[Results of partial transfusion exchange in 42 homozygous sickle cell patients at university hospital of Brazzaville].

The standard of care for major sickle cell diseases in crisis is based on blood transfusion, but this remains a risky therapy in sub-Saharan Africa. The objective of this retrospective and prospective study was to assess exchange transfusion (ET) in homozygous sickle cell disease between 1st July 2005 and 30th June 2008 at the transfusion centre of university hospital of Brazzaville. The ET technique used was manual and made of three stages: bleeding, infusion of solution, and infusion of red cell concentrate. Clinical and biological assessments were done before and after exchanges. The indication for ET were: pregnancy (19 cases); strokes (seven cases); vaso-occlusive crisis (five cases), priapism (four cases), cardiac failure (three cases) and miscellaneous (four cases), the values of hematocut in red cell blood bag between 0.55 and 0.70 (median 0.65). The median haemoglobin level before exchange was about 5.8 g/dl (4.1-7.4 g/dl), that of HbS from haemoglobin electrophoresis about 98.4 % (94.6-100 %). Before the exchanges, viral serological tests were done with the following results: two patients with HBV antigen positive and one patient antibodies to HCV. In acute situation interval between exchanges is 3 to 10 days, whereas during chronic situation is between 14 to 28 days. No major immediate complications have been observed. Clinical situation after exchange characterized by stabilization of cerebral vascular stroke and over and control of one case of priapism complications. Assessment after exchange showed the following results: medium rate of Hb level: 9.5 g/dl (an increase of 3.7 g/dl); medium percentage of HbS reduced to 46.8 % (approximately a decrease of 51.6 %). Patient's serological status to HCV changed for one patient. This study illustrates the benefit and the limitations of the transfusion exchange during sickle cell disease in sub-Saharan Africa.