Platelet antibody detection assays: a single-laboratory comparison of MAIPA, PIFT, and microsphere-based multiplex assays Pak-Lx.

Background And Objectives: The identification of platelet antibodies is essential for diagnosing and managing conditions such as fetal and neonatal alloimmune thrombocytopenic purpura, post-transfusion purpura, and immune platelet refractoriness. Monoclonal antibody immobilization of platelet antigens (MAIPA) is the standard method for detecting anti-human platelet antigen (HPA) antibodies, while the detection of anti-HLA antibodies once relied on the complement-dependent cytotoxicity method, however advanced technologies such as enzyme-linked immunosorbent assay and Luminex have significantly improved sensitivity and accuracy in identifying these antibodies. Flow cytometry-based techniques (platelet immunofluorescence test - PIFT) and Luminex platform-driven microsphere-based multiplex assays (Pak-Lx) are widely employed in platelet immunology laboratories owing to their remarkable flexibility and versatility.

Virtual platelet cross-matching as transfusion management for patients with immune platelet refractoriness.

Background And Objectives: This study describes the use of the Epvix platform for virtual cross-matching (VC) of human leucocyte antigen (HLA)-compatible platelets for patients with immune platelet refractoriness, and demonstrates effectiveness of the selected platelets.

Materials And Methods: A prospective cohort of haematological patients was evaluated from 2018 to 2022. HLA-typed donor bank profile was previously uploaded to the Epvix platform.

The relevance of a bank with genotyped platelets donors.

Objective: Describe the clinical and laboratory characteristics and the transfusion strategy of patients at Hospital Israelita Albert Einstein with platelet refractoriness and identify their etiological characteristics. Standardize the platelet immunofluorescence technique by flow cytometry as a test for platelet compatibility in immune platelet refractoriness in transfusion support.

Methods: Review of medical records of refractory platelet patients followed at HIAE from January 2011 to May 2017.

Platelet antibodies identification: comparison between two laboratory tests.

Introduction: Platelet antibody identification is indispensable for diagnosing the human platelet antigen (HPA) or human leukocyte antigen (HLA) immunization, mostly because it can restrict the compatibility and results of transfusions. Correct detection of these antibodies is of utmost importance for the diagnosis and treatment.

Method: We present 16 platelet alloimmunization results, comparing two tests with different technologies: the MAIPA (monoclonal antibody immobilization of platelet antigens), as a reference technique, and a bead-based assay, the Pak-Lx.

Duffy phenotyping and FY*B-67T/C genotyping as screening test for benign constitutional neutropenia.

Objective: Low levels of neutrophils can be an intrinsic condition, with no clinical consequences or immunity impairment. This condition is the benign constitutional neutropenia (BCN), defined as an absolute neutrophils count (ANC) ≤2000 cells/mm. Diagnosis of BCN is of exclusion where patients are submitted to blood tests and possibly to invasive diagnostic search until secondary causes of neutropenia are ruled out.

Allele and haplotype frequencies of human platelet and leukocyte antigens in platelet donors.

Objective: To described the allele and haplotype frequencies of human leukocyte antigen genes at the -A, -B loci and human platelet antigen genes for human platelet antigen systems 1 to 9, 11 and 15 in blood.

Methods: We included 867 healthy unrelated volunteer donors who donated platelets between January 2011 and December 2014. Microarray genotyping was performed using a BeadChip microarray.

RHD alleles among pregnant women with serologic discrepant weak D phenotypes from a multiethnic population and risk of alloimmunization.

Background: A considerable number of RHD alleles responsible for weak and partial D phenotypes have been identified. Serologic determination of these phenotypes is often doubtful and makes genetic analysis of RHD gene highly desirable in transfusion recipients and pregnant women. We analyzed the RHD gene in a cohort of pregnant women with doubtful D phenotypes.

HLA-typing analysis following allogeneic bone grafting for sinus lifting.

According to the Brazilian Association of Organ Transplants, in 2015, 19,408 bone transplants were performed in Brazil, over 90% by Dental Surgeons. The surgical technique itself has a respectable number of reports regarding its clinical efficacy, as measured by long-term survival of dental implants in grafted areas. Uncertainty remains, however, as to whether fresh frozen grafts from human bone donors remain immunologically innocuous in the body of the host.

Successful management of neonatal alloimmune thrombocytopenia in the second pregnancy: a case report.

Neonatal alloimmune thrombocytopenia is a serious disease, in which the mother produces antibodies against fetal platelet antigens inherited from the father; it is still an underdiagnosed disease. This disease is considered the platelet counterpart of the RhD hemolytic disease of the fetus and newborn, yet in neonatal alloimmune thrombocytopenia the first child is affected with fetal and/or neonatal thrombocytopenia. There is a significant risk of intracranial hemorrhage and severe neurological impairment, with a tendency for earlier and more severe thrombocytopenia in subsequent pregnancies.