Mismatched related donors of hematopoietic SCT (HSCT) for severe aplastic anemia (SAA) present challenges mainly associated with graft failure and GVHD. The greater the HLA disparity, the poorer the OS. About 19 consecutive SAA/very SAA (VSAA) patients who received HSCT from haploidentical family donors in our center are reported in this study, 18/19 pairs had 2-3 loci mismatched. All 19 cases failed to respond to previous therapy and were heavily transfused before transplantation. The conditioning regimen before HSCT included BU, CY and thymoglobulin. The recipients received CsA, mycophenolate mofetil (MMF) and short-term MTX for GVHD prophylaxis. The source of stem cell grafts was a combination of G-CSF-primed BM and G-CSF-mobilized peripheral blood stem cells. All patients achieved 100% donor myeloid engraftment; the median time for myeloid engraftment was 12 days (ranging from 10-29 days) and for platelets was 18 days (ranging from 8-180 days) with a cumulative platelet engraftment incidence of 84.21 ± 10.53%. The cumulative incidence was 42.1 ± 11.3% for grade II-IV acute GVHD and 56.2 ± 12.4% for chronic GVHD. The OS was 64.6 ± 12.4% with a median 746-day (90-1970) follow-up for surviving patients. These limited retrospective analysis data suggest that HLA-haploidentical HSCT for SAA patients without an HLA-identical sibling donor might be feasible. Further research to increase OS by decreasing GVHD while maintaining stable engraftment will be needed in the future.

To study the efficacy and safety of a low dose of MTX combined with a low dose of methylprednisolone (MP) as a first-line therapy in the treatment of acute GVHD (aGVHD) after allogeneic hematopoietic SCT, 32 patients received i.v. MTX at a dose of 10 mg or oral MTX at a dose of 15 mg every 3-7 days (repeated at day 3 after the first dose and then at a weekly interval) combined with a low dose of MP (0.5 mg/kg/day) until a complete or partial response was achieved, or until treatment failure or intolerable side effects occurred. The overall treatment response rate was 81% (26/32 patients) and the response rate at day 28 was 75% (24/32 patients). The response rate for GVHD involving various organs was 88% (23/26) in the skin, 75% (3/4) in the liver and 81% (9/11) in the gut. Grade 3 toxicities occurred in only three patients presenting cytopenias. The estimated survival at 2 years was 77%. From this analysis, MTX in combination with a low dose of MP appears to be a well-tolerated, effective and inexpensive regime when used as a first-line treatment for aGVHD.