Unidentified Inclusions Within the Erythrocytes in Certain Gases of Febrile Anemia

This brief report concerns 3 cases of progressive febrile anemia, 2 ending fatally, which were characterized by the presence within the red cells of unidentified coccoid and bacillary bodies. These were stained dark blue or bluish purple with Wright or Giemsa stains (Fig. 1). From one to 20 or more bodies were present in a single cell, and from 10 to 55% of the cells were affected. They were somewhat pleomorphic, but frequently appeared in the form of diploids, tetrads, or short batonnets, straight or slightly curved. The presence of the structures was often associated with a de-hemoglobinization of the cells; in such cases, they were clustered at the margin.

In unstained preparations, the bodies were colorless, very slightly refractile and possessed of an oscillatory motion within the cell. Treated with HCl and potassium ferrocyanide, they gave a positive iron reaction; the iron staining persisted in acid solutions, but disappeared after exposure to alkali at about pH 10. The morphology of the bodies was not altered by these procedures. They were not blackened by (NH₄)₂S, as is hemosiderin, nor by silver nitrate; they gave no histochemical reaction for alkaline phosphatase; the Feulgen reaction was also negative. They were resistant to autolysis, and to tryptic digestion.

By laking the blood with distilled water or saponin, it was possible to obtain a very great concentration of the bodies in the centrifuged sediment (Fig. 2). When a suspension of intact red cells containing the bodies was placed in a strong electro-magnetic field, the cells with the inclusions were drawn in a linear streak along the sharp edge of the magnet.

In Giemsa stained sections of the spleen, in all 3 cases, minute blue-staining bodies were present within the endothelial cells lining the sinuses. They were found also in reticuloendothelial cells of lymph-nodes and bone marrow, and in Kuppfer cells, in the 2 fatal cases.