Age dependence of serum angiotensin-converting enzyme activity [letter].

We examined the age dependence of serum angiotensin-converting enzyme (SACE) activity in 
healthy controls. While we found no age dependence in controls older 
than 20 years, those under 20 had much increased SACE values. 
We feel that it is inappropriate to evaluate SACE activity in 
patients under 20 years old with diagnostic criteria determined in adults. 
- Dr Romer and colleagues reported high activities of SACE in 
3 patients out of 10 with chronic granulomatous disease (CGD) and 
concluded that "CGD is associated with increased levels of SACE". Unfortunately, 
Romer et al. did not study an adequate paedeatric age control 
group, and their mean values are compared primarily with that in 
5 children with cystic fibrosis. Our most recent studies confirm our 
earlier observation that children under the age 19 years definitely have 
higher mean SACE values than do adults. Cystic-fibrosis patients should not 
be used for comparison since they tend to have lower SACE 
levels than comparable aged controls. In my opinion patients with CGD, 
according to the data published by Romer et al., show no 
increase in SACE levels for their age. 