Hematopoietic stem cell transplantation or enzyme replacement therapy in Gaucher disease type 3

Gaucher disease (GD) is a lysosomal storage disorder with glucocerebroside accumulation in the macrophages. The disease is divided into three types based on neurocognitive involvement with GD1 having no involvement while the acute (GD2) and chronic (GD3) are neuronopathic. The non-neurological symptoms of GD3 are well treated with enzyme replacement therapy (ERT) which has replaced hematopoietic stem cell transplantation (HSCT). ERT is unable to prevent neurological progression as the enzyme cannot cross the blood-brain barrier. In this retrospective study, we report the general, neurocognitive, and biochemical outcomes of three siblings with GD3 after treatment with ERT or HSCT. Two were treated with HSCT (named HSCT1 and HSCT2) and one with ERT (ERT1). All patients were homozygous for the c.1448 T > C, (p.Leu483Pro) variant in the GBA1 gene associated with GD3. ERT1 experienced neurocognitive progression with development of seizures, oculomotor apraxia, perceptive hearing loss and mental retardation. HSCT1 had no neurological manifestations, while HSCT2 developed perceptive hearing loss and low IQ. Chitotriosidase concentrations were normal in plasma and cerebrospinal fluid (CSF) for HSCT1 and HSCT2, but both were markedly elevated in ERT1. We report a better neurological outcome and a normalization of chitotriosidase in the two siblings treated with HSCT compared to the ERT-treated sibling. With the advancements in HSCT over the past 25 years, we may reconsider using HSCT in GD3 to achieve a better neurological outcome and limit disease progression.