Improving the generalizability of white blood cell classification with few-shot domain adaptation.

The morphological classification of nucleated blood cells is fundamental for the diagnosis of hematological diseases. Many Deep Learning algorithms have been implemented to automatize this classification task, but most of the time they fail to classify images coming from different sources. This is known as "domain shift".

Long-term assessment of haematological recovery following somatic genetic rescue in a MYSM1-deficient patient: Implications for in vivo gene therapy.

MYSM1 deficiency causes inherited bone marrow failure syndrome (IBMFS). We have previously identified an IBMFS patient with a homozygous pathogenic variant in MYSM1 who recovered from cytopenia due to spontaneous correction of one MYSM1 variant in the haematopoietic compartment, an event called somatic genetic rescue (SGR). The study of the genetic and biological aspects of the patient's haematopoietic/lymphopoietic system over a decade after SGR shows that one genetically corrected haematopoietic stem cell (HSC) can restore a healthy and stable haematopoietic system.

Metabolic adaptation pilots the differentiation of human hematopoietic cells.

A continuous supply of energy is an essential prerequisite for survival and represents the highest priority for the cell. We hypothesize that cell differentiation is a process of optimization of energy flow in a changing environment through phenotypic adaptation. The mechanistic basis of this hypothesis is provided by the established link between core energy metabolism and epigenetic covalent modifications of chromatin.

Modulation of bone marrow and peripheral blood cytokine levels by age and clonal hematopoiesis in healthy individuals.

Aging is associated with bone marrow (BM) inflammaging and, in some individuals, with the onset of clonal hematopoiesis (CH) of indeterminate potential. In this study conducted on 94 strictly healthy volunteers (18 to 80 yo), we measured BM and peripheral blood (PB) plasma levels of 49 hematopoietic and inflammatory cytokines. With aging, 7 cytokines increased in BM (FLT3L, CXCL9, HGF, FGF-2, CCL27, IL-16, IL-18) and 8 decreased (G-CSF, TNF, IL-2, IL-15, IL-17A, CCL7, IL-4, IL-10).

Transinteractome analysis reveals distinct niche requirements for isotype-based plasma cell subsets in the bone marrow.

Bone marrow (BM) long-lived plasma cells (PCs) are essential for long-term protection against infection, and their persistence within this organ relies on interactions with Cxcl12-expressing stromal cells that are still not clearly identified. Here, using single cell RNAseq and in silico transinteractome analyses, we identified Leptin receptor positive (LepR ) mesenchymal cells as the stromal cell subset most likely to interact with PCs within the BM. Moreover, we demonstrated that depending on the isotype they express, PCs may use different sets of integrins and adhesion molecules to interact with these stromal cells.

Clinical and biological impact of ATP-binding cassette transporter activity in adult acute myeloid leukemia.

Chemotherapy resistance is the main cause of treatment failure in acute myeloid leukemia (AML) and has been related to ATP-binding cassette (ABC) transporter activity. However, the links between ABC activity, immunophenotype, and molecular AML parameters have been poorly evaluated. Moreover, the prognostic value of ABC activity, when compared to new molecular markers, is unknown.

Aberrant DNA methylation impacts HOX genes expression in bone marrow mesenchymal stromal cells of myelodysplastic syndromes and de novo acute myeloid leukemia.

DNA methylation, a major biological process regulating the transcription, contributes to the pathophysiology of hematologic malignancies, and hypomethylating agents are commonly used to treat myelodysplastic syndromes (MDS) and acute myeloid leukemias (AML). In these diseases, bone marrow mesenchymal stromal cells (MSCs) play a key supportive role through the production of various signals and interactions. The DNA methylation status of MSCs, likely to reflect their functionality, might be relevant to understand their contribution to the pathophysiology of these diseases.

Macrophage migration inhibitory factor is overproduced through EGR1 in TET2 resting monocytes.

Somatic mutation in TET2 gene is one of the most common clonal genetic events detected in age-related clonal hematopoiesis as well as in chronic myelomonocytic leukemia (CMML). In addition to being a pre-malignant state, TET2 mutated clones are associated with an increased risk of death from cardiovascular disease, which could involve cytokine/chemokine overproduction by monocytic cells. Here, we show in mice and in human cells that, in the absence of any inflammatory challenge, TET2 downregulation promotes the production of MIF (macrophage migration inhibitory factor), a pivotal mediator of atherosclerotic lesion formation.

Circulating cytokines present in multiple myeloma patients inhibit the osteoblastic differentiation of adipose stem cells.

Myeloma is characterized by bone lesions, which are related to both an increased osteoclast activity and a defect in the differentiation of medullary mesenchymal stem cells (MSCs) into osteoblasts. Outside the medullary environment, adipocyte-derived MSCs (ASCs) could represent a source of functional osteoblasts. However, we recently found a defect in the osteoblastic differentiation of ASCs from myeloma patients (MM-ASCs).

Somatic genetic rescue of a germline ribosome assembly defect.

Indirect somatic genetic rescue (SGR) of a germline mutation is thought to be rare in inherited Mendelian disorders. Here, we establish that acquired mutations in the EIF6 gene are a frequent mechanism of SGR in Shwachman-Diamond syndrome (SDS), a leukemia predisposition disorder caused by a germline defect in ribosome assembly. Biallelic mutations in the SBDS or EFL1 genes in SDS impair release of the anti-association factor eIF6 from the 60S ribosomal subunit, a key step in the translational activation of ribosomes.

A circulating subset of BRAF -positive cells in infants with high-risk Langerhans cell histiocytosis treated with BRAF inhibitors.

BRAF inhibitors are an effective treatment for BRAF -mutated, risk-organ-positive Langerhans cell histiocytosis (RO LCH). However, cell-free BRAF DNA often persists during therapy and recurrence frequently occurs after therapy discontinuation. To identify a pathological reservoir of BRAF -mutated cells, we studied peripheral blood cells obtained from six infants with RO multisystem (MS) LCH that received targeted therapy.

Shwachman-Diamond syndrome and solid tumors: Three new patients from the French Registry for Severe Chronic Neutropenia and literature review.

Shwachman-Diamond syndrome with Shwachman-Bodian-Diamond syndrome (SBDS) biallelic variants is a rare disorder that predisposes the carrier to malignant hemopathies but solid-cancer predisposition is poorly known. Among 155 cases entered in the French Registry for Severe Chronic Neutropenia, three were identified with malignant solid tumors (ovary, breast, and esophagus). All cancers occurred during the fifth decade and, despite being localized at diagnosis, were rapidly fatal thereafter.

Unexplained recurrent implantation failures: Predictive factors of pregnancy and therapeutic management from a French multicentre study.

Introduction: Recurrent implantation failure is defined as the absence of pregnancy after at least three transfers of good-quality embryos after in vitro fecundation/intracytoplasic sperm injection.

Aim: The aim of this study was to describe a multicentre cohort of women with unexplained RIF, to analyse the factors associated with clinical pregnancy and to evaluate the immunomodulatory therapies efficacy.

Methods: Women were consecutively recruited from university departments with unexplained RIF.

Unexplained recurrent miscarriages: predictive value of immune biomarkers and immunomodulatory therapies for live birth.

Introduction: Recurrent miscarriages are defined as three or more early miscarriages before 12 weeks of gestation. The aim of this study was to describe a cohort of women with unexplained recurrent miscarriages, evaluate several potential biomarkers of immune origin, and describe the outcome of pregnancies under immunomodulatory therapies.

Methods: Women having a history of at least 3 early miscarriages without any etiology were recruited from 3 university hospitals.