Seventy-five years of service: an overview of the College of American Pathologists' proficiency testing program in histocompatibility and identity testing.

The Histocompatibility and Identity Testing Committee offers an overview of the College of American Pathologists' (CAP) Proficiency Testing (PT) program, commemorating its significant 75th anniversary in 2024. The CAP PT program has undergone significant growth and evolution over the years, ultimately achieving Centers for Medicare and Medicaid Services approval. In 1979, CAP's partnership with the American Association for Clinical Histocompatibility Testing marked a pivotal moment, leading to the creation of the first proficiency testing survey in 1980.

Identification of a DRB1*04:07-DRB4*01:03:01:02N haplotype in a native American individual.

The DRB4*01:03:01:02N null allele is predominantly associated with the HLA-DRB1*07-DQB1*03:03 haplotype. Several recent reports demonstrated a less frequent association of DRB4*01:03:01:02N with DRB1*04 carrying haplotypes in different populations. The ability to identify the presence of null alleles is extremely important in the setting of both solid organ transplants and hematopoietic cell transplants, and characterization of haplotypes carrying null alleles is crucial.

A simplified method for screening siblings for HLA identity using short tandem repeat (STR) polymorphisms.

Identifying an HLA-matched sibling donor for hematopoietic stem cell transplantation (HSCT) is time-consuming and expensive, and often limited by reimbursement caps imposed by insurance providers. To improve the effectiveness and efficiency of screening for HLA-matched siblings, we developed an assay for determining HLA identity using a panel of nine informative short tandem repeat (STR) loci located throughout the HLA complex. The STR panel was assessed for accuracy in identifying HLA-matched siblings in 88 family workups comprising a total of 132 related donor and recipient typing comparisons.

Diagnostic accuracy of solid phase HLA antibody assays for prediction of crossmatch strength.

Solid phase antibody assays are increasingly used to provide quantitative measures of donor-specific HLA antibodies for assessment of pretransplant risk, although cell-based crossmatches continue to serve as gold standards for determination of donor HLA antibody strength. This study determined the ability of HLA antibody solid phase assays to predict the strength of cell-based flow cytometric (FC) and complement-dependent cytotoxicity (CDC) crossmatches. Eighty-two recipient/donors pairs were analyzed using receiver operating characteristic (ROC) curve analyses to determine the accuracy of donor-specific median fluorescence intensity values (Σ MFI) from single antigen bead assays for predicting strong FC and CDC crossmatches.

Hepatitis C virus induces regulatory T cells by naturally occurring viral variants to suppress T cell responses.

Regulatory T cell markers are increased in chronically infected individuals with the hepatitis C virus (HCV), but to date, the induction and maintenance of Tregs in HCV infection has not been clearly defined. In this paper, we demonstrate that naturally occurring viral variants suppress T cell responses to cognate NS3(358-375) in an antigen-specific manner. Of four archetypal variants, S370P induced regulatory T cell markers in comparison to NS3(358-375)-stimulated CD4 T cells.

Single-nucleotide polymorphisms in the IL2RA gene are associated with age at diagnosis in late-onset Finnish type 1 diabetes subjects.

The onset of type 1 diabetes can occur at any age, with as many as half of all cases diagnosed after age 15. Despite this wide distribution in age at diagnosis, most genetic studies focus on cases diagnosed in childhood or during early adulthood. To better understand the genetics of late-onset type 1 diabetes, we collected a Finnish case/control cohort with all cases diagnosed between ages 15 and 40.

Meta-analysis of vitamin D receptor polymorphisms and type 1 diabetes: a HuGE review of genetic association studies.

Several polymorphisms in the vitamin D receptor (VDR) gene have been reported to be associated with the risk of developing type 1 diabetes, yet published findings have been conflicting. In this study, the authors attempted to evaluate the evidence regarding the association. They searched all relevant reports from original papers published from 1997 to December 2005.

Baculovirus apoptotic suppressor P49 is a substrate inhibitor of initiator caspases resistant to P35 in vivo.

Caspases play a critical role in the execution of metazoan apoptosis and are thus attractive therapeutic targets for apoptosis-associated diseases. Here we report that baculovirus P49, a homolog of pancaspase inhibitor P35, prevents apoptosis in invertebrates by inhibiting an initiator caspase that is P35 insensitive. Consequently P49 blocked proteolytic activation of effector caspases at a unique step upstream from that affected by P35 but downstream from inhibitor of apoptosis Op-IAP.