OBJECTIVETo evaluate the outcomes of allogeneic hematopoietic stem cell transplantation（allo-HSCT）for paroxysmal nocturnal haemoglobinuria（PNH）and aplastic anemia（AA）- PNH syndrome.

METHODSThe clinical data of 18 PNH or AA-PNH patients, including 4 classic PNH and 14 AA-PNH, received allo-HSCT from Dec 2007 to Feb 2015 were analyzed retrospectively. Nine patients received HLA-haploidentical donor HSCT（1 patient received salvage HLA-haploidentical donor HSCT after the graft failure of double cord blood transplantation）, 7 patients received HLA-identical sibling donor HSCT, and 2 HLA-identical unrelated donor HSCT. The conditioning regimens were as follow: 13 patients received modified BU/CY- based regimens, 5 non- myeloablative regimens ［fludarabine （Flu） + antithymocyte globulin（ATG）+ cyclophosphamide（CY）or busulfan（BU）］. Prophylaxis for graft- versushost disease（GVHD）: the patients with HLA-identical sibling donor received cyclosporine（CsA）plus short-term methotrexate（MTX）, the patients with HLA -haploidentical donor or HLA-identical unrelated donor received CsA or tacrolimus（FK506）+ mycophenolate mofetil（MMF）+ short- term methotrexate （MTX）.

RESULTSAll patients were engrafted successfully（1 patient engrafted by haploidentical donor after the graft failure of double cord blood transplantation）. The median days of neutrophils（ANC）above 0.5 × 109/L and platelets （PLT） more than 20 × 10⁹/L were 11（10- 26）days and 15（11- 120）days, respectively. Three patients（17.6%）developed acute GVHD（aGVHD）, 2 for grade Ⅱ aGVHD, 1 for grade Ⅳ aGVHD. Of 16 patients, 2 occurred limited chronic GVHD（cGVHD）. After a median follow-up of 14.6（2.0-86.7）months, 3 patients（17.6%）died, out of which one died of severe aGVHD, one died of severe pulmonary infection, one pulmonary infection with transplant- associated thrombotic microangiopathy. The 5- year estimated disease free survival was（80.5 ± 10.2）%. No patient relapsed.

CONCLUSIONAllo-HSCT is an effective and curable therapy for PNH or AA-PNH with improved prognosis, and offers a valid therapeutic option for these patients before humanized monoclonal antibody against C5 are widely used clinically.