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

Background: 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.

Objective: 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).

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.