Analysis of glycosaminoglycans in cerebrospinal fluid from patients with mucopolysaccharidoses by isotope-dilution ultra-performance liquid chromatography-tandem mass spectrometry.

BACKGROUND: New therapies for the treatment of mucopolysaccharidoses that target the brain, including intrathecal enzyme replacement, are being explored. Quantitative analysis of the glycosaminoglycans (GAGs) that accumulate in these disorders is required to assess the disease burden and monitor the effect of therapy in affected patients. Because current methods lack the required limit of quantification and specificity to analyze GAGs in small volumes of cerebrospinal fluid (CSF), we developed a method based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). METHODS: Samples of CSF (25 µL) were evaporated to dryness and subjected to methanolysis. The GAGs were degraded to uronic acid-N-acetylhexosamine dimers and mixed with internal standards derived from deuteriomethanolysis of GAG standards. Specific dimers derived from heparan, dermatan and chondroitin sulfates (HS, DS and CS) were separated by UPLC and analyzed by electrospray ionization MS/MS using selected reaction monitoring for each targeted GAG product and its corresponding internal standard. RESULTS: CSF from control pediatric subjects (n = 22) contained <0.38 mg/L HS, 0.26 mg/L DS, and 2.8 mg/L CS, whereas CSF from patients with Hurler syndrome (n = 7) contained concentrations of DS and HS that were at least 6-fold greater than the upper control limits. These concentrations were reduced by 17.5% to 82.5% after allogeneic transplantation and treatment with intrathecal and intravenous enzyme replacement therapy. CONCLUSIONS: The method described here has potential value in monitoring patients with mucopolysaccharidoses receiving treatment targeted to the brain.

Demonstration of uronic acid capsular material in the cerebrospinal fluid of a patient with meningitis caused by mucoid Pseudomonas aeruginosa.

A 39-year-old female with insulin-dependent diabetes mellitus developed Rhizopus infection of the maxillary sinus. Subsequent to successful treatment with amphotericin B and surgical debridement, she developed purulent meningitis due to a mucoid strain of Pseudomonas aeruginosa. Analysis of cerebrospinal fluid documented the presence of a uronic acid polymer at a concentration of 40 micrograms/ml. In spite of parenteral and intrathecal antibiotic therapy, the patient died. This case illustrates that mucoid strains of P. aeruginosa may result in fatal infection and that alginate capsule is produced in vivo in humans.