[Gaucher disease: MR evaluation of bone marrow features during treatment with enzyme replacement]

Enzyme replacement therapy (ERT) arrests and reverses the hematological and visceral symptoms of adult Gaucher disease, the most frequent lysosomal storage disorder. There are only a few studies available evaluating bone disease during ERT. The aim of this study was to investigate the features of bone marrow (bm) by magnetic resonance imaging (MRI) in these patients during ERT.

MRI was performed prospectively in thirty adult type I Gaucher patients before and during ERT with a mean follow-up of 3 years. Spin-echo sequences (T(1)/T(2)) of the lower extremities were obtained and the reconversion (response) or lack of reconversion (non-response) to fatty marrow during treatment was analyzed. The morphological features of bm involvement, a homogeneous or non-homogeneous distribution of bm changes and focal bone lesions surrounded by a rim of reduced signal intensity (SI), were analyzed.

Infiltration of bm by Gaucher cells is characterized by a reduction of SI on both T(1)- and T(2)-weighted sequences. Bone marrow responses were seen in 19 patients (63 %) during treatment. Focal bone lesions, surrounded by a rim of reduced SI, did not respond to ERT and correlated with a non-homogenous distribution of bone involvement and splenectomy.

In adult patients with type I Gaucher disease receiving ERT, treatment effects on bone disease can be demonstrated by MRI using Spin-echo sequences due to the partial reconversion of fat marrow. A non-homogeneous type of signal appearance and a status post splenectomy correlate with the presence of bone infarcts.