Spherocyte Information and Courses from MediaLab, Inc.

A ten-year-old boy came to a physician's attention because of recent jaundice and icteric sclerae. The immediate laboratory work revealed: Hct 24%(normal 36%-47%), MCV 79.5 fl (normal 78-95fl),RDW 13%(normal 11.5-15.0%). His blood smear findings are reflected in these photomicrographs. Note particularly the spherocytes in the upper picture. Some resemble a half-blister with the other half of the cell containing solidly-staining hemoglobin. These are called eccentrocytes. When present, they should trigger a search for red cell hereditary G-6PD deficiency and the oxidant that triggered hemolysis. These morphological findings are only clues; specific testing for G-6PD deficiency should be performed. The blue arrows in the upper photomicrograph are directed toward solid-staining spherocytes in which the cell membrane is beaded by inclusions wrapped within the cell membrane, suggesting the remains of denatured hemoglobin. Included on the smear is a target cell, several acanthocytes, a smudge cell, and a few schistocytes. The lower photomicrograph is supravital staining of affected red blood cells, verifying the presence of Heinz bodies. This disorder was first recognized during the Korean war in 10% of black American soldiers given the antimalarial drug primiquine.

The peripheral smear illustrated in the photograph was obtained from a patient with a recent renal transplant. The patient developed a rash, accompanied by nausea and diarrhea. Graft vs. host disease was clinically suspected. The peripheral smear findings are consistent with that diagnosis. The presence of spherocytes suggests a hemolytic process which is supported by the presence of nucleated RBCs. A few scattered schistocytes and the decrease of platelets suggests DIC. The presence of target cells presents the possibility of associated liver disease. Additional tests, particularly coagulation studies, should confirm the diagnosis of microangiopathic hemolytic anemia.

Jaundice was recognized in a day-old infant. Notice particularly the size variation (anisocytosis) of the erythrocytes on the infant's peripheral smear. What does this observation mean? Does it provide immediate information that might serve as guidance in expediting diagnosis and treatment? Note that normal-sized red blood cells, microcytes, microspherocytes, macrocytes, and nucleated red blood cells are all present. Red cell variations are expected findings in healthy neonates, but the variations here are exaggerated. Hyposplenic functional features may appear, including acanthocytes, spherocytes, and possibly Howell-Jolly bodies, especially if hemolysis is particularly vigorous. A high (3-7%) reticulocyte count is not unusual during the first three or four days after birth, however, the marrow in this jaundiced infant is proliferating vigorously in response to hemolysis. A call for more red cells is urgent. Immature red cells (in the form of nucleated red cells) and red cells with stippling of RNA (basophilic stippling) are readily identified. Red cell maturation sequence has not been totally processed in the marrow nor is all residual red cell debris removed by the spleen. In the lower photograph are reticulocytes stained by supravital stain (new methylene blue). Basophilic stippling (specks of RNA) stains with both supravital stains and with routine Wright-Giemsa stain.

Stomatocytes are erythrocytes with a slit-like central pallor. Otherwise, they resemble typical RBC's in size and shape. Unless 10% or more of the RBC's are stomatocytes, their presence is probably artifactual. Stomatocytes form at a low blood acidic pH as seen in exposure to cationic detergents, and in patients receiving phenolthiazine. Hereditary stomatocytosis has some resemblance to hereditary spherocytosis, as stomatocytes may develop into spherocytes with further metamorphosis. In hereditary stomatocytosis, mild anemia and findings of on-going hemolysis should be evident if the condition presents as a clinical problem at all.

Another example of a knizocyte is seen in this slide. These forms are seen in conditions in which spherocytes are visible and in some types of hemolytic anemia.

Spherocytes are red cells which have a decreased surface-to-volume ratio. As a result, this type of cell is thicker in diameter than normal red cells and on a Wright’s stained smear, in the proper viewing area, they appear to be round, darkly-stained cells without central pallor. A spherocyte can be seen in the center of this slide.