Chitotriosidase (Gaucher Disease Biomarker)
Related Gene(s): CHIT1, GBA
Plasma chitotriosidase is a biomarker of macrophage activation that can be elevated in various lysosomal and non-lysosomal diseases, including Gaucher disease, Niemann-Pick disease, galactosialidosis, glycogen storage diseases, malaria, thalassemia, and fungal infections.
In Gaucher patients, chito activity is clinically useful for monitoring disease severity and effectiveness of therapy. This level usually decreases and remains stable with adequate enzyme replacement therapy or substrate reduction therapy. However, a null CHIT1 allele, 24 bp duplication in exon 10, is highly prevalent. 5% of individuals are homozygous and 35% individuals are heterozygous for this null allele in the Caucasian population. Therefore, the interpretation of chitotriosidase activity needs to be in the context of the CHIT1 genotype.
Chitotriosidase activity is measured by a fluorometric method using artificial 4-MU-β-D-triacetylchitotriosidase substrate.
- Plasma: 2-3 mL blood in EDTA tube (lavender top) or sodium heparin tube (green top). A minimum of 0.5 mL blood (0.2 mL plasma) is required
- Ship at room temperature; sample must be received on the day of collection
- If the sample cannot be sent on the same day, centrifuge immediately, freeze plasma, and ship frozen on dry ice
- 7 days