Antithymocyte Globulin (ATG) Plus Cyclosporine (CsA) and Combined with Cord Blood Infusion Is Superior to ATG Plus Csa for the Treatment of Severe Aplastic Anemia

Standard initial immunosuppressive therapy (IST) is ATG and CsA, which produces hematologic recovery in 60% to 70% of severe aplastic anemia (SAA), but the shortcoming is the long duration for hematologic response, the higher relapse rate and clonal evolution. In addition to stem cells, Cord blood contains plenty of mesenchymal cells, regulatory T cells, dendritic cells and hematopoietic factors. So we predicted that cord blood coinfusion could improve the effect of ATG plus CsA for treating SAA. The aim of the current study was to investigate the safety and effect of ATG plus CsA combined with cord blood infusion SAA.

From August 2008 to May 2012, nine patients (6 males and 3 females), with a median age of 22 years (14–52) were diagnosed with SAA. They received an IST of rabbit ATG (3mg/kg/d, for 5 days) plus CsA (5mg/d, continuously), and then accepted a five or six loci matched cord blood infusion in 7–10 days after the end of ATG. The median nuclear cells were 4.02 (3.1–5.62) ×10⁷/kg.

After a median duration follow-up of 38 (1–50) months, the response rate was 88.9% (8/9), the median duration of plantlet transfusion independence was 34(18–72) days and that of red blood cell was 30 (18–56) days, which were shorter than those of standard IST for SAA. Only 2 patients underwent serum sickness, 1 patients was diagnosed as having upper respiratory tract infection, and none underwent sepsis and invasive fungal infection. In addition, EB viremia was found in 3 patients, and all of them were cured by antiviral therapy. Of all 9 patients, only one showed evidence of partly engraftment (the percentage of cord blood was 24.6%) as determined by STR-PCR at 15 days after cord blood infusion, the others had no evidence of engraftment at 15days, 1 month and three months after infusion. No myelodysplastic syndrome or acute myeloid leukemia was found among the patients. No patient relapsed till now.

ATG plus CsA and combined with cord blood infusion was safe, the rate of hematologic response was higher than traditional IST for SAA. The duration of transfusion independence was shorter than that of traditional IST.

No relevant conflicts of interest to declare.