Minor impact of patient alloantibodies against human platelet antigen (HPA)-15 in the effectiveness of platelet transfusion: A pilot study.

Background: Alloantibodies against human platelet antigen (HPA)-15 are sometimes detected in patients with platelet transfusion refractoriness (PTR); however, little is known about their impact on PTR.

Study Design And Methods: Two patients who possessed HPA-15 alloantibodies (Patient 1, anti-HPA-15b; Patient 2, anti-HPA-15a) and human leukocyte antigen (HLA) antibodies were enrolled. The efficacy of HPA-15-compatible vs -incompatible platelet transfusion was compared by focusing on ABO- and HLA-matched transfusions on the basis of the 24-hour corrected count increment (CCI-24 hours) for platelets.

A novel simple assay system for the detection of human platelet antigen 15 (HPA-15) alloantibodies based on three techniques: an HPA-15 expressing cell line, a monoclonal antibody-specific antigen-capture method and mixed-passive haemagglutination.

Background And Objectives: To detect HPA-15 alloantibodies, we previously developed a human platelet antigen 15 (HPA-15)-expressing cell line-based modified rapid monoclonal antibody immobilization of platelet antigen (CL-MR-MAIPA) assay. In this study, the protocol was modified for easier performance by introducing the mixed-passive haemagglutination (MPHA) principle.

Material And Methods: In total, 20 samples that tested negative for HPA alloantibodies and eight that tested positive for HPA-15 alloantibodies (two and six positive for HPA-15a and HPA-15b antibodies, respectively) by CL-MR-MAIPA assay were used in this study.

Mitochondrial damage-associated molecular patterns as potential proinflammatory mediators in post-platelet transfusion adverse effects.

Background: Platelet concentrates (PCs) are the most common blood components eliciting nonhemolytic transfusion reactions (NHTRs), such as allergic transfusion reactions and febrile reactions. However, the precise mechanisms of NHTRs in PC transfusion remain largely unknown. Previous studies reported that mitochondria-derived damage-associated molecular patterns (DAMPs) could be important mediators of innate cell inflammation.

High-resolution melting analysis as an alternative method for human neutrophil antigen genotyping.

Human neutrophil antigen (HNA)-typed granulocyte panels are widely used to screen for the presence of HNA antibodies and to determine antibody specificity. Many laboratories screen donors for HNA genotypes using low-throughput methods such as allele-specific polymerase chain reaction (PCR), PCR-restriction fragment-length polymorphism, and multiplex PCR. In the present study, we used a high-resolution melting (HRM) analysis to determine HNA genotypes.

The IgE-dependent pathway in allergic transfusion reactions: involvement of donor blood allergens other than plasma proteins.

On transfusion, several plasma proteins can cause anaphylaxis in patients deficient in the corresponding plasma proteins. However, little is known about other allergens, which are encountered much more infrequently. Although it has been speculated that an allergen-independent pathway underlying allergic transfusion reactions (ATRs) is elicited by biological response modifiers accumulated in blood components during storage, the exact mechanisms remain unresolved.

Metagenomic profiling of the viromes of plasma collected from blood donors with elevated serum alanine aminotransferase levels.

Background: In Japanese Red Cross (JRC) blood centers, blood collected from donors with serum alanine aminotransferase (ALT) levels of more than 60 U/L are disqualified even if serologically negative for transfusion-transmitted infections (TTIs). To assess potential risks of TTIs in plasma with elevated serum ALT levels in the current donor screening program of the JRC, we conducted a metagenomic analysis (MGA) of virome profiles in the plasma of blood donors with or without elevated serum ALT levels.

Study Design And Methods: Based on serum ALT levels, donors were classified into three groups: "high," more than 79 U/L; "middle," 61 to 79 U/L; and "low," less than 61 U/L.

Slower uncoating is associated with impaired replicative capability of simian-tropic HIV-1.

Human immunodeficiency virus type 1 (HIV-1) productively infects only humans and chimpanzees, but not Old World monkeys, such as rhesus and cynomolgus (CM) monkeys. To establish a monkey model of HIV-1/AIDS, several HIV-1 derivatives have been constructed. We previously generated a simian-tropic HIV-1 that replicates efficiently in CM cells.

Improved capacity of a monkey-tropic HIV-1 derivative to replicate in cynomolgus monkeys with minimal modifications.

Human immunodeficiency virus type 1 (HIV-1) hardly replicates in Old World monkeys. Recently, a mutant HIV-1 clone, NL-DT5R, in which a small part of gag and the entire vif gene are replaced with SIVmac239-derived ones, was shown to be able to replicate in pigtail monkeys but not in rhesus monkeys (RM). In the present study, we found that a modified monkey-tropic HIV-1 (HIV-1mt), MN4-5S, acquired the ability to replicate efficiently in cynomolgus monkeys as compared with the NL-DT5R, while neither NL-DT5R nor MN4-5S replicated in RM cells.

A single amino acid substitution of the human immunodeficiency virus type 1 capsid protein affects viral sensitivity to TRIM5 alpha.

Background: Human immunodeficiency virus type 1 (HIV-1) productively infects only humans and chimpanzees but not Old World monkeys, such as rhesus and cynomolgus (CM) monkeys. To establish a monkey model of HIV-1/AIDS, several HIV-1 derivatives have been constructed. We previously reported that efficient replication of HIV-1 in CM cells was achieved after we replaced the loop between alpha-helices 6 and 7 (L6/7) of the capsid protein (CA) with that of SIVmac239 in addition to the loop between alpha-helices 4 and 5 (L4/5) and vif.

Modification of a loop sequence between alpha-helices 6 and 7 of virus capsid (CA) protein in a human immunodeficiency virus type 1 (HIV-1) derivative that has simian immunodeficiency virus (SIVmac239) vif and CA alpha-helices 4 and 5 loop improves replication in cynomolgus monkey cells.

Background: Human immunodeficiency virus type 1 (HIV-1) productively infects only humans and chimpanzees but not cynomolgus or rhesus monkeys while simian immunodeficiency virus isolated from macaque (SIVmac) readily establishes infection in those monkeys. Several HIV-1 and SIVmac chimeric viruses have been constructed in order to develop an animal model for HIV-1 infection. Construction of an HIV-1 derivative which contains sequences of a SIVmac239 loop between alpha-helices 4 and 5 (L4/5) of capsid protein (CA) and the entire SIVmac239 vif gene was previously reported.

Replication of chicken anemia virus (CAV) requires apoptin and is complemented by VP3 of human torque teno virus (TTV).

To test requirement for apoptin in the replication of chicken anemia virus (CAV), an apoptin-knockout clone, pCAV/Ap(-), was constructed. DNA replication was completely abolished in cells transfected with replicative form of CAV/Ap(-). A reverse mutant competent in apoptin production regained the full level of DNA replication.

Silencing of tripartite motif protein (TRIM) 5alpha mediated anti-HIV-1 activity by truncated mutant of TRIM5alpha.

Tripartite motif protein (TRIM) 5alpha is a restriction factor of human immunodeficiency virus type 1 in Old World monkey cell. It was found that both naturally occurring and artificial TRIM5alpha variants lacking the SPRY domain could silence TRIM5alpha activity. Specifically, the artificial TRIM5alpha mutant could suppress TRIM5alpha activity of various primate species with even higher efficiency than could small interfering RNAs.

Spliced mRNAs detected during the life cycle of Chicken anemia virus.

The existence of spliced mRNA in Chicken anemia virus (CAV) was investigated, as three proteins appeared to be derived from a single 2.0 kb mRNA species. Human Torque teno virus (TTV), which displays a number of genomic similarities to CAV, is known to transcribe three mRNA species, suggesting that CAV may also have multiple mRNAs.