Correlation of MRI-Based Bone Marrow Burden Score with Genotype and Spleen Status in Gaucher's Disease

Abstract

OBJECTIVE The purpose of this study was to correlate skeletal pathologic findings quantified by MRI-based bone marrow burden score with genotype and spleen status and other clinical parameters, including liver size and duration of enzyme replacement therapy, in patients with Gaucher’s disease. MATERIALS AND METHODS Two radiologists retrospectively reviewed MR images of 47 patients with Gaucher’s disease and determined bone marrow burden scores by consensus on the basis of previously published criteria. The bone marrow burden scores were correlated with genotype, liver volume, spleen status, age, and cumulative duration of enzyme replacement therapy. RESULTS Subjects with compound heterozygous N370S alleles had significantly higher overall, lumbar spinal, and femoral bone marrow burden scores than did N370S homozygotes. There was a significant positive correlation between an enlarged or surgically absent spleen and bone marrow burden score. There were no significant associations between bone marrow burden score and liver volume, age, cumulative duration of enzyme replacement therapy, or cumulative duration of untreated disease. Femoral and lumbar spinal bone marrow burden scores had a weak but significant positive correlation across all patients. CONCLUSION Skeletal pathologic findings in Gaucher’s disease encapsulated as bone marrow burden score correlate significantly with the number of copies of the N370S allele, which has an ameliorative effect on bone marrow disease. Splenectomy or splenomegaly is associated with greater risk of bone marrow disease. Femoral and lumbar spinal bone marrow burden scores, although only weakly correlated, independently illustrated both the protective role of the N370S allele and the unfavorable implication of splenectomy. This finding suggests that axial and appendicular bone marrow burdens are related but distinct and justifies multiple-compartment evaluation in Gaucher’s disease.

Characteristics of type I Gaucher disease associated with persistent thrombocytopenia after treatment with imiglucerase for 4–5 years

“…Persistent severe and life-threatening thrombocytopenia may be one of the few circumstances where splenectomy may still be justified in GD . Imiglucerase treatment following splenectomy usually normalizes the platelet count within 1 year , although splenectomy is itself a risk factor for further complications in GD, such as exacerbation of bone disease as well as increased risk of infections DeMayo et al, 2008).…”

An overview on bone manifestations in Gaucher disease

“…However, in the long term splenectomy has a negative effect on the course of bone involvement in GD [33]. Using BMB scores, splenectomized GD patients had higher BMB scores indicative of severe bone disease than non-splenectomized patients [97]. Besides severe bone diseases splenectomized GD patients also revealed bone manifestations more progressive over time compared with GD patients without splenectomy [33,98].…”

Vertebral fractures in Gaucher disease type I: data from the French “Observatoire” on Gaucher disease (FROG)

“…However, genotype-phenotype correlation studies have shown that splenomegaly and compound heterozygosity for the N370S mutant allele of the glucocerebrosidase gene are associated with bone disease in affected patients [8].…”