Serum angiotensin converting enzyme activity in patients with histoplasmosis

The association between increased serum angiotensin converting enzyme (ACE) activity and active sarcoidosis is well documented. During a recent outbreak of acute histoplasmosis, a disease that shares many of the clinical and roentgenographic features of sarcoidosis, we examined serum ACE activity. Twenty-one (25%) of 86 patients with histoplasmosis had increased serum ACE activity. There were neither roentgenographic nor other substantive clinical differences between the groups of patients with increased and normal ACE values. Therefore, an increase in serum ACE activity must not be assumed to be caused by sarcoidosis unless histoplasmosis had been excluded.