Allogeneic marrow transplantation using T cell depletion for patients with juvenile chronic myelogenous leukemia without HLA-identical siblings.

Six children with clinical and hematologic features of juvenile chronic myelogenous leukemia (JCML) underwent bone marrow transplantation (BMT) using T cell-depleted marrow from non-HLA-matched related or closely HLA-matched unrelated donors. Patient ages ranged from 1.2 to 5 years. Four patients received cytoreductive chemotherapy prior to BMT conditioning, and four had undergone pretransplant splenectomies. The donor-recipient matching included: four transplants disparate at one HLA locus (three from unrelated donors and one from a related donor), one transplant disparate at two HLA loci, and one transplant from a one haplotype-mismatched donor. All patients were MLC reactive with their donors. Graft-versus-host disease (GVHD) prophylaxis consisted of in vitro T cell depletion with a monoclonal antibody directed against CD3, and complement in conjunction with cyclosporin A begun on day -1. Conditioning included busulfan, cytosine arabinoside, cyclophosphamide, methyl-prednisolone, and hyperfractionated total body irradiation. All patients engrafted, with median time to neutrophils greater than 500 x 10(6)/l and platelets greater than 25 x 10(9)/l of 20 and 21 days, respectively. Acute GVHD was less than or equal to grade II in all patients. Two patients died of infection (Candida, CMV) at days 74, 157. One patient relapsed at day 177, and subsequently died on day 939. Three patients are alive and disease free at 180 +, 1610 + and 2400 + days from BMT. Although intensive chemotherapy may play a role in providing transient disease control in patients with JCML, allogeneic BMT is the only curative therapy.(ABSTRACT TRUNCATED AT 250 WORDS)