Graft-versus-host disease in pediatric patients with acute leukemia after alloSCT

This study investigated the occurrence of graft-versus-host disease (GVHD) in pediatric patients who underwent an allogeneic stem cell transplant (alloSCT). This study concluded that both umbilical cord blood cells and bone marrow cells led to similar rates of GVHD in children with acute leukemia.

Allogeneic stem cell transplantation is one type of stem cell transplant (SCT) used to treat leukemia. This procedure requires a close tissue type match between the donor and the patient so that the donor’s immune cells do not attack the patient’s healthy cells. This immune attack is called GVHD. It is a common complication of SCT.

If an exact tissue type match cannot be found, partially matched bone marrow (BM) or umbilical cord blood (UBC) cells can be used. These types of cells are not often used in children due to complications that may occur, including GVHD. However, the potential to use partially matched tissue can make it easier to find donors and treat patients more quickly. The outcomes of children with acute leukemia who receive these non-matched donor cell types in SCT remain under investigation.

This study involved 1613 pediatric patients with acute leukemia. 172 patients received BM stem cells. 1441 patients received UBC stem cells. Before the transplant, patients received radiation therapy (65%) or chemotherapy (60%). Patients were followed-up for an average of 71 to 96 months.

Overall, more patients who received BM cells developed severe short-term GVHD compared to patients who received UCB cells (38% vs. 29%). At 100 days after the transplant, this rate was 29% vs. 18%. Receiving BM cells was significantly associated with a 1.70-fold higher risk for developing severe short-term GVHD. 

Significantly more patients who received BM cells developed long-lasting GVHD 1 year later compared to patients who received UB cells (28% vs. 22%). 14 months later, patients who received BM cells had a significant 6-fold higher risk of developing this condition. 2 years later, this rate was 34% versus 23%. 

Significantly more patients who received UCB cells survived without developing GVHD or having the cancer come back compared to patients who received BM cells (33% vs. 22%). Significantly more of these patients also survived without developing long-lasting GVHD compared to patients who received BM cells (38% vs. 27%).

This study concluded that both umbilical cord blood cells and bone marrow cells led to similar rates of GVHD in children with acute leukemia. However, the authors suggest that umbilical cord blood cells may be better for these patients due to a smaller chance of developing severe GVHD.

This study was retrospective. This means it looked back in time to analyze data. More studies are needed to confirm these results.