OBJECTIVETo study the curative effect and safety of menchymal stem cell infusion in treatment of children with refractory late-onset hemorrhagic cystitis(LOHC) after allogeneic HSCT.

METHODSThirty cases of children with refractory LOHC after allo-HSCT in our department between December 2010 and July 2016 were analyzed retrospectively, out of 30 cases 7 received MSC treatment. The used MSC of all were four-to-five generation MSC from bone marrows of third party donors, and were infused into patients with (1.87±0.456)×10/kg MSCs once a week (1-4 times in total) until the hematuria and odynuria symptoms being improved. To observe whether unfavorable reactions occurred after MSC treatment, the patients accepted daily physical examination and regular assistant examination. The cytokine levels were also measured and dynamically detected in 2 cases before and after MSC treatment.

RESULTSIn 30 children with refractory LOHC, the hematuria difficultly reached the remission after routine hydration, alkalizing and antiviral therapy, Among 25 cases who were received methylprednisolone, MTX and CTX therapy, 7 cases received MSC infusion for 1-4 times with dose of (1.87±0.456)×10/(kg·time) as a result, 7 cases of LOHC were cured. The TNF-α and IL-2R levels in 2 cases progressively decreased after MSC infusion, no occurence of fever, rash, embolism and so on were found in 7 cases received MSC infusion; the BKV detection showed that the viral load did not increase; the leukemia relapse or secondary cancer did not occure.

CONCLUSIONThe MSC treatment is safe and effective for refractory LOHC after allo-HSCT.