Chronic transfusion therapy effectiveness as primary stroke prophylaxis in sickle cell disease patients

About 10% of sickle cell anemia patients will have ischemic stroke. Adams showed stroke incidence reduction in children receiving monthly erythrocyte transfusions by reducing transcranial Doppler (TCD) velocities. Since then, chronic transfusion is recommended as primary stroke prophylaxis. This study aims to assess the effectiveness of chronic transfusions as stroke prophylaxis.

Retrospective study, reviewing medical records from 15 sickle cell anemia patients undergoing chronic transfusion. Data collected were age, sex, adverse reactions, stroke, hemoglobin, reticulocytes, ferritin, HbS and TCD values (baseline, after 12 and 24months of treatment).

The mean age was 118.67±41.40 months; six patients experienced allergic reactions. No stroke was recorded. One patient had alloimmunization. There was a decrease in the HbS rate and an increase in hemoglobin values in the first 12months. Values were maintained after 24months, but with no improvement of data. Before treatment, the mean HbS rate was 75.18%±11.69; after 12months, 41.63±14.99 and after 24months, 43.78±10.6. Thirteen patients initiated chelation after 12months from the beginning of chronic transfusions and ferritin decline after 24months. Pre-transfusional TCD velocities were 204.28±9.41cm/s (right) and 198.85±33.37cm/s (left). After a 12-month treatment, these values were 158.5±28.89cm/s and 157.62±34.43cm/s, respectively, and this reduction was statistically significant (p=0.002 right and p=0.02 left). After 24months, these values were 149.63±26.95cm/s (right) and 143.7±32.27cm/s (left).

Significant reduction of TCD velocity occurred after treatment with chronic transfusion in sickle cell anemia patients, leading to a normal or conditional test and reducing stroke risk in all but one patient.