, which is associated with low levels of C1INH, normal levels of C1q and normal C4d/C4. It differentiated them from angioedema (hereditary or acquired form); they had no known precipitating factors or a family history of angioedema.