Tartrate-resistant acid phosphatase staining of monocytes in Gaucher disease.

Cytochemical studies were performed on peripheral blood from 30 patients with type 1 Gaucher disease. In 29 of the patients, peripheral blood monocytes stained positively for tartrate-resistant acid phosphatase, whereas monocytes from 18 normal individuals and 14 patients with monocytosis did not. In the Gaucher patients, the percentage of monocyte positivity for tartrate-resistant acid phosphatase ranged from 2 to 97. There was no correlation between the percent monocyte staining and the degree of disease severity, as measured by hepatosplenomegaly, pancytopenia, or extent of bone disease, for the group as a whole. In Gaucher patients who had not undergone splenectomy, however, there was a significant correlation between percent monocyte staining and the degree of hepatosplenomegaly, anemia, and thrombocytopenia. The presence of tartrate-resistant acid phosphatase may be secondary to the lysosomal accumulation of glucosyl ceramide within these monocytes, although this remains to be confirmed. If so, these circulating cells may represent precursors of the Gaucher cells in tissues. Tartrate-resistant acid phosphatase staining of peripheral blood monocytes may be useful as a diagnostic marker for Gaucher type 1 disease and for further studies on the pathogenesis of the disease.