Placenta-Derived Decidua Stromal Cells for Hemorrhagic Cystitis after Stem Cell Transplantation

Background/Aims: Hemorrhagic cystitis (HC) is a serious complication after hematopoietic stem cell transplantation (HSCT). Stromal cells have been tested as therapy for HC. Decidua stromal cells (DSCs) protect the fetus from the mother's immune system. Methods: Eleven patients with HC of grades 3-4 were treated with DSCs after HSCT. The median age was 33 years (range 8-50), and the median dose of DSCs was 1.5 × 10 6 /kg (range 0.7-2.5). The patients were given 1 dose (1-4). Results: In 5 patients, HC disappeared within 5 days after DSC infusion. Patients who received DSCs within 3 days after the start of HC had a duration of HC of 5 days and a shorter duration of pain than patients who were given DSCs later (p = 0.02). Three patients received DSCs prepared in albumin instead of AB-plasma and tended to have a shorter duration of pain (p = 0.07). There was no infusion toxicity. Adverse events were those often seen after HSCT. Nine of the 11 patients (82%) were alive 1 year after HSCT. Conclusions: Based on this pilot study, we started a randomized, placebo-controlled double-blind study using 2 doses of 1 × 10 6 DSCs/kg suspended in albumin for treatment of early HC.