Diagnostic potential of serum and urine glycosidases in acquired diseases

Glycosidases are generally glycoproteins from lysosomal origin that catalyze the hydrolysis of glycoproteins, glycolipids and glycosaminoglycans, as well as synthetic substrates. They accomplish a very important role (partially known) in physiological circumstances, and their dysfunction causes pathological processes, where they have been mainly studied in connection to the lysosomal storage diseases. After a brief review on the biosynthesis and catabolism of glycosidases and the factors influencing their activity, the present review article summarizes our own results on some glycosidase activities (-N-acetylhexosaminidase, c-L-fucosidase, o—D—galactosidase, —D—galactosidase, cx—D—glucosidase, —D—glucosidase, 0—D-mannosidase, —D—glucuronidase and -D—fucosidase) determined in sera from patients of several acquired diseases (diabetes, pancreatitis, hepatitis, cirrhosis, breast and gastric carcinomas, myocardial infarction and renal deficiencies). Related papers of other authors are also quoted. In addition, we discuss our own results on some glycosidase activities determined in sera from patients who ingested a toxic oil and those from the same patients in their convalescence period; these determinations are an example of glycosidases as a useful index which contributes to follow the course of a disease. The signification of these enzymes in some renal disorders is also discussed. Finally, the convenience of introducing some glycosidase determinations (specially -N-acetylhexosaminidase) in the routine work of Clinical Enzymology is proposed.