Hemoglobin fractionation by Sebia Capillarys 2 Flex Piercing System as primary method for evaluation of hemoglobinopathies.

BACKGROUND: Hemoglobin fractionation by capillary zone electrophoresis (CE) is becoming a popular method for the identification of hemoglobin variants that can cause hemoglobinopathies. The goal of this study was to compare the performance of capillary electrophoresis using Sebia Capillarys 2 Flex Piercing system (CE-S) with high-pressure liquid chromatography (HPLC) using Primus Ultra2 Resolution Variants System (HPLC-P) as a primary method in hemoglobinopathy work-up. METHODS: A total of 306 blood specimens submitted for evaluation of hemoglobinopathies were studied using HPLC-P and CE-S. RESULTS: The reference ranges for Hb A, A2 and F agreed well between methods. All common variants containing Hb S and Hb C were detected by both methods. Quantification of Hb A2 with HPLC-P required a correction in the presence of Hb S, while quantification of Hb A2 was slightly overestimated by CE-S in the presence of Hb C. Of 41 samples containing other variants, 2 were not identified by HPLC-P and 3 were not identified by CE-S. CONCLUSION: CE-S provides comparable information to that obtained by HPLC-P and it is a reliable primary method for the evaluation of hemoglobin variants.

Compound heterozygosity for Hb S [ß6(A3)Glu→Val] and Hb Kenya (Aγ81Leu-ß86Ala) in a Ugandan woman.

Hb Kenya is a hemoglobin (Hb) tetramer composed of two normal α- and two non α-globin chains. The latter are the product of a fusion gene in which the 5' end is (A)γ and the 3' end is ß. The crossover point is between codon 81 of the (A)γ gene and codon 86 of the ß gene. Like the other non α genes, the hybrid protein product ((A)γ81Leu-ß86Ala) has 146 amino acids. The purpose of this report is to highlight the laboratory findings of Hb Kenya and to emphasize the pitfalls in misdiagnosis, particularly when associated with another variant such as Hb S [ß6(A3)Glu→Val].