An easy and sensitive method for determination of globotriaosylceramide (Gb3) from urinary sediment: utility for Fabry disease diagnosis and treatment monitoring.

BACKGROUND

Fabry disease is an X-linked disorder that results from the deficiency of the lysosomal enzyme alpha-galactosidase A. The defect leads to the accumulation of globotriaosylceramide (Gb3). The detection of Gb3 accumulated in different tissues may help in the diagnosis and enzyme replacement therapy monitoring. For this reason, we developed a simple method available to clinical laboratories to measure this analyte.

METHODS

Gb3 excretion was determined by the incubation of urine sediment glycolipids from Fabry patients with agalsidase alpha and subsequent determination of galactose produced.

RESULTS

The amount of urinary Gb3 in Fabry hemizygotes was significantly higher (p = 0.00001) than the amount in normal controls. Patients undergoing enzyme replacement therapy with agalsidase alpha showed a significantly lower content of Gb3 in urine sediment. This method showed a good recovery and comparability with a previously validated method.

CONCLUSIONS

We developed an easy method for quantification of Gb3 in urine samples from Fabry patients, by the use of the specific recombinant enzyme for this glycolipid, that does not require complex infrastructure. Urinary Gb3 as measured by this enzymatic method could be useful for the diagnosis and monitoring of treatment in Fabry patients.