Point prevalence of Gaucher disease (GD) is 0.5% among patients referred to a hematologist for thrombocytopenia, according to the results of a single-center study in Canada.
The findings were presented by Vidushi Swarup, MS, clinical research coordinator of the Hematology-Oncology Clinical Research Group at St Michael’s Hospital in Toronto, Ontario, Canada, and colleagues at the Thrombosis & Hemostasis Summit of North America (THSNA) 2020 Virtual Conference.
GD is a genetic disease that leads to the accumulation of lipids within the cells and can affect some organs more than others, in particular the spleen. GD has diverse clinical manifestations, such as anemia, thrombocytopenia, and splenomegaly.
“A multicenter observational study in Italy found a 3.6% (7 of 196 patients) point prevalence of GD in patients with splenomegaly and/or thrombocytopenia. While a prevalence of 3.6% may be true in Italy due to founder effect, the prevalence in Canada remains unclear,” wrote the authors.
The aim of this prospective, cross-sectional, single-center study was to determine the point prevalence of GD in unselected, consecutive adult patients with thrombocytopenia as the reason for consultation referred to hematology clinics in Canada. Patients receiving chemotherapy for a hematologic malignancy were excluded from the analysis.
Blood samples were screened for enzymatic activity of the GD-associated protein β-glucocerebrosidase (GBA), and those deficient in activity were sent for genetic sequencing to determine the presence of GD-associated pathogenic mutations.
In total, 448 patients with thrombocytopenia were screened for GD. Of those, 424 patients (94.6%) had normal GBA activity (GD-negative), while 24 patients had reduced or borderline-reduced GBA activity (GD-positive).
Of the GD-positive patients, samples were collected from 23 patients for subsequent genetic sequencing. No known pathogenic mutations were identified in 21 patients, while pathogenic mutations were identified in 2 patients. A single patient was lost to follow-up and, therefore, not tested for pathogenic mutations due to lack of consent.
Overall, with genetic confirmation, the findings indicate a point prevalence of GD of 0.5% (95% CI, 0.1-1.6) among Canadian patients referred for thrombocytopenia.
“Our findings are in stark contrast to the previously cited Italian study,” wrote the authors, “[and] suggest limited utility for screening for GD in Canadian patients with thrombocytopenia in the absence of other GD-defining signs and symptoms.”
The investigators highlight the need for additional research in other geographical locations to assess the utility of screening for GD in patient populations of different ethnicities/racial backgrounds.
Swarup V, Veloce N, Jiwajee A, et al. Gaucher disease screening in patients with thrombocytopenia: a cross-sectional study. Abstract presented at: THSNA 2020 Thrombosis & Hemostasis Summit of North America; October 27-30, 2020. Abstract 72.