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An important problem in the selection of unrelated donors for bone marrow transplantation (UD-BMT), is HLA matching, between selected donor and recipient. Serological screening, mixed lymphocyte culture (MLC), and sequence specific oligonucleotide genotyping (PCR-SSO) are the methods commonly used for typing of HLA-genes. These ways to select donor candidates are time-expensive. We set up new applications of the "fingerprinting-PCR" technique, to analyse the polymorphic second exon of DRB, DQB, DQA, DPB of HLA Class II and second exon A, B, C HLA-Class I genes, and to search for identity between patient and serologically selected unrelated donors. In an assessment of the technique, 50 normal samples, and 4 unrelated HLA-A and HLA-B serological matched patient-donor pairs were analysed for HLA polymorphic regions. In 3 of the 4 cases (UD-BMT) at least HLA-DRB mismatched different donor-transplanted patterns were identified. In all cases PCR-SSO analysis was performed as control. Based on our data, we suggest that identification of UD for allogeneic BMT should follow these steps: 1) serological HLA-Class I and II genes screening; 2) HLA-Class II DRB gene PCR fingerprinting; 3) confirmation by SSO analysis in case of fingerprinting identity. 4) HLA-Class II DQA, DQB, DPB PCR fingerprinting. Moreover, confirmation by PCR fingerprinting or protein isoelectrofocusing of HLA-Class I identity is recommended. This "strategy" may contribute to rapid and specific selection of unrelated marrow donors.

We report on 24 patients with leukemia (19 pts), congenital disorders (4 pts) or severe aplastic anemia (1 pt) who received bone marrow transplantation from unrelated volunteer donors in 8 Italian Institutions. All the donor/recipient pairs were serologically HLA-A,B,DR matched; MLR was non reactive in 21 out of 24 cases. Preparative regimens were in accord with standards for diagnosis and disease status and included TBI in 15 patients, busulfan in 8, cyclophosphamide alone in one patient with SAA. GvHD prophylaxis consisted of cyclosporine/methotrexate in the majority of cases; 6 patients received additional immunotherapy with anti-lymphocyte globulin and 1 patient in vivo Campath-1G. The bone marrow was T-cell depleted in 2 cases. Acute GvHD grade II-IV occurred in 87% of patients (gr.III-IV: 57%) and was the main cause of death in 8 cases. Six patients (25%) survive with a median follow-up of 9 months, (16% actuarial survival at 3 years). A trend in favour of a better outcome has been found for age < 20 yrs at BMT (33% vs 22%), intensified GvHD prophylaxis (33% vs 22%) and transplants performed in more recent years (31% vs 18%).