Bone marrow involvement in Gaucher disease at MRI : what long-term evolution can we expect under enzyme replacement therapy?

PURPOSE

To study the long-term evolution of the bone marrow burden (BMB) score at MRI in patients with Gaucher disease (GD) under enzyme replacement therapy (ERT).

MATERIAL AND METHODS

Forty patients treated for GD were retrospectively studied in a referral centre. BMB scores were assessed on spine and femur MR examinations performed between January 2003 and June 2014. The long-term evolution of the BMB scores was analyzed using a linear mixed model.

RESULTS

A total of 121 MRI examinations were performed during the study period with a mean follow-up of 7.1 years ± 5.6, an average rate of 3.1 MR examinations ± 1.7 per patient and an interval of 2.3 years ± 1.1 between examinations. Patients had received ERT during 12 years on average ± 6.7. The trend of BMB scores with time decreased significantly by 15% (P = 0.008) during the total study period and 39% (P = 0.01) during the first 5 years of treatment. No changes in BMB scores were observed after five years of treatment.

CONCLUSION

In Gaucher patients, the trend of MRI BMB scores with time decreased significantly under ERT the first 5 years of treatment before a long-term stabilization.

KEY POINTS

• Bone marrow infiltration of Gaucher patients responds to enzyme replacement therapy • MRI BMB score decreases mainly during the first five years of treatment • MRI BMB score tends to stabilize after five years of treatment • MR examinations could be limited after five years of treatment.