Immunohistochemical evaluation of bone marrow biopsies in myelodysplastic syndromes.

Immunohistochemical studies were performed with monoclonal antibodies (MAbs) reactive on paraffin embedded bone marrow biopsies in 19 patients with myelodysplastic syndromes, 8 of them during r gamma-interferon treatment. CD15 MAbs stained mature myeloid cells predominantly located close to the bone marrow trabeculae. Anti-gpIIIa MAbs permitted precise identification of megakaryocytic cells including precursors and dysplastic megakaryocytes. Labelling with CD45 and CD68 MAbs, recognizing lymphocytes and macrophages respectively, was intense in patients in steady state, but progressively decreased during leukemic transformation. Increase in CD45+ and/or CD68+ cells was also observed in most bone marrow biopsies after 3 months of r gamma-interferon therapy.