Expanding the phenotypic and genetic landscape of congenital neutropenia through whole-exome and genome sequencing.

Congenital neutropenia (CN) comprises a heterogeneous group of rare genetic disorders. While some CN cases present only with neutropenia, others present with additional extra-hematological manifestations. The most common cause of CN is variants in ; however, approximately 30 other genes have been implicated.

[Update on acute leukemia of ambiguous lineage in 2023 - Recommendations of the French Society for Childhood and Adolescent Cancer and Leukemia (SFCE)].

Acute leukemias of ambiguous lineage (ALAL) represent between 3 and 5% of childhood AL. This term encompasses many subtypes of AL that have been defined according to the immunophenotypic profile based on the expression of various lineage markers. This classification has been modified and enriched during the last decade thanks to the improvement of molecular biology techniques, which have led to reconsider the ontogenic proximity existing between certain forms of ALAL.

Activated phosphoinositide 3-kinase δ syndrome: Update from the ESID Registry and comparison with other autoimmune-lymphoproliferative inborn errors of immunity.

Background: Activated phosphoinositide-3-kinase δ syndrome (APDS) is an inborn error of immunity (IEI) with infection susceptibility and immune dysregulation, clinically overlapping with other conditions. Management depends on disease evolution, but predictors of severe disease are lacking.

Objectives: This study sought to report the extended spectrum of disease manifestations in APDS1 versus APDS2; compare these to CTLA4 deficiency, NFKB1 deficiency, and STAT3 gain-of-function (GOF) disease; and identify predictors of severity in APDS.

Molecular and clinicopathologic characterization of pediatric histiocytoses.

The spectrum of somatic mutations in pediatric histiocytoses and their clinical implications are not fully characterized, especially for non-Langerhans cell histiocytosis (-LCH) subtypes. A cohort of 415 children with histiocytosis from the French histiocytosis registry was reviewed and analyzed for BRAF . Most BRAF samples were analyzed by next-generation sequencing (NGS) with a custom panel of genes for histiocytosis and myeloid neoplasia.

Single-dose (4.5 mg/m ) gemtuzumab ozogamicin in combination with fludarabine, cytarabine and anthracycline as reinduction therapy in relapsed or refractory paediatric acute myeloid leukaemia.

Despite major therapeutic improvements, children with relapsed/refractory Acute Myeloid Leukaemia still have poor outcomes and overall survival does not exceed 40%. New treatments are required to improve their outcome; Gemtuzumab ozogamicin (GO), an anti-CD33 immunoconjugate antibody, is a potent cytotoxic agent whose efficacy has been demonstrated mainly in adults. The main objective of this retrospective multicentre study was to assess the outcome of children treated, between February 2008 and August 2019, with GO at a single 4.

Human MAIT cells are devoid of alloreactive potential: prompting their use as universal cells for adoptive immune therapy.

Background: Mucosal-associated invariant T (MAIT) cells are semi-invariant T cells that recognize microbial antigens presented by the highly conserved MR1 molecule. MAIT cells are predominantly localized in the liver and barrier tissues and are potent effectors of antimicrobial defense. MAIT cells are very few at birth and accumulate gradually over a period of about 6 years during the infancy.

Two Monogenetic Disorders, Activated PI3-Kinase-δ Syndrome 2 and Smith-Magenis Syndrome, in One Patient: Case Report and a Literature Review of Neurodevelopmental Impact in Primary Immunodeficiencies Associated With Disturbed PI3K Signaling.

Activated PI3-kinase-δ syndrome 2 (APDS2) is caused by autosomal dominant mutations in the gene encoding the p85α, p55α, and p50α regulatory subunits. Most diagnosed APDS2 patients carry mutations affecting either the splice donor or splice acceptor sites of exon 11 of the gene responsible for an alternative splice product and a shortened protein. The clinical presentation of APDS2 patients is highly variable, ranging from mild to profound combined immunodeficiency features as massive lymphoproliferation, increased susceptibility to bacterial and viral infections, bronchiectasis, autoimmune manifestations, and occurrence of cancer.

Novel variants in the BLOC1S3 gene in patients presenting a mild form of Hermansky-Pudlak syndrome.

Hermansky-Pudlak syndrome (HPS) associates oculocutaneous albinism and systemic affections including platelet dense granules anomalies leading to bleeding diathesis and, depending on the form, pulmonary fibrosis, immunodeficiency, and/or granulomatous colitis. So far, 11 forms of autosomal recessive HPS caused by pathogenic variants in 11 different genes have been reported. We describe three HPS-8 consanguineous families with different homozygous pathogenic variants in BLOC1S3 (NM_212550.

Bacteremia: Clinical Expression and Bacterial Genomics.

Whooping cough's primary etiological agent is . The closely related rarely causes severe disease. Here we report an unusual case of bacteremia caused by , review the literature, and characterize the genomic sequence of the bacterial isolate in comparison with isolates from respiratory infections.

Ontogeny of human mucosal-associated invariant T cells and related T cell subsets.

Mucosal-associated invariant T (MAIT) cells are semi-invariant Vα7.2 CD161CD4 T cells that recognize microbial riboflavin precursor derivatives such as 5-OP-RU presented by MR1. Human MAIT cells are abundant in adult blood, but there are very few in cord blood.

GSTA1 diplotypes affect busulfan clearance and toxicity in children undergoing allogeneic hematopoietic stem cell transplantation: a multicenter study.

Busulfan (BU) dose adjustment following therapeutic drug monitoring contributes to better outcome of hematopoietic stem cell transplantation (HSCT). Further improvement could be achieved through genotype-guided BU dose adjustments. To investigate this aspect, polymorphism within glutathione S transferase genes were assessed.