Metachromatic Leukodystrophy (MLD)

Abstract
A precipitating antibody was produced by immunizing rabbits with normal human sulfatase A. The rabbit antibody precipitated both the normal and the metachromatic leukodystrophy (MLD) sulfatase A from liver supernatant fractions. In the MLD samples, there was negligible sulfatase A activity in the resulting precipitin lines. Thus, the enzyme protein is present in MLD but is functionally abnormal. Ouchterlony double diffusion studies indicated that the sulfatase A protein in MLD was antigenically equivalent to the normal sulfatase A. The antibody does increase the activity of normal sulfatase A. It did not restore any substantial activity to the MLD enzyme, or to the heat inactivated normal enzyme. The existence of an enzyme protein in MLD is of interest. It raises the possibility that the activity of this protein might be increased by a therapeutic agent.