Sickle Cell Disease: Laboratory Investigations And Hemoglobin Study (pp. 137-155)
Authors: Wajcman, Henri (Hôpital H. Mondor, Créteil, France)
Abstract: The diagnosis of any sickle cell disease syndrome is based on the unambiguous identification of the Hb S mutation. Electrophoretic tests are usually the first that are performed. A much better resolution is obtained with isoelectric focusing than with the more conventional cellulose acetate electrophoresis at alkaline pH. In some laboratories the first test which is performed is now cation exchange HPLC. The diagnosis of Hb S should never be accepted if not confirmed by a second test, more specific of this Hb, such as the solubility test or electrophoresis on agar in citrate buffer. The laboratory should also evaluate the other factors interacting with Hb S, such as Hb F level, sickle cell restriction haplotype, association with á-thalassemia or other á or â globin gene variants. It should also evaluate other cellular factors and, in case of symptomatic heterozygous patients, help in the understanding of the underlying mechanisms.