Hydralazine and lupus nephritis.

Renal involvement is uncommon in the hydralazine induced systemic lupus erythematosus syndrome. Six women with hypertension are described who developed an immune complex glomerulonephritis after taking 50-300 mg hydralazine daily for 6 months to 7 years. Associated features were anemia (100%), hypocomplementemia (50%), a positive antinuclear antibody test (100%) and antibodies to double-stranded DNA (66%). All patients were slow acetylators and four had HLA-DR 4 genotype. Renal function deteriorated in all cases. Cessation of hydralazine combined with immunosuppressive therapy resulted in amelioration of the disease. It is likely that the patients had a hydralazine induced lupus glomerulonephritis, or alternatively had an unmasking of an inherent tendency to idiopathic lupus nephritis by hydralazine.