Figure 8.

Typical TRAP⁺ large osteoclasts and also smaller TRAP⁺ cells are present in bone biopsies from CLL patients. (Ai) Large TRAP⁺ cells (brown; red arrows) were observed on trabeculae rims ‘B’ while smaller TRAP⁺ cells were detectable in the marrow stroma ‘BM’. Representative images from two CLL patients (LSA01, DA06) are shown. (Aii) TRAP and CD79a co-immunostaining revealed that TRAP⁺ osteoclasts (brown) are often proximal to CD79a⁺ leukemic B cells (pink), as shown in the enlargements. (Aiii) Positive controls for TRAP immunostaining: two patients with multiple myeloma and myelofibrosis. The bar represents 125 μm except in the inserts in which they represent 32 μm. (B) Number of TRAP⁺ osteoclasts, related to the number of bone trabeculae, as observed in bone biopsies sections from three patients with CLL (LSA01, DA06, BS13), one patient with multiple myeloma and one normal control. Among CLL patients, LSA01 and DA06 had unmutated IGVH and were in Binet stage B and C, respectively, while BS13 was in Binet stage C.