Clinical utility of different bone marrow examination methods in the diagnosis of adults with sporadic Gaucher disease type 1

INTRODUCTION In the absence of a known affected family member, frequent symptoms of Gaucher disease (GD), a rare lysosomal storage disorder, such as thrombocytopenia or splenomegaly, often lead to hematological diagnostic workup.

OBJECTIVES The aim of the study was to compare the clinical utility of aspiration biopsy of the bone marrow (ASP) with trephine biopsy (TB) for the diagnosis of GD type 1 (GD1).

PATIENTS AND METHODS Six non-Jewish patients with sporadic GD1 were initially examined with ASP and TB to establish the cause of cytopenia and splenomegaly. In the current study, samples from each patient consisted of 2 bone marrow slides. On each slide, 500 nucleated cells were counted and then averaged. The composition of bone marrow TBs was assessed using digital images analyzed on a computer.

RESULTS Of 6 patients, 5 carried at least 1 N370S allele with a c.1226A>G mutation in the GBA1 gene. The median number of Gaucher cells identified during cytological assessment of bone marrow smears was 4 (range, 1–18), and the median percentage of Gaucher cells was 0.4% (range, 0.1%–1.8%). The absolute proportion of Gaucher cells in histological samples ranged from 22% to 36% (median value, 28%), and the ratio of Gaucher cell infiltrate to hematopoietic tissue ranged from 34% to 54% (median

value, 47%). The median value of the ratio of Gaucher cells to hematopoietic tissue was strikingly lower when using ASP compared with TB (P = 0.028).

CONCLUSIONS Our results indicate that ASP is not a reliable diagnostic tool for the detection of GD1. Thus, patients with unclear long-lasting splenomegaly and/or thrombocytopenia, in whom bone marrow aspirate cytology is negative for Gaucher cells, should be routinely referred for an enzymatic assay for GD.