Successful treatment with mesenchymal stromal cells-Frankfurt am Main in a pediatric patient with steroid-refractory and ruxolitinib-refractory acute gastrointestinal graft-versus-host disease.

Acute graft-versus-host disease (aGVHD) as complication after allogeneic hematopoetic stem cell transplantation (allo-HSCT) occurs in up to 70% of patients. The survival prognosis depends on the severity of GVHD and response to first-line therapy. In patients who are refractory to both, steroids and ruxolitinib, an unmet medical need exists, especially in severe gastrointestinal forms of aGVHD. We report the case of a 12-year-old male patient who developed severe gastrointestinal aGVHD after allo-HSCT for the treatment of high-risk acute myeloid leukemia. The grade IV aGVHD of the intestine showed no improvement under triple immunosuppression with corticosteroids, cyclosporine A and ruxolitinib. After receiving four weekly infusions of human allogeneic mesenchymal stromal cells DRK-BaWü-He-FFM (MSC-FFM), intestinal inflammation finally improved, as reflected by ameliorated symptoms, normalized intestinal wall thickness (ultrasonography) and decreasing calprotectin levels. Intestinal mucosal healing was further supported by a strict, formula-based modular diet. The present case supports efficacy and safety of MSC-FFM in combination with modular nutrition in complicated courses of aGVHD of the intestine refractory to multiple lines of therapy and introduces intestinal wall thickness and calprotectin levels as valuable markers of disease activity.