| G6PD deficiency 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. | View Page |
| Hemolytic disease of the newborn 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. | View Page |
| Spherocytes and reticulocytes The photograph represents peripheral blood smear findings in another patient with hereditary spherocytosis. The red cells vary in size (anisocytosis)with a mixture of microcytes (red cells with central pallor) and microspherocytes (red cells with central staining). Macrocytes are conspicuous, some staining light blue. They are immature erythrocytes (reticulocytes)released from the bone marrow early. The bone marrow, geared up for rapid cell release in response to severe hemolysis, expels young red blood cells into the circulation before completing their 24 hour maturation cycle. Hemolysis, jaundice, and gall stone formation disappear following splenectomy. Gallbladder and stone removal eliminate the right upper quadrant pain. A serious consideration, especially in children with hereditary spherocytosis, is hemolytic crisis. A viral infection may allow red blood cell destruction to continue unabated. Anemia of such sudden onset and severity may become catastrophic, with death as the outcome. Splenectomy removes this possibility. | View Page |
| Warm antibody hemolytic disease A 49-year-old male with pneumonia was treated with penicillin. He became jaundiced with yellow sclera. Observe the photograph of his peripheral blood smear. Anisocytosis was observed with pale-centered microcytes and polychromatophilic macrocytes. Since penicillin is a classic offender for autoimmune hemolytic disease, the clinician asked for an antihuman globulin (AHG) test, also known as the Coombs test. A positive AHG reaction occurs when the antibody stimulated by penicillin becomes attached to red blood cells. Hemolysis follows, leaving the patient with jaundice and a peripheral blood smear, as demonstrated in the photograph. | View Page |
| A 10-year-old child presents with jaundice and scleral icterus. The photograph captures a section of the peripheral blood smear. The report should direct attention to: | View Page |
| Considering the predominance of microspherocytes on the blood smear, and the patient's jaundiced condition, what is the most likely diagnosis? | View Page |
| Leptocytes and target cells The peripheral blood smear of HbH disease presented before is reviewed in the upper photograph.As mentioned, these leptocytes are pale-staining with hemoglobin confined to a thin, flat, cell membrane.Illustrated in the lower photograph are target cells or codocytes (a term derived from a Greek word for hat)Membrane accumulations of phospholipids and cholesterol (particularly in obstructive jaundice) promote target cell formation.When these cells are spread out on a glass slide, a central bump of hemoglobin appears to produce the target, a manifestation of excess cellular membrane compared to the amount of hemoglobin inside.The early descriptions of thalassemias, then called hereditary leptocytosis (Mediterranean anemia, Cooley's anemia), include description of leptocyes, which may have represented HbH disease. | View Page |
| Reporting of laboratory data in regard to blood cell abnormalities Laboratory data must be presented to clinicians in a user friendly way to promote effective decision making. Databases must be designed to provide clear information that leads quickly to the best patient care outcome. We continue learning how to collect and retrieve laboratory data from our machines, but we are not always in tune to how entry and retrieval of data is geared to and, more directly, influences patient care outcomes. Examples of blood cell abnormalities on a peripheral blood smear that may immediately direct the physician to a specific diagnosis are: (1) presence of target cells as found in thalassemia or hemoglobinopathies and target cells in liver disease, particularly with obstructive jaundice; (2) burr cells as a signal of chronic renal disease and uremia; and (3)atypical neutrophil inclusions relating to genetic disorders. Critical appraisal of such observations could add valuable clues for a diagnosis. Laboratory professionals must establish a set of principles for orderly observation of blood cell morphology, have a clear vision of the applications of their work, and understand the potential clinical implications of their reports and interpretations. Emphasis on values and relevance focuses on patient care outcomes and their dependency on prompt availability of results and contextual interpretations. | View Page |