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Frontiers in Cellular and Infection... 2023Patients with Human Hyper IgM syndromes (HIGM) developed pulmonary and gastrointestinal infections since infancy and most patients have mutations in the CD40 ligand...
Elevated levels of enteric IgA in an unimmunised mouse model of Hyper IgM syndrome derived from gut-associated secondary lymph organs even in the absence of germinal centres.
INTRODUCTION
Patients with Human Hyper IgM syndromes (HIGM) developed pulmonary and gastrointestinal infections since infancy and most patients have mutations in the CD40 ligand (CD40L) gene. Most HIGM patients compared to healthy subjects have higher/similar IgM and lower IgG, and IgA serum concentrations but gut antibody concentrations are unknown. CD40L on activated T-cells interacts with CD40 on B-cells, essential for the formation of germinal centres (GCs) inside secondary lymphoid organs (SLOs), where high-affinity antibodies, long-lived antibody-secreting plasma cells, and memory B-cells, are produced. C57BL6-CD40 ligand deficient mice (C57BL6- ), are a model of HIGM, because serum immunoglobulin concentrations parallel levels observed in HIGM patients and have higher faecal IgA concentrations. In mice, TGFβ and other cytokines induce IgA production.
AIMS
To compare and evaluate B-cell populations and IgA-producing plasma cells in peritoneal lavage, non-gut-associated SLOs, spleen/inguinal lymph nodes (ILN), and gut-associated SLOs, mesenteric lymph nodes (MLN)/Peyer´s patches (PP) of unimmunised C57BL6- and C57BL6-wild-type (WT) mice.
MATERIAL AND METHODS
Peritoneal lavages, spleens, ILN, MLN, and PP from 8-10 weeks old C57BL6- and WT mice, were obtained. Organ cryosections were analysed by immunofluorescence and B-cell populations and IgA-positive plasma cell suspensions by flow cytometry.
RESULTS
In unimmunised WT mice, GCs were only observed in the gut-associated SLOs, but GCs were absent in all C57BL6- SLOs. PP and MLN of C57BL6- mice exhibited a significantly higher number of IgA-producing cells than WT mice. In the spleen and ILN of C57BL6- mice IgA-producing cells significantly decreased, while IgM-positive plasma cells increased. C57BL6- B-1 cells were more abundant in all analysed SLOs, whereas in WT mice most B-1 cells were contained within the peritoneal cavity. C57BL6- B-cells in MLN expressed a higher TGFβ receptor-1 than WT mice. Mouse strains small intestine microvilli (MV), have a similar frequency of IgA-positive cells.
DISCUSSION
Together our results confirm the role of PP and MLN as gut inductive sites, whose characteristic features are to initiate an IgA preferential immune response production in these anatomical sites even in the absence of GCs. IgA antibodies play a pivotal role in neutralising, eliminating, and regulating potential pathogens and microorganisms in the gut.
Topics: Humans; Mice; Animals; CD40 Ligand; Hyper-IgM Immunodeficiency Syndrome; Germinal Center; Intestine, Small; Immunoglobulin A; Immunoglobulin M; Transforming Growth Factor beta
PubMed: 37457961
DOI: 10.3389/fcimb.2023.1172021 -
Clinical Immunology (Orlando, Fla.) Aug 2023X-Linked Hyper-IgM Syndrome is caused by pathogenic variants in CD40LG. Three patients with atypical clinical and immunological features were identified with variants in...
X-Linked Hyper-IgM Syndrome is caused by pathogenic variants in CD40LG. Three patients with atypical clinical and immunological features were identified with variants in CD40LG requiring further characterization. Flow cytometry was used to evaluate CD40L protein expression and binding capacity to a surrogate receptor, CD40-muIg. Though functional anomalies were observed, there was still a lack of clarity regarding the underlying mechanism. We developed structural models for wild-type and the three variants of CD40L protein observed in these patients (p. Lys143Asn, Leu225Ser and Met36Arg) to evaluate structural alterations by molecular mechanic calculations, and assess protein movement by molecular dynamic simulations. These studies demonstrate that functional analysis of variants of unknown significance in CD40LG can be supplemented by advanced computational analysis in atypical clinical contexts. These studies in combination identify the deleterious effects of these variants and potential mechanisms for protein dysfunction.
Topics: Humans; CD40 Antigens; CD40 Ligand; Hyper-IgM Immunodeficiency Syndrome; Hyper-IgM Immunodeficiency Syndrome, Type 1; Immunoglobulin M; Mutation
PubMed: 37433422
DOI: 10.1016/j.clim.2023.109692 -
Nutrients Apr 2023The increase in life expectancy can be a consequence of the world's socioeconomic, sanitary and nutritional conditions. Some studies have demonstrated that individuals...
UNLABELLED
The increase in life expectancy can be a consequence of the world's socioeconomic, sanitary and nutritional conditions. Some studies have demonstrated that individuals with a satisfactory diet variety score present a lower risk of malnutrition and better health status. Zinc and selenium are important micronutrients that play a role in many biochemical and physiological processes of the immune system. Deficient individuals can present both innate and adaptive immunity abnormalities and increased susceptibility to infections. Primary immunodeficiency diseases, also known as inborn errors of immunity, are genetic disorders classically characterized by an increased susceptibility to infection and/or dysregulation of a specific immunologic pathway. IgA deficiency (IgAD) is the most common primary antibody deficiency. This disease is defined as serum IgA levels lower than 7 mg/dL and normal IgG and IgM levels in individuals older than four years. Although many patients are asymptomatic, selected patients suffer from different clinical complications, such as pulmonary infections, allergies, autoimmune diseases, gastrointestinal disorders and malignancy. Knowing the nutritional status as well as the risk of zinc and selenium deficiency could be helpful for the management of IgAD patients.
OBJECTIVES
to investigate the anthropometric, biochemical, and nutritional profiles and the status of zinc and selenium in patients with IgAD.
METHODS
in this descriptive study, we screened 16 IgAD patients for anthropometric and dietary data, biochemical evaluation and determination of plasma and erythrocyte levels of zinc and selenium.
RESULTS
dietary intake of zinc and selenium was adequate in 75% and 86% of the patients, respectively. These results were consistent with the plasma levels (adequate levels of zinc in all patients and selenium in 50% of children, 25% of adolescents and 100% of adults). However, erythrocyte levels were low for both micronutrients (deficiency for both in 100% of children, 75% of adolescents and 25% of adults).
CONCLUSION
our results highlight the elevated prevalence of erythrocyte zinc and selenium deficiency in patients with IgAD, and the need for investigation of these micronutrients in their follow-up.
Topics: Adolescent; Adult; Child; Humans; Selenium; IgA Deficiency; Zinc; Malnutrition; Adaptive Immunity
PubMed: 37432290
DOI: 10.3390/nu15092145 -
Journal of Clinical Immunology Oct 2023
Topics: Humans; Hyper-IgM Immunodeficiency Syndrome; Hyper-IgM Immunodeficiency Syndrome, Type 1; Homozygote; Lymphopenia; Cytidine Deaminase; Immunoglobulin M
PubMed: 37402930
DOI: 10.1007/s10875-023-01546-z -
Journal of Otolaryngology - Head & Neck... Jun 2023Patients with chronic rhinosinusitis (CRS) and immunoglobulin deficiencies (ID) have more recalcitrant sinonasal disease and a subset of these patients undergo surgical...
BACKGROUND
Patients with chronic rhinosinusitis (CRS) and immunoglobulin deficiencies (ID) have more recalcitrant sinonasal disease and a subset of these patients undergo surgical management for their CRS. However, there is a paucity of literature on the surgical outcomes in this patient population and appropriate treatment algorithms for CRS in patients with ID. The objective of this study was to better elucidate the outcomes of endoscopic sinus surgery (ESS) in patients with ID in terms of disease-specific quality-of-life scores and the need for revision surgery.
METHODS
A case-control study was performed comparing adult patients with ID and healthy controls that had undergone ESS for CRS. Patients were matched based on age, sex, CRS phenotype, and preoperative Lund-Mackay score. The revision surgery rates, time to revision surgery, and changes in sinonasal outcome tests (SNOT-22) were evaluated.
RESULTS
Thirteen patients with CRS and ID were matched to 26 control patients with CRS. The revision surgery rate for cases and controls was 31% and 12%, respectively, but there was no statistical difference (p > 0.05). There was a clinically meaningful reduction in SNOT-22 scores in both groups from the preoperative to postoperative period [mean of 12 points in patients with ID (p = 0.323) and 25 points in controls (p < 0.001)], however, there was again no significant difference between cases and controls (p > 0.05).
CONCLUSION
Our data suggests that patients with ID have clinically meaningful improvement in SNOT-22 scores after ESS but may have higher revision rates than immunocompetent patients with CRS. ID are rare disease entities, thus most attempts at studying this cohort would be limited by sample size. Further homogenous data on immunoglobulin deficient patients is required for future meta-analysis to better understand the impact of ESS in patients with ID.
Topics: Humans; Algorithms; Case-Control Studies; Chronic Disease; Phenotype; Sinusitis; Dysgammaglobulinemia; Nasal Surgical Procedures; Endoscopy
PubMed: 37386535
DOI: 10.1186/s40463-023-00648-3 -
Science Immunology May 2023The ability of most patients with selective immunoglobulin A (IgA) deficiency (SIgAD) to remain apparently healthy has been a persistent clinical conundrum. Compensatory...
The ability of most patients with selective immunoglobulin A (IgA) deficiency (SIgAD) to remain apparently healthy has been a persistent clinical conundrum. Compensatory mechanisms, including IgM, have been proposed, yet it remains unclear how secretory IgA and IgM work together in the mucosal system and, on a larger scale, whether the systemic and mucosal anti-commensal responses are redundant or have unique features. To address this gap in knowledge, we developed an integrated host-commensal approach combining microbial flow cytometry and metagenomic sequencing (mFLOW-Seq) to comprehensively define which microbes induce mucosal and systemic antibodies. We coupled this approach with high-dimensional immune profiling to study a cohort of pediatric patients with SIgAD and household control siblings. We found that mucosal and systemic antibody networks cooperate to maintain homeostasis by targeting a common subset of commensal microbes. In IgA-deficiency, we find increased translocation of specific bacterial taxa associated with elevated levels of systemic IgG targeting fecal microbiota. Associated features of immune system dysregulation in IgA-deficient mice and humans included elevated levels of inflammatory cytokines, enhanced follicular CD4 T helper cell frequency and activation, and an altered CD8 T cell activation state. Although SIgAD is clinically defined by the absence of serum IgA, the symptomatology and immune dysregulation were concentrated in the SIgAD participants who were also fecal IgA deficient. These findings reveal that mucosal IgA deficiency leads to aberrant systemic exposures and immune responses to commensal microbes, which increase the likelihood of humoral and cellular immune dysregulation and symptomatic disease in patients with IgA deficiency.
Topics: Humans; Child; Mice; Animals; IgA Deficiency; Immunoglobulin A, Secretory; Immunoglobulin M; Homeostasis
PubMed: 37235682
DOI: 10.1126/sciimmunol.ade2335 -
Revista Alergia Mexico (Tecamachalco,... Apr 2023Hyper-IgM syndrome is an innate error of immunity in which there is a defect in change of isotype of immunoglobulins, with decreased values of IgG, IgA, and IgE, but...
INTRODUCTION
Hyper-IgM syndrome is an innate error of immunity in which there is a defect in change of isotype of immunoglobulins, with decreased values of IgG, IgA, and IgE, but normal or increased level of IgM. This predisposes to infectious processes at the respiratory and gastrointestinal levels, as well as autoimmune diseases and neoplasm.
CASE REPORT
A 5 year 7-month-old boy with a history of 2 pneumonias, one of them severe, and chronic diarrhea since he was 2 years old. Persistent moderate neutropenia decreased IgG and elevated IgM. Cytometry flow confirmed absence of CD40L. Clinical evolution with early hepatic involvement.
DISCUSSION
Hyper-IgM syndrome predisposes to liver damage, so a complete evaluation is required as well as early diagnosis. Active anti-infective treatment and control of the inflammatory response are key to the treatment of liver damage.
Topics: Child, Preschool; Humans; Male; CD40 Ligand; Hyper-IgM Immunodeficiency Syndrome; Immunoglobulin G; Immunoglobulin M; Liver
PubMed: 37218048
DOI: 10.29262/ram.v69i4.1091 -
BMC Pediatrics May 2023D40LG-associated X-linked hyper-IgM syndrome with pulmonary alveolar proteinosis has rarely been reported, and its genotype-phenotypic correlation remains elusive.
BACKGROUND
D40LG-associated X-linked hyper-IgM syndrome with pulmonary alveolar proteinosis has rarely been reported, and its genotype-phenotypic correlation remains elusive.
CASE PRESENTATION
We describe a five-month-old boy with CD40LG mutation (c.516T > A, p.Tyr172Ter) X-linked hyper-IgM syndrome with pulmonary alveolar proteinosis as the first manifestation. The patient completely recovered after immunotherapy and allogeneic hematopoietic stem cell transplantation. In addition, four previously reported patients with CD40LG mutation with pulmonary alveolar proteinosis were also analyzed. All of these patients presented with early onset of pulmonary infections and a good response to immunotherapy. The structural model of CD40LG indicated that all mutations caused the X-linked hyper-IgM syndrome with pulmonary alveolar proteinosis to be located within the tumor necrosis factor homology domain.
CONCLUSIONS
A case was presented, and the characteristics of four cases of CD40LG-associated X-linked hyper-IgM syndrome with pulmonary alveolar proteinosis were summarized. The variant locations may explain the phenotypic heterogeneity of patients with the CD40LG mutation.
Topics: Male; Humans; Infant; Pulmonary Alveolar Proteinosis; Hyper-IgM Immunodeficiency Syndrome; Mutation; Hyper-IgM Immunodeficiency Syndrome, Type 1; CD40 Ligand
PubMed: 37173671
DOI: 10.1186/s12887-023-04054-6 -
The Journal of Allergy and Clinical... Sep 2023Secretory IgA interacts with commensal bacteria, but its impact on human mycobiota ecology has not been widely explored. In particular, whether human IgA-deficiency is...
BACKGROUND
Secretory IgA interacts with commensal bacteria, but its impact on human mycobiota ecology has not been widely explored. In particular, whether human IgA-deficiency is associated with gut fungal dysbiosis remains unknown.
OBJECTIVES
Our goal was to study the impact of IgA on gut mycobiota ecology.
METHODS
The Fungi-Flow method was used to characterize fecal, systemic, and maternal IgA, IgM, and IgG responses against 14 representative fungal strains (yeast/spores or hyphae forms) in healthy donors (HDs) (n = 34, 31, and 20, respectively) and to also compare gut mycobiota opsonization by secretory antibodies in HDs (n = 28) and patients with selective IgA deficiency (SIgAd) (n = 12). Stool mycobiota composition was determined by internal transcribed spacer gene sequencing in HDs (n = 23) and patients with SIgAd (n = 17). Circulating CD4 T-cell cytokine secretion profiles were determined by intracellular staining. The impact of secretory IgA, purified from breast milk (n = 9), on Candidaalbicans growth and intestinal Caco-2 cell invasion was tested in vitro.
RESULTS
Homeostatic IgA binds commensal fungi with a body fluid-selective pattern of recognition. In patients with SIgAd, fungal gut ecology is preserved by compensatory IgM binding to commensal fungi. Gut Calbicans overgrowth nevertheless occurs in this condition but only in clinically symptomatic patients with decreased T17/T22 T-cell responses. Indeed, secretory IgA can reduce in vitro budding and invasion of intestinal cells by Calbicans and therefore exert control on this pathobiont.
CONCLUSION
IgA has a selective impact on Calbicans ecology to preserve fungal-host mutualism.
Topics: Female; Humans; Candida albicans; Caco-2 Cells; IgA Deficiency; Immunoglobulin A; Immunoglobulin A, Secretory; Immunoglobulin M
PubMed: 37169153
DOI: 10.1016/j.jaci.2023.03.033 -
Iranian Journal of Immunology : IJI May 2023Individuals with Selective Immunoglobulin-A Deficiency (SIgAD) are often asymptomatic, and symptomatic SIgAD patients often have autoimmune comorbidities. A 48-year-old... (Review)
Review
Individuals with Selective Immunoglobulin-A Deficiency (SIgAD) are often asymptomatic, and symptomatic SIgAD patients often have autoimmune comorbidities. A 48-year-old Han Chinese man presented with abdominal discomfort, hematochezia, and a large tumor in the anogenital region. The primary diagnosis of SIgAD was based on the patient's age, serum IgA concentration (0.067 g/L), and the evidence of chronic respiratory infection. No other immunoglobulin deficiency or evidence of immunosuppression was present. The primary diagnosis of giant condyloma acuminatum was based on human papilloma virus-6-positive laboratory results and histological characteristics. The tumor and adjacent skin lesions were resected. Hemoglobin concentration fell to 5.50 g/dL, and an emergency erythrocyte transfusion was performed. The body temperature increased to 39.8 ºC, suggesting a transfusion reaction, and 5 mg dexamethasone was administered intravenously. Hemoglobin concentration stabilized at 10.5 g/dL. The clinical signs and laboratory results indicated autoimmune hemolytic anemia, systemic lupus erythematosus, and Hashimoto's thyroiditis. Abdominal discomfort and hematochezia subsided. Though uncommon, the manifestation of multiple autoimmune comorbidities can occur in SIgAD patients. Further research is needed regarding the causes of SIgAD and the autoimmune disorders that often occur as comorbidities.
Topics: Male; Humans; Middle Aged; IgA Deficiency; Autoimmune Diseases; Immunoglobulins; Hemoglobins
PubMed: 37158141
DOI: 10.22034/iji.2023.97452.2513