The feasibility of using urine samples for the identification of
patients with Gaucher disease and carriers has been investigated. It was
found that the pH of a urine sample should be pH 6.0 or lower to ensure
stability of lysosomal hydrolases. Two parameters of glucocerebrosidase,
which is deficient in Gaucher disease, were studied using urine samples
from control subjects, obligate carriers and patients. Firstly, the
relative level of glucocerebrosidase activity was measured by relating
the activity of the enzyme to that of another lysosomal hydrolase.
Secondly, the enzymic activity of glucocerebrosidase per unit of protein
was measured using an immunological method. The first method allowed
discrimination of nearly all obligate carriers of type 1 Gaucher disease
from normal individuals. The second method allowed clear discrimination
of the majority of carriers from normal individuals, but some obligate
carriers were not distinguishable from normal subjects on the basis of
this parameter. However, the combination of both methods allowed
discrimination between all obligate carriers examined so far (n = 34)
and controls (n = 86).
There was variability between healthy individuals in the relative amount
of glucocerebrosidase in urine samples. A small proportion of healthy
individuals have a relatively high activity of glucocerebrosidase in
urine samples, reminiscent of observations made in white blood cells by
other investigators.
In urine samples from two unrelated parents of Gaucher disease patients
a level of glucocerebrosidase activity was present that could not be
distinguished from that in samples of patients. These individuals
represent cases with subclinical manifestation of Gaucher disease,
illustrating once more the remarkable heterogeneity in clinical
expression of this disorder
