Neonatal alloimmune thrombocytopenia due to a new alloantigen Bl(a) defined by an Asp458Gly substitution in GPIIIa.

Background: Neonatal alloimmune thrombocytopenia (NAIT) commonly arises due to antibodies against a small number of well-defined human platelet antigens (HPAs). A minority of NAIT cases occur due to maternal immunization against low-frequency polymorphisms in platelet glycoprotein that result in new immunogenic epitopes. Antibodies to these novel epitopes can be detected by the incubation of maternal serum with paternal platelets and is usually performed after initial investigation using HPA-typed panel platelets has failed to provide evidence of NAIT.

Human platelet antigen (HPA)-specific immunoglobulin M antibodies in neonatal alloimmune thrombocytopenia can inhibit the binding of HPA-specific immunoglobulin G antibodies.

Background: A term baby with unexplained thrombocytopenia and a platelet (PLT) count of 14 × 10 /L (maternal PLT count was 200 × 10 /L) was investigated for neonatal alloimmune thrombocytopenia.

Study Design And Methods: Serologic investigations were performed using the PLT immunofluorescence test (PIFT), monoclonal antibody immobilization of PLT antigens (MAIPA), and a bead-based assay (BBA) with maternal sera taken up to 56 days postdelivery. One serum sample was also separated into "immunoglobulin (Ig)M-rich" and "IgM-depleted" fractions and tested for PLT-specific antibodies.

Estimating the total incidence of kidney failure in Australia including individuals who are not treated by dialysis or transplantation.

Background: To date, incidence data for kidney failure in Australia have been available for only those who start renal replacement therapy (RRT). Information about the total incidence of kidney failure, including non-RRT-treated cases, is important to help understand the burden of kidney failure in the community and the characteristics of patients who die without receiving treatment.

Study Design: Data linkage study of national observational data sets.

Recipient-derived HPA-1a antibodies: a cause of prolonged thrombocytopenia after unrelated donor stem cell transplantation.

Background: Patients with human platelet antigen (HPA) specific antibodies in cases of neonatal alloimmune thrombocytopenia and platelet (PLT) refractoriness derive clinical benefit from the use of HPA-selected PLTs.

Study Design And Methods: This study describes three patients with underlying diagnoses of acute myeloid leukemia, chronic lymphocytic leukemia, and myelodysplasia, respectively, who underwent allogeneic bone marrow transplantation (BMT) with unrelated donors matched at the HLA-A, B, C, Dr, and DQ loci but who failed to achieve an adequate PLT count. Investigation using PLT immunofluorescence test, monoclonal antibody immobilization of PLT antigens assay, and genotyping revealed the presence of recipient-derived HPA-1a antibodies.

A large kindred with X-linked neutropenia with an I294T mutation of the Wiskott-Aldrich syndrome gene.

X-linked neutropenia (XLN, OMIM #300299) is a rare form of severe congenital neutropenia. It was originally described in a three-generation family with five affected members that had an L270P mutation in the GTP-ase binding domain (GBD) of the Wiskott-Aldrich syndrome protein (WASP) [Devriendt et al (2001) Nature Genetics, Vol. 27, 313-317].

Transfusion-related alloimmune neutropenia: an undescribed complication of blood transfusion.

Alloimmune neutropenia in neonates is rare. We describe severe and persistent neutropenia in a 4-week-old neonate, which arose within 2 h of a transfusion of blood that contained about 28 mL of plasma and in which strong antibodies against human neutrophil antigen 1b (HNA-1b) were subsequently identified. The infant was positive for HNA-1b.