Peripheral blood haploidentical hematopoietic cell transplantation patients frequently develop signs and symptoms consistent with cytokine-release syndrome, previously described with the use of cellular therapies, including chimeric antigen receptor T cells.

Some of these patients develop severe cytokine-release syndrome and need aggressive supportive care

Severe cytokine-release syndrome is associated with poor survival and delayed neutrophil engraftment

Anti–IL-6 therapy is safe and well tolerated and may be an effective treatment for haploidentical hematopoietic cell transplantation–related cytokine-release syndrome