Journal of Clinical Immunology最新文献

We describe a 3-year-old patient with xeroderma pigmentosum (XP) and genetically confirmed XPA deficiency who presented with recurrent infections in early childhood. Immunological assessment revealed mild hypogammaglobulinemia with IgG2 and IgG3 subclass deficiencies, as well as impaired humoral immunity demonstrated by a reduced antibody response to repeated vaccinations against bacterial antigens. Flow cytometric analysis further showed an altered distribution of peripheral T helper (TH) cell subsets. In addition, we report a second case: a 33-year-old XP patient with ERCC4 deficiency who also exhibited IgG3 subclass deficiency and reduced response to booster vaccination. Functional studies revealed defective nucleotide excision repair (NER) following UV-C exposure, along with reduced B-cell activation capacity. These findings suggest a potential link between XP and immunoglobulin subclass deficiencies, indicating a susceptibility to infections in affected individuals. We therefore recommend that patients diagnosed with XP undergo comprehensive immunological evaluation to allow early detection of immunodeficiency and timely intervention, including booster vaccinations or prophylactic measures such as low-dose antibiotics or immunoglobulin replacement therapy when indicated.

Patient-reported outcomes are critical to multidisciplinary, patient-centred approaches in diseases requiring lifelong management. Among inborn errors of immunity (IEIs), reports on this subject are typically limited to specific diagnostic subgroups or focus narrowly on the route of immunoglobulin replacement therapy (IgRT), offering a restricted perspective. We aimed to evaluate the health-related quality of life (HRQoL) and IgRT-related treatment satisfaction (TS) of a heterogeneous cohort of IEI patients and identify factors influencing these outcomes to guide improving the health and well-being of IEI patients. We conducted a cross-sectional survey targeting IEI patients on IgRT, assessing TS (TSQM-9) and HRQoL (KINDL/SF-36). Patient/caregiver-reported data were integrated with clinical data to identify outcomes and influencing factors. The survey included 500 IEI patients (356 children, 144 adults) diagnosed 54% Primary Antibody Deficiency (PAD), 36% combined immunodeficiency, 7% immune-dysregulation, and 3% other IEIs. Non-PAD diagnoses, comorbidities, absence of school/work attendance, and IgRT-related systemic adverse reactions negatively impacted HRQoL. Severe infections and related hospitalizations adversely influenced both HRQoL and TS. The subcutaneous route of IgRT, particularly at home, was associated with higher TS due to its convenience and reduced school/work absenteeism. However, the IgRT route did not influence adult HRQoL. Patient-reported well-being and satisfaction in IEIs are multifactorial and cannot be solely attributed to the route of IgRT. Minimizing negative experiences related to the disease or its treatment and, where possible, encouraging patients to maintain school/work attendance or engage in activities that promote societal participation can enhance self-esteem, coping abilities, and overall well-being.

The tumor necrosis factor (TNF) receptor superfamily member, transmembrane activator and CAML interactor (TACI) encoded by TNFRSF13B, are extensively involved in immune responses. In our previous work, TNFRSF13B exon 2 variants were recurrently identified in chronic active Epstein-Barr virus disease (CAEBV). Here we aim to reveal the roles of TNFRSF13B variants in CAEBV, and investigate the feasibility of targeting TNFRSF13B/TACI as a new approach to control EBV infection. The lymphoblastoid cell lines (LCL) models carrying homozygous TNFRSF13B exon 2 frameshift mutations were constructed using CRISPR/Cas9. Immunological assays, transcriptomic analysis, and gene silencing experiments were performed on LCL models to measure the effect of TNFRSF13B exon 2 variants and explore the underlying mechanisms. TACI ligands and a TLR9 agonist were applied to modulate TACI signaling and EBV activities. Frameshift mutations in exon 2 of TNFRSF13B significantly up-regulated the short isoforms of TACI (TACI-S) at the expense of its long isoforms (TACI-L) in LCLs. The up-regulated TACI-S induced more intense activation of NF-κB, MAPK, and Rho signaling pathways, leading to the switch of EBV activities to lytic reactivation. The subsequent increased viral load and viral IL-10 provide a rational for the susceptibility of variant carriers to CAEBV. The BAFF trimer, an indirect TACI-signaling inhibitor, also significantly suppressed the EBV lytic program. Gene silencing experiments indicated that XBP-1 might be involved in the TACI-mediated regulation of EBV lytic activities in EBV-immortalized B cells. This study underscores the impact of TNFRSF13B variants on EBV infection and host immune responses, offering insights into CAEBV pathogenesis and potential therapeutic strategies.

Objective: The presence of unique monocyte subsets and sub-populations plays a significant role in the onset and progression of rheumatic diseases. This study aimed to characterize variations in monocyte subsets and sub-populations and functional roles in patients with primary Sjögren's syndrome (pSS) using single-cell RNA sequencing (scRNA-seq).

Method: Monocyte samples from patients with pSS and healthy controls (HCs) were analyzed using single-cell RNA sequencing (scRNA-seq). This approach identified divergent gene expression patterns, transcription factors, and immune cells interactions within monocyte subset and sub-populations, highlighting pathways potentially involved in the pathogenesis of pSS.

Results: The scRNA-seq analysis delineated three major monocyte subsets: classical monocytes (CD14⁺⁺CD16^-), non-classical monocytes (CD14^-CD16⁺), and cDC2, with further identification of sub-populations within the classical and non-classical monocyte subsets. A notable increase in the proportions of classical monocyte sub-population 2 and non-classical monocyte sub-population 2 was observed in pSS patients. Compared to the HCs, pSS patients exhibited enhanced immune cell interactions within monocyte subsets. Furthermore, in pSS patients, the dominant increased pathways within monocytes were those related to viral responses, interferon activity, and oxidative phosphorylation. Additionally, significantly elevated expression levels of IFI44, IFI44L, HBA2, LY6E, XAF1, EPSTI1, APOBEC3A, and IFIT3 were identified in pSS monocytes.

Conclusion: This research revealed irregular alterations in monocyte subsets and sub-populations, transcription factors, and gene expression patterns within pSS patients, pinpointing prospective biomarkers in pSS as viable targets for therapeutic intervention.

Type II interferon (IFN) immunity is crucial for controlling intramacrophagic infections, driven by the interaction between innate immunity (macrophage-derived IL-12) and adaptive immunity (Th-derived IFN-γ). This study examines the maturation of type II IFN immunity in 55 healthy children (ages 1-18) to enable proper identification of deficiencies as part of the diagnostic evaluation of Mendelian Susceptibility to Mycobacterial Diseases (MSMD). The IL-12/IFN-γ axis was assessed through: (1) cytokine production after mycobacterial stimulation (Luminex and ELISA for IFN-γ, IL-12p70, TNF, CXCL10, IL-1RA, IL-10, IL-1β and IL-6), (2) IFN-γR1/R2 expression on monocytes, and (3) STAT1 phosphorylation/dephosphorylation. T cell maturation (primary IFN-γ source) was evaluated via immunophenotyping (naïve/memory/activated, Th1; Th2; Th17; Th1/17; Tfh) and proliferation assays. Main findings: (1) stable expression/production of key components of the IL-12/IFN-γ axis (IFN-γ, IL-12, TNF, IFN-γR1/2, and STAT1 activity) across ages confirming the stability of innate immune function throughout childhood; (2) increasing responses to IFN-γ with age reflected by increased CXCL10 production, and increase in the IFN-γ counter-acting anti-inflammatory cytokines (IL-10, IL-1RA); and (3) progressive T cell maturation, including Th1, Th17 and Th1/17 subsets, with significant milestones between 6 and 8.6 years, while T cell proliferative capacity remained stable. These observations highlight the stability of IL-12/IFN-γ axis innate components with age, accompanied by enhanced downstream IFN-γ signaling, aligning with the maturation of Th cell compartment. These underscore the limited benefit of age-specific controls in the evaluation of IL-12/IFN-γ axis in MSMD diagnosis, while emphasizing the importance of T cell maturation in the overall type II IFN immunity.

Trained immunity, a de-facto innate immune memory, has been extensively studied in response to live-attenuated vaccines, but its presence following the new COVID-19 vaccines has not yet been fully elucidated. In this study, we investigate markers of trained immunity in individuals vaccinated with mRNA-1273 or BNT162b2. As part of the vaccine roll-out in Denmark and recruited for a comparative study. Our primary objective was to determine whether these vaccines elicit lasting changes in innate immune responses, particularly in monocyte populations and cytokine production following stimulation with a panel of agonists. The study was conducted at four time points: Day-0 (pre-vaccination), Day-28, Day-90, and Day-180 post-vaccination. We observed no significant differences in monocyte subpopulations between vaccine groups; however, cytokine and chemokine analysis revealed distinct immune signatures. While IL-6 and TNFα production remained unchanged after ex-vivo restimulation in the BNT162b2 group, individuals vaccinated with mRNA-1273 exhibited a sustained increase in the production of these cytokines, persisting for up to 180 days post-vaccination. Additionally, CCL2, a key chemokine involved in monocyte recruitment, was upregulated following mRNA-1273 vaccination but decreased in the BNT162b2 group, further supporting the finding of differential innate immune responses between the two vaccines. In conclusion, our study provides evidence that mRNA-1273, but not BNT162b2, induces immune responses consistent with the concept of trained immunity. These results highlight the potential for mRNA vaccine platforms to shape innate immunity, with implications for future vaccine design aimed at enhancing non-specific and specific protection against infectious diseases.

Introduction: Primary 'predominantly antibody deficiencies' (PADs) are rare disorders characterized by increased susceptibility to infections, autoimmunity, allergies, and malignancies. Their low prevalence and heterogeneity often delay diagnosis, increasing morbidity and mortality. This study identifies infection patterns in PAD patients and analyzes predictors of bronchiectasis presence at PAD diagnosis (BPAD), aiming to facilitate early diagnosis and improve prognosis.

Methods: Using fully monitored data on PAD patients without identified genetic origin from the ESID Registry, infection types and pathogens across PADs were compared (chi-square analysis) and predictive factors for BPAD were identified (generalized mixed-effects logistic regression). Additionally, five machine learning classifiers (logistic regression, (bagged) decision tree, random forest and support vector machines) were trained and evaluated by area under the receiver operating characteristics curve (ROC-AUC), confusion matrices and F1-score.

Results: Recurrent respiratory infections were predominant in our cohort of 861 patients from 11 centers. Cultures were conducted in only 5.9-12.3% of infections. Encapsulated bacteria were most frequently isolated. The number of organ systems affected by recurrent infections, occurrence of specific serious bacterial infections, number of identified encapsulated bacteria and common variable immunodeficiency disorders (CVID) diagnosis were predictive of BPAD. Machine learning models achieved moderate discrimination (ROC-AUC range 0.679-0.746).

Discussion: This study highlights the predominance of recurrent and encapsulated bacterial respiratory tract infections in PAD and the underutilization of microbiological cultures. Generalized mixed-effects logistic regression best predicted BPAD. Clinicians should consider immunologic evaluation in patients presenting with serious bacterial infections, multi-system recurrent infections or the repeated isolation of encapsulated bacteria in unusually severe or recurrent infections.

Purpose: Long COVID (LC) is a long-term debilitating disease of which the exact pathophysiology is unknown. A dysregulated immune response resulting in hyperresponsive immune cells is hypothesized as a key mechanism in the development of LC. Several studies suggest that acute infections can leave lasting epigenetic changes, which result in heightened immune reactivity. Upon stimulation, these primed immune cells may exhibit exaggerated responses. This form of epigenetic memory can contribute to altered immune dynamics, particularly in response to induction of type I Interferons (IFN-I) pathway activation using a viral mimic. Therefore, we investigated if LC patients exhibit a hyperresponsive response towards viral mimics in comparison with healthy controls (HC).

Methods: PBMCs of two distinct LC cohorts, characterized by a different disease course and duration, were collected and transfected using Lyovec with the cGAS and RIG-I agonists G3-YSD and 3p-RNA followed by measurement of IFN-I bioactivity with a reporter cell line.

Results: Transfection of PBMCs of LC patients with the cGAS and RIG-I agonists resulted in increased IFN-I bioactivity in comparison with HC. Unsupervised hierarchical clustering revealed two distinct clusters, each predominantly composed of either patients or HC. In addition, a moderate correlation between RIG-I stimulation with 3p-RNA and fatigue severity scores was found.

Conclusion: These data show a hyperresponsive phenotype of immune cells of LC patients upon stimulation with viral mimics. The current availability of biologicals and small molecule inhibitors that interfere with aberrant IFN-I pathway activation underscores the importance of pursuing future investigations into this phenomenon.