A unique STK4 mutation truncating only the C-terminal SARAH domain results in a mild clinical phenotype despite severe T cell lymphopenia: Case report.

Mutations in STK4 (MST1) are implicated in a form of autosomal recessive combined immunodeficiency, resulting in recurrent infections (especially Epstein-Barr virus viremia), autoimmunity, and cardiac malformations. Here we report a patient with an atypically mild presentation of this disease, initially presenting with severe T cell lymphopenia (< 500 per mm) and intermittent neutropenia, but now surviving well on immunoglobulins and prophylactic antibacterial treatment. She harbors a unique STK4 mutation that lies further downstream than all others reported to date.

Quality of Life Evaluation in Saudi Arabian Pediatric Patients with Primary Immunodeficiency Diseases Receiving 20% Subcutaneous IgG Infusions at Home.

Background And Aims: Subcutaneous immunoglobulin (SCIG) home infusion is widely used as an alternative to intravenous immunoglobulin (IVIG). This study aimed to determine the quality of life (QoL) of patients with primary immunodeficiency (PID) after switching to home-based SCIG.

Methods: In this prospective open-label single-center study, QoL was determined using the validated Arabic version of the Child Health Questionnaire at baseline and 3 and 6 months after switching from IVIG to SCIG.

Phenotypic and Genotypic Characterization of Hereditary Angioedema in Saudi Arabia.

Hereditary angioedema (HAE) is a potentially life-threatening autosomal dominant disorder affecting roughly 1:50,000 individuals. It is commonly characterized by swelling of the larynx, gastrointestinal tract, extremities, and skin. There is growing genetic heterogeneity associated with this disease but more than 95% of mutations are found in SERPING1, the gene which encodes complement 1 inhibitor (C1-INH).

The Middle East and North Africa Diagnosis and Management Guidelines for Inborn Errors of Immunity.

Human inborn errors of immunity (IEI) are a group of 485 distinct genetic disorders affecting children and adults. Signs and symptoms of IEI are heterogeneous, and accurate diagnosis can be challenging and depends on the available human expertise and laboratory resources. The Middle East and North Africa (MENA) region has an increased prevalence of IEI because of the high rate of consanguinity with a predominance of autosomal recessive disorders.

A homozygous truncating mutation of FGL2 is associated with immune dysregulation.

Background: The type II transmembrane protein fibrinogen-like protein 2 (FGL2) plays critical roles in hemostasis and immune regulation. The C-terminal immunoregulatory domain of FGL2 can be secreted and is a mediator of regulatory T (Treg) cell suppression. Fgl2 mice develop autoantibodies and glomerulonephritis and have impaired Treg cell function.

Proteomics Profiling to Distinguish DOCK8 Deficiency From Atopic Dermatitis.

Dedicator of cytokinesis 8 deficiency is an autosomal recessive primary immune deficiency disease belonging to the group of hyperimmunoglobulinemia E syndrome (HIES). The clinical phenotype of dedicator of cytokinesis 8 (DOCK8) deficiency, characterized by allergic manifestations, increased infections, and increased IgE levels, overlaps with the clinical presentation of atopic dermatitis (AD). Despite the identification of metabolomics and cytokine biomarkers, distinguishing between the two conditions remains clinically challenging.

Clinical and Immunological Characterization of Combined Immunodeficiency Due to TFRC Mutation in Eight Patients.

Purpose: Combined immunodeficiency (CID), due to mutations in TFRC gene that encodes the transferrin receptors (TfR1), is a rare monogenic disorder. In this study, we further characterize the clinical and immunological phenotypes in a cohort of eight patients.

Methods: A retrospective review of clinical and immunological features of patients diagnosed with a TFRC gene mutation between 2015 and 2019 in three tertiary centers.

TREC and KREC profiling as a representative of thymus and bone marrow output in patients with various inborn errors of immunity.

Primary immune deficiency (PID) disorders are clinically and molecularly heterogeneous diseases. T cell receptor excision circles (TRECs) and κ (kappa)-deleting excision circles (KRECs) are markers of T and B cell development, respectively. They are useful tools to assess T and B cell function and immune reconstitution and have been used for newborn screening for severe combined immunodeficiency disease (SCID) and agammaglobulinemia, respectively.

A Case with Purine Nucleoside Phosphorylase Deficiency Suffering from Late-Onset Systemic Lupus Erythematosus and Lymphoma.

Background: Purine nucleoside phosphorylase (PNP) deficiency accounts for about 4% of severe combined immunodeficiency diseases. PNP deficiency is a variable disease with recurrent infections and neurodevelopmental delay. Autoimmunity and malignancy can still occur in one-third of patients.

Hematopoietic stem cell transplantation in children with Griscelli syndrome type 2: a single-center report on 35 patients.

In 2010, we reported the outcome of hematopoietic stem cell transplantation (HSCT) in 11 children with Griscelli syndrome type 2 (GS2). We report here the update on this cohort to include 35 patients. Twenty-seven (77%) patients received conditioning regimen including busulfan, cyclophosphamide with etoposide.

PAX1 is essential for development and function of the human thymus.

We investigated the molecular and cellular basis of severe combined immunodeficiency (SCID) in six patients with otofaciocervical syndrome type 2 who failed to attain T cell reconstitution after allogeneic hematopoietic stem cell transplantation, despite successful engraftment in three of them. We identified rare biallelic rare variants in all patients. We demonstrated that these mutant PAX1 proteins have an altered conformation and flexibility of the paired box domain and reduced transcriptional activity.

Improved transplant survival and long-term disease outcome in children with MHC class II deficiency.

MHC class II deficiency is a rare, but life-threatening, primary combined immunodeficiency. Hematopoietic cell transplantation (HCT) remains the only curative treatment for this condition, but transplant survival in the previously published result was poor. We analyzed the outcome of 25 patients with MHC class II deficiency undergoing first HCT at Great North Children's Hospital between 1995 and 2018.

Hypomorphic variants in AK2 reveal the contribution of mitochondrial function to B-cell activation.

Background: The gene AK2 encodes the phosphotransferase adenylate kinase 2 (AK2). Human variants in AK2 cause reticular dysgenesis, a severe combined immunodeficiency with agranulocytosis, lymphopenia, and sensorineural deafness that requires hematopoietic stem cell transplantation for survival.

Objective: We investigated the mechanisms underlying recurrent sinopulmonary infections and hypogammaglobulinemia in 15 patients, ranging from 3 to 34 years of age, from 9 kindreds.

Metabolomics Distinguishes DOCK8 Deficiency from Atopic Dermatitis: Towards a Biomarker Discovery.

Bi-allelic mutations in the dedicator of cytokinesis 8 () are responsible for a rare autosomal recessive primary combined immunodeficiency syndrome, characterized by atopic dermatitis, elevated serum Immunoglobulin E (IgE) levels, recurrent severe cutaneous viral infections, autoimmunity, and predisposition to malignancy. The molecular link between DOCK8 deficiency and atopic skin inflammation remains unknown. Severe atopic dermatitis (AD) and DOCK8 deficiency share some clinical symptoms, including eczema, eosinophilia, and increased serum IgE levels.

Graft Versus Host Disease Following HLA-Matched Sibling Donor Compared with Matched Related Donor for Hematopoietic Stem Cell Transplantation for the Treatment of Severe Combined Immunodeficiency Disease.

Background: One of the limiting factors for successful hematopoietic stem cell transplantation (HSCT) is graft versus host disease (GVHD). The EBMT/ESID guidelines for HSCT in severe combined immunodeficiency (SCID) recommend no GVHD prophylaxis for a matched sibling donor (MSD).

Objective: To determine the risk of GVHD in MSD HSCT for SCID patients compared to matched related donor (MRD).

Hematopoietic stem cell transplantation for CD40 ligand deficiency: Results from an EBMT/ESID-IEWP-SCETIDE-PIDTC study.

Background: CD40 ligand (CD40L) deficiency, an X-linked primary immunodeficiency, causes recurrent sinopulmonary, Pneumocystis and Cryptosporidium species infections. Long-term survival with supportive therapy is poor. Currently, the only curative treatment is hematopoietic stem cell transplantation (HSCT).

Early Introduction of Egg and the Development of Egg Allergy in Children: A Systematic Review and Meta-Analysis.

Background: The timing of the introduction of egg to an infant's diet is of current interest, as new evidence raises questions regarding the benefit of delaying egg introduction. The objective of this study was to systematically review the existing literature regarding the effect of the early introduction of egg on the development of egg allergy.

Methods: Literature searches were conducted in MEDLINE, EMBASE, and CENTRAL, and trial protocols were searched in Meta Register and OpenGREY.

Multiplexed detection of DOCK8, PGM3 and STAT3 proteins for the diagnosis of Hyper-Immunoglobulin E syndrome using gold nanoparticles-based immunosensor array platform.

Multiplexed biosensors hold great promise for early diagnosis of diseases where the detection of multiple biomarkers is required. Hyper Immunoglobulin E syndromes (HIES) are rare primary immunodeficiency disorders associated with mutations either in the signal transducer and activator of transcription 3 (STAT3), dedicator of cytokinesis 8 DOCK8) or phosphoglucomutase 3 (PGM3) genes. Yet, the diagnosis of HIES is challenged by the complexity of the existing laboratory assays.