Haploidentical hematopoietic stem cell transplant in paroxysmal nocturnal hemoglobinuria

Eighteen patients with paroxysmal nocturnal hemoglobinuria (PNH) receiving allogeneic hematopoietic stem cell transplant (allo-HSCT), either from HLA-haploidentical donors (HRD; n = 10) or HLA-matched donors (n = 5 from siblings and n = 3 from unrelated donors), were retrospectively evaluated. One showed primary graft failure following unrelated-donor HSCT. He was given a second HRD-HSCT, but died from cytomegalovirus pneumonia after achieving hematopoietic recovery. The other 17 patients achieved sustained engraftment and full-donor chimerism. Four in the HRD-HSCT group experienced grade II/III acute graft-versus-host disease (aGVHD), and five in the HLA-matched HSCT group developed grade II aGVHD. Among all 18 patients, 10 developed chronic GVHD (cGVHD), only one patient receiving HRD-HSCT developed extensive cGVHD. Nine in the HRD-HSCT group and all those in the HLA-matched HSCT group were alive and transfusion-independent at last follow-up. Our findings suggest that allo-HSCT is a promising treatment for PNH, and HRD-HSCT is a viable option for patients with PNH who lack HLA-matched donors.