Group Of Primary Immunodeficiency Diseases Research Articles

Dysbiosis and primary B-cell immunodeficiencies: current knowledge and future perspective.

According to Elie Metchnikoff, an originator of modern immunology, several pivotal functions for disease and health are provided by indigenous microbiota. Nonetheless, important mechanistic insights have been elucidated more recently, owing to the growing availability of DNA sequencing technology. There are 10 to 100 trillion symbiotic microbes (such as viruses, bacteria, and yeast) in each human gut microbiota. Both locally and systemically, the gut microbiota has been demonstrated to impact immune homeostasis. Primary B-cell immunodeficiencies (PBIDs) are a group of primary immunodeficiency diseases (PIDs) referring to the dysregulated antibody production due to either intrinsic genetic defects or failures in functions of B cells. Recent studies have found that PBIDs cause disruptions in the gut's typical homeostatic systems, resulting in inadequate immune surveillance in the gastrointestinal (GI) tract, which is linked to increased dysbiosis, which is characterized by a disruption in the microbial homeostasis. This study aimed to review the published articles in this field to provide a comprehensive view of the existing knowledge about the crosstalk between the gut microbiome and PBID, the factors shaping the gut microbiota in PBID, as well as the potential clinical approaches for restoring a normal microbial community.

Clinical and Immunological Features of 96 Moroccan Children with SCID Phenotype: Two Decades' Experience.

Severe combined immunodeficiency (SCID) is a heterogeneous group of primary immunodeficiency diseases (PIDs) characterized by a lack of autologous T lymphocytes. This severe PID is rare, but has a higher prevalence in populations with high rates of consanguinity. The epidemiological, clinical, and immunological features of SCIDs in Moroccan patients have never been reported. The aim of this study was to provide a clinical and immunological description of SCID in Morocco and to assess changes in the care of SCID patients over time. This cross-sectional retrospective study included 96 Moroccan patients referred to the national PID reference center at Casablanca Children's Hospital for SCID over two decades, from 1998 to 2019. The case definition for this study was age < 2years, with a clinical phenotype suggestive of SCID, and lymphopenia, with very low numbers of autologous T cells, according to the IUIS Inborn Errors of Immunity classification. Our sample included 50 male patients, and 66% of the patients were born to consanguineous parents. The median age at onset and diagnosis were 3.3 and 6.5months, respectively. The clinical manifestations commonly observed in these patients were recurrent respiratory tract infection (82%), chronic diarrhea (69%), oral candidiasis (61%), and failure to thrive (65%). The distribution of SCID phenotypes was as follows: T-B-NK+ in 44.5%, T-B-NK- in 32%, T-B+NK- in 18.5%, and T-B+NK+ in 5%. An Omenn syndrome phenotype was observed in 15 patients. SCID was fatal in 84% in the patients in our cohort, due to the difficulties involved in obtaining urgent access to hematopoietic stem cell transplantation, which, nevertheless, saved 16% of the patients. The autosomal recessive forms of the clinical and immunological phenotypes of SCID, including the T-B-NK+ phenotype in particular, were more frequent than those in Western countries. A marked improvement in the early detection of SCID cases over the last decade was noted. Despite recent progress in SCID diagnosis, additional efforts are required, for genetic confirmation and particularly for HSCT.

Antioxidant Defense, Redox Homeostasis, and Oxidative Damage in Children With Ataxia Telangiectasia and Nijmegen Breakage Syndrome.

Ataxia-telangiectasia (AT) and Nijmegen breakage syndrome (NBS) belong to a group of primary immunodeficiency diseases (PI) characterized by premature aging, cerebral degeneration, immunoglobulin deficiency and higher cancer susceptibility. Despite the fact that oxidative stress has been demonstrated in vitro and in animal models of AT and NBS, the involvement of redox homeostasis disorders is still unclear in the in vivo phenotype of AT and NBS patients. Our study is the first to compare both enzymatic and non-enzymatic antioxidants as well as oxidative damage between AT and NBS subjects. Twenty two Caucasian children with AT and twelve patients with NBS were studied. Enzymatic and non-enzymatic antioxidants – glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase-1 (SOD) and uric acid (UA); redox status—total antioxidant capacity (TAC) and ferric reducing ability of plasma (FRAP); and oxidative damage products−8-hydroxy-2′-deoxyguanosine (8-OHdG), advanced glycation end products (AGE), advanced oxidation protein products (AOPP), 4-hydroxynonenal (4-HNE) protein adducts, and 8-isoprostanes (8-isop) were evaluated in serum or plasma samples. We showed that CAT, SOD and UA were significantly increased, while TAC and FRAP levels were statistically lower in the plasma of AT patients compared to controls. In NBS patients, only CAT activity was significantly elevated, while TAC was significantly decreased as compared to healthy children. We also showed higher oxidative damage to DNA (↑8-OHdG), proteins (↑AGE, ↑AOPP), and lipids (↑4-HNE, ↑8-isop) in both AT and NBS patients. Interestingly, we did not demonstrate any significant differences in the antioxidant defense and oxidative damage between AT and NBS patients. However, in AT children, we showed a positive correlation between 8-OHdG and the α-fetoprotein level as well as a negative correlation between 8-OHdG and IgA. In NBS, AGE was positively correlated with IgM and negatively with the IgG level. Summarizing, we demonstrated an imbalance in cellular redox homeostasis and higher oxidative damage in AT and NBS patients. Despite an increase in the activity/concentration of some antioxidants, the total antioxidant capacity is overwhelmed in children with AT and NBS and predisposes them to more considerable oxidative damage. Oxidative stress may play a major role in AT and NBS phenotype.

Common variable immunodeficiency patients display elevated plasma levels of granulocyte activation markers elastase and myeloperoxidase.

Common variable immunodeficiency disorders (CVIDs) represent a group of primary immunodeficiency diseases characterized by hypogammaglobulinemia and dysfunctional immune response to invading pathogens. Previous studies have indicated that CVID is associated with microbial translocation and systemic myeloid cell activation.The goal of this study was to determine whether patients with CVID display elevated systemic levels of markers of granulocyte activation and whether the levels are further influenced by intravenous immunoglobulin (IVIg) infusions. The plasma levels of granulocyte activation markers elastase and myeloperoxidase were determined using enzyme-linked immunosorbent assay (ELISA) in 46 CVID patients and 44 healthy controls. All CVID patients were in a stable state with no apparent acute infection. In addition, granulocyte activation markers’ plasma levels in 24 CVID patients were determined prior to and 1 h following IVIg administration. Neutrophil elastase and myeloperoxidase plasma levels were significantly higher in CVID patients than in healthy controls. Systemic elastase levels were further increased following IVIg administration. In vitro stimulation of 13 CVID patients’ whole blood using IVIg in a therapeutically relevant dose for 2 h resulted in a significant increase in plasma elastase levels compared to unstimulated blood. The data presented here indicate that CVID is associated with chronic granulocytic activation which is further exacerbated by administering IVIg. Increased myeloperoxidase and elastase levels may contribute to associated comorbidities in CVID patients.

Neutrophil and Granulocytic Myeloid-Derived Suppressor Cell-Mediated T Cell Suppression Significantly Contributes to Immune Dysregulation in Common Variable Immunodeficiency Disorders.

Common variable immunodeficiency disorders (CVID) represent a group of primary immunodeficiency diseases characterized by hypogammaglobulinemia and impaired specific Ab response, resulting in recurrent infections due to dysfunctional immune response. The specific mechanisms mediating immune deficiency in CVID remain to be determined. Previous studies indicated that immune dysregulation in CVID patients is associated with chronic microbial translocation, systemic immune activation, and altered homeostasis of lymphocytic and myeloid lineages. A detailed phenotypic, functional characterization of plasma markers and immune cell populations was performed in 46 CVID patients and 44 healthy donors. CVID patients displayed significantly elevated plasma levels of a marker of neutrophil activation neutrophil gelatinase-associated lipocalin. Neutrophils from CVID patients exhibited elevated surface levels of CD11b and PD-L1 and decreased levels of CD62L, CD16, and CD80, consistent with a phenotype of activated neutrophils with suppressive properties. Neutrophils from CVID patients actively suppressed T cell activation and release of IFN-γ via the production of reactive oxygen species. Furthermore, CVID was associated with an increased frequency of low-density neutrophils (LDNs)/granulocytic myeloid-derived suppressor cells. LDN/granulocytic myeloid-derived suppressor cell frequency in CVID patients correlated with reduced T cell responsiveness. Exogenous stimulation of whole blood with bacterial LPS emulated some but not all of the phenotypic changes observed on neutrophils from CVID patients and induced neutrophil population with LDN phenotype. The presented data demonstrate that neutrophils in the blood of CVID patients acquire an activated phenotype and exert potent T cell suppressive activity. Specific targeting of myeloid cell-derived suppressor activity represents a novel potential therapeutic strategy for CVID.

Chronic Mucocutaneous Candidiasis Due to Gain-of-Function Mutation in STAT1

Background: Chronic mucocutaneous candidiasis (CMC) is a heterogeneous group of primary immunodeficiency diseases characterized by susceptibility to chronic or recurrent superficial Candida infection of skin, nails, and mucous membranes. Gain-of-function mutations in the STAT1 gene (STAT1-GOF) are the most common reported cause of CMC. We describe here the clinical and genetic findings for 3 patients with CMC caused by novel gain-of-function mutations in STAT1-GOF.

Monogenic polyautoimmunity in primary immunodeficiency diseases.

Primary immunodeficiency diseases (PIDs) consist of a large group of genetic disorders that affect distinct components of the immune system. PID patients are susceptible to infection and non-infectious complications, particularly autoimmunity. A specific group of monogenic PIDs are due to mutations in genes that are critical for the regulation of immunological tolerance and immune responses. This group of monogenic PIDs is at high risk of developing polyautoimmunity (i.e., the presence of more than one autoimmune disease in a single patient) because of their impaired immunity. In this review, we discuss the mechanisms of autoimmunity in PIDs and the characteristics of polyautoimmunity in the following PIDs: IPEX; monogenic IPEX-like syndrome; LRBA deficiency; CTLA4 deficiency; APECED; ALPS; and PKCδ deficiency.

Accurate clinical genetic testing for autoinflammatory diseases using the next-generation sequencing platform MiSeq

Autoinflammatory diseases occupy one of a group of primary immunodeficiency diseases that are generally thought to be caused by mutation of genes responsible for innate immunity, rather than by acquired immunity. Mutations related to autoinflammatory diseases occur in 12 genes. For example, low-level somatic mosaic NLRP3 mutations underlie chronic infantile neurologic, cutaneous, articular syndrome (CINCA), also known as neonatal-onset multisystem inflammatory disease (NOMID). In current clinical practice, clinical genetic testing plays an important role in providing patients with quick, definite diagnoses. To increase the availability of such testing, low-cost high-throughput gene-analysis systems are required, ones that not only have the sensitivity to detect even low-level somatic mosaic mutations, but also can operate simply in a clinical setting. To this end, we developed a simple method that employs two-step tailed PCR and an NGS system, MiSeq platform, to detect mutations in all coding exons of the 12 genes responsible for autoinflammatory diseases. Using this amplicon sequencing system, we amplified a total of 234 amplicons derived from the 12 genes with multiplex PCR. This was done simultaneously and in one test tube. Each sample was distinguished by an index sequence of second PCR primers following PCR amplification. With our procedure and tips for reducing PCR amplification bias, we were able to analyze 12 genes from 25 clinical samples in one MiSeq run. Moreover, with the certified primers designed by our short program—which detects and avoids common SNPs in gene-specific PCR primers—we used this system for routine genetic testing. Our optimized procedure uses a simple protocol, which can easily be followed by virtually any office medical staff. Because of the small PCR amplification bias, we can analyze simultaneously several clinical DNA samples with low cost and can obtain sufficient read numbers to detect a low level of somatic mosaic mutations.

A gain-of-function mutation of STAT1 in a 3-year-old child with chronic mucocutaneous candidiasis and autoimmune hepatitis: a case report

Background Chronic mucocutaneous candidiasis (CMC) is a heterogeneous group of primary immunodeficiency diseases (PID) characterized by chronic and recurrent infections of the skin, nails, and oropharynx, mostly caused by Candida sp. CMC is often associated with autoimmune and endocrine disorders. However, CMC may be the only or the main phenotype in patients with AD IL-17F and AR IL-17RA deficiencies, as well as gain-of-function (GOF) mutations of STAT1. Methods Case report - we describe a 3-year-old female child with a history of chronic candidiasis since 11 days of age (oral, genital, skin and nails), as well as several episodes of acute otitis media. The patient also presented local reaction to BCG. Her mother had systemic lupus erythematosus and CMC. Evolution: At 2 years of age the patient developed recurrent fever, hepatomegaly, jaundice, dark urine and abdominal distension. She was hospitalized and diagnosed with overlapping cholangitis and autoimmune hepatitis. The laboratory evaluation showed progressive increase of liver aminotransferases; presence of nodules in the spleen, infectious bronchiolitis and maxillary sinusopathy (all by CT scan), and esophageal candidiasis. The patient was treated with amphotericin, corticosteroids, antibiotics and azathioprine, and she had progressive improvement of general state and of the symptoms. She was discharged with fluconazole and azathioprine continuously; she maintains little skin and nails lesions. Results Immunoglobulins complement and lymphocytes subpopulations were normal. A genetic analysis was performed and revealed a GOF heterozygous mutation in STAT1coiled-coin domain NM_007315: exon 1:C.G821: pR274Q.

Primary Immunodeficiency Diseases at Reference and High-Specialty Hospitals in the State of Guanajuato, Mexico

Background. In general, primary immunodeficiency diseases (PIDs) are underdiagnosed in most countries. The objective of this study was to describe the frequency and clinical spectrum of PID in the most important tertiary hospitals in our region. Methods. An observational, cross-sectional, with retrospective chart, review study was conducted. A total of 26 patients were included and grouped according to the updated classification of PIDs. Results. PIDs spectra were as follows: predominantly antibody deficiency diseases were the most common category (65.38%), followed by other well-defined immunodeficiency syndromes (11.55%), congenital defects of phagocyte number and/or function (7.69%), complement deficiencies (3.85%), combined T- and B-cell immunodeficiencies (3.85%), and defects in innate immunity (3.85%). The mean time elapsed from the onset of symptoms to the reference and diagnosis by a tertiary hospital was of 4.65 ± 6.95 years. Conclusions. Predominant antibody deficiency disease was the most common group of PIDs, agreeing with international reports. Awareness of underdiagnosis by physicians is crucial for a prompt diagnosis and treatment, which in turn should improve the quality of life among patients with PIDs.

Chronic Mucocutaneous Candidiasis Caused by a Gain-of-Function Mutation in the STAT1 DNA-Binding Domain

Chronic mucocutaneous candidiasis (CMC) is a heterogeneous group of primary immunodeficiency diseases characterized by chronic and recurrent Candida infections of the skin, nails, and oropharynx. Gain-of-function mutations in STAT1 were very recently shown to be responsible for autosomal-dominant or sporadic cases of CMC. The reported mutations have been exclusively localized in the coiled-coil domain, resulting in impaired dephosphorylation of STAT1. However, recent crystallographic analysis and direct mutagenesis experiments indicate that mutations affecting the DNA-binding domain of STAT1 could also lead to persistent phosphorylation of STAT1. To our knowledge, this study shows for the first time that a DNA-binding domain mutation of c.1153C>T in exon 14 (p.T385M) is the genetic cause of sporadic CMC in two unrelated Japanese patients. The underlying mechanisms involve a gain of STAT1 function due to impaired dephosphorylation as observed in the coiled-coil domain mutations.

Age‐matched Reference Values for B‐lymphocyte Subpopulations and CVID Classifications in Children

Age-matched reference values are generally presented with 5th and 95th percentiles as 'normal' reference range. However, they are mostly determined in relatively small groups, which renders this presentation inaccurate. We determined reference values for B-lymphocyte subpopulations in healthy children with the statistical method of tolerance intervals that deals far better with the relatively small numbers tested, and compared these to the cut-off values used in the currently used EUROclass classification for common variable immunodeficiency disorders (CVID) in children. CVID is a heterogeneous group of primary immunodeficiency diseases characterized by low serum immunoglobulin levels and inadequate response to vaccination. Disease-modifying heterozygous amino acid substitutions in TACI are found in around ±10% of CVID patients. Interestingly, we found that age is the primary determinant of TACI-expression on B-lymphocytes, independent of switched memory B-lymphocyte numbers. Immunophenotyping of B-lymphocyte subpopulations is increasingly used to classify patients with CVID into subgroups with different clinical prognosis according to the composition of their B-lymphocyte compartment. These classifications were mainly developed with data obtained in adults. Because of the maturing paediatric immune system, they may not be equally applicable in children: our and other age-matched reference values show great changes in the composition of the B-lymphocyte compartment during development. Although the greatest changes in B-lymphocyte subpopulations occur below the age of 2 years, when the diagnosis of CVID cannot yet be made, it is likely that a classification developed in adults cannot be used to classify the prognosis of children.

Liver transplantation for severe hepatitis in patients with common variable immunodeficiency

CVID is a heterogeneous group of primary immunodeficiency diseases characterized by hypogammaglobulinemia, recurrent bacterial infections, and frequent autoimmune manifestations. The post-transplant course of liver transplant recipients with CVID is rarely described. We report two patients with CVID complicated by severe enteropathy who underwent living donor liver transplantation for liver failure because of severe hepatitis. The post-transplant course was complicated by recurrent acute rejection, leading to ductopenic rejection in one and recurrent hepatitis in the other. We reviewed the tissue samples histologically and immunohistochemically. Native livers showed submassive hepatocyte necrosis in one and cirrhotic liver with active hepatitis in the other, both with infiltration of CD8+ T cells accompanied by endothelialitis and bile duct damage; the intestine contained increased numbers of intraepithelial CD8+ T cells with apoptosis of epithelial cells. The liver allograft exhibited acute rejection, with prominent CD8+ T cells infiltrating the bile duct or endothelium. In the allograft following the diagnosis of post-transplant recurrent hepatitis, CD8+ T cells comprised the majority of infiltrating cells in portal areas spilling over into hepatic parenchyma. Our cases suggest that T cells contribute to the pathogenesis of CVID in native organs as well as allografts and may constitute evidence of T-cell deregulation in the pathogenesis of CVID.

Proinflammatory cytokine gene single nucleotide polymorphisms in common variable immunodeficiency

Common variable immunodeficiency (CVID) is a heterogeneous group of primary immunodeficiency diseases. Cytokine production could be affected in CVID patients, whereas its alteration could be due to genetic polymorphisms within coding and promoter regions of the cytokine genes. This study was performed to analyse the proinflammatory cytokine single nucleotide polymorphisms in CVID. The allele and genotype frequencies of a number polymorphic genes coding tumour necrosis factor (TNF)-alpha, interleukin (IL)-1alpha, IL-1beta, IL-1R, IL-1RA and IL-6 were investigated and compared between two groups of CVID patients and controls. The IL-6 GA genotype at position nt565 was significantly over-represented in the patient group (P<0.001), while the IL-6 GG genotype at position -174 (P=0.006) and the GG genotype at position nt565 (P<0.001) were significantly lower than controls. The TNF-alpha AG genotype at position -308 in the patient group was increased significantly in comparison with controls (P=0.027), but the GG genotype at the same position was significantly decreased (P=0.011). IL-6 CA and GA haplotypes were the most frequent haplotypes in the patients (P<0.005), whereas TNF-alpha GA (P=0.002) and IL-6 GG (P<0.001) haplotypes were decreased significantly in the patients in comparison with controls. Cytokine single nucleotide polymorphisms could have a role in pathophysiology of CVID. High production of TNF-alpha is expected in some CVID patients based on the frequency of genotypes/haplotypes of these cytokine gene polymorphisms.

Inmunodeficiencias primarias. Clínica y formas variantes

Periodically the World Health Organization and currently the International Union of Immunology Societies publish a classification of primary immunodeficiency diseases (PID) that includes diagnostic and therapeutic guidelines. The latest of these publications dates from 1999 and includes a new group of PID, the proliferative autoimmune syndromes. Furthermore, new forms of severe combined immunodeficiency (SCID) and of recessive autosomal agammaglobulinemia are described. From the publication of this classification until the end of the year 2000 a minimum of three new PIDs have been described and a further two should probably be added. Progress in the molecular biology of these diseases has given rise not only to more accurate diagnosis but also to greater insight into the clinical spectrum of these diseases. A mutation or deletion in a gene can provoke the complete absence of its product; sometimes expression is partial or normal but functional activity is absent or defective. In certain cases, partial or defective activity causes variant forms of the disease presenting symptomatology or atypical cellular phenotype. In other cases, this is not cause of the variant form, which can appear in interfamilial cases sharing the same mutation. In these cases, these differences can be attributed to environmental factors or to other genes able to modify the affected gene. In this article we provide examples of variant forms in several PIDs. Some are late onset forms, such as X-linked agammaglobulinemias diagnosed in adults, since until diagnosis, clinical symptomatology was minimal. In adenosine-deaminase deficiency, a serious and highly lymphoproliferative form of SCID, patients have been described whose symptomatology began after the age of 20 years. Another SCID, RAG1 and RAG2 recombinase deficiency, may produce a typical form with a characteristic T-B-NK + phenotype, Omenn's syndrome, or forms with an unexpected T-B + NK + phenotype. Deficiency in common gamma chain receptor for IL-2 may produce phenotypical variants that can lead to diagnostic error. X-linked lymphoproliferative syndrome may present as fulminant infectious mononucleosis, as leukemia or lymphoma or as hipo- or agammaglobulinemia. Possibly, some patients diagnosed with common variable immunodeficiency or with x-linked agammaglobulinemia do in fact have this syndrome. Chronic granulomatous disease is usually of early-onset, but late-onset forms have been described. In one case the first clinical manifestation was produced when the patient was 60 years old. The above examples serve to highlight that, even though PIDs are usually suspected by pediatricians, in some cases the diagnosis may be missed by internists or non-pediatricians. Moreover, the clinical and laboratory findings of these variant forms must be determined to carry out an early diagnosis, which is essential for a favorable therapeutic outcome.