Remission of refractory Crohn's disease by high-dose cyclophosphamide and autologous peripheral blood stem cell transplantation

Background Despite advances in immunosuppressive therapy, up to 10% of patients with severe Crohn's disease (CD) remain refractory to conventional treatment. Limited evidence from pilot trials suggests that high-dose immunosuppression and autologous peripheral blood stem cell transplantation (autoPBSCT) may induce remission in these patients, but there is substantial controversy regarding the safety and efficacy of this approach. Aim To address this issue, a monocentre phase I/II trial of autoPBSCT was performed in patients with refractory CD in our hospital. Methods Here, we report on the outcome of 12 patients with refractory CD treated with autoPBSCT. Briefly, CD34+-selected PBSCs were harvested after mobilisation therapy with cyclophosphamide and granulocyte-colony stimulating factor. Later, immunoablative conditioning therapy with high-dose cyclophosphamide followed by autoPBSCT was applied and clinical and endoscopic responses were analysed after a mean follow-up of 3.1 similar to years (range 0.510.3 similar to years). Results PBSC harvest following mobilisation chemotherapy was successful in 11/12 patients and resulted in a clinical and endoscopic improvement in 7/12 patients. Subsequent conditioning and autoPBSCT were performed in nine patients and were relatively well tolerated. Among those, five patients achieved a clinical and endoscopic remission within 6 similar to months after autoPBSCT. However, relapses occurred in 7/9 patients during follow-up, but disease activity could be controlled by low-dose corticosteroids and conventional immunosuppressive therapy. Conclusion Immunoablation by cyclophosphamide and autologous peripheral blood stem cell transplantation is safe and effective to induce remission of refractory Crohn's disease, and should be further evaluated in randomised controlled trials.