Red blood cell inclusions can arise from a variety of sources. Correct identification of these abnormalities is important since it can provide insights into metabolic, physiologic, and pathologic conditions affecting the red blood cells. Show
Basophilic stippling Basophilic stippling of erythrocytes Basophilic stippling represents the spontaneous aggregation of ribosomal RNA in the cytoplasm of erythrocytes. These aggregates stain, and hence are visible, with routine hematology stains. Basophilic stippling of erythrocytes may be seen in the following conditions:
Heinz bodiesHeinz body under electron microscope Oxidation of exposed sulfhydryl groups on hemoglobin causes formation of disulfide bonds and distortion of the tertiary structure of the hemoglobin molecule. The result is precipitation of hemoglobin, which may then coalesce to form intracellular inclusions called Heinz bodies. Small, non-pathologic “endogenous” Heinz bodies can be found in blood of many healthy cats, but their presence is abnormal in other species. Increased numbers of these “endogenous” Heinz bodies are found in cats with diabetes mellitus (associated with ketone production), lymphoma and hyperthyroidism. Although many of these cats are not anemic, their red blood cell lifespans are reduced and they have lower hematocrits than cats with the same disease but lower numbers of Heinz bodies. Heinz bodies may be seen in Wright’s stained smears, especially if they are large and distort the red cell membrane. In contrast, small “endogenous” Heinz bodies, such as those that can be seen in cats, are harder to visualize. Heinz bodies can be easily observed with supravital stains, such as new methylene blue, as illustrated in the picture below. Extensive Heinz body formation and attachment to the membrane increase the rigidity of the red blood cells and render them susceptible to fragmentation and entrapment in the spleen where they are phagocytized. Heinz body hemolytic anemia in cat with acetaminophen toxicosis Diagnosis of an is based on finding a regenerative anemia with characteristic red blood cell morphologic abnormalities of Heinz bodies and . Some causes of oxidant injury also cause intravascular red blood cell lyse (rupturing of red blood cell membranes) and manifest with hemoglobinemia and hemoglobinuria. Some animals may also develop methemoglobinemia (brown plasma) from oxidant-induced injury to the iron in hemoglobin (reduced iron or Fe2+ is converted to oxidized iron or Fe3+ in the porphyrin of hemoglobin, producing methemoglobin). Note, that methemoglobemia, Heinz bodies or eccentrocytes may dominate in a particular condition. Causes of oxidant-induced hemolytic anemia are:
Howell-Jolly bodiesHowell-Jolly bodies from a splenectomized dog Howell-Jolly bodies (also called micronuclei) are small fragments of non-functional nucleus which were not extruded as the erythrocyte left the bone marrow. Usually, but not always, the host erythrocyte contains only a single Howell-Jolly body, which appears as a blue, perfectly round inclusion. Occasionally, uneven staining of an Howell-Jolly body can result in a ring-like appearance which may mimic a parasite. In dogs and ruminants, Howell-Jolly bodies are not routinely observed in peripheral blood because they are removed from red blood cells by the pitting function of the sinusoidal spleen. Howell-Jolly bodies can be seen in the following situations:
SiderocytesSiderocytes in a cat Siderocytes are anucleate erythrocytes with iron-containing (siderotic) cytoplasmic inclusions. The inclusions can be due to aggregates of iron in the cytoplasm or within mitochondria (the latter are called Pappenheimer bodies). A nucleated erythoid cell with the same inclusions (usually within mitochondria) is termed a sideroblast. Siderocytes should be distinguished from (aggregates of RNA) because they mean different things. Generally, siderocytes have small focal accumulation of light blue to grey material, whereas basophilic stippling is more chunky and diffusely distributed throughout the cytoplasm. Siderocytes will also stain blue with Prussian blue reaction (detects ferric iron), if the iron is in sufficient amounts to readily visualize (small amounts do not stain well with Prussian blue). Which cell inclusion bodies can be stained by supravital stain?20 Heinz Bodies
Inclusions can only be visualized with supravital stains. After staining, Heinz body inclusions appear dark blue-purple and are located at the periphery of the red blood cell at the membrane.
What are the red blood cell inclusion bodies that stain Supravitally?Other RBC inclusions that stain supravitally include Heinz, Howell-Jolly, and Pappenheimer bodies (Table 16.3). Heinz bodies are precipitated hemoglobin, usually appear round or oval, and tend to adhere to the cell membrane (Figure 11.12). Howell-Jolly bodies are round nuclear fragments and are usually singular.
Which of the following erythrocyte inclusions can be visualized with supravital stain?Which of the following erythrocyte inclusions can be visualized with supravital stain but cannot be detected on a Wright's-stained blood smear? Heinz bodies are irregular, refractile, purple inclusions that are not visible with Wright's stain but show up with supravital staining.
Which cells are demonstrated by supra vital staining?Myeloblasts may or may not contain neutral red vacuoles, and may or may not contain a rosette. 9. Supravital staining is a good technic for the identification of monocytes from human blood and marrow, and is the method of choice for the study of macrophages.
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