Publications by authors named "Dhalla F"

The importance of calcium (Ca2+) as a second messenger in T cell signaling is exemplified by genetic deficiencies of STIM1 and ORAI1, which abolish store-operated Ca2+ entry (SOCE) resulting in combined immunodeficiency (CID). We report five unrelated patients with de novo missense variants in ITPR3, encoding a subunit of the inositol 1,4,5-trisphosphate receptor (IP3R), which forms a Ca2+ channel in the endoplasmic reticulum (ER) membrane responsible for the release of ER Ca2+ required to trigger SOCE, and for Ca2+ transfer to other organelles. The patients presented with CID, abnormal T cell Ca2+ homeostasis, incompletely penetrant ectodermal dysplasia, and multisystem disease.

View Article and Find Full Text PDF
Article Synopsis
  • Congenital athymia is a serious condition that affects the immune system and makes babies very sick because their thymus (an important organ for immunity) doesn't work properly.
  • Babies with this condition are very vulnerable to infections and sometimes have other health issues.
  • The best treatment is a special surgery called thymus transplantation, and catching this condition early helps kids stay healthier.
View Article and Find Full Text PDF
Article Synopsis
  • * It is mostly caused by mutations in the C1 inhibitor gene, which is a protein that helps control a specific system in the body related to swelling.
  • * A case is reported where an infant with this condition, after undergoing a liver transplant for a different issue, experienced normalization of C1 inhibitor levels, suggesting a potential cure for hereditary angioedema.
View Article and Find Full Text PDF
Article Synopsis
  • Whole genome sequencing (WGS) is being increasingly used to diagnose rare diseases, but traditional methods often have low diagnostic yields, typically 25-30%.
  • In a study involving 122 rare disease patients and their relatives, a comprehensive bioinformatics approach led to a diagnostic yield of 35%, with 39% solved when including novel gene candidates.
  • The study also identified several novel genes, expanded the phenotypic understanding of existing conditions, and resulted in critical changes to clinical diagnoses and treatments for some patients.
View Article and Find Full Text PDF

Background: Low back pain (LBP) has been shown to have various biological, psychological, and social factors that affect prognosis. However, it is unclear how personality may influence self-reported outcome measures and therapeutic alliance (TA).

Methods: Eysenck's personality inventory was used to assess personality, while the numeric pain rating scale (NPRS), Oswestry Disability Index (ODI), Tampa Scale of Kinesiophobia (TSK), Global Rating of Change (GROC), and the Working Alliance Inventory (WAI) measured patient progress and relationship strength.

View Article and Find Full Text PDF

The network of thymic stromal cells provides essential niches with unique molecular cues controlling T cell development and selection. Recent single-cell RNA sequencing studies have uncovered previously unappreciated transcriptional heterogeneity among thymic epithelial cells (TEC). However, there are only very few cell markers that allow a comparable phenotypic identification of TEC.

View Article and Find Full Text PDF
Article Synopsis
  • In March 2020, the UK Primary Immunodeficiency Network created a registry to track outcomes of individuals with Primary Immunodeficiency Diseases (PID) and Secondary Immunodeficiency Diseases (SID) after infection with SARS-CoV-2, reporting 310 cases.
  • The overall mortality rate was 17.7%, with certain groups experiencing higher rates; for example, Common Variable Immunodeficiency Disease (CVID) had an infection fatality rate (IFR) of 18.3%.
  • Individuals with PID and SID faced greater risks in terms of inpatient mortality and generally died at younger ages than the broader population, with risk factors including older age, low lymphocyte count before infection, and existing co-morbidities
View Article and Find Full Text PDF

The thymic stroma is composed of epithelial and nonepithelial cells providing separate microenvironments controlling homing, differentiation, and selection of hematopoietic precursor cells to functional T cells. Here, we explore at single-cell resolution the complex composition and dynamic changes of the nonepithelial stromal compartment across different developmental stages in the human and mouse thymus, and in an experimental model of the DiGeorge syndrome, the most common form of human thymic hypoplasia. The detected gene expression signatures identify previously unknown stromal subtypes and relate their individual molecular profiles to separate differentiation trajectories and functions, revealing an unprecedented heterogeneity of different cell types that emerge at discrete developmental stages and vary in their expression of key regulatory signaling circuits and extracellular matrix components.

View Article and Find Full Text PDF

Genetic variants in PIK3CD, PIK3R1 and NFKB1 cause the primary immune deficiencies, activated PI3Kδ syndrome (APDS) 1, APDS2 and NFκB1 haploinsufficiency, respectively. We have identified a family with known or potentially pathogenic variants NFKB1, TNFRSF13B and PIK3R1. The study's aim was to describe their associated immune and cellular phenotypes and compare with individuals with monogenic disease.

View Article and Find Full Text PDF
Article Synopsis
  • FOXN1 is a key regulator for the development and function of thymic epithelial cells (TECs) and is differently regulated during organ formation.
  • The C-terminal sequence of FOXN1 influences its behavior in nuclear condensates, affecting its ability to bind to gene regulatory regions.
  • A mutant version of FOXN1, which has changes in its C-terminal sequence, loses transcriptional function and disrupts normal FOXN1 activity, leading to immune issues like athymia and lymphopenia in affected individuals.
View Article and Find Full Text PDF
Article Synopsis
  • Human nude SCID is a genetic disorder causing immune deficiency, characterized primarily by a lack of thymus development (congenital athymia), hair loss (alopecia), and nail deformities (nail dystrophy), with only a few cases documented so far.
  • Recent advancements in newborn screening and genetic sequencing have uncovered new cases and a range of immune system issues in patients with different mutation types in the FOXN1 gene.
  • The study analyzed clinical data from 18 patients, revealing variations in symptoms and severity; many exhibited forms of severe immune deficiency, while some showed atypical phenotypes, suggesting that mutation type and residual gene function impact disease severity.
View Article and Find Full Text PDF

Interstitial lung disease (ILD) is an important non-infectious complication in several primary immune deficiencies. In common variable immune deficiency (CVID) it is associated with complex clinical phenotypes and adverse outcomes. The histology of ILD in CVID is heterogeneous and mixed patterns are frequently observed within a single biopsy, including non-necrotising granulomatous inflammation, lymphoid interstitial pneumonitis, lymphoid hyperplasia, follicular bronchiolitis, organizing pneumonia, and interstitial fibrosis; ILD has to be differentiated from lymphoma.

View Article and Find Full Text PDF

As the primary site for T cell development, the thymus is responsible for the production and selection of a functional, yet self-tolerant T cell repertoire. This critically depends on thymic stromal cells, derived from the pharyngeal apparatus during embryogenesis. Thymic epithelial cells, mesenchymal and vascular elements together form the unique and highly specialised microenvironment required to support all aspects of thymopoiesis and T cell central tolerance induction.

View Article and Find Full Text PDF

Ageing is characterised by cellular senescence, leading to imbalanced tissue maintenance, cell death and compromised organ function. This is first observed in the thymus, the primary lymphoid organ that generates and selects T cells. However, the molecular and cellular mechanisms underpinning these ageing processes remain unclear.

View Article and Find Full Text PDF

To induce central T-cell tolerance, medullary thymic epithelial cells (mTEC) collectively express most protein-coding genes, thereby presenting an extensive library of tissue-restricted antigens (TRAs). To resolve mTEC diversity and whether promiscuous gene expression (PGE) is stochastic or coordinated, we sequenced transcriptomes of 6,894 single mTEC, enriching for 1,795 rare cells expressing either of two TRAs, TSPAN8 or GP2. Transcriptional heterogeneity allowed partitioning of mTEC into 15 reproducible subpopulations representing distinct maturational trajectories, stages and subtypes, including novel mTEC subsets, such as chemokine-expressing and ciliated TEC, which warrant further characterisation.

View Article and Find Full Text PDF

Whole-genome sequencing (WGS) is becoming widely used in clinical medicine in diagnostic contexts and to inform treatment choice. Here we evaluate the potential of the Oxford Nanopore Technologies (ONT) MinION long-read sequencer for routine WGS by sequencing the reference sample NA12878 and the genome of an individual with ataxia-pancytopenia syndrome and severe immune dysregulation. We develop and apply a novel reference panel-free analytical method to infer and then exploit phase information which improves single-nucleotide variant (SNV) calling performance from otherwise modest levels.

View Article and Find Full Text PDF

Nude severe combined immunodeficiency is a rare inherited disease caused by autosomal recessive loss-of-function mutations in FOXN1. This gene encodes a transcription factor essential for the development of the thymus, the primary lymphoid organ that supports T-cell development and selection. To date nine cases have been reported presenting with the clinical triad of absent thymus resulting in severe T-cell immunodeficiency, congenital alopecia universalis and nail dystrophy.

View Article and Find Full Text PDF

Background: X-linked hyper-IgM syndrome (XHIGM) is a primary immunodeficiency with high morbidity and mortality compared with those seen in healthy subjects. Hematopoietic cell transplantation (HCT) has been considered a curative therapy, but the procedure has inherent complications and might not be available for all patients.

Objectives: We sought to collect data on the clinical presentation, treatment, and follow-up of a large sample of patients with XHIGM to (1) compare long-term overall survival and general well-being of patients treated with or without HCT along with clinical factors associated with mortality and (2) summarize clinical practice and risk factors in the subgroup of patients treated with HCT.

View Article and Find Full Text PDF

Patients with chronic lymphocytic leukemia (CLL) and multiple myeloma (MM) are prone to present with antibody production deficits associated with recurrent or severe bacterial infections that might benefit from human immunoglobulin (Ig) (IVIg/SCIg) replacement therapy. However, the original IVIg trial data were done before modern therapies were available, and the current indications do not take into account the shift in the immune situation of current treatment combinations and changes in the spectrum of infections. Besides, patients affected by other B cell malignancies present with similar immunodeficiency and manifestations while they are not covered by the current IVIg indications.

View Article and Find Full Text PDF

Secondary immunodeficiencies occur as a consequence of various diseases, including hematological malignancies, and the use of pharmacological therapies, such as immunosuppressive, anti-inflammatory, and biological drugs. Infections are the main cause of morbidity and mortality in multiple myeloma (MM) and chronic lymphocytic leukemia (CLL) patients. Recent advances in treatment have prolonged the duration of remission and the time between relapse phases in MM and CLL patients.

View Article and Find Full Text PDF

Chronic mucocutaneous candidiasis (CMC) is characterized by recurrent and persistent superficial infections, with Candida albicans affecting the mucous membranes, skin and nails. It can be acquired or caused by primary immune deficiencies, particularly those that impair interleukin (IL)-17 and IL-22 immunity. We describe a single kindred with CMC and the identification of a STAT1 GOF mutation by whole exome sequencing (WES).

View Article and Find Full Text PDF
Secondary antibody deficiencies.

Curr Opin Allergy Clin Immunol

December 2015

Purpose Of Review: Antibody deficiency can occur in the context of primary immune deficiency due to inherited genetic defects or secondary to a variety of causes. This review aims to summarize current data concerning the causes of secondary antibody deficiency and where possible evidence regarding the use of prophylactic replacement immunoglobulin. (Figure is included in full-text article.

View Article and Find Full Text PDF

XMEN disease (X-linked immunodeficiency with Magnesium defect, Epstein-Barr virus infection and Neoplasia) is a novel primary immune deficiency caused by mutations in MAGT1 and characterised by chronic infection with Epstein-Barr virus (EBV), EBV-driven lymphoma, CD4 T-cell lymphopenia, and dysgammaglobulinemia [1]. Functional studies have demonstrated roles for magnesium as a second messenger in T-cell receptor signalling [1], and for NKG2D expression and consequently NK- and CD8 T-cell cytotoxicity [2]. 7 patients have been described in the literature; the oldest died at 45 years and was diagnosed posthumously [1-3].

View Article and Find Full Text PDF

Hypogammaglobulinemia is a common finding in chronic lymphocytic leukemia (CLL). Its incidence increases with disease duration and stage such that it is present in up to 85 % of patients at some point in their disease course. It is therefore important to monitor patients for the development of an antibody deficiency.

View Article and Find Full Text PDF