The Diagnostic Assessment of Inherited Platelet Function Defects - Part 1: An Overview of the Diagnostic Approach and Laboratory Methods.

In this article, our goal is to offer an introduction and overview of the diagnostic approach to inherited platelet function defects (iPFDs) for clinicians and laboratory personnel who are beginning to engage in the field. We describe the most commonly used laboratory methods and propose a diagnostic four-step approach, wherein each stage requires a higher level of expertise and more specialized methods. It should be noted that our proposed approach differs from the ISTH Guidance on this topic in some points.

The Diagnostic Assessment of Platelet Function Defects - Part 2: Update on Platelet Disorders.

Congenital platelet disorders are rare and targeted treatment is usually not possible. Inherited platelet function disorders (iPFDs) can affect surface receptors and multiple platelet responses such as defects of platelet granules, signal transduction, and procoagulant activity. If iPFDs are also associated with a reduced platelet count (thrombocytopenia), it is not uncommon to be misdiagnosed as immune thrombocytopenia.

C-Type Lectin-like Receptor 2 Expression Is Decreased upon Platelet Activation and Is Lower in Most Tumor Entities Compared to Healthy Controls.

The C-type lectin-like receptor 2 (CLEC-2) is expressed on platelets and mediates binding to podoplanin (PDPN) on various cell types. The binding to circulating tumor cells (CTCs) leads to platelet activation and promotes metastatic spread. An increased level of soluble CLEC-2 (sCLEC-2), presumably released from activated platelets, was shown in patients with thromboinflammatory and malignant disease.

Evaluation of Single Nucleotide Variants in Intron 1 of the ABO Gene as Diagnostic Markers for the A Blood Group.

Introduction: The molecular diagnosis of the A blood group is based on the exclusion of gene variants causing blood groups A, B, or O. A specific genetic marker for the A blood group is still missing. Recently, long-read ABO sequencing revealed four sequence variations in intron 1 as promising markers for the * allele.

Correlation between Clinical Characteristics and Antibody Levels in COVID-19 Convalescent Plasma Donor Candidates.

COVID-19 convalescent plasma (CCP) with high neutralizing antibodies has been suggested in preventing disease progression in COVID-19. In this study, we investigated the relationship between clinical donor characteristics and neutralizing anti-SARS-CoV-2 antibodies in CCP donors. COVID-19 convalescent plasma donors were included into the study.

Humoral SARS-CoV-2 Immune Response in COVID-19 Recovered Vaccinated and Unvaccinated Individuals Related to Post-COVID-Syndrome.

Background: The duration of anti-SARS-CoV-2-antibody detectability up to 12 months was examined in individuals after either single convalescence or convalescence and vaccination. Moreover, variables that might influence an anti-RBD/S1 antibody decline and the existence of a post-COVID-syndrome (PCS) were addressed.

Methods: Forty-nine SARS-CoV-2-qRT-PCR-confirmed participants completed a 12-month examination of anti-SARS-CoV-2-antibody levels and PCS-associated long-term sequelae.

Booster dose of mRNA vaccine augments waning T cell and antibody responses against SARS-CoV-2.

A gradual decay in humoral and cellular immune responses over time upon SAR1S-CoV-2 vaccination may cause a lack of protective immunity. We conducted a longitudinal analysis of antibodies, T cells, and monocytes in 25 participants vaccinated with mRNA or ChAdOx1-S up to 12 weeks after the 3 (booster) dose with mRNA vaccine. We observed a substantial increase in antibodies and CD8 T cells specific for the spike protein of SARS-CoV-2 after vaccination.

Platelets and Sera from Donors of Convalescent Plasma after Mild COVID-19 Show No Procoagulant Phenotype.

Coronavirus disease-2019 (COVID-19) is associated with increased thromboembolic complications. Long-term alteration in coagulation system after acute COVID-19 infection is still a subject of research. Furthermore, the effect of sera from convalescent subjects on platelets is not known.

Pooled human bone marrow-derived mesenchymal stromal cells with defined trophic factors cargo promote dermal wound healing in diabetic rats by improved vascularization and dynamic recruitment of M2-like macrophages.

Human Mesenchymal Stromal Cells (hMSCs) are a promising source for cell-based therapies. Yet, transition to phase III and IV clinical trials is remarkably slow. To mitigate donor variabilities and to obtain robust and valid clinical data, we aimed first to develop a manufacturing concept balancing large-scale production of pooled hMSCs in a minimal expansion period, and second to test them for key manufacture and efficacy indicators in the clinically highly relevant indication wound healing.

Loss-of-function variant in chymotrypsin like elastase 3B (CELA3B) is associated with non-alcoholic chronic pancreatitis.

Background: Genetic alterations in digestive enzymes have been associated with chronic pancreatitis (CP). Recently, chymotrypsin like elastase 3B (CELA3B) emerged as a novel risk gene. Thus, we evaluated CELA3B in two European cohorts with CP.

The three common polymorphisms p.A986S, p.R990G and p.Q1011E in the calcium sensing receptor (CASR) are not associated with chronic pancreatitis.

Background: The calcium sensing receptor (CASR) is a G protein-coupled receptor that is responsible for assessing extracellular Ca levels and thus plays a crucial role in calcium homeostasis. Hypercalcemia is a metabolic risk factor for pancreatitis and rare CASR variants have been described in patients with chronic pancreatitis. At the carboxy-terminal tail of CASR, there is a cluster of three common polymorphisms, p.

Recommendation for validation and quality assurance of non-invasive prenatal testing for foetal blood groups and implications for IVD risk classification according to EU regulations.

Background And Objectives: Non-invasive assays for predicting foetal blood group status in pregnancy serve as valuable clinical tools in the management of pregnancies at risk of detrimental consequences due to blood group antigen incompatibility. To secure clinical applicability, assays for non-invasive prenatal testing of foetal blood groups need to follow strict rules for validation and quality assurance. Here, we present a multi-national position paper with specific recommendations for validation and quality assurance for such assays and discuss their risk classification according to EU regulations.

Adverse Prognostic Impact of the D816V Transcriptional Activity in Advanced Systemic Mastocytosis.

In systemic mastocytosis (SM), qualitative and serial quantitative assessment of the D816V mutation is of diagnostic and prognostic relevance. We investigated peripheral blood and bone marrow samples of 161 patients (indolent SM (ISM), = 40; advanced SM, AdvSM, = 121) at referral and during follow-up for the D816V variant allele frequency (VAF) at the DNA-level and the D816V expressed allele burden (EAB) at the RNA-level. A round robin test with four participating laboratories revealed an excellent correlation ( > 0.

Correlation of haplotypes with plasma levels of soluble CLEC-2 in healthy individuals.

Binding of podoplanin to the C-type lectin-like receptor 2 (CLEC-2) promotes platelet activation and soluble CLEC-2 (sCLEC-2) is shed from activated platelets. The role of sCLEC-2 in the plasma is unknown. The expression level and plasma concentration of sCLEC-2 could be affected by variants of the corresponding gene, .

Multicenter Study on Differential Human Neutrophil Antigen 2 Expression and Underlying Molecular Mechanisms.

Background: The human neutrophil antigen 2 (HNA-2), which is expressed on CD177, is undetectable in 3-5% of the normal population. Exposure of these HNA-2 individuals to HNA-2-positive cells can cause immunization and pro-duction of HNA-2 antibodies, which can induce immune neutropenia and transfusion-related acute lung injury. In HNA-2-positive individuals, neutrophils are divided into a CD177 and a CD177 subpopulation.

Sequencing of the complex CTRB1-CTRB2 locus in chronic pancreatitis.

Background: /Objectives: A recent Genome-wide Association Study (GWAS) in alcoholic chronic pancreatitis (ACP) identified a novel association with the CTRB1-CTRB2 (chymotrypsinogen B1, B2) locus, linked to a 16.6 kb inversion that was confirmed in non-alcoholic chronic pancreatitis (NACP). Moreover, recent findings on the function of CTRB1 and CTRB2 suggest a protective role in pancreatitis development.

Introduction of Noninvasive Prenatal Testing for Blood Group and Platelet Antigens from Cell-Free Plasma DNA Using Digital PCR.

Background: Noninvasive prenatal testing (NIPT) for fetal antigens is a common standard for targeted immune prophylaxis in RhD-mediated hemolytic disease of the fetus and newborn, and is most frequently done by quantitative PCR (qPCR). A similar approach is considered for other blood group and human platelet alloantigens (HPA). Because of a higher sensitivity compared to qPCR for rare molecule detection, we established and validated digital PCR (dPCR) assays for the detection of exons 3, 5 and 7, KEL1, HPA-1a, and HPA-5b from cell-free DNA (cfDNA) in plasma.