chondroitin-sulfates and Mucopolysaccharidosis-II

Topics: beta-Galactosidase; Cells, Cultured; Child, Preschool; Chondroitin Sulfates; Female; Fucose; Gangliosidoses; Genetic Carrier Screening; Hexosyltransferases; Humans; Iduronidase; Liver; Lysosomes; Mannose; Mucolipidoses; Mucopolysaccharidoses; Mucopolysaccharidosis I; Mucopolysaccharidosis II; Mucopolysaccharidosis III; Mucopolysaccharidosis IV; Mucopolysaccharidosis VI

We compared substrate reduction in patients with lysosomal storage disorder treated with hematopoietic stem cell transplant and found that it was significantly reduced compared with patients treated with pharmacological enzyme replacement therapy. These data might support the wider application of hematopoietic stem cell transplant in the treatment of lysosomal storage disorders.

Topics: Biomarkers; Chondroitin Sulfates; Dermatan Sulfate; Enzyme Therapy; Enzymes; Hematopoietic Stem Cell Transplantation; Humans; Mucopolysaccharidosis I; Mucopolysaccharidosis II; Mucopolysaccharidosis VI

Mucopolysaccharidoses (MPS) are complex storage disorders that result in the accumulation of glycosaminoglycans (GAGs) in urine, blood, brain and other tissues. Symptomatic patients are typically screened for MPS by analysis of GAG in urine. Current screening methods used in clinical laboratories are based on colorimetric assays that lack the sensitivity and specificity to reliably detect mild GAG elevations that occur in some patients with MPS. We have developed a straightforward, reliable method to quantify chondroitin sulfate (CS), dermatan sulfate (DS) and heparan sulfate (HS) in urine by stable isotope dilution tandem mass spectrometry. The GAGs were methanolyzed to uronic acid-N-acetylhexosamine or iduronic acid-N-glucosamine dimers and mixed with stable isotope labeled internal standards derived from deuteriomethanolysis of GAG standards. Specific dimers derived from HS, DS and CS were separated by ultra-performance liquid chromatography and analyzed by electrospray ionization tandem mass spectrometry using selected reaction monitoring for each targeted GAG product and its corresponding internal standard. The method was robust with a mean inaccuracy from 1 to 15%, imprecision below 11%, and a lower limit of quantification of 0.4mg/L for CS, DS and HS. We demonstrate that the method has the required sensitivity and specificity to discriminate patients with MPS III, MPS IVA and MPS VI from those with MPS I or MPS II and can detect mildly elevated GAG species relative to age-specific reference intervals. This assay may also be used for the monitoring of patients following therapeutic intervention. Patients with MPS IVB are, however, not detectable by this method.

Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Chondroitin Sulfates; Chromatography, Liquid; Dermatan Sulfate; Glycosaminoglycans; Heparitin Sulfate; Humans; Infant; Middle Aged; Mucopolysaccharidoses; Mucopolysaccharidosis II; Mucopolysaccharidosis III; Mucopolysaccharidosis IV; Mucopolysaccharidosis VI; Radioisotope Dilution Technique; Reference Values; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Young Adult

Enzymatic and chemical analyses of the structures of heparan sulfates excreted in the urine by patients with Sanfilippo's and Hunter's syndromes revealed that their nonreducing ends differ from each other and reflect the enzyme deficiency of the syndromes. The heparan sulfates from the different syndromes were treated with heparitinase II, crude enzyme extracts from Flavobacterium heparinum, and nitrous acid degradation. The heparan sulfates from patients with Sanfilippo A (deficient in heparan N-sulfatase) and Sanfilippo B (deficient in alpha-N-acetylglucosaminidase) were degraded with heparitinase II producing, besides unsaturated disaccharides, substantial amounts of glucosamine N-sulfate and N-acetylglucosamine, respectively. The heparan sulfate from patients with Hunter's syndrome (deficient in iduronate sulfatase) were degraded by heparitinase II or crude enzyme extracts to several products, including two saturated disaccharides containing a sulfated uronic acid at their nonreducing ends. The heparan sulfate from patients with Sanfilippo's C syndrome (deficient in acetyl Co-A: alpha-glucosaminide acetyltransferase) produced, by action of heparitinase II, among other products, two sulfated trisaccharides containing glucosamine with a nonsubstituted amino group. In addition to providing a new tool for the differential diagnosis of the mucopolysaccharidoses, these results bring new insights into the specificity of the heparitinases from Flavobacterium heparinum.

Topics: Biomarkers; Carbohydrate Sequence; Chondroitin Sulfates; Dermatan Sulfate; Diagnosis, Differential; Electrophoresis, Agar Gel; Heparitin Sulfate; Humans; Molecular Sequence Data; Mucopolysaccharidosis II; Mucopolysaccharidosis III; Polysaccharide-Lyases; Reference Values; Substrate Specificity

The chemical structure of dermatan sulfate (DS) in the urine of a patient the Hunter syndrome was studied through the analysis of disaccharide units which were derived from the urinary DS by digestion with chondroitinase ABC and separated on a Dowex 1 column. The DS was basically composed of repeating disaccharide units of iduronyl N-acetylgalactosamine 4-sulfate. About 90% of the excess sulfate were linked to the iduronate residues as an additional sulfate group in the unit. N-Acetylgalactosamine 6-sulfate and N-acetylgalactosamine 4,6-disulfate residues were minor components. No non-sulfated disaccharide unit was detected in the digestion products. Only sulfoiduronate residue was found as the non-reducing terminal sugar of the DS molecule, consistent with the lack of iduronosulfate sulfatase in this disease.

Topics: Acetylgalactosamine; Animals; Chemical Phenomena; Chemistry; Child, Preschool; Chondroitin; Chondroitin Sulfates; Chondroitinases and Chondroitin Lyases; Dermatan Sulfate; Disaccharides; Humans; Male; Mucopolysaccharidosis II; Skin; Swine

The separation and quantitative analysis of enzymatic degradation products of isomeric chondroitin sulfates by high-performance liquid chromatography (HPLC) are described. The substituted unsaturated disaccharides which result from digestion of chondroitin sulfates with chondroitinase are quickly separated on polar absorbents such as silica gel. The UV absorption properties of these unsaturated disaccharides permit UV measurement with detection limits of approximately 100 ng. Their separation by HPLC facilitates the use of enzymatic methods for the determination of chondroitin sulfates A, B and C. The potential of this method in clinical application is demonstrated by quantitative assays of glycosaminoglycans from a normal urine and urine from a patient with Hunter syndrome. The results are consistent with amount of isomeric chondroitin sulfates found in comparable urines by others.

Topics: Autoanalysis; Biodegradation, Environmental; Chondroitin; Chondroitin Sulfates; Chondroitinases and Chondroitin Lyases; Chromatography, High Pressure Liquid; Disaccharides; Glycosaminoglycans; Humans; Isomerism; Mucopolysaccharidosis II