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

A Real-World Investigation of MRI Changes in Bone in Patients with Type 1 Gaucher Disease Treated with Velaglucerase Alfa: The EIROS Study

Background/Objectives: Gaucher disease type 1 (GD1) is characterized by hepatosplenomegaly, thrombocytopenia, and disabling bone manifestations requiring regular MRI monitoring. The EIROS study assessed the real-world impact of velaglucerase alfa on GD1 bone disease, using MRI data collected in French clinical practice. Methods: MRIs collected retrospectively from treatment initiation and prospectively during follow-up (12-months) were analyzed centrally by a blinded expert radiologist to evaluate bone infiltration using the Bone Marrow Burden (BMB) score and a qualitative method (stable, improved or worsened for the spine and femur). Abdominal MRIs were also centrally analyzed to assess hepatosplenomegaly. Bone manifestations, hepatosplenomegaly, and hematologic parameters were analyzed from medical records. Results: MRI data were available for 20 patients: 6 treatment-naive patients and 14 patients who switched to velaglucerase alfa from another GD treatment. Interpretable MRIs for BMB scoring were available for seven patients for the spine and one patient for the femur. Qualitative assessments (n = 18) revealed stability in spine and femur infiltration in 100.0% and 84.6% of treatment-switched patients (n = 13), respectively, and improvements in 80.0% and 60.0% of treatment-naive patients (n = 5), respectively; no worsening of bone infiltration was observed. Liver, spleen, and hematologic parameters improved in treatment-naive patients and remained stable in treatment-switched patients. Conclusions: The qualitative real-world data support findings from clinical trials suggesting the long-term effectiveness of velaglucerase alfa on GD1 bone manifestations. When MRI assessment by radiologists with experience of GD is not possible, a simplified qualitative assessment may be sufficient in clinical practice for monitoring bone disease progression and treatment response.

The Bone Biomarker of Quantitative Chemical Shift Imaging in Patients with Type 1 Gaucher Disease Receiving Low-Dose Long-Term Enzyme Replacement Therapy

Quantitative chemical shift imaging (QCSI) is the most sensitive imaging biomarker to assess bone marrow involvement in Gaucher disease. Widespread QCSI use is limited by test availability. Anecdotal reports describe two patients demonstrating significant improvement in fat fraction (FF) assessed by QCSI following a switch from imiglucerase to taliglucerase alfa. This analysis evaluated bone marrow involvement in adults with Type 1 Gaucher disease receiving low-dose enzyme replacement therapy (ERT) with imiglucerase and/or velaglucerase alfa. We report baseline data for 30 patients meeting eligibility criteria. Median (range) duration and dose of ERT were 18 (5–26) years and 30 (30–60) U/kg/month, respectively. Low FF scores (<0.30) were observed for seven patients (23%; 95% confidence interval, 10–42%) and were more common in females (n = 6) versus males (n = 1; p < 0.025); one female was menopausal. These baseline data demonstrate that prolonged low-dose ERT with imiglucerase or velaglucerase alfa led to an adequate bone response, assessed by QCSI, in the majority of patients. A minority of such patients with suboptimal bone response require therapeutic change. The next phase of the study will address the effect of switching to taliglucerase alfa on bone status for patients with less than optimal QCSI scores (<0.30).

Bone marrow burden score is not useful as a follow-up parameter in stable patients with type 1 Gaucher disease after 5 years of treatment

INTRODUCTION

Gaucher disease (GD) is one of the most prevalent lysosomal disorders, with an estimated incidence of 1 in 40,000 live births worldwide. Skeletal involvement is one of the main features of GD, causing morbidity and impacting long-term quality of life in patients with type 1 GD.

OBJECTIVES

To characterize bone marrow infiltration in patients with type 1 GD followed at the Gaucher Disease Referral Center of Porto Alegre, Brazil, and to assess whether the Bone Marrow Burden score (BMB) correlates with clinical or laboratory parameters. We also evaluated whether the BMB score is a suitable parameter for long-term follow-up of patients with type 1 GD.

METHODS

All included patients underwent magnetic resonance imaging for BMB score calculation at baseline, 1 year, and every other year thereafter or as clinically indicated from 2012 to 2018.

RESULTS

The BMB score tended to decrease during the first 5 years of treatment, at a rate of -1.08 points per year; after the 5-year mark, BMB tended to remain stable.

CONCLUSIONS

The BMB score is useful for response monitoring in the first five years of treatment. We recommend that, after 5 years of treatment, MRI for BMB evaluation should only be performed in non-adherent patients or in those who develop symptoms of acute skeletal disease.

Skeletal involvement in Gaucher disease: extent of bone disease, splenic volume, and quality of life

Objective

To investigate the correlations among the extent of bone involvement, splenic volume, and quality of life in patients with Gaucher disease.

Materials and Methods

This was a descriptive, prospective cross-sectional study of 18 patients with Gaucher disease who underwent 3-T magnetic resonance imaging of both femurs and the lumbar spine. Semiquantitative analyses were performed on the basis of the bone marrow burden (BMB) score. We looked for linear relationships among the variables splenic volume, quality of life score, and BMB score.

Results

We identified a linear relationship between the BMB scores and splenic volume. The quality of life score showed no statistically significant relationship with splenic volume or the BMB score.

Conclusion

The linear relationship between the BMB score and the splenic volume indicates that the extent of bone disease is greater in individuals with splenomegaly. No correlation was found between the BMB and quality of life scores, illustrating the insidious and silent progression of Gaucher disease.

Rare GBA1 genotype associated with severe bone disease in Gaucher disease type 1

Introduction

Gaucher disease (GD) type 1 is a lysosomal disease characterised by hepatosplenomegaly, anemia, thrombocytopenia, bone changes, and bone marrow infiltration. The disease is caused by biallelic pathogenic variants in GBA1 which codes for glucocerebrosidase, an enzyme involved in the catabolic pathway of complex lipids.

Aims

To report on the case of two sisters with GD type 1 who bear a genotype never reported in the literature.

Case report

Patient 1 is a 47-year-old female diagnosed at 42 years of age with chronic lumbar pain, mild splenomegaly, slightly reduced platelets and normal hemoglobin values, severe Bone Marrow Burden (BMB) score, high chitotriosidase activity, and low glucocerebrosidase. Patient 2 is a 50-year-old female, sister of patient 1, who was diagnosed after familial screening. At 45 years of age, she had osteonecrosis of the left femur and a total hysterectomy because of uncontrollable bleeding. At first evaluation, she had bone pain with a high BMB score, mild splenomegaly, normal hemoglobin, normal platelets count, elevated chitotriosidase activity, and low glucocerebrosidase activity. Both patients were found to be compound heterozygotes for the p.Glu388Lys and the p.Ser405Asn variants in GBA1.

Conclusions

This is the first family with GD and this combination of variants which causes a phenotype remarkable for severe bone disease with no or mild hematological manifestations.

Imaging of non-neuronopathic Gaucher disease: recent advances in quantitative imaging and comprehensive assessment of disease involvement

Gaucher disease is an inherited metabolic disorder resulting in deficiency of lysosomal enzyme β-glucocerebrosidase causing the accumulation of abnormal macrophages (“Gaucher cells”) within multiple organs, most conspicuously affecting the liver, spleen, and bone marrow. As the most common glycolipid metabolism disorder, it is important for radiologists encountering these patients to be familiar with advances in imaging of organ and bone marrow involvement and understand the role of imaging in clinical decision-making. The recent advent of commercially available, reliable, and reproducible quantitative MRI acquisitions to measure fat fractions prompts revisiting the role of quantitative assessment of bone marrow involvement. This manuscript reviews the diverse imaging manifestations of Gaucher disease and discusses more optimal quantitative approaches to ascertain solid organ and bone marrow involvement with an emphasis on future applications of other quantitative methods including elastography.

Gaucher Disease in Bone: From Pathophysiology to Practice

Gaucher disease (GD) is a rare, genetic lysosomal disorder leading to lipid accumulation and dysfunction in multiple organs. Involvement of the skeleton is one of the most prevalent aspects of GD and a major cause of pain, disability, and reduced quality of life. Uniform recommendations for contemporary evaluation and management are needed. To develop practical clinical recommendations, an international group of experienced physicians conducted a comprehensive review of 20 years' of the literature, defining terms according to pathophysiological understanding and pointing out best practice and unmet needs related to the skeletal features of this disorder. Abnormalities of bone modeling, reduced bone density, bone infarction, and plasma cell dyscrasias accompany the displacement of healthy adipocytes in adult marrow. Exposure to excess bioactive glycosphingolipids appears to affect hematopoiesis and the balance of osteoblast and osteoclast numbers and activity. Imbalance between bone formation and breakdown induces disordered trabecular and cortical bone modeling, cortical bone thinning, fragility fractures, and osteolytic lesions. Regular assessment of bone mineral density, marrow infiltration, the axial skeleton and searching for potential malignancy are recommended. MRI is valuable for monitoring skeletal involvement: It provides semiquantitative assessment of marrow infiltration and the degree of bone infarction. When MRI is not available, monitoring of painful acute bone crises and osteonecrosis by plain X-ray has limited value. In adult patients, we recommend DXA of the lumbar spine and left and right hips, with careful protocols designed to exclude focal disease; serial follow-up should be done using the same standardized instrument. Skeletal health may be improved by common measures, including adequate calcium and vitamin D and management of pain and orthopedic complications. Prompt initiation of specific therapy for GD is crucial to optimizing outcomes and preventing irreversible skeletal complications. Investing in safe, clinically useful, and better predictive methods for determining bone integrity and fracture risk remains a need. © 2019 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.

A Review of Gaucher Disease Pathophysiology, Clinical Presentation and Treatments

Gaucher disease (GD, ORPHA355) is a rare, autosomal recessive genetic disorder. It is caused by a deficiency of the lysosomal enzyme, glucocerebrosidase, which leads to an accumulation of its substrate, glucosylceramide, in macrophages. In the general population, its incidence is approximately 1/40,000 to 1/60,000 births, rising to 1/800 in Ashkenazi Jews. The main cause of the cytopenia, splenomegaly, hepatomegaly, and bone lesions associated with the disease is considered to be the infiltration of the bone marrow, spleen, and liver by Gaucher cells. Type-1 Gaucher disease, which affects the majority of patients (90% in Europe and USA, but less in other regions), is characterized by effects on the viscera, whereas types 2 and 3 are also associated with neurological impairment, either severe in type 2 or variable in type 3. A diagnosis of GD can be confirmed by demonstrating the deficiency of acid glucocerebrosidase activity in leukocytes. Mutations in the GBA1 gene should be identified as they may be of prognostic value in some cases. Patients with type-1 GD-but also carriers of GBA1 mutation-have been found to be predisposed to developing Parkinson's disease, and the risk of neoplasia associated with the disease is still subject to discussion. Disease-specific treatment consists of intravenous enzyme replacement therapy (ERT) using one of the currently available molecules (imiglucerase, velaglucerase, or taliglucerase). Orally administered inhibitors of glucosylceramide biosynthesis can also be used (miglustat or eliglustat).