Familial hyper-angiotensin converting enzyme (ACE)-emia: increased production of ACE by monocyte-macrophage.

We report here a familial clustering of elevated serum angiotensin converting enzyme (ACE) levels. The patient was a 58-year-old Japanese female. She had been in excellent health until the age of 45, when she noticed a decrease in visual acuity of her left eye. Despite intensive therapy under the diagnosis of occulusion of the central retinal vein, she lost her visual acuity at the age of 45. Thereafter, she has been in excellent health. The only abnormality found in this case has been a markedly elevated level of serum ACE (625 n mol/min/ml; normal range; 22-40 n mol/min/ml of serum). Her blood pressure was within normal limits (140/80 mmHg). There was no evidence for the diagnosis of sarcoidosis, Gaucher's disease, leprosy, hyperthyroidism, diabetic retinopathy, or liver disease. One of her two sisters also showed a marked increase in serum ACE activity (303 n mol/min/ml), and remarkably high levels of serum ACE (276 and 294 n mol/min/ml) were demonstrated in both of two sons of this sister. All the members of this family have been in excellent health. The serum ACE activity was activated by chloride and cobalt ions, and inhibited by EDTA, captopril and rabbit antiserum to purified human plasma ACE. Thus, our study showed a familial clustering of "hyper-ACE-emia", and the disorder appears to have been inherited as an autosomal dominant trait.