From the Guidelines
A CBC in sickle cell anemia typically shows a low hemoglobin level, often between 60 and 90 g.l-1, with decreased red blood cell count, as well as elevated white blood cell and platelet counts, reflecting the underlying pathophysiology of the disease 1. The severity of sickle cell disease varies according to genotype and within genotype, with HbSS, HbSß0-thalassaemia, and HbSD disease being associated with severe sickle cell disease, early onset of painful crises, and severe anemia.
- Key characteristics of a CBC in sickle cell anemia include:
- Low hemoglobin level, often between 60 and 90 g.l-1
- Decreased red blood cell count
- Elevated white blood cell count
- Elevated platelet count
- Presence of sickle-shaped red blood cells, target cells, nucleated red blood cells, and Howell-Jolly bodies on peripheral blood smear
- Increased reticulocyte count, often 10-20%, as the bone marrow attempts to compensate for the shortened red cell lifespan These findings are consistent with the pathophysiology of sickle cell anemia, where abnormal hemoglobin S causes red blood cells to become rigid and sickle-shaped under low-oxygen conditions, leading to hemolysis and vaso-occlusion, as described in the guideline on the peri-operative management of patients with sickle cell disease 1. Regular CBC monitoring is essential for patients with sickle cell anemia to track disease severity, detect complications, and guide treatment decisions, such as the use of hydroxycarbamide to raise fetal hemoglobin levels and reduce the severity of the disease 1.
From the Research
Characteristics of a Complete Blood Count (CBC) in Sickle Cell Anemia
- The CBC in sickle cell anemia typically shows reduced values of hemoglobin and hematocrit, with a mean hemoglobin level of 7.9 ± 1.3g/dl and a mean hematocrit of 25.7 ± 4.4% 2, 3
- Leucocytosis is a common feature, with a mean total leucocyte count (TLC) of 14.3 ± 4.5 x 10^3/mm^3 3
- Thrombocytosis is also seen in some patients, with a mean platelet count of 391.5 ± 182.6 x 10^3/mm^3 3
- The mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) are typically low, with mean values of 81.3 ± 7.1 fl, 28.6 ± 2.9 pg, and 35.2 ± 1.7 g/dl, respectively 3, 4
- Fetal hemoglobin levels are often increased, with a mean level of 12 ± 7% 2
Age-Related Variations in CBC Parameters
- Children aged 1-4 years tend to have lower mean hemoglobin and platelet counts, as well as lower MCV, MCH, and MCHC values 3
- Leucocytosis is more common in younger subjects, with the highest TLC values seen in children aged 1-4 years 3