Bone manifestations in neuronopathic Gaucher disease while receiving high-dose enzyme replacement therapy

Abstract

Avascular necrosis (AVN), one type of bone infarction, is a major irreversible complication of Gaucher disease (GD). In this report, two pediatric patients with GD type 3, homozygous for the L483P pathogenic variant (formerly L444P), developed AVN despite treatment on long-term, high-dose enzyme replacement therapy (ERT). ERT was initiated in both patients, who had intact spleens, shortly after diagnosis with an initial dramatic response. However, both patients exhibited AVN after 5.5 and 11 years on high-dose ERT, respectively, despite good compliance and normalized hematological findings and visceral symptoms. This report demonstrates the importance of careful, regular surveillance of the musculoskeletal system in addition to monitoring the neurological symptoms associated with neuronopathic GD. Additionally, it highlights the limitations of ERT in terms of targeting certain sanctuary sites such as bone marrow and suggests the need for new treatment modalities other than ERT monotherapy to address these limitations.

Keywords: ACE; AVN; Avascular necrosis; BMD; Bone manifestations; CHITO; DXA; ERT; Enzyme replacement therapy; GD; Gaucher disease; MRI; Osteonecrosis; SRT; TRAP; angiotensin-converting enzyme; avascular necrosis; bone mineral density; chitotriosidase; dual-energy X-ray absorptiometry; enzyme replacement therapy; magnetic resonance imaging; substrate reduction therapy; tartrate-resistant acid phosphatase.