Bone marrow disorders: characterization with quantitative MR imaging

Thirty patients with various hematologic disorders and 15 healthy control subjects underwent quantitative magnetic resonance (MR) imaging of the lumbar spine with spin-echo techniques. Images of patients with infiltrative bone marrow disorders showed significantly more prolonged T1 times than those of control subjects (P less than .001). It was not possible to distinguish different diffuse infiltrative bone marrow disorders on the basis of T1 values. Aplastic anemia could be distinguished from normality because of significantly shortened T1 (P less than .001). A significant correlation was seen between T1 and bone marrow cellularity (r = .74, P less than .001). T2 was of no value in the characterization of bone marrow disorders. Quantitative MR imaging dose not improve the diagnostic potential of bone marrow imaging in the detection of diffuse marrow infiltrates.     

Adhesion molecule expression on B-cell chronic lymphocytic leukemia cells: malignant cell phenotypes define distinct disease subsets

Expression of surface adhesion molecules of the Ig superfamily (CD54 and CD58), of the integrin family (beta 1, beta 2, and beta 3 chains), of the selectin family (L-selectin), and of the lymphocyte homing receptor (CD44) was analyzed on B-cell chronic lymphocytic leukemia (B- CLL) cells from 74 patients. The aim of the study was the definition of phenotypically distinct disease subsets and the correlation of adhesion molecule phenotypes with clinical parameters. Expression of CD58 on B- CLL cells defined more advanced disease stages. In comparison with beta chain-positive cases, patients whose cells did not express beta 1, beta 2, and beta 3 integrin chains fell into the most favorable prognostic group, with lower lymphocytosis and the absence of splenomegaly, diffuse bone marrow infiltration, and therapy requirement. A novel finding was the expression of beta 3 chains on cells from a minority (12 of 74) of B-CLL cases. beta 3 chains were always coexpressed with beta 1 and beta 2 chains. Two-color immunofluorescence analyses of adhesion molecules such as alpha x beta 2 integrin (LeuM5) and L- selectin (Leu8) showed that these markers were detectable on variable proportions of leukemic cells, thus confirming the intraclonal phenotypic heterogeneity of B-CLL. Differences in the intensity of CD44 expression were also shown among the various B-CLL clones. Finally, no major variations were shown by comparison of adhesion molecule phenotypes of leukemic cells simultaneously obtained from blood and bone marrow, and of CD5+ versus CD5- clones.