Immunogenetic studies in essential hypertension among black patients. I. Correlative studies of serum autoantibody formation.

Serum antinuclear antibody (ANA) and HLA phenotype frequency were studied in 100 black subjects with essential hypertension and 100 normotensive black controls matched for age and sex. 11% of hypertensive individuals had a positive serum ANA test compared with 2% of controls (p less than 0.01). Among the hypertensive patients, positive serum ANA test was seen exclusively in patients who were receiving treatment with methyldopa. Although ANA also correlated with hypertensive vascular damage as assessed by retinal and EKG abnormalities, this was believed to have been due to the higher dose of methyldopa that may have been required to treat hypertension in these more severe cases. A statistically significant correlation of HLA-A11 and HLA-B12 with hypertension was observed, but only studied when uncorrected for the number of HLA specificities. It was concluded that autoantibody formation in essential hypertension is most likely to have been a consequence of antihypertensive drug therapy. In addition, further studies using larger number of patients and controls might more clearly establish the question of whether or not HLA is associated with essential hypertension.