Immunohistochemical assessment of ferritin in bone marrow trephine biopsies: correlation with marrow hemosiderin.

In 340 bone marrow biopsies we compared ferritin, stained with an immunoperoxidase method, with hemosiderin, stained with Perls' reaction. Ferritin and hemosiderin showed the same distribution in reticuloendothelial cells. All the Perls-positive cases (n = 177) were ferritin-positive too. None of the ferritin-negative cases (n = 13) were Perls-positive. Of 163 cases with negative Perls' reaction in bone marrow, 13 (12.5%) were also ferritin-negative: these patients were mainly affected by polycythemia vera or by untreated iron deficiency anemia. Thus, immunohistochemical assessment of bone marrow ferritin can be a more sensitive tool for the evaluation of body iron stores in iron deficiency than Perls' reaction.