title: Leukemia specific loss of heterozygosity of MHC in a CLL patient: disease state impacts timing of confirmatory typing.
abstract: A 63 year old white male with refractory B-CLL presented for allogeneic HSCT evaluation; HLA typing was performed on PBL at time of WBC = 53K, ALC = 47K and revealed homozygosity at Class I locus and heterozygosity at Class II locus. Two siblings were full mismatches with the recipient and an unrelated search initiated. The patient was treated with Fludaribine and Rituxan complicated by aplastic anemia and bacteremia. Prior to transplant, confirmatory typing performed on PB revealed two full haplotypes at Class I and II. Sample identification error and the presence of third party lymphocyte engraftment as a result of prior red cell or granulocyte transfusion(s) were ruled out by STR analysis of 8 loci of all samples, T and B cells from cryopreserved PB at blast crisis were HLA typed independently. T cell typing yielded both complete haplotypes (genotype verified by offspring HLA typing); B cells typed for homozygous haplotype indicating loss of heterozygosity of MHC locus. Microarray based comparative genomic hybridization of tumor cells confirmed LOH at 6p.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Rochester Medical Center and the Wilmot Cancer Center, Rochester, NY, USA. myra_coppage@urmc.rochester.edu
authors.forename: Myra
authors.initials: M
authors.lastname: Coppage
authors.forename: Anwar
authors.initials: A
authors.lastname: Iqbal
authors.forename: Ausaf
authors.initials: A
authors.lastname: Ahmad
authors.forename: Michael W
authors.initials: MW
authors.lastname: Becker
mesh_terms: D058846:Antibodies, Monoclonal, Murine-Derived / Q000494:pharmacology / Q000627:therapeutic use; D006239:Haplotypes; D018380:Hematopoietic Stem Cell Transplantation; D015395:Histocompatibility Antigens Class I / Q000235:genetics* / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000235:genetics* / Q000276:immunology; D006650:Histocompatibility Testing; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics* / Q000276:immunology / Q000473:pathology / Q000628:therapy; D019656:Loss of Heterozygosity; D008297:Male; D008875:Middle Aged; D019653:Myeloablative Agonists / Q000494:pharmacology / Q000627:therapeutic use; D000069283:Rituximab; D013997:Time Factors; D019172:Transplantation Conditioning; D061349:Unrelated Donors; D014740:Vidarabine / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D019653:Myeloablative Agonists; D000069283:Rituximab; D014740:Vidarabine; C024352:fludarabine