Serum neutral alpha-D-glucosidase from patients with cystic fibrosis and chronic pulmonary disease.

Previous studies have indicated that alpha-D-glucosidase activity is increased and exhibits abnormal properties in tissues from patients with cystic fibrosis (CF). In the present investigation serum alpha-D-glucosidase from patients with CF and from patients with chronic pulmonary disease (e.g. asthma and bronchiectasis) has been studied to determine the specificity of the alpha-D-glucosidase alteration(s) in CF sera. Both groups of patients have elevated alpha-D-glucosidase activity levels and similarly abnormal isoelectric focusing profiles with significantly less activity associated with acidic enzymatic forms (i.e. having isoelectric points below 4.8). These results suggest that the abnormalities of CF serum alpha-D-glucosidase may be secondary to chronic pulmonary disease and emphasize the importance of including appropriate pathological controls in biochemical studies on CF.