A unique cohort of HIV-1-infected long term nonprogressors (LTNP) with normal CD4 ؉ T cell counts and <50 copies͞ml of plasma were prospectively recruited for study. HLA typing revealed a dramatic association between the HLA B*5701 class I allele and nonprogressive infection [85% (11 of 13) vs. 9.5% (19 of 200) in progressors; P < 0.001]. Antigen-specific CD8 ؉ T cells were enumerated by flow cytometric detection of intracellular IFN-␥ in response to HIV antigens and HLA B*57-gag tetramer staining. No quantitative differences in the total HIV-specific CD8 ؉ T cell responses were observed between B*57 ؉ LTNP and five B*57 ؉ progressors (P ‫؍‬ 0.4). Although similar frequencies of peptide specific CD8 ؉ T cells were also found, the gag-specific CD8 ؉ T cell response in the LTNP group was highly focused on peptides previously shown to be B*57-restricted. These findings indicate that, within this phenotypically and genotypically distinct cohort, a host immune factor is highly associated with restriction of virus replication and nonprogressive disease. They also strongly suggest a mechanism of virus specific immunity that directly operates through the B*5701 molecule. Further characterization of qualitative differences in the virus-specific responses that distinguish HLA B*57 ؉ LTNP from progressors may ultimately define mechanisms of effective immune mediated restriction of virus replication.

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C omposite endpoints that not only encompass mortality and relapse, but other critical post-transplant events such as graft-versus-host disease, are being increasingly utilized to quantify survival without significant morbidity after allogeneic blood or marrow transplantation. High-dose, post-transplantation cyclophosphamide reduces severe graft-versus-host disease with allogeneic marrow transplantation, making composite endpoints after this management particularly interesting. We retrospectively analyzed 684 adults with hematologic malignancies who received T-cell-replete bone marrow grafts and cyclophosphamide after myeloablative HLA-matched related (n=192) or unrelated (n=120), or non-myeloablative HLA-haploidentical (n=372) donor transplantation. The median follow up was 4 (range, 0.02-11.4) years. Graft-versus-host disease-free, relapse-free survival was defined as the time after transplantation without grade III-IV acute graft-versus-host disease, chronic graft-versus-host disease requiring systemic treatment, relapse, or death. Chronic graft-versus-host disease-free, relapse-free survival was defined as the time after transplantation without moderate or severe chronic graft-versus-host disease, relapse, or death. One-year graftversus-host disease-free, relapse-free survival and chronic graft-versushost disease-free, relapse-free survival estimates were, respectively, 47% (95% CI: 41-55%) and 53% (95% CI: 46-61%) after myeloablative HLAmatched related, 42% (95% CI: 34-52%) and 52% (95% CI: 44-62%) after myeloablative HLA-matched unrelated, and 45% (95% CI: 40-50%) and 50% (95% CI: 45-55%) after non-myeloablative HLA-haploidentical donor transplantation. In multivariable models, there were no differences in graft-versus-host disease-free, or chronic graft-versus-host disease-free, relapse-free survival after either myeloablative HLAmatched unrelated or non-myeloablative HLA-haploidentical, compared with myeloablative HLA-matched related donor transplantation. Although limited by inclusion of dissimilar cohorts, we found that posttransplantation cyclophosphamide-based platforms yield comparable composite endpoints across conditioning intensity, donor type, and HLA match.

Pharmacogenetic testing is becoming more common; however, very few quality control and other reference materials that cover alleles commonly included in such assays are currently available. To address these needs, the Centers for Disease Control and Prevention's Genetic Testing Reference Material Coordination Program, in collaboration with members of the pharmacogenetic testing community and the Coriell Cell Repositories, have characterized a panel of 107 genomic DNA reference materials for five loci (CYP2D6, CYP2C19, CYP2C9, VKORC1, and UGT1A1) that are commonly included in pharmacogenetic testing panels and proficiency testing surveys. Genomic DNA from publicly available cell lines was sent to volunteer laboratories for genotyping. Each sample was tested in three to six laboratories using a variety of commercially available or laboratory-developed platforms. The results were consistent among laboratories, with differences in allele assignments largely related to the manufacturer's assay design and variable nomenclature, especially for CYP2D6. The alleles included in the assay platforms varied, but most were identified in the set of 107 DNA samples. Nine additional pharmacogenetic loci (CYP4F2, EPHX1, ABCB1, HLAB, KIF6, CYP3A4, CYP3A5, TPMT, and DPD) were also tested. These samples are publicly available from Coriell and will be useful for quality assurance, proficiency testing, test development, and research. Many laboratories are testing for pharmacogenetic (PGx) markers, common genetic variants that are usually considered only when a patient is likely to be exposed to a Accepted for publication June 21, 2010. R.B., A.E.-B., C.S., A.V., and M.Z. are employees of AutoGenomics (manufacturer of several pharmacogenetic assays used in this study); M.B., A.B., and K.M. are employees of Quest Diagnostics Inc.; J.M. is an employee of Idaho Technology (manufacturer of the reagents used to genotype CYP2C9 and VKORC1 loci for this project);

No abstract

Background: Adoptive immune and vaccine therapies have been used to prevent cytomegalovirus (CMV) disease in recipients of hematopoietic progenitor cell transplants, but the nature of T cell responses to CMV have not been completely characterized.

Increasing attention has been devoted to elucidating the mechanism of lost or decreased expression of MHC or melanoma-associated antigens (MAAs), which may lead to tumor escape from immune recognition. Loss of expression of HLA class I or MAA has, as an undisputed consequence, loss of recognition by HLA class I-restricted cytotoxic T cells (CTLs). However, the relevance of downregulation remains in question in terms of frequency of occurrence. Moreover the functional significance of epitope down-regulation, defining the relationship between MHC/epitope density and CTL interactions, is a matter of controversy, particularly with regard to whether the noted variability of expression of MHC/epitope occurs within a range likely to affect target recognition by CTLs. In this study, bulk metastatic melanoma cell lines originated from 25 HLA-A*0201 patients were analyzed for expression of HLA-A2 and MAAs. HLA-A2 expression was heterogeneous and correlated with lysis by CTLs. Sensitivity to lysis was also independently affected by the amount of ligand available for binding at concentrations of 0.001 to 1 mM. Natural expression of MAA was variable, independent from the expression of HLA-A*0201, and a significant co-factor determining recognition of melanoma targets. Thus, the naturally occurring variation in the expression of MAA and/or HLA documented by our in vitro results modulates recognition of melanoma targets and may (i) partially explain CTL-target interactions in vitro and (ii) elucidate potential mechanisms for progressive escape of tumor cells from immune recognition in vivo.

Compared with standard graft-versus-host disease (GVHD) prophylaxis platforms, post-transplantation cyclophosphamide (PTCy) after T cell-replete HLA-haploidentical (haplo) bone marrow transplantation (BMT) reduces the risk of grades III to IV acute (a) and chronic (c) GVHD, but maintains similar rates of grade II aGVHD. Given that mild GVHD has been associated with reduced treatment failure in HLA-matched BMT, we evaluated the risk factors for and effects of GVHD on survival in 340 adults with hematologic malignancies who engrafted after nonmyeloablative haplo-BMT with PTCy, mycophenolate mofetil, and tacrolimus. The cumulative incidence at 100 days of grade II and grades III to IV aGVHD were 30% (95% confidence interval [CI], 25% to 35%) and 2% (95% CI, 1% to 4%), respectively. The 1-year cumulative incidence of cGVHD was 10% (95% CI, 7% to 13%). In landmark analyses at 100 days, the 4-year probabilities of overall survival (OS) and progression-free survival (PFS) were, 48% (95% CI, 41% to 56%) and 39% (95% CI, 32% to 47%) for patients without grades II to IV aGVHD, compared with 63% (95% CI, 53% to 73%) and 59% (95% CI, 50% to 71%) for patients with grade II aGVHD (P = .05 and P = .009). In multivariable modeling, when compared with patients who never experienced GVHD, the hazard ratio (HR) for OS and PFS in patients with grade II aGVHD was .78 (95% CI, .54 to 1.13; P = .19) and .69 (95% CI, .48 to .98; P = .04). Higher nucleated cell graft dose was also associated with improved OS (HR, .88; 95% CI, .78 to 1.00; P = .05) and PFS (HR, .89; 95% CI, .79 to 1.0; P = .05) and decreased risk of grades III to IV aGVHD (subdistribution HR, .66; 95% CI, .46 to .96; P = .03). PTCy reduces grades III to IV aGVHD and cGVHD, but retains similar incidence of grade II aGVHD, the development of which improves PFS. Higher nucleated cell graft dose goals may also improve survival after nonmyeloablative haplo-BMT with PTCy.