DOCK8 functions as an adaptor that links TLR-MyD88 signaling to B cell activation.

The adaptors DOCK8 and MyD88 have been linked to serological memory. Here we report that DOCK8-deficient patients had impaired antibody responses and considerably fewer CD27(+) memory B cells. B cell proliferation and immunoglobulin production driven by Toll-like receptor 9 (TLR9) were considerably lower in DOCK8-deficient B cells, but those driven by the costimulatory molecule CD40 were not. In contrast, TLR9-driven expression of AICDA (which encodes the cytidine deaminase AID), the immunoglobulin receptor CD23 and the costimulatory molecule CD86 and activation of the transcription factor NF-κB, the kinase p38 and the GTPase Rac1 were intact. DOCK8 associated constitutively with MyD88 and the tyrosine kinase Pyk2 in normal B cells. After ligation of TLR9, DOCK8 became tyrosine-phosphorylated by Pyk2, bound the Src-family kinase Lyn and linked TLR9 to a Src-kinase Syk-transcription factor STAT3 cascade essential for TLR9-driven B cell proliferation and differentiation. Thus, DOCK8 functions as an adaptor in a TLR9-MyD88 signaling pathway in B cells.

Therapeutic options for CTLA-4 insufficiency.

BACKGROUND: Heterozygous germline mutations in cytotoxic T lymphocyte-associated antigen-4 (CTLA4) impair the immunomodulatory function of regulatory T cells. Affected individuals are prone to life-threatening autoimmune and lymphoproliferative complications. A number of therapeutic options are currently being used with variable effectiveness. OBJECTIVE: Our aim was to characterize the responsiveness of patients with CTLA-4 insufficiency to specific therapies and provide recommendations for the diagnostic workup and therapy at an organ-specific level. METHODS: Clinical features, laboratory findings, and response to treatment were reviewed retrospectively in an international cohort of 173 carriers of CTLA4 mutation. Patients were followed between 2014 and 2020 for a total of 2624 months from diagnosis. Clinical manifestations were grouped on the basis of organ-specific involvement. Medication use and response were recorded and evaluated. RESULTS: Among the 173 CTLA4 mutation carriers, 123 (71%) had been treated for immune complications. Abatacept, rituximab, sirolimus, and corticosteroids ameliorated disease severity, especially in cases of cytopenias and lymphocytic organ infiltration of the gut, lungs, and central nervous system. Immunoglobulin replacement was effective in prevention of infection. Only 4 of 16 patients (25%) with cytopenia who underwent splenectomy had a sustained clinical response. Cure was achieved with stem cell transplantation in 13 of 18 patients (72%). As a result of the aforementioned methods, organ-specific treatment pathways were developed. CONCLUSION: Systemic immunosuppressants and abatacept may provide partial control but require ongoing administration. Allogeneic hematopoietic stem cell transplantation offers a possible cure for patients with CTLA-4 insufficiency.

Simple Measurement of IgA Predicts Immunity and Mortality in Ataxia-Telangiectasia.

Patients with ataxia-telangiectasia (A-T) suffer from progressive cerebellar ataxia, immunodeficiency, respiratory failure, and cancer susceptibility. From a clinical point of view, A-T patients with IgA deficiency show more symptoms and may have a poorer prognosis. In this study, we analyzed mortality and immunity data of 659 A-T patients with regard to IgA deficiency collected from the European Society for Immunodeficiencies (ESID) registry and from 66 patients with classical A-T who attended at the Frankfurt Goethe-University between 2012 and 2018. We studied peripheral B- and T-cell subsets and T-cell repertoire of the Frankfurt cohort and survival rates of all A-T patients in the ESID registry. Patients with A-T have significant alterations in their lymphocyte phenotypes. All subsets (CD3, CD4, CD8, CD19, CD4/CD45RA, and CD8/CD45RA) were significantly diminished compared to standard values. Patients with IgA deficiency (n = 35) had significantly lower lymphocyte counts compared to A-T patients without IgA deficiency (n = 31) due to a further decrease of naïve CD4 T-cells, central memory CD4 cells, and regulatory T-cells. Although both patient groups showed affected TCR-ß repertoires compared to controls, no differences could be detected between patients with and without IgA deficiency. Overall survival of patients with IgA deficiency was significantly diminished. For the first time, our data show that patients with IgA deficiency have significantly lower lymphocyte counts and subsets, which are accompanied with reduced survival, compared to A-T patients without IgA deficiency. IgA, a simple surrogate marker, is indicating the poorest prognosis for classical A-T patients. Both non-interventional clinical trials were registered at clinicaltrials.gov 2012 (Susceptibility to infections in ataxia-telangiectasia; NCT02345135) and 2017 (Susceptibility to Infections, tumor risk and liver disease in patients with ataxia-telangiectasia; NCT03357978).

Phenotype, penetrance, and treatment of 133 cytotoxic T-lymphocyte antigen 4-insufficient subjects.

BACKGROUND: Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is a negative immune regulator. Heterozygous CTLA4 germline mutations can cause a complex immune dysregulation syndrome in human subjects. OBJECTIVE: We sought to characterize the penetrance, clinical features, and best treatment options in 133 CTLA4 mutation carriers. METHODS: Genetics, clinical features, laboratory values, and outcomes of treatment options were assessed in a worldwide cohort of CTLA4 mutation carriers. RESULTS: We identified 133 subjects from 54 unrelated families carrying 45 different heterozygous CTLA4 mutations, including 28 previously undescribed mutations. Ninety mutation carriers were considered affected, suggesting a clinical penetrance of at least 67%; median age of onset was 11 years, and the mortality rate within affected mutation carriers was 16% (n = 15). Main clinical manifestations included hypogammaglobulinemia (84%), lymphoproliferation (73%), autoimmune cytopenia (62%), and respiratory (68%), gastrointestinal (59%), or neurological features (29%). Eight affected mutation carriers had lymphoma, and 3 had gastric cancer. An EBV association was found in 6 patients with malignancies. CTLA4 mutations were associated with lymphopenia and decreased T-, B-, and natural killer (NK) cell counts. Successful targeted therapies included application of CTLA-4 fusion proteins, mechanistic target of rapamycin inhibitors, and hematopoietic stem cell transplantation. EBV reactivation occurred in 2 affected mutation carriers after immunosuppression. CONCLUSIONS: Affected mutation carriers with CTLA-4 insufficiency can present in any medical specialty. Family members should be counseled because disease manifestation can occur as late as 50 years of age. EBV- and cytomegalovirus-associated complications must be closely monitored. Treatment interventions should be coordinated in clinical trials.

Long-term observational studies of chronic granulomatous disease.

PURPOSE OF REVIEW: Chronic granulomatous disease (CGD) is a primary immunodeficiency, with a defect of phagocytes in killing specific pathogens. CGD is characterized by severe recurrent bacterial and fungal infections and dysregulated inflammatory response. Since its first description as fatal disease about 60 years ago, a significant improvement in outcome has been achieved in the last 20 years. The purpose of this review is to framework recent advances in CGD immunopathogenesis, management of disease manifestation and cure of CGD patients. RECENT FINDINGS: For years, CGD is a known cause of life-threatening infections and excessive inflammation. The cause and the management of inflammatory reactions, however, have not been clarified, and the range of clinical presentation is growing with corresponding novel therapeutic interventions. Recent work focuses on the best outcome of hematopoietic stem cell transplantation (HSCT) and gene therapy for the cure of CGD patients, more specifically, those with X-linked and p47 mutations. SUMMARY: The genetics and phenotype of CGD is well characterized; however, the underlying mechanisms, the treatment of its inflammatory manifestations and the cure of CGD is under further investigation.

Long-term outcomes of 176 patients with X-linked hyper-IgM syndrome treated with or without hematopoietic cell transplantation.

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. METHODS: Physicians caring for patients with primary immunodeficiency diseases were identified through the Jeffrey Modell Foundation, United States Immunodeficiency Network, Latin American Society for Immunodeficiency, and Primary Immune Deficiency Treatment Consortium. Data were collected with a Research Electronic Data Capture Web application. Survival from time of diagnosis or transplantation was estimated by using the Kaplan-Meier method compared with log-rank tests and modeled by using proportional hazards regression. RESULTS: Twenty-eight clinical sites provided data on 189 patients given a diagnosis of XHIGM between 1964 and 2013; 176 had valid follow-up and vital status information. Sixty-seven (38%) patients received HCT. The average follow-up time was 8.5 ± 7.2 years (range, 0.1-36.2 years). No difference in overall survival was observed between patients treated with or without HCT (P = .671). However, risk associated with HCT decreased for diagnosis years 1987-1995; the hazard ratio was significantly less than 1 for diagnosis years 1995-1999. Liver disease was a significant predictor of overall survival (hazard ratio, 4.9; 95% confidence limits, 2.2-10.8; P < .001). Among survivors, those treated with HCT had higher median Karnofsky/Lansky scores than those treated without HCT (P < .001). Among patients receiving HCT, 27 (40%) had graft-versus-host disease, and most deaths occurred within 1 year of transplantation. CONCLUSION: No difference in survival was observed between patients treated with or without HCT across all diagnosis years (1964-2013). However, survivors treated with HCT experienced somewhat greater well-being, and hazards associated with HCT decreased, reaching levels of significantly less risk in the late 1990s. Among patients treated with HCT, treatment at an early age is associated with improved survival. Optimism remains guarded as additional evidence accumulates.

Novel genetic risk variants for pediatric celiac disease.

BACKGROUND: Celiac disease is a complex chronic immune-mediated disorder of the small intestine. Today, the pathobiology of the disease is unclear, perplexing differential diagnosis, patient stratification, and decision-making in the clinic. METHODS: Herein, we adopted a next-generation sequencing approach in a celiac disease trio of Greek descent to identify all genomic variants with the potential of celiac disease predisposition. RESULTS: Analysis revealed six genomic variants of prime interest: SLC9A4 c.1919G>A, KIAA1109 c.2933T>C and c.4268_4269delCCinsTA, HoxB6 c.668C>A, HoxD12 c.418G>A, and NCK2 c.745_746delAAinsG, from which NCK2 c.745_746delAAinsG is novel. Data validation in pediatric celiac disease patients of Greek (n = 109) and Serbian (n = 73) descent and their healthy counterparts (n = 111 and n = 32, respectively) indicated that HoxD12 c.418G>A is more prevalent in celiac disease patients in the Serbian population (P < 0.01), while NCK2 c.745_746delAAinsG is less prevalent in celiac disease patients rather than healthy individuals of Greek descent (P = 0.03). SLC9A4 c.1919G>A and KIAA1109 c.2933T>C and c.4268_4269delCCinsTA were more abundant in patients; nevertheless, they failed to show statistical significance. CONCLUSIONS: The next-generation sequencing-based family genomics approach described herein may serve as a paradigm towards the identification of novel functional variants with the aim of understanding complex disease pathobiology.

The extended phenotype of LPS-responsive beige-like anchor protein (LRBA) deficiency.

BACKGROUND: LPS-responsive beige-like anchor protein (LRBA) deficiency is a primary immunodeficiency caused by biallelic mutations in LRBA that abolish LRBA protein expression. OBJECTIVE: We sought to report the extended phenotype of LRBA deficiency in a cohort of 22 LRBA-deficient patients. METHODS: Clinical criteria, protein detection, and genetic sequencing were applied to diagnose LRBA deficiency. RESULTS: Ninety-three patients met the inclusion criteria and were considered to have possible LRBA deficiency. Twenty-four patients did not express LRBA protein and were labeled as having probable LRBA deficiency, whereas 22 were genetically confirmed as having definitive LRBA deficiency, with biallelic mutations in LRBA. Seventeen of these were novel and included homozygous or compound heterozygous mutations. Immune dysregulation (95%), organomegaly (86%), recurrent infections (71%), and hypogammaglobulinemia (57%) were the main clinical complications observed in LRBA-deficient patients. Although 81% of LRBA-deficient patients had normal T-cell counts, 73% had reduced regulatory T (Treg) cell numbers. Most LRBA-deficient patients had low B-cell subset counts, mainly in switched memory B cells (80%) and plasmablasts (92%), with a defective specific antibody response in 67%. Of the 22 patients, 3 are deceased, 2 were treated successfully with hematopoietic stem cell transplantation, 7 are receiving immunoglobulin replacement, and 15 are receiving immunosuppressive treatment with systemic corticosteroids alone or in combination with steroid-sparing agents. CONCLUSION: This report describes the largest cohort of patients with LRBA deficiency and offers guidelines for physicians to identify LRBA deficiency, supporting appropriate clinical management.

Primary immunodeficiency diseases: a 30-year patient registry from the referral center for primary immunodeficiencies in Greece.

Primary Immunodeficiencies (PID) represent a group of heterogeneous immune diseases with important biological significance. We reviewed the records of children diagnosed with PID in the Referral Center for PID in our country in order to describe the epidemiological, clinical and laboratory characteristics of immunodeficient patients. During a 30-year period, 147 patients (101 males, 68.7 %), with a mean age of 6.5 years at the time of diagnosis, were diagnosed with PID. The most prevalent diagnoses of PID were: "Combined Immunodeficiency" in 46 (31.3 %) patients, "Well-defined immunodeficiency syndrome" in 35 (23.1 %) patients, "Predominantly antibody deficiency" in 30 (20.4 %) patients and "Congenital defect of phagocyte function or both" in 28 (19 %) patients. There was a higher prevalence of males with "Combined immunodeficiency" (p < 0.033) and "Predominantly antibody deficiency" (p < 0.02) compared to females. The median age of children at the onset of symptoms and at the time of diagnosis was 0.5y (IQR: 0.1-2.5) and 2y (IQR: 0.6-7.2), respectively. The median diagnostic delay was 0.9y (IQR: 0.2-4.8). This period was shorter for patients with "Combined immunodeficiency" [median 0.3y (IQR: 0.1-1)], and longer for those with "Predominantly antibody deficiency" [median 3.2y (IQR: 0.2-5.9) or "Disease of immune dysregulation" [median 3.2y (IQR: 0.1-6.6)]. Comparing the rates in our population with those of the European Registry (ESID), the rates of "Combined immunodeficiencies", "Well-defined syndromes" and "Congenital birth defects and/or function of phagocytes" were significantly higher in this study (p <0,001). PID registry analysis improves knowledge in the field of Immunology and enhances awareness, early detection, diagnosis, and management of this rare but significant group of diseases.

X-linked thrombocytopenia in three males with normal sized platelets due to novel WAS gene mutations.

The authors describe two young brothers and a 12-year-old male with long-standing thrombocytopenia with normal sized platelets, in whom novel mutations of the WAS gene were identified. Their clinical picture and the in vitro assessment of the T-cell function were consistent with X-linked thrombocytopenia (XLT). A high index of suspicion for XLT is required, even in the setting of normal sized platelets for males with affected maternally-related male family members, and males with moderately severe chronic thrombocytopenia that have failed to respond to treatments that are usually effective for immune thrombocytopenia.

Flow cytometric analysis of the CD4+ TCR Vß repertoire in the peripheral blood of children with type 1 diabetes mellitus, systemic lupus erythematosus and age-matched healthy controls.

BACKGROUND: Data regarding the quantitative expression of TCR Vß subpopulations in children with autoimmune diseases provided interesting and sometimes conflicting results. The aim of the present study was to assess by comparative flow cytometric analysis the peripheral blood CD4+ TCR Vß repertoire of children with an organ-specific autoimmune disorder, such as type 1 diabetes mellitus (T1DM), in comparison to children with a systemic autoimmune disease, such as Systemic Lupus Erythematosus (SLE) in comparison to healthy age-matched controls of the same ethnic origin. The CD4+ TCR Vß repertoire was analysed by flow cytometry in three groups of participants: a) fifteen newly diagnosed children with T1DM (mean age: 9.2 ± 4.78 years old), b) nine newly diagnosed children with SLE, positive for ANA and anti-dsDNA, prior to treatment (mean age: 12.8 ±1.76 years old) and c) 31 healthy age-matched controls (mean age: 6.58 ± 3.65 years old), all of Hellenic origin. RESULTS: CD4 + TCR Vß abnormalities (± 3SD of controls) were observed mainly in SLE patients. Statistical analysis revealed that the CD4 + Vß4 chain was significantly increased in patients with T1DM (p < 0.001), whereas CD4 + Vß16 one was significantly increased in SLE patients (p < 0.001) compared to controls. CONCLUSIONS: CD4 + Vß4 and CD4 + Vß16 chains could be possibly involved in the cascade of events precipitating the pathogenesis of T1DM and SLE in children, respectively.

Chronic granulomatous disease: a 25-year patient registry based on a multistep diagnostic procedure, from the referral center for primary immunodeficiencies in Greece.

Chronic Granulomatous Disease (CGD) is an uncommon primary immunodeficiency caused by the absence or dysfunction of one of NADPH oxidase subunits, with heterogeneous genetic aetiologies. The aim of this study was the CGD patient registry in Greece, the identification of the responsible genotype and the potential correlation with the patient's clinical phenotype. Medical charts of 24 CGD patients, investigated by NBT test or DHR for NADPH oxidase activity, Western blot analysis for NADPH oxidase component expression and DNA sequencing (pyro- and cycle sequencing) for mutation analysis, were reviewed. All patients, but one, were classified into the different types of CGD. Sixteen patients from 14 unrelated families had X-linked CGD (66.7 %), four had mutations in the NCF1 gene (19 %), and three, from two unrelated families, had mutations in NCF2 (9.5 %) [Corrected]. Fifteen mutations were detected in the CYBB gene, including nonsense (53.8 %), splice site (30.8 %) and missense mutations (7.7 %), and deletions (7.7 %). Two novel mutations were identified; one in CYBB and one in NCF1. Carrier detection for X-CGD revealed that the de novo mutation rate was about 7 %. Prenatal diagnosis identified one affected male in three male fetuses tested. In both the X-linked and the autosomal recessive (AR-CGD) group, the gastrointestinal and respiratory manifestations were more common, followed by lympadenopathy in X-CGD and skin infections in the AR-CGD group. The patients with a mutation in CYBB had a wider variability of clinical manifestations and earlier diagnosis (4.6 years) compared to the AR-CGD group (12.9 years). The incidence of CGD in Greece is estimated at 0.90 (95 % CI 0.89-0.91) per 100,000 live births for the last decade.

Transporter associated with antigen processing deficiency syndrome: case report of an adolescent with chronic perforated granulomatous skin lesions due to TAP2 mutation.

A previously unreported case of transporter associated with antigen processing (TAP) deficiency syndrome (with no parental consanguinity) due to a homozygous TAP2 mutation is presented. Characteristic nonhealing, chronic, ulcerative granulomatous leg lesions combined with recurrent otitis media and sinopulmonary infections led to this boy being diagnosed at 15 years old. The role of the dermatologist was crucial in making the correct diagnosis and thereby positively influencing the quality of life and life expectancy of this boy.

Ex Vivo Evaluation of Glutamine Treatment in Sepsis and Trauma in a Human Peripheral Blood Mononuclear Cells Model.

We aimed to assess the lipopolysaccharide (LPS), or heat shock (HS) induction, and glutamine-modulating effects on heat shock protein-90α (HSP90α) and cytokines in an ex vivo model using peripheral blood mononuclear cells (PBMCs). The PBMCs of patients with septic shock, trauma-related systemic inflammatory response syndrome (SIRS), and healthy subjects were incubated with 1 µg/mL LPS at 43 °C (HS). Glutamine 10 mM was added 1 hour before or after induction or not at all. We measured mRNA HSP90α, monocyte (m) and lymphocyte (l) HSP90α proteins, interleukin (IL)-1b, -6, -8, -10, tumor necrosis factor-α (TNF-α), and monocyte chemoattractant protein-1 (MCP-1) supernatant levels. Heat shock increased the HSP90α mRNA and mHSP90α in all groups (10-fold in sepsis, p < 0.001 and p = 0.047, respectively). LPS induced the mHSP90α and lHSP90α in healthy (p < 0.001) and mHSP90α in SIRS (p = 0.004) but not in sepsis. LPS induced the cytokines at 24 and 48 h in all groups, especially in trauma (p < 0.001); HS only induced the IL-8 in healthy (p = 0.003) and septic subjects (p = 0.05). Glutamine at 10 mM before or after stimulation did not alter any induction effect of LPS or HS on HSP90α mRNA and mHSP90α protein in sepsis. In SIRS, glutamine before LPS decreased the mHSP90α but increased it when given after HS (p = 0.018). Before or after LPS (p = 0.049) and before HS (p = 0.018), glutamine decreased the lHSP90α expression in sepsis but increased it in SIRS when given after HS (p = 0.003). Regarding cytokines, glutamine enhanced the LPS-induced MCP-1 at 48 h in healthy (p = 0.011), SIRS (p < 0.001), and sepsis (p = 0.006). In conclusion, glutamine at 10 mM, before or after LPS and HS, modulates mHSP90α and lHSP90α in sepsis and SIRS differently and unpredictably. Although it does not alter the stimulation effect on interleukins, glutamine enhances the LPS induction effect on supernatant MCP-1 in all groups. Future research should seek to elucidate better the impact of glutamine and temperature modulation on HSP90α and MCP-1 pathways in sepsis and trauma.

Corrigendum: Do common infections trigger disease-onset or -severity in CTLA-4 insufficiency?

[This corrects the article DOI: 10.3389/fimmu.2022.1011646.].