Journal of Clinical Immunology最新文献

Background: Inborn errors of immunity (IEI) affecting B-cell receptor signaling cause predominantly antibody deficiency (PAD) with varying degrees of severity. Recently, four heterozygous variants in SYK were reported to cause hypogammaglobulinemia, multiorgan inflammatory disease and diffuse large B-cell lymphoma.

Objective: We aimed to unravel the genetic and functional cause of PAD in a 43-year-old female presenting with hypogammaglobulinemia, congenital heart disease and pulmonary hypertension requiring lung transplantation.

Methods: Patient gDNA was subjected to whole-exome and Sanger sequencing. Blood B- and T-cell subsets, as well as tonic and antigen-receptor induced expression levels of phosphorylated-SYK, phosphorylated-ribosomal S6 and phosphorylated p38 were evaluated by flow cytometry.

Results: A novel heterozygous missense SYK variant was identified, mutating a residue in the protein kinase domain (c.1769G > A; p.R590Q), which is highly conserved across vertebrates. While total B- and T-cell numbers were within the normal range, the patient had reduced unswitched and class-switched memory B-cell numbers. Resting B cells from the patient demonstrated enhanced autophosphorylation of SYK, and tonic and ligand-induced phospho-S6 levels. Spontaneous SYK autophosphorylation, S6 and p38 phosphorylation were recapitulated in a pre-clinical cell model, i.e. expression of the SYK R590Q variant in HEK293T cells.

Conclusions: We identified a novel gain-of-function variant in SYK to underlie hypogammaglobulinemia and atypical autoinflammatory disease. Flowcytometric screening for phospho-S6 in lymphocytes of IEI patients can guide genetic diagnosis of B-cell signaling abnormalities.

Background: Primary immunodeficiency disease (PID)/Inborn Errors of Immunity (IEI) with T-cell dysfunction is well-known for susceptibility to opportunistic/viral infections. Epstein-Barr virus-positive smooth muscle tumor (EBV-SMT) is a rare entity primarily seen in the setting of immunodeficiency, such as transplantation, HIV/AIDS, and IEI.

Aim: This study aimed to characterize patients' clinical/immunologic/genetic features with EBV-SMT and assess their association with IEI.

Methods: We reviewed the medical records of patients with EBV-SMT in an outpatient immunology clinic and analyzed a total of 33 patients, including 24 identified from the literature.

Results: The study included nine patients (male/ female = 6/3). The median ages at the onset of symptoms, clinical diagnosis of PID, genetic diagnosis, and EBV-SMT diagnosis were 12 months (1-84 months), 6 years (2-15 years), 10 years (6-18 years), and 10 years (4-18 years), respectively. The parental consanguinity ratio was 7/9(78%). Four patients had combined immunodeficiency. Five out of nine patients (56%) received a genetic IEI diagnosis: JAK3 deficiency (n = 1), STAT1 GOF (n = 1), CARMIL2 deficiency (n = 1), DOCK8 deficiency (n = 1), and ITK deficiency (n = 1). Recurrent infections (100%), chronic diarrhea/colitis (78%), organomegaly (67%), and lymphadenopathy (56%) were prevalent among the patients. Six patients exhibited leiomyoma-like morphology, while three had leiomyosarcoma-like morphology. Five out of nine patients (55%) died, two of whom succumbed due to the complications of hematopoietic stem cell transplantation.

Conclusion: EBV-SMT may suggest an underlying immunodeficiency. Since the mortality is high, early genetic diagnosis of IEI, monitoring the patients with IEI for chronic EBV and cancer, and an individualized therapeutic approach will minimize complications.

Hypogammaglobulinemia (HG) predisposes patients to gastrointestinal Campylobacter infections. This prospective study determined the prevalence of Campylobacter in stool samples from patients with immunoglobulin (Ig)-substituted HG at Bordeaux University Hospital. 73 patients (42 women, median age: 61) receiving Ig substitution therapy were enrolled from July 2022 to July 2024. Stool samples were analysed with culture, PCR, faecal calprotectin levels, and immune profiles were also assessed. A second stool sample was collected from 38 patients after 6-12 months, totalling 111 samples. 53 patients had primary HG (32 common variable immunodeficiency, 7 IgG subclass deficiencies, 4 Bruton's agammaglobulinemias) and 20 had secondary HG (7 drug-induced, 8 lymphoid hemopathy-related, 5 mixed). Campylobacter were detected in 11 patients (15.1%), with species identified as Campylobacter jejuni, Campylobacter coli, and Aliarcobacter butzleri. Diarrhea was reported in 42% of Campylobacter-positive patients versus 15% of negative patients. Campylobacter-positive patients exhibited higher median faecal calprotectin levels (255 µg/g vs. 52 µg/g). Among positive patients, 44% (versus 34% in negative patients) had non-infectious complications such as immune complications. Mean residual IgG levels were similar between groups, although IgA and IgM were lower in Campylobacter-positive patients (0 vs. 0.36 g/L and 0.17 vs. 0.40 g/L, respectively). The mean CD4/CD8 ratio was also lower in the positive group (1.71 ± 0.85 vs. 2.06 ± 1.18). This study reveals a high prevalence of Campylobacter in HG patients despite receiving Ig therapy. Elevated faecal levels of calprotectin in symptomatic patients suggests active infection. Screening for Campylobacter should be considered in HG patients presenting with digestive symptoms.

Introduction: Specific determinants of target-organ damage in autoimmune diseases are complex and multifactorial, several genetic and environmental factors are recognized but mostly remain unknown. Immunotherapy with "check-point inhibitors" (CPI) is complicated by immune related adverse events (IRAE), occurring in a large fraction of patients, with organ-specific inflammation of immunologic aetiology. We hypothesized that such IRAE are associated to regulatory T cell (Treg) dysfunction. To start testing this hypothesis, we have now compared organ targets of CPI-induced IRAE with those described in IPEX (Immune dysregulation polyendocrinopathy enteropathy X-linked) patients carriers of deleterious mutations in the Foxp3 gene leading to deficient/absent Treg.  METHOD: We compared the frequency of autoimmune diseases (AID) in three groups of conditions: CPI-induced IRAE, IPEX patients, and the General Population (GP) through a PubMed search from 01/01/1998 to 31/05/2024. For each group, and each autoimmune disease, the highest reported frequency was selected, listed in reference to CPI-IRAE and classified from the highest to lowest prevalence. Identified were enteropathy, rash (eczema or other dermatitis), transaminitis/hepatitis, hypothyroidism, increased lipase/exocrine pancreatitis, arthralgia/inflammatory arthritis, hypophysitis, adrenal insufficiency, type 1 diabetes mellitus, haemolytic anaemia, Sjögren´s syndrome, polymyalgia rheumatica, ankylosing spondylitis, systemic lupus erythematosus, multiple sclerosis and systemic sclerosis.  RESULTS: While dermatitis and thyroid disease are also the most frequent AID in the GP, the latter, together with enteropathy, hepatitis, and adrenal insufficiency are much more frequent in CPI-IRAE and IPEX. Of note, the most frequent systemic AID in the GP such as de novo Sjögren´s syndrome, polymyalgia rheumatica, ankylosing spondylitis, systemic lupus erythematosus, multiple sclerosis and systemic sclerosis are extremely rare in CPI-IRAE (few case reports) and not described in IPEX.

Conclusion: Our finding provides further evidence for the possibility that the functional inhibition/inactivation of Treg is a plausible contributing mechanism in the physiopathology of CPI-IRAE.

Objective: Mutations in the HOIP gene, encoding Heme-oxidized IRP2 ubiquitin ligase-1 (HOIL-1) interacting protein, a key component of the linear ubiquitination chain assembly complex (LUBAC), affect the activation of the NF-κB pathway and result in autoinflammation and immunodeficiency. To date, only three patients with HOIP mutations have been reported in the English literature. This study aimed to identify the genetic cause in a 1-year-6-month-old boy with early-onset autoinflammation and immunodeficiency.

Methods: Clinical manifestations and immunological phenotypes were assessed in a Chinese patient with novel compound heterozygous mutations in HOIP. Swiss-PdbViewer was used to predict the pathogenicity of the mutations. HOIP and LUBAC protein levels were evaluated by western blot. Immunological phenotypes and intracellular NF-κB phosphorylation in T and B cells were analyzed by flow cytometry, and the interferon (IFN) signature was assessed using quantitative reverse transcription PCR (RT-qPCR).

Results: The patient experienced recurrent fever, multiple site infections, and chronic diarrhea from the neonatal period, requiring repeated hospitalizations. Targeted gene sequencing identified novel compound heterozygous mutations in HOIP (c.1654 C > T, p.Gln552Ter; c.3038 A > C, p.His1013Pro). These mutations significantly reduced HOIP and LUBAC protein expression and altered the HOIP protein structure. Immunophenotyping revealed a reduction in CD8 + T cells, central memory (CD8 CM) and effector memory (CD8 EM) T cells, and CD4 + T cells. Subset analysis of CD4 + T cells showed decreased T follicular helper cells (Tfh) and increased IL-17-producing T helper (Th17) cells. The patient also exhibited a higher percentage of naïve B cells and a lower percentage of memory B cells, alongside impaired NF-κB phosphorylation in T and B cells upon LPS stimulation. The expression of the patient's interferon-stimulated gene (ISG) was markedly higher than that of healthy controls.

Conclusion: HOIP mutations may lead to multiple immune abnormalities, impaired NF-κB activation, and activation of the type I interferon pathway. These findings highlight the diversity of HOIP mutations and expand the clinical spectrum of associated diseases.

NLRP3 mosaicism is a well-established mechanism causing the monogenic autoinflammatory disease named cryopyrin-associated periodic syndromes (CAPS). The number of reported patients with NLRP3 mosaicism is small, and the knowledge about the long-term disease behavior is limited. Herein we assembled the largest cohort of individuals with NLRP3 mosaicism reported to date to obtain additional evidence that strengthens the understanding of this disease. The novel genetic data were obtained by using Sanger and next-generation sequencing methods, whereas in vitro analyses determined the functional consequences of detected variants. A total of seventeen individuals with NLRP3 mosaicism were enrolled, with 16/17 experiencing different CAPS phenotypes. An overrepresentation of late-onset forms was detected (37.5%). Overall, clinical manifestations, analytical results, and outcomes of treatments were markedly similar to those detected in patients with germline variants. A large mutational diversity was identified, with 16 different variants among 17 individuals. Two main patterns of mosaicism (extended vs. myeloid-restricted) were detected, with the last one overrepresented in the late-onset group. The evaluation of mosaicism over time identified three different patterns, being the group with stable mosaicism the largest one. Collected evidence supports the marked similarities among patients carrying somatic or germline NLRP3 variants. The overrepresentation of NLRP3 mosaicism in late-onset forms should be considered in patients with inflammatory manifestations starting in adulthood. Analysis of mosaicism at the biological level confirms the two known patterns of corporal distribution and reveals that mosaicism remains stable over time in most patients, but it may also vary during the course of the disease.

Purpose: Type I interferonopathy encompasses disorders marked by systemic inflammation and neurological involvement, arising from genetic mutations that result in the upregulation of type I IFN signaling through various mechanisms. Currently, therapeutic options are limited, and no standard therapy exists. This study aims to develop a strategy for identifying new therapeutic targets for type I interferonopathy using induced pluripotent stem cells (iPSCs).

Methods: The IFIH1 R779H variant was introduced into iPSCs through genome editing. RNA sequencing of iPSC-derived dendritic cells (DCs) was performed, and differentially expressed genes (DEGs) were identified. IFN-α secretion, reactive oxygen species (ROS), and mitochondrial oxygen consumption rate (OCR) were analyzed in iPSC-derived DCs. An in silico prediction of compounds binding to the OAS-like domain was conducted. Candidate compounds were evaluated for their ability to inhibit IFN secretion from IFIH1 R779H-mutated iPSC-derived DCs.

Results: Transcriptome analysis indicated upregulation of the IFN-related and metabolic pathways. IFIH1 R779H-mutated iPSC-derived DCs exhibited increased OCR and ROS generation, and blocking mitochondrial metabolism significantly reduced excessive IFN-α secretion. Among the DEGs, PML was upregulated, and targeting this gene with arsenic trioxide (ATO), a PML antagonist, suppressed IFN-α secretion from IFIH1 R779H-mutated iPSC-derived DCs. Additionally, bisantrene, phthalylsulfathiazole and ganaplacide were predicted to bind to the RNA binding groove of OAS-like domain of human OASL in silico, effectively inhibiting IFN-α secretion from IFIH1 R779H-mutated DCs.

Conclusion: Our iPSC-based disease modeling and drug investigation approach provides a robust platform for validating the efficacy and toxicity of candidate therapeutic agents for rare and intractable human diseases such as type I interferonopathy.