Sickle Cell Disease: Diagnosis

Prenatal screening is possible through chorionic villous sampling if the fetus is at risk for SCD. Other tests may be routinely available in the near future.

Universal newborn screening by electrophoresis (or other diagnostic testing) is performed in all states. Sickle cell anemia is indicated by the presence of fetal hemoglobin (hemoglobin F) and hemoglobin S, and an absence of hemoglobin A.

Electrophoretic findings for sickle cell anemia are:

• Hemoglobin S at 85% to 98% (normally 0%).
• Hemoglobin A at 0% (normally 95%-98%).
• Hemoglobin F at 5% to 15% (normally 0.8%-2.0%).

Additional findings are likely to include a normochromic, normocytic anemia, reticulocytosis, and sickle cells (and other abnormal findings including polychromasia) visible on peripheral blood smear. Other findings consistent with hemolysis may also be present.

Subsequent to diagnosis, patients should undergo periodic testing, which includes complete blood count (CBC), iron studies, liver function tests, and tests of renal function, such as urinalysis, blood urea nitrogen (BUN), and creatinine. These data can be compared with those assessed during exacerbations to guide medical management.