Ten candidate serum and synovial protein levels provide early indication of joint impairment in lysosomal storage disorders.

The Mucopolysaccharidoses (MPS) group of lysosomal storage diseases occur once in every 25,000 births, all MPS subtypes share deficits in enzymatic degradation. Children with MPS suffer from a suite of variable and severe symptoms including respiratory/cardiac deficits, and commonly synovial joint skeletal abnormalities. There are no known specific biomarkers used to track MPS patients at risk for joint complications and with the potential to be responsive to earlier intervention.

The inventors used a canine model of MPS I, and obtained serum and synovial fluid samples to identify 10 significant and highly predictive biomarkers.

To identify candidate proteins that are altered early in MPS I, the inventors took joint fluid and blood from canines aged 1 years old. Hundreds of proteins were assayed simultaneously using tandem liquid chromatography-mass spectrometry. Ultimately out of 812 total identified proteins, 151 are differentially abundant in the synovial fluid of MPS groups and 154 are different in serum of diseased canines. These MPS affected proteins are filtered further to identify 32 candidates that correlate and share MPS-dependent directionality in both joint fluid and serum. Finally using spearman rank correlation, the inventors produce a shortlist of ten useful markers, that are validated across joint fluid and blood, and can be assayed to significantly predict synovial joint disease.

• Multiple viable biomarkers
• All biomarkers are correlated to and validated by elevated serum samples
• 9 out of 10 biomarkers demonstrate one-hundred percent predictive ROC values
• Biomarkers serve as targetable therapeutics