Tacrolimus and Mini-dose Methotrexate for Prevention of Graft-Versus-Host Disease after Unrelated Hematopoietic Stem Cell Transplantation in Children: A Single-center Study in Korea / 임상소아혈액종양

ABSTRACT

BACKGROUND: Currently, data on the role of tacrolimus and mini-dose methotrexate (MTX) in pediatric unrelated hematopoietic stem cell transplantation (HSCT) is limited. We report the outcomes of unrelated hematopoietic stem cell recipients, evaluating engraftment status, incidence of acute and chronic graft-versus-host disease (GVHD) and toxicities after use of tacrolimus and mini-dose MTX for GVHD prophylaxis. METHODS: Thirty-five children who received tacrolimus and mini-dose MTX as prophylaxis from January 2004 to December 2013 were reviewed. All patients received tacrolimus beginning the day prior to transplant at a dose of 0.03 mg/kg/day by continuous intravenous infusion. MTX was administered at a dose of 5 mg/m2 IV on days 1, 3, 6 and 11. RESULTS: Median age at transplantation was 8.42 years (range 0.75-18.9 years). Seventeen patients received human leukocyte antigen (HLA) fully matched donor transplants and 18 received partially mismatched transplants. All but two patients who received unrelated cord blood transplants showed successful engraftment. The median time to ANC recovery was 12 days. The incidence of acute GVHD was 33.3% including 15.1% grade III-IV GVHD. Localized chronic GVHD developed in only 2 of 27 (7.4%) evaluable patients. Lower tacrolimus levels during days 1-21 were associated with a higher incidence of acute GVHD (P=0.033). The estimated 4-year event free survival and overall survival of the patients were 71.2% and 80.0%. CONCLUSION: Overall, the combination of tacrolimus and mini-dose MTX could be effectively administered in the setting of pediatric unrelated HSCT.