Long Term Prospective Follow-Up after Treatment Intensification in Pediatric Sickle Cell Patients: Comparative Effects of Transfusion Program (TP), Hydroxyurea (HU) or Stem Cell Transplant (SCT) on Annual Check-Ups.

Treatment intensifications in SCD with HU, TP or SCT are applied in order to reduce SCD related complications but their comparative effects have still to be described. We report our experience concerning the annual check-up performed in SCD pediatric patients.

Patients and Methods: Among our cohort of 397 SS/Sb0 pediatric SCD patients, 157 of them were intensified with HU (n= 86), TP (n=104) or SCT (n=36) and some of them received successively HU, TP and SCT. HU was proposed to patients > 3 years of age and having experienced more than 3 VOC/ACS/year or < 7g/dl severe anemia. TP defined as > 4 months program was applied in patients with cerebral vasculopathy defined by an history of stroke or abnormal TCD (> 200 cm/sec). TP was also proposed in patients with HU-failure and in patients with frequent VOC, less than 3 years old. SCT was proposed in patients with an indication of treatment intensification and an available HLA identical sibling donor. Annual check-up were performed in our day-care unit. We analysed 1261 check-ups performed and recorded since 1992 in 341 SS/Sb0 patients (sex: 164 F, 177 M). Median age was 8.8 ± 5.1 years. Mean number of annual check-ups per patient was 3.7 ± 2.8 (range 1 to 13): 816 were performed in non intensified patients, 196 in HU, 123 in TP and 126 in transplanted patients. Categories of age were distinguished: < 2 y of age (n=110), 2–5y (n=244), 5–10y (n=415), 10–15y (n=317) and 15–20y (n=175).

Results: Respective follow-up were 4.4 y ± 3.3 in HU, 2.6 y ± 2.6 inTP and 5.8 y ± 4.7 in SCT patients. Comparison with non intensified patients showed that weight was significantly higher in SCT patients > 15 y of age (p=0.001), spleen size was significantly higher in (2–5y) young patients treated with HU (p=0.005) or TP (0.001) and in 5–10 y old patients on HU (p=0.046) but no difference was observed after the age of 10 y. O2 saturation was significantly improved after SCT (p<0.001) (98.8 ± 1.0 vs 97.1 ± 2.6) and was unchanged on HU and TP. Cardiac pulsations were significantly (p<0.001) decreased after all type of intensification. Biological data are shown (table1and 2).

Conclusion : Treatment intensifications (TP, HU, SC) reduced the decrease of weight observed with aging in SCD patients and significantly reduced anemia using different mechanisms. SCT was the most effective to correct anemia, supress hemolysis and decrease leucocytosis.