Changes in serum lysosomal hydrolases in marasmus

The activities of several lysosomal hydrolases including β-glucuronidase , acid phosphatase and hexosaminidase were compared in serum from 19 well-nourished subjects and 13 children (age 5–24 months) who were suffering from marasmus. The marasmic children exhibited growth retardation and muscle wastage but had normal serum protein values and absence of psychomotor retardation or oedema. Significant changes were observed in serum β-glucuronidase and acid phosphatase activities. Compared to the control group, serum β-glucuronidase (determined at pH 4.5 using the fluorogenic substrate, 4-methylumbelliferyl-β- d-glucuronide) was 2.3-fold higher ( p < 0.001) in the marasmic children. In contrast, serum acid phosphatase values were approximately 50% lower ( p < 0.01) in the marasmic population. Serum hexosaminidase values in the two groups under study were not significantly different. Determination of the β-glucuronidase to acid phosphatase ratio permitted effective discrimination ( p < 0.001) of serum from normal and protein-calorie malnourished children. The finding that the elevated value of the β-glucuronidase : acid phosphatase ratio (0.64–1.37) decreased to within the normal range of values (0.10–0.43) after nutritional rehabilitation of several marasmic cases indicates that the determination of serum lysosomal hydrolases using fluorogenic substrates might provide a rapid and sensitive quantitative method for objectively evaluating the status of protein-calorie malnourished children and their responsiveness to nutritional therapy.