Valeurs de référence de l'hémoglobine A2dans le district de Bamako au Mali

In contexts where molecular biology is not available, the characterization of thalassemia syndromes is based on data from the complete blood cell count, iron status and hemoglobin typing. Routine typing of hemoglobin is done by the technic of electrophoresis at alkaline pH. This technic does not allow separating and quantifying hemoglobins C and A2. The separation of hemoglobins C and A2 followed by their quantification is made possible since the advent of capillary zone electrophoresis. To characterize the thalassemia syndromes in the Malian populations characterized by a high frequency of hemoglobin C gene, we decided to determine the reference values of hemoglobin A2 in the District of Bamako, Mali. The study was conducted among 41 volunteers aged 6 months to 45 years. The hemoglobin electrophoresis was performed using the technic in capillary zone using a Capillarys2® machine of Sebia Laboratories. Evaluation of biological parameters needed for reference values establishment was, focused on the determination of red cell indices, the rate of reticulocytes, serum ferritin and hemoglobin fractions. Data entry and data analysis were done using SPSS 12.0. The ANOVA test was used to compare mean values and medians with a significance level set at a p ≤ 0.05. The 2.5 and 97.5 percentiles of hemoglobin A2 were calculated. Analysis of these data showed that the reference values of hemoglobin A2 of the study population ranged from 2.50 to 3.68% (mean ± 1SD = 2.98 ± 0.23). These values did not differ by age or sex of study participants; they differed, however, from that published by other authors in populations different from ours. These results allow a better characterization of thalassemia syndromes in our context where a molecular diagnosis of hemoglobinopathies is not possible and underline the importance of systematically determination of reference values of hemoglobin fractions of each population.