[Current development and usefulness of biomarkers for Gaucher disease follow up]

Gaucher's disease is due to glucocerebrosidase deficiency which is responsible for the accumulation of non degraded glucosylceramide within the lysosomes of macrophages: these "Gaucher cells", overloaded and alternatively activated, release in patient's plasma numerous compounds (cytokines, chemokines, hydrolases...) some of which contribute to the various tissue damages. Some of these compounds are surrogate biomarkers which contribute to the evaluation of disease severity, progression and stabilisation or regression during treatment. To date, the most interesting biomarkers are chitotriosidase and the chemokine CCL18/PARC, especially in chitotriosidase deficient patients. These biomarkers together with the clinical evaluation help to therapeutic choice (treatment by enzyme replacement therapy or substrate reduction therapy) and initiation decision, response follow-up and dose adjustments. Biomarkers should be assessed every 12 months together with clinical evaluation in patients not receiving specific treatments. An assessment every 3 months is recommended during the first year of treatment. Then when clinical goals have been achieved, the frequency can be reduced to every 12 months if the therapeutic scheme is not modified.