Immunocytochemical studies on bone marrow and peripheral blood smears from healthy controls and patients with sideroblastic anemia.

(A) Immuno-alkaline phosphatase staining of bone marrow cells from a healthy control using the monoclonal antibody rH02 specific for the H subunit of ferritin shows strong diffuse positivity in the cytoplasm of some erythroblasts. (B) Immuno-alkaline phosphatase staining of bone marrow cells from the previous healthy control using a polyclonal antibody raised against the MtF. Most erythroblasts are negative; the erythroblast on the left (arrow) shows weak positivity. (C) Immuno-alkaline phosphatase staining of bone marrow cells from a patient with XLSA using the anti-HF monoclonal antibody shows diffuse cytoplasmic positivity in a few erythroblasts. (D) Immuno-alkaline phosphatase staining for MtF of bone marrow cells from the previous XLSA patient. Many erythroblasts are positive with granules ringing the nucleus. (E) Immuno-alkaline phosphatase staining for HF of bone marrow cells from a patient with RARS. Diffuse cytoplasmic positivity is present in some erythroblasts. (F) Immuno-alkaline phosphatase staining for MtF of bone marrow cells from the previous patient with RARS. Positivity with granules surrounding the nucleus is present in 2 erythroblasts. (G) Double immunocytochemical staining for HF (immuno-alkaline phosphatase reaction) and MtF (immuno-β–galactosidase reaction) on a bone marrow smear from a patient with XLSA. The cellular distributions of HF and MtF are quite different, HF being diffusely distributed in the cytoplasm (red staining) and MtF localized in perinuclear granules (turquoise staining). (H) Perls Prussian blue staining of a peripheral blood smear from a patient with RARS; positive granules are visible in 2 red cells. (I) Immuno-alkaline phosphatase staining for MtF of peripheral blood smear from a patient with RARS; unequivocal positivity is observable in a circulating red cell. (J) Immuno-alkaline phosphatase staining for MtF of bone marrow cells from a patient with XLSA; a positive erythroblast (on the left) and a positive red cell (on the right) are shown. Original magnification, × 1250.