INDOLENT SYSTEMIC MAST-CELL DISEASE IN ADULTS - IMMUNOPHENOTYPIC CHARACTERIZATION OF BONE-MARROW MAST-CELLS AND ITS DIAGNOSTIC IMPLICATIONS

The aim of the present study was to explore the diagnostic value of th e immunophenotypic analysis of bone marrow mast cells (BMMC) in indole nt systemic mast cell disease (SMCD) patients. For that purpose, a tot al of 10 SMCD patients and 19 healthy controls were analyzed. Our resu lts show that BMMC from SMCD are different from normal BMMC with regar d to both their light scatter and immuno-phenotypic characteristics. A ccordingly, forward light scatter (FSC), side (90 degrees) light scatt er (SSC), and baseline autofluorescence levels were higher in BMMC fro m indolent SMCD patients than they were in control subjects. From the immunophenotypic point of view, the most striking findings were the co nstant expression of CD2 (P =.0001), CD25 (P =.0001), and CD35 (P =.06 ) molecules by BMMC from SMCD patients, markers that were absent from all normal controls. In contrast, CD71, absent in BMMC from indolent S MCD, was positive in BMMC from normal subjects. Although, slight diffe rences between BMMC from SMCD patients and normal controls were found in several other markers, they did not reach statistical significance. In conclusion, our results show that simultaneous assessment of FSC/S SC and reactivity for the CD117, CD2, CD25, CD33, and CD35 forms the b asis for the immunophenotypic characterization of BMMC from SMCD in ad ults and should be integrated with clinical and morphologic studies fo r the diagnosis of the disease. (C) 1998 by The American Society of He matology.