Test code links throughout this Guide refer to the corresponding test in the User's Guide. HPLC utilizes the principles of cation-exchange for the separation and determination of the relative percent of normal and abnormal hemoglobins. It has the unique property of combining reversibly with oxygen and is the medium by which oxygen is transported within the body. The primary hemoglobin in a normal adult is Hgb A, with small amounts of Hgb A2 and Hgb F. Approximately 400 mutant hemoglobins are now known, some of which may cause serious clinical effects. This is especially true in the homozygous state or in combination with another abnormal hemoglobin.
Differential diagnosis can lead to improved treatment of the patient, as well as genetic counseling.
However, with early detection and treatment, survival into the adult years is possible. HPLC is a rapid and reproducible method for the determination of hemoglobin variants. They are not clearly separated by gel. Additional studies may include tests of hemoglobin solubility for Hb S, isopropanol stability for the unstable hemoglobins, alkali denaturation to measure Hb F, and Heinz body stains. Rarely, globulin-chain synthesis studies are required to characterize a thalassemia.