Treatment of refractory secondary hemophagocytic lymphohistiocytosis with umbilical cord mesenchymal stem cells

Hemophagocytic lymphohistiocytosis (HLH) is an aggressive and life-threatening syndrome of excessive immune activation. Mesenchymal stem cells (MSCs) generate an immunosuppressive microenvironment by secreting cytokines and have been used to treat autoimmune diseases. We report the first case of refractory secondary HLH treated with umbilical cord MSCs. A 52-year-old Chinese female patient with a history of type 2 diabetes was diagnosed with refractory secondary HLH based upon the HLH-2004 protocol and was treated by infusion of third-party umbilical cord MSCs (1.4 × 10(6) cells/kg of body weight, 70 × 10(6) cells in total) from the stem cell bank of Hainan Province. Body temperature recovered to normal on the sixth day after infusion with umbilical cord MSCs, and the levels of inflammatory factors macrophage inflammatory protein (MIP)-1α, interleukin (IL)-12p70, stromal cell-derived factor (SDF)-1α, and IL-7 decreased significantly. Blood glucose levels were significantly lower than before treatment, and the amount of insulin needed was significantly reduced. Umbilical cord MSCs can relieve the symptoms of refractory secondary HLH and have a therapeutic effect on insulin resistance in type 2 diabetes mellitus.