A Retrospective Evaluation of the Effects of Severe Aplastic Anemia Treatment in Children with Horse and Rabbit ATG.Polish Pediatric Hematology Group

Abstract 4375

Antithymocyte horse globulin (hATG) or rabbit (rATG) is used to treat children with severe aplastic anemia (SAA) in the absence of a compatible bone marrow family donor’s. We presenting (viewing) retrospective evaluation of the effects of SAA therapy using hATG and rATG.

49 children (20 girls and 29 boys, aged 1.2–17) were treated between 1993 and 2000 - hATG (15mg/kg/day for 5 days with cyclosporine 5mg/kg/day for 12–24 mths). On day 180 day of treatment there was a complete response (CR) in 22 of 49 children (44.5%) and a partial response (PR) in 12 children (24.4%). 34 of 49 children (69,4%) responded to treatment. There was no remission (NR) in 15 of 49 children (30.6%). In the whole group there were 7 deaths during the first 6 months. There were no relapses within 5 years of observation. The 5-year probability of survival in this group was 84%.

55 children (22 girls and 33 boys, aged 3,5–17,7 years) were treated in the years 1996–2009 using rATG (3.75 mg/kg/day for 5 days and cyclosporine 5mg/kg/day for 12–24 mths). On day 180 of treatment 5 patients (9%) achieved a CR, 23 children (41.8%) had a PR. 28 of 55 children (50.9%) responded to treatment. NR was found in 27 children (49%).In the rATG group 15 deaths (27%) were recorded, 4 patients (7%) had relapses. In one child paroxysmal nocturnal hemoglobinuria was noted.The 5-year survival in the rATG.group was 63.54%.

Our results show the greater effectiveness of treatment with horse globulin than rabbit globulin in terms of hematological response and overall survival.