B-cell immune deficiency in twin sisters expands the phenotype of MOPDI.

Microcephalic osteodysplastic primordial dwarfism type I (MOPDI) is a very rare and severe autosomal recessive disorder characterized by marked intrauterine growth retardation, skeletal dysplasia, microcephaly and brain malformations. MOPDI is caused by biallelic mutations in RNU4ATAC, a non-coding gene involved in U12-type splicing of 1% of the introns in the genome, which are recognized by their specific splicing consensus sequences. Here, we describe a unique observation of immunodeficiency in twin sisters with mild MOPDI, who harbor a novel n.

Monitoring monocyte HLA-DR expression and CD4 + T lymphocyte count in dexamethasone-treated severe COVID-19 patients.

Background: A 10-day dexamethasone regimen has emerged as the internationally adopted standard-of-care for severe COVID-19 patients. However, the immune response triggered by SARS-CoV-2 infection remains a complex and dynamic phenomenon, leading to various immune profiles and trajectories. The immune status of severe COVID-19 patients following complete dexamethasone treatment has yet to be thoroughly documented.

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Introduction: Le niveau d'expression des molécules HLA-DR à la surface des monocytes (mHLA-DR) est un marqueur diagnostique utilisé pour évaluer l'immunité des patients en réanimation (choc septique, polytraumatisés, brulures, greffe et plus récemment Covid-19). Il est également utilisé comme un outil de stratification dans les essais cliniques utilisant des thérapies immunostimulantes chez ces patients. L'objectif de cette étude était d'évaluer les performances analytiques d'une méthode de cytométrie en flux pour mesurer mHLA-DR afin de répondre aux exigences de la norme NF EN ISO 15189 dans le cadre de l'accréditation des laboratoires de biologie médicale.

Cross-sectional reassessment after 4 years of clinical routine use of AQUIOS CL for absolute T cell quantitation in a university hospital.

Background: We had previously reported appropriate performances of automated AQUIOS CL cytometer (Beckman Coulter) for regulatory approval of absolute T cell enumeration. However, after 4 years of routine use, we still observed recurrent histogram anomalies that may affect both absolute values and T cell subset percentages results. The objective of the current study was thus to perform a cross-sectional evaluation of these graphical anomalies within a university hospital context, to assess their influence on results and ultimately to propose a standardized decision tree to circumvent graphical disturbances at the time of results validation.

Polyclonal expansion of TCR Vbeta 21.3 CD4 and CD8 T cells is a hallmark of Multisystem Inflammatory Syndrome in Children.

Multiple Inflammatory Syndrome in Children (MIS-C) is a delayed and severe complication of SARS-CoV-2 infection that strikes previously healthy children. As MIS-C combines clinical features of Kawasaki disease and Toxic Shock Syndrome (TSS), we aimed to compare the immunological profile of pediatric patients with these different conditions. We analyzed blood cytokine expression, and the T cell repertoire and phenotype in 36 MIS-C cases, which were compared to 16 KD, 58 TSS, and 42 COVID-19 cases.

Clinical significance of a single cerebrospinal fluid immunoglobulin band: A retrospective study.

Background: To demonstrate an inflammatory process in the central nervous system, the presence of at least two immunoglobulin (Ig) bands in the cerebrospinal fluid (CSF) is required. So far, the presence of a single abnormal Ig band is considered as negative.

Objective: The objective was to assess retrospectively the significance of a single CSF Ig band in clinical practice.

Torque Teno Virus Viral Load as a Marker of Immune Function in Allogeneic Haematopoietic Stem Cell Transplantation Recipients.

Torque teno virus (TTV) has been proposed as a surrogate biomarker of T-cell function in allogeneic-haematopoietic-stem-cell transplantation (allo-HSCT). Conflicting data exists regarding the value of TTV to assess the degree of immunosuppression. The aim of the present study was to investigate the correlation between TTV viral load and immune function.

Contribution of rare and predicted pathogenic gene variants to childhood-onset lupus: a large, genetic panel analysis of British and French cohorts.

Background: Systemic lupus erythematosus (SLE) is a rare immunological disorder and genetic factors are considered important in its causation. Monogenic lupus has been associated with around 30 genotypes in humans and 60 in mice, while genome-wide association studies have identified more than 90 risk loci. We aimed to analyse the contribution of rare and predicted pathogenic gene variants in a population of unselected cases of childhood-onset SLE.

Proof of concept study of mass cytometry in septic shock patients reveals novel immune alterations.

Innovative single cell technologies such as mass cytometry (CyTOF) widen possibilities to deeply improve characterisation of immune alterations mechanisms in human diseases. So far, CyTOF has not been used in sepsis - a condition characterized by complex immune disorders. Here, we evaluated feasibility of CyTOF analysis in patients with septic shock.

Clinical management and viral genomic diversity analysis of a child's influenza A(H1N1)pdm09 infection in the context of a severe combined immunodeficiency.

Introduction: A child with severe combined immunodeficiency (SCID) had an influenza A(H1N1)pdm09 infection with viral excretion longer than 6 months, during 2013-2014 influenza season, despite cord blood transplantation and antiviral treatments.

Methods: Conventional real-time RT-PCR methods were used to estimate viral load and to detect the presence of the common N1 neuraminidase (NA) H275Y substitution responsible for oseltamivir resistance. Next-generation sequencing (NGS) of influenza viruses was performed retrospectively to characterize viral quasispecies in specimens.

Septic Shock Shapes B Cell Response toward an Exhausted-like/Immunoregulatory Profile in Patients.

Septic shock is accompanied by the development of immune dysfunctions whose intensity and duration are associated with increased risk of secondary infections and mortality. Although B lymphocytes play a pivotal role in the immune response to infections, no comprehensive exploration of circulating B cell status has been performed during the immunosuppressive phase of septic shock. Thus, our aim was to extensively characterize the phenotype and function of B cells in septic shock, including IL-10 production.

Familial and syndromic lupus share the same phenotype as other early-onset forms of lupus.

Objective: Studies of early-onset systemic lupus erythematosus (SLE) have identified monogenic forms of the disease. The primary objective of this study was to compare the clinical and laboratory features of the first patients included in the GENIAL/LUMUGENE cohort to those reported in previous publications. The secondary objective was to determine whether subgroups with a distinctive pattern of clinical and biological features are seen in predominantly genetic forms of SLE.

T-Lymphocytes Traffic into the Brain across the Blood-CSF Barrier: Evidence Using a Reconstituted Choroid Plexus Epithelium.

An emerging concept of normal brain immune surveillance proposes that recently and moderately activated central memory T lymphocytes enter the central nervous system (CNS) directly into the cerebrospinal fluid (CSF) via the choroid plexus. Within the CSF space, T cells inspect the CNS environment for cognate antigens. This gate of entry into the CNS could also prevail at the initial stage of neuroinflammatory processes.

Evaluation of a novel automated volumetric flow cytometer for absolute CD4+ T lymphocyte quantitation.

Background: Bead-based single platform cytometry technology (SPT) is the gold standard when performing CD4 absolute counting. However, it presents drawbacks as precision depends on various critical steps (for example, pipetting methodology, overtime stability of beads, stability of fluidics, regular recalibration…) and thus requires skilled operators. The fully automated volumetric SPT AQUIOS CL (Beckman Coulter) has recently emerged as an alternative with no need of beads.

Marked alterations of neutrophil functions during sepsis-induced immunosuppression.

Severe septic syndromes deeply impair innate and adaptive immunity and are responsible for sepsis-induced immunosuppression. Although neutrophils represent the first line of defense against infection, little is known about their phenotype and functions a few days after sepsis, when the immunosuppressive phase is maximal (i.e.

Increased Regulatory T-Cell Percentage Contributes to Poor CD4(+) Lymphocytes Recovery: A 2-Year Prospective Study After Introduction of Antiretroviral Therapy.

Background.  The primary aim of this study was to determine the impact of regulatory T cells (Tregs) percentage on immune recovery in human immunodeficiency virus (HIV)-infected patients after antiretroviral therapy introduction. Methods.

PRKDC mutations associated with immunodeficiency, granuloma, and autoimmune regulator-dependent autoimmunity.

Background: PRKDC encodes for DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a kinase that forms part of a complex (DNA-dependent protein kinase [DNA-PK]) crucial for DNA double-strand break repair and V(D)J recombination. In mice DNA-PK also interacts with the transcription factor autoimmune regulator (AIRE) to promote central T-cell tolerance.

Objective: We sought to understand the causes of an inflammatory disease with granuloma and autoimmunity associated with decreasing T- and B-cell counts over time that had been diagnosed in 2 unrelated patients.

Effect of pneumatic tube transport on T lymphocyte subsets analysis.

Background: Pneumatic tube system (PTS) for transportation of blood specimens may present with advantages for hospital organization as it provides faster tube transfer from medical wards to routine labs. These characteristics are expected to result in faster sample processing and decreased turnaround time, therefore benefiting the patient particularly in emergency units. However, PTS could affect sample quality and therefore laboratory results.

B-cell subpopulations in children: National reference values.

Peripheral B-lymphocytes undergo a series of changes during the first few years of life. Encounters with foreign antigens lead to maturation and differentiation. Several primary antibody deficiencies (PADs) affecting B-cell development are associated with abnormalities in the composition and/or differentiation of B-cell compartments.

Flow cytometric evaluation of lymphocyte transformation test based on 5-ethynyl-2'deoxyuridine incorporation as a clinical alternative to tritiated thymidine uptake measurement.

In clinical laboratories, the evaluation of lymphocyte proliferative response (lymphocyte transformation test-LTT) is routinely performed by the measurement of [(3)H]-thymidine uptake after stimulation. In this study we evaluated the performances of a recently developed non-radioactive test based on the detection by flow cytometry of 5-ethynyl-2'deoxyuridine (EdU) incorporation for the measurement of LTT in routine lab conditions. After definition of optimal protocol parameters, EdU incorporation test showed good repeatability and reproducibility.