Haematological values in steady-state sickle cell anaemia patients and matched heamoglobin AA Controls in a Rural Area of Eastern Gabon.

BACKGROUND: In Gabon, universal neonatal screening of sickle cell disease is not carried out in rural areas, often leading to late detection of the disease. However, complete blood counts are available in rural areas. MATERIALS AND METHODS: We evaluated the haematological parameters of 45 homozygous steady-state sickle cell anaemia (SCA) patients and compared them with 45 sex- and age-matched Haemoglobin AA controls in Koula-Moutou, a rural area in Eastern Gabon. RESULTS: Homozygous SCA patients had low erythrocyte values (red blood cells: 2.50 × 1012/L, haemoglobin: 7.20 g/dL and haematocrit: 20.70%) and high leucocyte values (white blood cells: 14.40 × 109/L, lymphocytes: 5.24 × 109/L and monocytes: 1.60 × 109/L). Most of the SCA patients had severe anaemia (67%), normochromia (76%), lymphocytosis (73%) and monocytosis (84%). A haemoglobin level of < 8.5 g/dL together with a leucocyte level above 9.5 × 109 cells/L was used as screening test to detect homozygous SCA patients, with sensitivity of 84.4% and specificity of 97.8%. CONCLUSION: The values for erythrocyte and leucocyte cell lines of SCA patients in steady state are clearly different from those of the matched HbA/A controls. This makes it possible to set up a tool to detect SCA based on the haemogram in a rural area that does not possess haemoglobin electrophoresis. This tool could be used by healthcare workers in the absence of universal newborn screening for SCA.

Haemoglobin F, A2, and S levels in subjects with or without sickle cell trait in south-eastern Gabon.

BACKGROUND: Infant mortality due to sickle cell disease in sub-Saharan Africa is high, necessitating a better understanding of the modulating factors of the disease in this region. METHODS: We assessed the hereditary persistence of foetal haemoglobin and α-thalassemia. We diagnosed 787 subjects, with or without sickle cell trait, by capillary electrophoresis in the Medical Diagnostic Laboratory of the CIRMF (Franceville, Gabon). RESULTS: Heterocellular and pancellular forms of hereditary persistence of foetal haemoglobin occurred at low rates of 10.9 and 2.3%, respectively. The distribution of HbS levels in individuals with sickle cell trait was trimodal, showing a high percentage (52.4%) of heterozygous subjects with α-thalassemia. The distribution of HbA2 levels was bimodal in individuals without sickle cell trait, estimated to be comprised of 12 and 15% of α and ß-thalassemic heterozygous subjects, respectively. CONCLUSIONS: In sub-Saharan Africa, α-thalassemia is a far more prevalent modulating factor than hereditary persistence of foetal haemoglobin. Our study highlights the need for further investigation of thalassemia, haemoglobinopathies that are neglected in sub-Saharan Africa.