CY TBI-800 AS A PRETRANSPLANT REGIMEN FOR ALLOGENEIC BONE-MARROW TRANSPLANTATION FOR SEVERE APLASTIC-ANEMIA USING HLA-HAPLOIDENTICAL FAMILYDONORS/

Allogeneic BMT is the treatment of choice for patients with SAA who ha ve an HLA-identical sibling donor, The results, however, have been rel atively poor for transplants from partially matched family donors or u nrelated donors because of the high incidence of graft rejection and/o r GVHD, Six multiply transfused patients received a novel conditioning regimen of CY 200 mg/kg and TBI 800 cGy prior to receiving marrow fro m their HLA-haploidentical family donors, Three recipient-donor pairs were mismatched for one HLA locus, one for two loci and two for three loci, A combination of MTX and CsA was used for GVHD prophylaxis, Engr aftment was noted in all six patients, Acute GVHD occurred in four pat ients, two each for grade I and II, respectively, One patient, who was ABO-compatible ,vith her donor had delayed onset of pure red cell apl asia (PRCA) which completely recovered 6 months after additional immun otherapy with prednisolone, There were two deaths; both occurred while patients were on treatment for GVHD, One was from systemic fungemia a nd the other probably from cytomegalovirus interstitial pneumonitis (C MV-IP), Four patients (66.7%) have been alive and disease-free for mor e than 8.2, 27.3, 38.4 and 47.2 months after BMT, respectively, The re sults suggest that CY/TBI-800 may be a simple and effective conditioni ng regimen for SAA patients receiving BMT from family members other th an HLA-identical siblings.