Feasibility and efficacy of chronic transfusion for stroke prevention in children with sickle cell disease

In children with sickle cell disease (SCD), chronic transfusion to maintain haemoglobin S (HbS) below 30% markedly decreases both the risk of a first stroke when transcranial Doppler (TCD) ultrasonography shows abnormal cerebral blood flow velocities and the risk of recurrent stroke. Maintaining HbS below 30% may be difficult, especially in countries where blood donors and recipients belong to different ethnic groups and where the availability of closely matched blood products is limited. We assessed the feasibility and efficacy of chronic transfusion with an HbS target of 30% in children with SCD living in the Paris area.

We retrospectively studied 29 children aged 6.8 +/- 3.0 yr (3-15 yr) at inclusion who received chronic transfusion either because of abnormal TCD findings (primary prevention group, PPG, n = 17) or because of a previous cerebrovascular event (secondary prevention group, SPG, n = 12 including nine with a history of stroke and three of transient ischaemic attacks).

Mean follow-up was 3.5 +/- 3.0 yr (0.5-12 yr). No cases of stroke occurred in the PPG. In the SPG, one patient with a history of stroke and severe cerebrovascular disease had a recurrence after 11 yr of chronic transfusion, when the HbS level was 20%. The stroke recurrence rate (SPG group) was 1.6/100 patient-years. Mean HbS levels before and after transfusion were 30 +/- 10% and 20.6 +/- 7%, respectively. Two patients acquired red-cell alloantibodies. Of the 29 patients, 22 required iron chelation.

Regular transfusion maintaining HbS below 30% is feasible and safe in children with SCD in France and protects from overt stroke.