SIMILAR INCIDENCE OF GRAFT-VERSUS-HOST DISEASE USING HLA-A, HLA-B ANDHLA-DR IDENTICAL UNRELATED BONE-MARROW DONORS AS WITH HLA-IDENTICAL SIBLINGS

Among 42 consecutive recipients of unrelated marrow were 39 HLA-A, -B, -DR identical, matched unrelated donors (MUD) and three with one HLA antigen mismatch. The majority were genomically typed for DRB, DQA, DQ B and DPB. The recipients of MUD marrow were compared with 39 recipien ts of marrow from HLA-identical siblings with similar diagnoses, disea se status and age. Each group included 24 patients with hematological malignancies, 6 with severe aplastic anemia and 9 inherited disorders. Immunosuppression consisted of anti-thymocyte globulin (ATG; pre-BMT mainly to recipients of unrelated marrow), CsA and four doses of MTX. Grade I acute GVHD was treated with prednisolone 2 mg/kg. In a compari son of MUD marrow recipients and HLA-identical siblings 34 of 39 and 3 6 of 39 of the patients engrafted, respectively. Recipients of MUD mar row and HLA-identical siblings achieved 0.2 x 10(9) WBC/I on day 16 (m edian) and 14, respectively (P = 0.03). Furthermore, the recipients of MUD marrow needed more platelet transfusions (P = 0.04). The incidenc e of acute GVHD grade II-III was 15% in the MUD marrow recipients comp ared with 11% among the HLA-identical siblings. The 2-4 year cumulativ e incidence of chronic GVHD was 29% acid 22% in the two groups, respec tively. The overall 2-year survival was 59 and 78%, respectively. Amon g patients ,vith CML in chronic phase or accelerated phase (n = 26), 2 -year relapse-free survival was 79% in both groups, Among the 3 recipi ents of one HLA antigen class I or DR/DQ mismatched unrelated marrow, two died of GVHD and one died of meningitis 9 months after re-transpla ntation following an initial rejection, In conclusion, acute and chron ic GVHD was similar using MUD or HCA-identical sibling marrow with con ditioning including ATG and GVHD prophylaxis with MTX and high-dose Cs A.