Regulatory T-cell dysfunction and cutaneous exposure to Staphylococcus aureus underlie eczema in DOCK8 deficiency.

BACKGROUND: Dedicator of cytokinesis 8 (DOCK8)-deficient patients have severe eczema, elevated IgE, and eosinophilia, features of atopic dermatitis (AD). OBJECTIVE: We sought to understand the mechanisms of eczema in DOCK8 deficiency. METHODS: Skin biopsy samples were characterized by histology, immunofluorescence microscopy, and gene expression. Skin barrier function was measured by transepidermal water loss. Allergic skin inflammation was elicited in mice by epicutaneous sensitization with ovalbumin (OVA) or cutaneous application of Staphylococcus aureus. RESULTS: Skin lesions of DOCK8-deficient patients exhibited type 2 inflammation, and the patients' skin was colonized by Saureus, as in AD. Unlike in AD, DOCK8-deficient patients had a reduced FOXP3:CD4 ratio in their skin lesions, and their skin barrier function was intrinsically intact. Dock8-/- mice exhibited reduced numbers of cutaneous T regulatory (Treg) cells and a normal skin barrier. Dock8-/- and mice with an inducible Dock8 deletion in Treg cells exhibited increased allergic skin inflammation after epicutaneous sensitization with OVA. DOCK8 was shown to be important for Treg cell stability at sites of allergic inflammation and for the generation, survival, and suppressive activity of inducible Treg cells. Adoptive transfer of wild-type, but not DOCK8-deficient, OVA-specific, inducible Treg cells suppressed allergic inflammation in OVA-sensitized skin of Dock8-/- mice. These mice developed severe allergic skin inflammation and elevated serum IgE levels after topical exposure to Saureus. Both were attenuated after adoptive transfer of WT but not DOCK8-deficient Treg cells. CONCLUSION: Treg cell dysfunction increases susceptibility to allergic skin inflammation in DOCK8 deficiency and synergizes with cutaneous exposure to Saureus to drive eczema in DOCK8 deficiency.

Cernunnos deficiency: Further delineation in 5 Egyptian patients.

Cernunnos deficiency is a rare genetic disorder characterized by immunodeficiency, microcephaly, growth retardation, bird-like facies, sensitivity to ionizing radiation, few autoimmune manifestations, premature aging of hematopoietic stem cells at an early age, and occasional myeloproliferative disease. Herein we present five Egyptian Cernunnos patients from 3 different families. We describe the patients' clinical phenotypes, their immunological profile as well as genetic results. Sequence analysis revealed three different mutations in the NHEJ1 gene: a nonsense variant c.532C > T; p.(Arg178Ter), an intronic variant c.178-1G > A and a frameshift insertion variant c.233dup; p.(Asn78LysfsTer14). In conclusion, Cernunnos deficiency can have a wide range of clinical features. The characteristic immune profile including a decrease in recent thymic emigrants and naive T cells, markedly elevated memory T cells together with normal to high IgM, and a decrease in IgG and IgA. This immune profile is highly suggestive of Cernunnos deficiency in T-B-NK + SCID patients especially surviving for older ages.

Chronic Granulomatous Disease: a Cohort of 173 Patients-10-Years Single Center Experience from Egypt.

PURPOSE: Chronic granulomatous disease (CGD) is an inherited primary immunodeficiency disorder of phagocytes, characterized by recurrent fungal and bacterial infections. Our aim is to describe the different clinical presentations, non-infectious auto-inflammatory features, types and sites of infections, and to estimate the mortality among our large cohort. METHODS: This is a retrospective study conducted at the Pediatric Department of Cairo University Children's Hospital in Egypt, including cases with a confirmed CGD diagnosis. RESULTS: One hundred seventy-three confirmed CGD patients were included. AR-CGD was diagnosed in 132 patients (76.3%) including 83 patients (48%) with p47phox defect, 44 patients (25.4%) with p22phox defect, and 5 patients (2.9%) with p67phox defect. XL-CGD was diagnosed in 25 patients (14.4%). The most common recorded clinical manifestations were deep-seated abscesses and pneumonia. Gram-negative bacteria and Aspergillus were the most frequently isolated species. Regarding the outcome, 36 patients (20.8%) were lost from follow-up. Among patients with known outcome, 94/137 patients (68.6%) are living, while 43/137 patients (31.4%) died. CONCLUSION: AR-CGD is predominant in Egypt; CGD must always be ruled out in any patient presenting with typical or atypical mycobacterial or BCG-disease.

Flow cytometry optimizing the diagnostic approach in inborn errors of immunity: experience from Egypt.

BACKGROUND: Human inborn errors of immunity (IEI) are a group of inherited genetic disorders of the immune system. IEI Patients suffer from severe repeated infections, autoimmunity, lymphadenopathy and/or increased susceptibility to malignancies. IEI are due to absence, disproportion, or loss of function of immune cells; mostly inherited in autosomal recessive manner, hence are more common in countries with high rate of consanguinity. Definite diagnosis of IEI is achieved by genetic analysis, however it is not always available. AIM: to report on different IEI categories and impact of expanding the use of flow cytometry (FCM) in diagnosis, categorization and follow up of IEI patients in a highly consanguineous population. METHODS: Retrospective chart review on different IEI categories diagnosed at the primary immunodeficiency center in Cairo University Specialized Pediatric hospital from 2011 to 2021 based on expanding the use of FCM. RESULTS: 1510 IEI patients were diagnosed; 480 were diagnosed genetically with FMF, 11 with cystic fibrosis and 1019 patients were diagnosed with other IEI disorders. Phagocytic defects were the commonest (30%) followed by severe combined immunodeficiency (22%) and combined immunodeficiency (18.3%). FCM testing properly diagnosed and categorized 73% of the cases. CONCLUSION: Using multi-color FCM to evaluate immune cells populations, subpopulations, functions, and intracellular proteins expression is proved a useful cost-effective method for screening, categorization and follow up of IEI patients. FCM can improve the diagnosis of IEI significantly when tests are properly targeted and well designed. This study presents a 10-year experience in diagnosis of IEI using FCM at a tertiary referral center in a setting of limited resources and yet high prevalence of IEI.

Genetic Testing in Egyptian Patients with Inborn Errors of Immunity: a Single-Center Experience.

BACKGROUND: Inborn errors of immunity (IEI) are a group of heterogeneous disorders with geographic and ethnic diversities. Although IEI are common in Egypt, genetic diagnosis is limited due to financial restrictions. This study aims to characterize the genetic spectrum of IEI patients in Egypt and highlights the adaptation of the molecular diagnostic methods to a resource-limited setting. METHODS: Genetic material from 504 patients was studied, and proper diagnosis was achieved in 282 patients from 246 families. Mutational analysis was done by Sanger sequencing, next-generation sequencing (NGS) targeting customized genes panels, and whole-exome sequencing (WES) according to the patients' phenotypes and availability of genetic testing. RESULTS: A total of 194 variants involving 72 different genes were detected with RAG1/2 genes being the most encountered followed by DOCK8, CYBA, LRBA, NCF1, and JAK3. Autosomal recessive (AR) inheritance was detected in 233/282 patients (82.6%), X-linked (XL) recessive inheritance in 32/282 patients (11.3%), and autosomal dominant (AD) inheritance in 18/282 patients (6.4%), reflecting the impact of consanguineous marriages on the prevalence of different modes of inheritance and the distribution of the various IEI disorders. CONCLUSION: The study showed that a combination of Sanger sequencing in selected patients associated with targeted NGS or WES in other patients is an effective diagnostic strategy for IEI diagnosis in countries with limited diagnostic resources. Molecular testing can be used to validate other nonexpensive laboratory techniques that help to reach definitive diagnosis and help in genetic counseling and taking proper therapeutic decisions including stem cell transplantation or gene therapy.

Fungal infections in primary immunodeficiency diseases.

Primary immunodeficiency diseases (PID), encompass a heterogeneous group of diseases, with increased susceptibility to recurrent, severe infections. Invasive fungal infections raise a serious concern related to their morbidity and mortality. Herein, we describe various fungal infections among different PID patients. Twenty-eight PID patients diagnosed with fungal infections were included; fourteen patients with chronic granulomatous disease, two with Hyper Immunoglobulin E syndrome, one with LRBA deficiency and one with MHC class II defect, one with unclassified immune dysregulation, one with CD4 lymphopenia and one patient with Immune dysregulation Polyendocrinopathy Enteropathy X-linked syndrome. Aspergillus species were the most common isolated causative organisms in 78% of patients, Candida species were the causative organisms in 32%, Pneumocystis jirovecii caused infections in 7% followed by Malassezia furfur, Fusarium spp., Mucormycosis, and Penicillium chrysogenium 3.5% for each. The mortality rate among our patients was 10/28 (35.7%). PID patients are at high risk of developing fungal infections.

Clinical Phenotypes and Immunological Characteristics of 18 Egyptian LRBA Deficiency Patients.

LPS-responsive beige-like anchor (LRBA) deficiency is an autosomal recessive primary immunodeficiency disorder, OMIM (#614700). LRBA deficiency patients suffer from variable manifestations including recurrent infections, immune dysregulation, autoimmunity, cytopenias, and enteropathy. This study describes different clinical phenotypes and immunological characteristics of 18 LRBA deficiency patients diagnosed from Egypt. T and B lymphocyte subpopulations, LRBA, and cytotoxic T lymphocyte-associated protein 4 (CTLA4) expression were evaluated in resting and stimulated T cells using flow cytometry. Next-generation sequencing was used to identify mutations in the LRBA gene. LRBA deficiency patients had significantly lower B cells and increased percentage of memory T cells. CTLA4 levels were lower in LRBA-deficient T regulatory cells in comparison to healthy donors at resting conditions and significantly increased upon stimulation of T cells. We identified 11 novel mutations in LRBA gene ranging from large deletions to point mutations. Finally, we were able to differentiate LRBA-deficient patients from healthy control and common variable immunodeficiency patients using a simple flow cytometry test performed on whole blood and without need to prior stimulation. LRBA deficiency has heterogeneous phenotypes with poor phenotype-genotype correlation since the same mutation may manifest differently even within the same family. Low LRBA expression, low numbers of B cells, increased numbers of memory T cells, and defective CTLA4 expression (which increase to normal level upon T cell stimulation) are useful laboratory tests to establish the diagnosis of LRBA deficiency. Screening of the siblings of affected patients is very important as patients may be asymptomatic at the beginning of the disease course.

Evaluation of the S100 protein A12 as a biomarker of neonatal sepsis.

Introduction: Sepsis has a grave impact on neonatal morbidity and mortality. Proper timely diagnosis and a subsequently tailored management are crucial to improving neonatal outcome and survival. New diagnostic methods are needed and much effort is directed to this objective. In this work, we aimed to evaluate S100A12 protein as a biomarker of neonatal sepsis.Materials and methods: In this prospective single-center study, 118 preterm and term neonates were enrolled and assigned to four groups: controls, infants with no infection, infants with probable infection and infants with proven infection. Clinical and routine laboratory data, the serum levels of S100A12 and additional cytokines (interleukin (IL)-1ß, IL-2, IL-6, IL-17A, IL-18, IL-22, IL-10, and interferon (IFN)-γ) were assessed. Using stepwise multivariate logistic regression analysis, S100A12 protein was evaluated as a biomarker of neonatal infection.Results: Significant differences of the parameters of complete blood count and level of C-reactive protein were documented between the study/the four groups. The studied marker S100A12, as well as IL-6 and IL-10, were highly significant (p < .001) between infected and control groups. S100A12 had a sensitivity of 96.8% and a specificity of 93.3%. Even after adjusting for the confounding factors sex, body weight, gestational age, mode of delivery, number of pregnancies, premature rupture of membranes, and preeclampsia S100A12 remained significant between the infected and control groups.Conclusions: S100A12 may be considered as a new biomarker of neonatal sepsis.

MHC-II Deficiency Among Egyptians: Novel Mutations and Unique Phenotypes.

BACKGROUND: MHC class II deficiency leads to defective CD4+ T-cell function that results from impaired antigen presentation. A genetic disorder in 1 of 4 genes results in this syndrome that is associated with the clinical phenotype of combined immunodeficiency. OBJECTIVE: To describe the clinical, immunological, and molecular characteristics of 10 Egyptian patients from 9 different families having presented with MHC class II deficiency between 2012 and 2017. METHODS: An initial diagnosis based on the combination of clinical features and low HLA-DR expression by flow cytometry was confirmed by genetic analyses. RESULTS: Symptoms included failure to thrive (n = 9), persistent diarrhea (n = 5), and pneumonia (n = 8). Septicemia due to coagulase-negative staphylococci (n = 1) and Candida krusei (n = 1) was diagnosed. Nine patients orally received the live attenuated polio vaccine, of whom 3 developed acute flaccid paralysis thereafter. Nine patients received the BCG vaccine and none developed obvious signs of BCGitis. Four patients carried RFXANK gene mutations, 3 carried RFX5 gene mutations, 1 carried a CIITA gene mutation, and none carried RFXAP gene mutations. Six of the 7 detected mutations were previously unreported mutations: c.431T>C, c.247_250delTCAG, and c.600delG in the RFXANK gene; c.116+1G>A and c.715C>T in the RFX5 gene; and c.929delA in the CIITA gene. CONCLUSIONS: Given that Egypt is a North African country with a high rate of consanguinity, MHC class II deficiency is not rare. However, the molecular defects differ from those reported in nearby countries. Early diagnosis must be based on suspicious clinical signs and laboratory diagnosis because the defect can be missed by T-cell receptor excision circles based on neonatal screening.

Genetic Counseling in Primary Immunodeficiency Disorders: An Emerging Experience in Egypt.

BACKGROUND: Primary immunodeficiency disorders (PIDs) are a heterogeneous group of diseases of the immune system leading to life-threatening infections, and, unless urgently treated with immune reconstitution, patients do not usually survive. With the continuing progress in molecular diagnosis, many mutations have been described in more than 300 genes. Genetic counseling has recently been considered an essential part of the management of PIDs. This study presents the experience of genetic counseling services in the largest PID center in Egypt, and reports on our management plan and the impact of prenatal diagnosis (PND) on families. METHODS: Based on the biochemical and molecular diagnosis of index cases, PND was offered for 10 families in 12 subsequent pregnancies. Five different genes were sequenced by Sanger sequencing in fetal samples. RESULTS: Seven fetuses were either normal or were carriers, while five fetuses were affected and human leukocyte antigen typing was performed, seeking a suitably related donor for stem cell transplantation. CONCLUSION: In spite of the genetic heterogeneity behind PIDs, genetic counseling should play a critical role in the management and future decisions of affected families.

Patterns of Primary Immunodeficiency Disorders Among a Highly Consanguineous Population: Cairo University Pediatric Hospital's 5-Year Experience.

INTRODUCTION: Primary immunodeficiency disorders (PIDs) are heterogeneous disorders that mainly present with severe, persistent, unusual, or recurrent infections in childhood. Reports from different parts of the world indicate a difference between Western and Eastern populations. AIM: The aim of this study was to report on the different patterns of PIDs and identify subgroup characteristics in a highly consanguineous population in Egypt. METHODS: We performed a retrospective chart review for children below 18 years diagnosed with PID at Cairo University Pediatric Hospital from 2010 to 2014. RESULTS: Four hundred seventy-six children were diagnosed with PID disorders. Major categories included combined immunodeficiency disorders, which constituted a large proportion (30 %) of cases, along with predominantly antibody disorders (18 %) followed by syndromic combined disorders (16.8 %), phagocytic disorders (13.2 %), immune dysregulation disorders (10.5 %), and autoinflammatory disorders (9 %). CONCLUSION: PIDs have different patterns within inbred populations with high consanguinity.