Types Of Sickle Cell
Sickle Cell Trait
Sickle Cell Trait is benign because patients do not get vaso-occlusive crisis; they have a better quality of life and mortality is the same as the rest of the general population. Due to the benign nature of sickle cell trait, it generally does not have any clinical implications. However, there have been reports of adverse conditions that occur due to patient's trait status. Therefore, sickle cell trait may not be completely benign and these patients should be managed aggressively whenever they develop some of these complications. This article discusses sickle cell trait etiology, epidemiology, histopathology, complications, and why more attention should be given to this condition.
Sickle Cell Anemia (SS), Sickle Hemoglobin-C Disease (SC)
Sickle Cell Anemia (SS): When a child inherits one substitution beta globin genes (the sickle cell gene) from each parents, the child has Sickle Cell Anemia (SS). Populations that have a high frequency of sickle cell anemia are those of African and Indian descents.
Sickle Hemoglobin- C Disease (SC): Individuals with Sickle Hemoglobin-C Disease (SC) have a slightly different substitution in their beta globin genes that produces both hemoglobin C and hemoglobin S. Sickle Hemoglobin-C disease may cause similar symptoms as sickle cell anemia but less anemia due to a higher blood count level. Populations that have a high frequency of Sickle Hemoglobin-C disease are those of West African, Mediterranean and Middle Eastern descents.
Sickle Beta-Plus Thalassemia and Sickle Beta-Zero Thalassemia
Sickle Beta-Plus Thalassemia: Individuals with Sickle Beta Thalassemia (SB) disease also contain substitutions in both beta globin genes. The severity of the disease varies according to the amount of normal beta globin produced. When no beta globin is produced, the symptoms are almost identical to sickle cell anemia, with severe cases needing chronic blood transfusions. Populations that have a high frequency of Sickle Beta Thalassemia are those of Mediterranean and Caribbean descents.
Sickle Hemoglobin-D Disease and Sickle Hemoglobin-O Disease
Sickle Hemoglobin-D Disease: Through research, hemoglobin D, which is a different substitution of the beta globin gene, has been found to interact with the sickle hemoglobin gene. Individuals with Sickle Hemoglobin-D disease (SD) have moderately severe anemia and occasional pain episodes. Populations that have a high frequency of Sickle Hemoglobin-D disease are those of Asian and Latin American descents.
Sickle Hemoglobin-O Disease: Hemoglobin O, another type of substitution in the beta globin gene, also interacts with sickle hemoglobin. Individuals with Sickle Hemoglobin- O disease (SO) can have symptoms of sickle cell anemia. Populations that have a high frequency of Sickle Hemoglobin-O disease are those of Arabian, North African and Eastern Mediterranean descents.
Do You Know Your Hemoglobin Base Line ?
Baseline Blood Study Abnormalities
Typical baseline abnormalities in the patient with SCD are as follows:
Hemoglobin level is 5-9 g/dL
Hematocrit is decreased to 17-29%
Total leukocyte count is elevated to 12,000-20,000 cells/mm3 (12-20 X 109/L), with a predominance of neutrophils
Platelet count is increased
Erythrocyte sedimentation rate is low
The reticulocyte count is usually elevated, but it may vary depending on the extent of baseline hemolysis
Peripheral blood smears demonstrate target cells, elongated cells, and characteristic sickle erythrocytes
Presence of RBCs containing nuclear remnants (Howell-Jolly bodies) indicates that the patient is asplenic
Results of hemoglobin solubility testing are positive, but they do not distinguish between sickle cell disease and sickle cell trait