Helper T cell immunity in humans with inherited CD4 deficiency

CD4+ T cells are vital for host defense and immune regulation. However, the fundamental role of CD4 itself remains enigmatic. We report seven patients aged 5-61 years from five families of four ancestries with autosomal recessive CD4 deficiency and a range of infections, including recalcitrant warts and Whipple's disease. All patients are homozygous for rare deleterious CD4 variants impacting expression of the canonical CD4 isoform. A shorter expressed isoform that interacts with LCK, but not HLA class II, is affected by only one variant. All patients lack CD4+ T cells and have increased numbers of TCRαβ+CD4-CD8- T cells, which phenotypically and transcriptionally resemble conventional Th cells. Finally, patient CD4-CD8- αβ T cells exhibit intact responses to HLA class II-restricted antigens and promote B cell differentiation in vitro. Thus, compensatory development of Th cells enables patients with inherited CD4 deficiency to acquire effective cellular and humoral immunity against an unexpectedly large range of pathogens. Nevertheless, CD4 is indispensable for protective immunity against at least human papillomaviruses and Trophyrema whipplei.

FLT3L governs the development of partially overlapping hematopoietic lineages in humans and mice

FMS-related tyrosine kinase 3 ligand (FLT3L), encoded by FLT3LG, is a hematopoietic factor essential for the development of natural killer (NK) cells, B cells, and dendritic cells (DCs) in mice. We describe three humans homozygous for a loss-of-function FLT3LG variant with a history of various recurrent infections, including severe cutaneous warts. The patients' bone marrow (BM) was hypoplastic, with low levels of hematopoietic progenitors, particularly myeloid and B cell precursors. Counts of B cells, monocytes, and DCs were low in the patients' blood, whereas the other blood subsets, including NK cells, were affected only moderately, if at all. The patients had normal counts of Langerhans cells (LCs) and dermal macrophages in the skin but lacked dermal DCs. Thus, FLT3L is required for B cell and DC development in mice and humans. However, unlike its murine counterpart, human FLT3L is required for the development of monocytes but not NK cells.

Effect of internal phase particle size on properties of site mixed emulsion explosive at plateau environment

To study the effect of internal particle size on the microstructure properties and thermal decomposition characteristics of site mixed emulsion explosive at different altitudes. Site mixed emulsion explosive was prepared with different shear rate. The particle size, viscosity, sensitized bubbles, detonation velocity and peak pressure of the emulsion explosive were tested after stored at different simulated altitudes. The thermal decomposition characteristics of emulsion matrix prepared at three different rotational speeds were measured by thermogravimetric analyzer and kinetic analysis was performed by non-isothermal model Kissinger-Akah-Sunose (KAS) method. The results show that with the increase in altitude, the internal phase size showed a trend of first increasing and then decreasing, and the number of sensitized bubbles within the emulsion explosive decreases. At an altitude of 0 m, the detonation velocity and peak overpressure of the emulsion explosive prepared by 1600 r min-1 increased 4.78% and 29.09%, respectively compared with 1200 r min-1, and at an altitude of 4500 m, the detonation velocity increased 11.87%, the peak overpressure increased 43.98%. The thermal decomposition activation energy of the emulsion matrix at 1600 r min-1 increased 13.14% compared to 1200 r min-1. It shows that in the production of site mixed emulsion explosive at high altitude, reducing the particle size of the internal phase of emulsion explosives in a certain range can effectively improve the performance of emulsion explosives.

Role of IL-27 in Epstein-Barr virus infection revealed by IL-27RA deficiency

Epstein-Barr virus (EBV) infection can engender severe B cell lymphoproliferative diseases1,2. The primary infection is often asymptomatic or causes infectious mononucleosis (IM), a self-limiting lymphoproliferative disorder3. Selective vulnerability to EBV has been reported in association with inherited mutations impairing T cell immunity to EBV4. Here we report biallelic loss-of-function variants in IL27RA that underlie an acute and severe primary EBV infection with a nevertheless favourable outcome requiring a minimal treatment. One mutant allele (rs201107107) was enriched in the Finnish population (minor allele frequency = 0.0068) and carried a high risk of severe infectious mononucleosis when homozygous. IL27RA encodes the IL-27 receptor alpha subunit5,6. In the absence of IL-27RA, phosphorylation of STAT1 and STAT3 by IL-27 is abolished in T cells. In in vitro studies, IL-27 exerts a synergistic effect on T-cell-receptor-dependent T cell proliferation7 that is deficient in cells from the patients, leading to impaired expansion of potent anti-EBV effector cytotoxic CD8+ T cells. IL-27 is produced by EBV-infected B lymphocytes and an IL-27RA-IL-27 autocrine loop is required for the maintenance of EBV-transformed B cells. This potentially explains the eventual favourable outcome of the EBV-induced viral disease in patients with IL-27RA deficiency. Furthermore, we identified neutralizing anti-IL-27 autoantibodies in most individuals who developed sporadic infectious mononucleosis and chronic EBV infection. These results demonstrate the critical role of IL-27RA-IL-27 in immunity to EBV, but also the hijacking of this defence by EBV to promote the expansion of infected transformed B cells.

The trajectory of human B-cell function, immune deficiency, and allergy revealed by inborn errors of immunity

The essential role of B cells is to produce protective immunoglobulins (Ig) that recognize, neutralize, and clear invading pathogens. This results from the integration of signals provided by pathogens or vaccines and the stimulatory microenvironment within sites of immune activation, such as secondary lymphoid tissues, that drive mature B cells to differentiate into memory B cells and antibody (Ab)-secreting plasma cells. In this context, B cells undergo several molecular events including Ig class switching and somatic hypermutation that results in the production of high-affinity Ag-specific Abs of different classes, enabling effective pathogen neutralization and long-lived humoral immunity. However, perturbations to these key signaling pathways underpin immune dyscrasias including immune deficiency and autoimmunity or allergy. Inborn errors of immunity that disrupt critical immune pathways have identified non-redundant requirements for eliciting and maintaining humoral immune memory but concomitantly prevent immune dysregulation. Here, we will discuss our studies on human B cells, and how our investigation of cytokine signaling in B cells have identified fundamental requirements for memory B-cell formation, Ab production as well as regulating Ig class switching in the context of protective versus allergic immune responses.

A Novel Heterozygous Variant in AICDA Impairs Ig Class Switching and Somatic Hypermutation in Human B Cells and is Associated with Autosomal Dominant HIGM2 Syndrome

B cells and their secreted antibodies are fundamental for host-defense against pathogens. The generation of high-affinity class switched antibodies results from both somatic hypermutation (SHM) of the immunoglobulin (Ig) variable region genes of the B-cell receptor and class switch recombination (CSR) which alters the Ig heavy chain constant region. Both of these processes are initiated by the enzyme activation-induced cytidine deaminase (AID), encoded by AICDA. Deleterious variants in AICDA are causal of hyper-IgM syndrome type 2 (HIGM2), a B-cell intrinsic primary immunodeficiency characterised by recurrent infections and low serum IgG and IgA levels. Biallelic variants affecting exons 2, 3 or 4 of AICDA have been identified that impair both CSR and SHM in patients with autosomal recessive HIGM2. Interestingly, B cells from patients with autosomal dominant HIGM2, caused by heterozygous variants (V186X, R190X) located in AICDA exon 5 encoding the nuclear export signal (NES) domain, show abolished CSR but variable SHM. We herein report the immunological and functional phenotype of two related patients presenting with common variable immunodeficiency who were found to have a novel heterozygous variant in AICDA (L189X). This variant led to a truncated AID protein lacking the last 10 amino acids of the NES at the C-terminal domain. Interestingly, patients' B cells carrying the L189X variant exhibited not only greatly impaired CSR but also SHM in vivo, as well as CSR and production of IgG and IgA in vitro. Our findings demonstrate that the NES domain of AID can be essential for SHM, as well as for CSR, thereby refining the correlation between AICDA genotype and SHM phenotype as well as broadening our understanding of the pathophysiology of HIGM disorders.

[Clinical characteristics and associated factors of mild cognitive impairment in patients with common cardiovascular diseases]

Objective: To analyze the clinical characteristics of patients with common cardiovascular diseases (CVD, including hypertension, coronary heart disease, atrial fibrillation, and heart failure) combined with mild cognitive impairment (MCI) and explore the potential risk factors of MCI in patients with CVD. Methods: A total of 2 294 patients with common cardiovascular diseases who met the criteria at Cardiology Medical Center in Beijing Anzhen Hospital, Capital Medical University, from June 1, 2021, to January 5, 2022, were retrospectively included. The patients were divided into the normal cognitive function group (1 107 cases) and the MCI group (1 187 cases). Demographic information and CVD status were collected. The information of cognitive function were collected using the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE) scales. The difference between normal cognitive function and MCI were compared and analyzed. The logistic regression analysis was used to explored risk factors of MCI in CVD patients. Results: A total of 2 294 patients aged (60.6±10.4) years were included, among whom there were 29.99% (688 cases) females. Compared with patients in the normal cognitive function group, patients in the MCI group were older [ (57.9±11.4) vs (63.1±8.9) years old, P<0.001], with a higher proportion of women [26.47% (293 cases) vs 33.28% (395 cases), P<0.001]; there was a higher proportion of patients suffering from hypertension in the MCI group [59.62% (660 cases) vs 64.62% (767 cases), P=0.014］, and more components of CVD [(1.68±0.62) vs (1.74±0.65) components, P=0.017]. The risk factors of MCI in patients with common CVD were increased age, increased depression score, combined with hypertension, and ≥3 common components of CVD, with OR (95%CI) of 1.043 (1.032-1.054), 1.021 (1.004-1.037), 1.151 (1.142-3.439), and 1.137 (1.023-1.797), respectively (all P values <0.05). Increasing education level was observed to be associated with reduced risk of MCI with OR (95%CI) of 0.319 (0.271-0.378) (P<0.05). Conclusions: The incidence of MCI was high in CVD patients. The risk factors of MCI in CVD patients included hypertension and≥3 common components of CVD.

Filaggrin-Associated Atopic Skin, Eye, Airways, and Gut Disease, Modifying the Presentation of X-Linked Reticular Pigmentary Disorder (XLPDR)

BACKGROUND

X-linked reticular pigmentary disorder (XLPDR) is a rare condition characterized by skin hyperpigmentation, ectodermal features, multiorgan inflammation, and recurrent infections. All probands identified to date share the same intronic hemizygous POLA1 hypomorphic variant (NM_001330360.2(POLA1):c.1393-354A > G) on the X chromosome. Previous studies have supported excessive type 1 interferon (IFN) inflammation and natural killer (NK) cell dysfunction in disease pathogenesis. Common null polymorphisms in filaggrin (FLG) gene underlie ichthyosis vulgaris and atopic predisposition.

CASE

A 9-year-old boy born to non-consanguineous parents developed eczema with reticular skin hyperpigmentation in early infancy. He suffered recurrent chest infections with chronic cough, clubbing, and asthma, moderate allergic rhinoconjunctivitis with keratitis, multiple food allergies, and vomiting with growth failure. Imaging demonstrated bronchiectasis, while gastroscopy identified chronic eosinophilic gastroduodenitis. Interestingly, growth failure and bronchiectasis improved over time without specific treatment.

METHODS

Whole-genome sequencing (WGS) using Illumina short-read sequencing was followed by both manual and orthogonal automated bioinformatic analyses for single-nucleotide variants, small insertions/deletions (indels), and larger copy number variations. NK cell cytotoxic function was assessed using 51Cr release and degranulation assays. The presence of an interferon signature was investigated using a panel of six interferon-stimulated genes (ISGs) by QPCR.

RESULTS

WGS identified a de novo hemizygous intronic variant in POLA1 (NM_001330360.2(POLA1):c.1393-354A > G) giving a diagnosis of XLPDR, as well as a heterozygous nonsense FLG variant (NM_002016.2(FLG):c.441del, NP_0020.1:p.(Arg151Glyfs*43)). Compared to healthy controls, the IFN signature was elevated although the degree moderated over time with the improvement in his chest disease. NK cell functional studies showed normal cytotoxicity and degranulation.

CONCLUSION

This patient had multiple atopic manifestations affecting eye, skin, chest, and gut, complicating the presentation of XLPDR. This highlights that common FLG polymorphisms should always be considered when assessing genotype-phenotype correlations of other genetic variation in patients with atopic symptoms. Additionally, while the patient exhibited an enhanced IFN signature, he does not have an NK cell defect, suggesting this may not be a constant feature of XLPDR.

Isolated Chronic Mucocutaneous Candidiasis due to a Novel Duplication Variant of IL17RC

PURPOSE

Inborn errors of the IL-17A/F-responsive pathway lead to chronic mucocutaneous candidiasis (CMC) as a predominant clinical phenotype, without other significant clinical manifestations apart from mucocutaneous staphylococcal diseases. Among inborn errors affecting IL-17-dependent immunity, autosomal recessive (AR) IL-17RC deficiency is a rare disease with only three kindreds described to date. The lack of an in vitro functional evaluation system of IL17RC variants renders its diagnosis difficult. We sought to characterize a 7-year-old Japanese girl with CMC carrying a novel homozygous duplication variant of IL17RC and establish a simple in vitro system to evaluate the impact of this variant.

METHODS

Flow cytometry, qPCR, RNA-sequencing, and immunoblotting were conducted, and an IL17RC-knockout cell line was established for functional evaluation.

RESULTS

The patient presented with oral and mucocutaneous candidiasis without staphylococcal diseases since the age of 3 months. Genetic analysis showed that the novel duplication variant (Chr3: 9,971,476-9,971,606 dup (+131bp)) involving exon 13 of IL17RC results in a premature stop codon (p.D457Afs*16 or p.D457Afs*17). Our functional evaluation system revealed this duplication to be loss-of-function and enabled discrimination between loss-of-function and neutral IL17RC variants. The lack of response to IL-17A by the patient's SV40-immortalized fibroblasts was restored by introducing WT-IL17RC, suggesting that the genotype identified is responsible for her clinical phenotype.

CONCLUSIONS

The clinical and cellular phenotype of the current case of AR IL-17RC deficiency supports a previous report on this rare disorder. Our newly established evaluation system will be useful for the diagnosis of AR IL-17RC deficiency, providing accurate validation of unknown IL17RC variants.

[Association between atrial fibrillation reoccurrence and new-onset ischemic stroke among patients with nonvalvular atrial fibrillation]

Objective: Explore the association between atrial fibrillation (AF) reoccurrence and new-onset ischemic stroke (IS) in patients with nonvalvular AF, and explore whether there is a high-risk period of IS after recurrent episodes of AF. Methods: A nested case-control study design was used. A total of 565 nonvalvular AF patients with new-onset IS after a follow-up of at least 2 years in the China-AF cohort were enrolled as the case group, and 1 693 nonvalvular AF patients without new-onset IS were matched as the control group at a ratio of 1∶3. Frequency and types of recurrent AF in the previous 1 or 2 years were compared between two groups, and the adjusted associations of AF reoccurrence with new onset IS were explored using conditional logistic regression analysis. The proportion of recurrent AF was compared between the case period and control period, and conditional logistic regression analysis was performed to calculate adjusted associations of case-period AF with IS. Results: The nested case-control study design results showed that the proportion of at least one record of recurrent AF in the previous 1 year was higher in the case group than in the control group (72.0% vs. 60.8%, P<0.05), and the recurrent AF was positively correlated with new-onset IS (adjusted OR=1.80, P<0.001). Similar results were also observed in the previous 2 years period. The case-crossover study design analysis showed that among 565 patients with new-onset IS, recurrent AF in the case period was positively correlated with IS (adjusted OR=1.61, P=0.003). Conclusion: Recurrent AF is associated with IS, and there may be a high-risk period of IS after recurrent episodes of AF.

Isolated chronic mucocutaneous candidiasis due to a novel duplication variant of IL17RC

Purpose

Inborn errors of the IL-17A/F-responsive pathway lead to chronic mucocutaneous candidiasis (CMC) as a predominant clinical phenotype, without other significant clinical manifestations apart from mucocutaneous staphylococcal diseases. Amongst inborn errors affecting IL-17-dependent immunity, autosomal recessive (AR) IL-17RC deficiency is a rare disease with only three kindreds described to date. The lack of an in vitro functional evaluation system of IL17RC variants renders its diagnosis difficult. We sought to characterize a seven-year-old Japanese girl with CMC carrying a novel homozygous duplication variant of IL17RC and establish a simple in vitro system to evaluate the impact of this variant.

Methods

Flow cytometry, qPCR, RNA-sequencing, and immunoblotting were conducted, and an IL17RC-knockout cell line was established for functional evaluation.

Results

The patient presented with oral and mucocutaneous candidiasis without staphylococcal diseases since the age of three months. Genetic analysis showed that the novel duplication variant (Chr3: 9,971,476-9,971,606 dup (+ 131bp)) involving exon 13 of IL17RC results in a premature stop codon (p.D457Afs*16 or p.D457Afs*17). Our functional evaluation system revealed this duplication to be loss-of-function and enabled discrimination between loss-of-function and neutral IL17RC variants. The lack of response to IL-17A by the patient's SV40-immortalized fibroblasts was restored by introducing WT-IL17RC, suggesting that the genotype identified is responsible for her clinical phenotype.

Conclusions

The clinical and cellular phenotype of the current case of AR IL-17RC deficiency supports a previous report on this rare disorder. Our newly established evaluation system will be useful for diagnosis of AR IL-17RC deficiency, providing accurate validation of unknown IL17RC variants.

[Analysis of factors associated with anxiety in patients with atrial fibrillation and their caregivers]

Objective: To explore the risk factors of anxiety in patients with atrial fibrillation and their caregivers. Methods: From September 2020 to March 2021, patients with atrial fibrillation and one primary family member as caregiver of each patient from Beijing Anzhen Hospital were enrolled. Basic data of patients and their caregivers were collected, and anxiety of patients and caregivers were evaluated by Generalized Anxiety Disorder-7 scale (GAD-7). A total of 374 patients with atrial fibrillation and their caregivers were included in this study. Multivariate logistic regression analysis was used to analyze the risk factors of anxiety of patients and their caregivers. Results: The mean age of the patients was (58.3±10.6) years, and 124 (33.2%) were female. The caregivers were (53.6±11.6) years old, and 247 (66%) were female. 69 (18.4%) patients and 38 (10.2%) caregivers had mild anxiety (GAD-7:5-9 scores), 13 (3.5%) patients and 9 (2.4%) caregivers had moderate or higher anxiety (GAD-7:10-21 scores). Multivariate analysis showed that the risk factors of anxiety in patients with atrial fibrillation included EHRA score≥3 (OR=1.73,95%CI:1.03-2.89,P=0.039) and female sex (OR=1.90,95%CI:1.06-3.40,P=0.032). EHRA score of patients≥3 (OR=2.11,95%CI:1.05-4.24, P=0.036) or anxiety of patients (OR=2.76,95%CI:1.36-5.60,P=0.005) were associated with higher anxiety of caregivers. Moreover, age of≥65 years old (OR=3.97,95%CI:1.68-9.38,P=0.002), female sex (OR=3.83,95%CI:1.64-8.93,P=0.002) and number of comorbidities of caregivers≥2 (OR=2.57,95%CI:1.03-6.41,P=0.043) were also associated with anxiety of caregivers. Conclusions: Patients with severe symptoms have a higher proportion of anxiety, and their caregivers are more likely to experience anxiety. Anxiety rate is higher in caregivers of patients with anxiety.

Inborn errors of human B cell development, differentiation, and function

B cells develop from hematopoietic stem cells in the bone marrow. Once generated, they serve multiple roles in immune regulation and host defense. However, their most important function is producing antibodies (Ab) that efficiently clear invading pathogens. This is achieved by generating memory B cells that rapidly respond to subsequent Ag exposure, and plasma cells (PCs) that continually secrete Ab. These B cell subsets maintain humoral immunity and host protection against recurrent infections for extended periods of time. Thus, the generation of antigen (Ag)-specific memory cells and PCs underlies long-lived serological immunity, contributing to the success of most vaccines. Our understanding of immunity is often derived from animal models. However, analysis of individuals with monogenic defects that disrupt immune cell function are unprecedented models to link genotypes to clinical phenotypes, establish mechanisms of disease pathogenesis, and elucidate critical pathways for immune cell development and differentiation. Here, we review fundamental breakthroughs in unraveling the complexities of humoral immunity in humans that have come from the discovery of inborn errors disrupting B cell function.

[Analysis of dyslipidemia management status in atrial fibrillation patients with very high and high risk of atherosclerotic cardiovascular disease]

Objective: To analyze the status of statins use and low-density lipoprotein cholesterol (LDL-C) management in patients with atrial fibrillation (AF) and very high/high risk of atherosclerotic cardiovascular disease (ASCVD) from Chinese Atrial Fibrillation Registry (CAFR). Methods: A total of 9 119 patients with AF were recruited in CAFR between January 1, 2015 to December 31, 2018, patients at very high and high risk of ASCVD were included in this study. Demographics, medical history, cardiovascular risk factors, and laboratory test results were collected. In patients with very high-risk, a threshold of 1.8 mmol/L was used as LDL-C management target and in patients with high risk, a threshold of 2.6 mmol/L was used as LDL-C management target. Statins use and LDL-C compliance rate were analyzed, multiple regression analysis was performed to explore the influencing factors of statins use. Results: 3 833 patients were selected (1 912 (21.0%) in very high risk of ASCVD group and 1 921 (21.1%) in high risk of ASCVD group). The proportion of patients with very high and high risk of ASCVD taking statins was 60.2% (1 151/1 912) and 38.6% (741/1 921), respectively. Attainment rate of LDL-C management target in patients with very high and high risk were 26.7% (511/1 912) and 36.4% (700/1 921), respectively. Conclusion: The proportion of statins use and attainment rate of LDL-C management target are low in AF patients with very high and high risk of ASCVD in this cohort. The comprehensive management in AF patients should be further strengthened, especially the primary prevention of cardiovascular disease in AF patients with very high and high risk of ASCVD.

Human PIK3R1 mutations disrupt lymphocyte differentiation to cause activated PI3Kδ syndrome 2

Heterozygous loss-of-function (LOF) mutations in PIK3R1 (encoding phosphatidylinositol 3-kinase [PI3K] regulatory subunits) cause activated PI3Kδ syndrome 2 (APDS2), which has a similar clinical profile to APDS1, caused by heterozygous gain-of-function (GOF) mutations in PIK3CD (encoding the PI3K p110δ catalytic subunit). While several studies have established how PIK3CD GOF leads to immune dysregulation, less is known about how PIK3R1 LOF mutations alter cellular function. By studying a novel CRISPR/Cas9 mouse model and patients' immune cells, we determined how PIK3R1 LOF alters cellular function. We observed some overlap in cellular defects in APDS1 and APDS2, including decreased intrinsic B cell class switching and defective Tfh cell function. However, we also identified unique APDS2 phenotypes including defective expansion and affinity maturation of Pik3r1 LOF B cells following immunization, and decreased survival of Pik3r1 LOF pups. Further, we observed clear differences in the way Pik3r1 LOF and Pik3cd GOF altered signaling. Together these results demonstrate crucial differences between these two genetic etiologies.

Inborn Errors of Immunity: A Role for Functional Testing and Flow Cytometry in Aiding Clinical Diagnosis

With the exponential discovery of new inborn errors of immunity (IEI), it is becoming increasingly difficult to differentiate between a number of the more recently defined disorders. This is compounded by the fact that although IEI primarily present with immunodeficiency, the spectrum of disease is broad and often extends to features typical of autoimmunity, autoinflammation, atopic disease, and/or malignancy. Here we use case studies to discuss the laboratory and genetic tests used that ultimately led to the specific diagnoses.

[Current use of oral anticoagulation therapy and influencing factors among coronary artery disease patients with nonvalvular atrial fibrillation in China]

Objective: To investigate current use of oral anticoagulant (OAC) therapy and influencing factors among coronary artery disease (CAD) patients with nonvalvular atrial fibrillation (NVAF) in China. Methods: Results of this study derived from "China Atrial Fibrillation Registry Study", the study prospectively enrolled atrial fibrillation (AF) patients from 31 hospitals, and patients with valvular AF or treated with catheter ablation were excluded. Baseline data such as age, sex and type of atrial fibrillation were collected, and drug history, history of concomitant diseases, laboratory results and echocardiography results were recorded. CHA₂DS₂-VASc score and HAS-BLED score were calculated. The patients were followed up at the 3rd and 6th months after enrollment and every 6 months thereafter. Patients were divided according to whether they had coronary artery disease and whether they took OAC. Results: 11 067 NVAF patients fulfilling guideline criteria for OAC treatment were included in this study, including 1 837 patients with CAD. 95.4% of NVAF patients with CAD had CHA₂DS₂-VASc score≥2, and 59.7% of patients had HAS-BLED≥3, which was significantly higher than NVAF patients without CAD (P<0.001). Only 34.6% of NVAF patients with CAD were treated with OAC at enrollment. The proportion of HAS-BLED≥3 in the OAC group was significantly lower than in the no-OAC group (36.7% vs. 71.8%, P<0.001). After adjustment with multivariable logistic regression analysis, thromboembolism(OR=2.48,95%CI 1.50-4.10,P<0.001), left atrial diameter≥40 mm(OR=1.89,95%CI 1.23-2.91,P=0.004), stain use (OR=1.83,95%CI 1.01-3.03, P=0.020) and β blocker use (OR=1.74,95%CI 1.13-2.68,P=0.012)were influence factors of OAC treatment. However, the influence factors of no-OAC use were female(OR=0.54,95%CI 0.34-0.86,P=0.001), HAS-BLED≥3 (OR=0.33,95%CI 0.19-0.57,P<0.001), and antiplatelet drug(OR=0.04,95%CI 0.03-0.07,P<0.001). Conclusion: The rate of OAC treatment in NVAF patients with CAD is still low and needs to be further improved. The training and assessment of medical personnel should be strengthened to improve the utilization rate of OAC in these patients.

The ups and downs of STAT3 function: too much, too little and human immune dysregulation

The STAT3 story has almost 30 years of evolving history. First identified in 1994 as a pro-inflammatory transcription factor, Signal Transducer and Activator of Transcription 3 (STAT3) has continued to be revealed as a quintessential pleiotropic signalling module spanning fields including infectious diseases, autoimmunity, vaccine responses, metabolism, and malignancy. In 2007, germline heterozygous dominant-negative loss-of-function variants in STAT3 were discovered as the most common cause for a triad of eczematoid dermatitis with recurrent skin and pulmonary infections, first described in 1966. This finding established that STAT3 plays a critical non-redundant role in immunity against some pathogens, as well as in the connective tissue, dental and musculoskeletal systems. Several years later, in 2014, heterozygous activating gain of function germline STAT3 variants were found to be causal for cases of early-onset multiorgan autoimmunity, thereby underpinning the notion that STAT3 function needed to be regulated to maintain immune homeostasis. As we and others continue to interrogate biochemical and cellular perturbations due to inborn errors in STAT3, we will review our current understanding of STAT3 function, mechanisms of disease pathogenesis, and future directions in this dynamic field.

[Chinese consensus on the use of antiarrhythmic drugs for rhythm control in atrial fibrillation]

Rhythm control is crucial part of comprehensive management of atrial fibrillation (AF). Rhythm control can reduce the burden of AF effectively, reduce symptoms, and improve the prognosis in early AF. Antiarrhythmic drugs (AADs) are the first-line treatment for rhythm-control strategies. This consensus focuses on the principle of rhythm control in AF, the characteristics of AADs, and the medication recommendations for patients in different populations suffering from AF. Hence, this consensus aims to support clinical decision-making for AF therapy.

T-helper-2 cells and atopic disease: lessons learnt from inborn errors of immunity

Inborn errors of immunity (IEI) are caused by monogenic variants that affect the host response to bacterial, viral, and fungal pathogens. As such, individuals with IEI often present with severe, recurrent, and life-threatening infections. However, the spectrum of disease due to IEI is very broad and extends to include autoimmunity, malignancy, and atopic diseases such as eczema, atopic dermatitis, and food and environmental allergies. Here, I review IEI that affect cytokine signaling pathways that dysregulate CD4⁺ T-cell differentiation, resulting in increased T-helper-2 (Th2) cell development, function, and pathogenicity. These are elegant examples of how rare IEI can provide unique insights into more common pathologies such as allergic disease that are impacting the general population at increased frequency.

Cytokine-mediated STAT-dependent pathways underpinning human B-cell differentiation and function

B cells are fundamental to host defence against infectious diseases; indeed, the ability of humans to elicit robust antibody responses following exposure to foreign antigens underpins long-lived humoral immunity and serological memory, as well as the success of most currently administered vaccines. However, B cells also have a dark side - they can cause myriad diseases, including autoimmunity, atopy, allergy and malignancy. Thus, it is critical to understand the molecular requirements for generating effective, high-affinity, specific immune responses following natural infection or vaccination, as well as for constraining B-cell function to mitigate B-cell-mediated immune dyscrasias. In this review, we discuss recent developments that have been derived from the identification and detailed analysis of individuals with inborn errors of immunity that disrupt cytokine signalling, resulting in immune dysregulatory conditions. These studies have defined fundamental cytokine/cytokine receptor/signal transducer and activator of transcription (STAT) signalling pathways that are critical for the generation and maintenance of human memory B-cell and plasma cell subsets during host defence, as well as revealed mechanisms of disease pathogenesis causing immune deficiency, autoimmunity and atopy. More importantly, these studies have identified molecules that could be targeted to either enhance humoral immunity in the settings of infection or vaccination, or attenuate humoral immunity that contributes to antibody-mediated autoimmunity or allergy.

Human IL-23 is essential for IFN-γ-dependent immunity to mycobacteria

Patients with autosomal recessive (AR) IL-12p40 or IL-12Rβ1 deficiency display Mendelian susceptibility to mycobacterial disease (MSMD) due to impaired IFN-γ production and, less commonly, chronic mucocutaneous candidiasis (CMC) due to impaired IL-17A/F production. We report six patients from four kindreds with AR IL-23R deficiency. These patients are homozygous for one of four different loss-of-function IL23R variants. All six patients have a history of MSMD, but only two suffered from CMC. We show that IL-23 induces IL-17A only in MAIT cells, possibly contributing to the incomplete penetrance of CMC in patients unresponsive to IL-23. By contrast, IL-23 is required for both baseline and Mycobacterium-inducible IFN-γ immunity in both Vδ2⁺ γδ T and MAIT cells, probably contributing to the higher penetrance of MSMD in these patients. Human IL-23 appears to contribute to IL-17A/F-dependent immunity to Candida in a single lymphocyte subset but is required for IFN-γ-dependent immunity to Mycobacterium in at least two lymphocyte subsets.

Human IRF1 governs macrophagic IFN-γ immunity to mycobacteria

Inborn errors of human IFN-γ-dependent macrophagic immunity underlie mycobacterial diseases, whereas inborn errors of IFN-α/β-dependent intrinsic immunity underlie viral diseases. Both types of IFNs induce the transcription factor IRF1. We describe unrelated children with inherited complete IRF1 deficiency and early-onset, multiple, life-threatening diseases caused by weakly virulent mycobacteria and related intramacrophagic pathogens. These children have no history of severe viral disease, despite exposure to many viruses, including SARS-CoV-2, which is life-threatening in individuals with impaired IFN-α/β immunity. In leukocytes or fibroblasts stimulated in vitro, IRF1-dependent responses to IFN-γ are, both quantitatively and qualitatively, much stronger than those to IFN-α/β. Moreover, IRF1-deficient mononuclear phagocytes do not control mycobacteria and related pathogens normally when stimulated with IFN-γ. By contrast, IFN-α/β-dependent intrinsic immunity to nine viruses, including SARS-CoV-2, is almost normal in IRF1-deficient fibroblasts. Human IRF1 is essential for IFN-γ-dependent macrophagic immunity to mycobacteria, but largely redundant for IFN-α/β-dependent antiviral immunity.

The efficacy and safety of pulsed-field ablation in para-Hisian paroxysmal supraventricular tachycardia: first-in-human pilot trial

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): National Key Research and Development Program of China

Background

Para-Hisian paroxysmal supraventricular tachycardia (PSVT) is associated with a higher risk of atrioventricular block due to proximity of the His bundle during catheter ablation. Pulsed-field ablation (PFA) with high tissue selectivity may be a promising technique for catheter ablation in patients with para-Hisian PSVT.

Purpose

This study aimed to evaluate the efficacy and safety of PFA for para-Hisian PSVT.

Methods

This investigator-initiated, single-center, single-arm, prospective study was the first in-human pilot phase to evaluate the efficacy and safety of a novel PFA system in patients with PSVT. Patients diagnosed with para-Hisian PSVT via electrophysiological examination were included and treated with PFA. The primary outcome was the ability to achieve acute ablation success. The secondary outcome was ablation success and safety after 3 months.

Results

A total of seven patients with a mean age of 49.4±13.1 years were included and underwent PFA. Acute ablation success was achieved in all seven patients. The skin-to-skin procedure time was 135.0±17.7 minutes, fluoroscopy time was 4.3±1.6 minutes, and the number of PFA applications was 7±1.6. No adverse events occurred in any patient during the ablation or during the 3-month follow-up.

Conclusion

PFA had favorable efficacy and safety in para-Hisian PSVT patients and can help minimize the risk of inadvertent atrioventricular block during ablation. PFA may be a favorable treatment choice for patients with para-Hisian PSVT.

[The timing of pericardial drainage catheter removal and restart of the anticoagulation in patients suffered from perioperative pericardial tamponade during atrial fibrillation catheter ablation and uninterrupted dabigatran: Experiences from 20 cases]

Objective: To investigate the timing of pericardial drainage catheter removal and restart of the anticoagulation in patients with atrial fibrillation (AF) suffered from perioperative pericardial tamponade during atrial fibrillation catheter ablation and uninterrupted dabigatran. Methods: A total of 20 patients with pericardial tamponade, who underwent AF catheter ablation with uninterrupted dabigatran in Beijing Anzhen Hospital from January 2019 to August 2021, were included in this retrospective analysis. The clinical characteristics of enrolled patients, information of catheter ablation procedures, pericardial tamponade management, perioperative complications, the timing of pericardial drainage catheter removal and restart of anticoagulation were analyzed. Results: All patients underwent pericardiocentesis and pericardial effusion drainage was successful in all patients. The average drainage volume was (427.8±527.4) ml. Seven cases were treated with idarucizumab, of which 1 patient received surgical repair. The average timing of pericardial drainage catheter removal and restart of anticoagulation in 19 patients without surgical repair was (1.4±0.7) and (0.8±0.4) days, respectively. No new bleeding, embolism and death were reported during hospitalization and within 30 days following hospital discharge. Time of removal of pericardial drainage catheter, restart of anticoagulation and hospital stay were similar between patients treated with idarucizumab or not. Conclusion: It is safe and reasonable to remove pericardial drainage catheter and restart anticoagulation as soon as possible during catheter ablation of atrial fibrillation with uninterrupted dabigatran independent of the idarucizumab use or not in case of confirmed hemostasis.

STAT3 gain-of-function mutations connect leukemia with autoimmune disease by pathological NKG2Dhi CD8+ T cell dysregulation and accumulation

The association between cancer and autoimmune disease is unexplained, exemplified by T cell large granular lymphocytic leukemia (T-LGL) where gain-of-function (GOF) somatic STAT3 mutations correlate with co-existing autoimmunity. To investigate whether these mutations are the cause or consequence of CD8⁺ T cell clonal expansions and autoimmunity, we analyzed patients and mice with germline STAT3 GOF mutations. STAT3 GOF mutations drove the accumulation of effector CD8⁺ T cell clones highly expressing NKG2D, the receptor for stress-induced MHC-class-I-related molecules. This subset also expressed genes for granzymes, perforin, interferon-γ, and Ccl5/Rantes and required NKG2D and the IL-15/IL-2 receptor IL2RB for maximal accumulation. Leukocyte-restricted STAT3 GOF was sufficient and CD8⁺ T cells were essential for lethal pathology in mice. These results demonstrate that STAT3 GOF mutations cause effector CD8⁺ T cell oligoclonal accumulation and that these rogue cells contribute to autoimmune pathology, supporting the hypothesis that somatic mutations in leukemia/lymphoma driver genes contribute to autoimmune disease.

[Efficacy and safety of radiofrequency catheter ablation of septal hypertrophy guided by intracardiac echocardiography in hypertrophic obstructive cardiomyopathy]

Nine patients identified as hypertrophic obstructive cardiomyopathy (HOCM) in Beijing Anzhen Hopspital who underwent ablation from March to July 2019 were included in the study. All patients had left ventricular outflow tract gradient (LVOTG) over 50 mmHg(1 mmHg=0.133 kPa)with significant symptoms despite not optimal drug therapy. Intracardiac echocardiography (ICE) was used to reconstruct septum and surrounding structures, and monitor the effect of ablation during procedure. Nine patients with HOCM were included,.of which 6 men and 3 women. The average age was (51.7±12.2) years. All patients underwent successful ablation after a mean of procedural time of (152.2±31.9) minutes and ablation time of (838.4±227.3) seconds. Except for one patients, all other patients had significant LVOTG reduction(P=0.001)within 50 mmHg after the procedure. Systolic anterior motion of the mitral valve disappeared in all patients after the procedure without major periprocedural complications. The LVOTG of these patients remained stable during follow-up. Radiofrequency ablation using ICE guidance is feasible in treating HOCM with promising efficacy and safety.

STAT5B restrains human B-cell differentiation to maintain humoral immune homeostasis

BACKGROUND

Lymphocyte differentiation is regulated by coordinated actions of cytokines and signaling pathways. IL-21 activates STAT1, STAT3, and STAT5 and is fundamental for the differentiation of human B cells into memory cells and antibody-secreting cells. While STAT1 is largely nonessential and STAT3 is critical for this process, the role of STAT5 is unknown.

OBJECTIVES

This study sought to delineate unique roles of STAT5 in activation and differentiation of human naive and memory B cells.

METHODS

STAT activation was assessed by phospho-flow cytometry cell sorting. Differential gene expression was determined by RNA-sequencing and quantitative PCR. The requirement for STAT5B in B-cell and CD4+ T-cell differentiation was assessed using CRISPR-mediated STAT5B deletion from B-cell lines and investigating primary lymphocytes from individuals with germline STAT5B mutations.

RESULTS

IL-21 activated STAT5 and strongly induced SOCS3 in human naive, but not memory, B cells. Deletion of STAT5B in B-cell lines diminished IL-21-mediated SOCS3 induction. PBMCs from STAT5B-null individuals contained expanded populations of immunoglobulin class-switched B cells, CD21loTbet+ B cells, and follicular T helper cells. IL-21 induced greater differentiation of STAT5B-deficient B cells into plasmablasts in vitro than B cells from healthy donors, correlating with higher expression levels of transcription factors promoting plasma cell formation.

CONCLUSIONS

These findings reveal novel roles for STAT5B in regulating IL-21-induced human B-cell differentiation. This is achieved by inducing SOCS3 to attenuate IL-21 signaling, and BCL6 to repress class switching and plasma cell generation. Thus, STAT5B is critical for restraining IL-21-mediated B-cell differentiation. These findings provide insights into mechanisms underpinning B-cell responses during primary and subsequent antigen encounter and explain autoimmunity and dysfunctional humoral immunity in STAT5B deficiency.

[A comparison of CAS risk model and CHA2DS2-VASc risk model in guiding anticoagulation treatment in Chinese patients with non-valvular atrial fibrillation]

Objective: To compare the differences between CAS risk model and CHA₂DS₂-VASc risk score in predicting all cause death, thromboembolic events, major bleeding events and composite endpoint in patients with nonvalvular atrial fibrillation. Methods: This is a retrospective cohort study. From the China Atrial Fibrillation Registry cohort study, the patients with atrial fibrillation who were>18 years old were randomly divided into CAS risk score group and CHA₂DS₂-VASc risk score group respectively. According to the anticoagulant status at baseline and follow-up, patients in the 2 groups who complied with the scoring specifications for anticoagulation were selected for inclusion in this study. Baseline information such as age and gender in the two groups were collected and compared. Follow-up was performed periodically to collect information on anticoagulant therapy and endpoints. The endpoints were all-cause death, thromboembolism events and major bleeding, the composite endpoint events were all-cause death and thromboembolism events. The incidence of endpoints in CAS group and CHA₂DS₂-VASc group was analyzed, and multivariate Cox proportional risk model was used to analyze whether the incidence of the endpoints was statistically different between the two groups. Results: A total of 5 206 patients with AF were enrolled, average aged (63.6±12.2) years, and 2092 (40.2%) women. There were 2 447 cases (47.0%) in CAS risk score group and 2 759 cases (53.0%) in CHA₂DS₂-VASc risk score group. In the clinical baseline data of the two groups, the proportion of left ventricular ejection fraction<55%, non-paroxysmal atrial fibrillation, oral warfarin and HAS BLED score in the CAS group were lower than those in the CHA₂DS₂-VASc group, while the proportion of previous diabetes history and history of antiplatelet drugs in the CAS group was higher than that in the CHA₂DS₂-VASc group, and there was no statistical difference in other baseline data. Patients were followed up for (82.8±40.8) months. In CAS risk score group, 225(9.2%) had all-cause death, 186 (7.6%) had thromboembolic events, 81(3.3%) had major bleeding, and 368 (15.0%) had composite endpoint. In CHA₂DS₂-VASc risk score group, 261(9.5%) had all-cause death 209(7.6%) had thromboembolic events, 112(4.1%) had major bleeding, and 424 (15.4%) had composite endpoint. There were no significant differences in the occurrence of all-cause death, thromboembolic events, major bleeding and composite endpoint between anticoagulation in CAS risk score group and anticoagulation in CHA₂DS₂-VASc risk score group (log-rank P =0.643, 0.904, 0.126, 0.599, respectively). Compared with CAS risk score, multivariable Cox proportional hazards regression models showed no significant differences for all-cause death, thromboembolic events, major bleeding and composite endpoint between the two groups with HR(95%CI) 0.95(0.80-1.14), 1.00(0.82-1.22), 0.83(0.62-1.10), 0.96(0.84-1.11), respectively. All P>0.05. Conclusions: There were no significant differences between CAS risk model and CHA₂DS₂-VASc risk score in predicting all-cause death, thromboembolic events, and major bleeding events in Chinese patients with non-valvular atrial fibrillation.

[Use of oral anticoagulants and related factors among new-onset acute ischemic stroke patients with nonvalvular atrial fibrillation: A report from the China Atrial Fibrillation Registry Study]

Objective: This study aimed to investigate the oral anticoagulant (OAC) usage among new-onset acute ischemic stroke (AIS) patients with nonvalvular atrial fibrillation (NVAF) in China, and to explore the possible influencing factors of influent anticoagulant therapy in these patients. Methods: The NVAF patients who experienced new-onset and non-fatal AIS from August 2011 to December 2018 in the China Atrial Fibrillation Registry (China-AF), were enrolled. The follow-up ended in December 2019. Information including patients' demographic characteristics, medical history, medication usage, which were collected before and after the index stroke, were analyzed. Patients were classified into OAC group or non-OAC group according to OAC usage within 3 months post stroke. Multivariate logistic regression analysis were conducted to calculate the odds ratios (ORs) of factors which might be associated with OAC usage within 3 months post stroke. Results: A total of 957 new-onset AIS patients were enrolled, 39.4% (377/957) patients were treated with OAC within 3 months after AIS. Covering by high-reimbursement-rate insurance (OR: 1.91, 95%CI: 1.28-2.86, P=0.002), higher number of concomitant drugs (1-2 types OR: 2.10, 95%CI: 1.36-3.23, P=0.001; ≥3 types OR: 2.31, 95%CI: 1.37-3.91, P=0.002) and 3-month-peri-stroke AF recurrence (OR: 3.34, 95%CI: 2.34-4.76, P<0.001) were associated with OAC usage within 3 months post stroke, while higher HASBLED score (OR: 0.49, 95%CI: 0.40-0.60, P<0.001) and pre-stroke antiplatelet usage (OR: 0.29, 95%CI: 0.20-0.43, P<0.001) were related to no OAC usage within 3 months post stroke. Conclusions: In China, the proportion of NVAF patients who initiated OAC therapy within 3 months after new-onset AIS is as low as about 39.4%. Factors related to the OAC usage within 3 months post stroke are 3-month-peri-stroke AF recurrence, number of concomitant drugs and patients with high-reimbursement-rate insurance coverage, but higher HASBLED score and pre-stroke antiplatelet usage are related to no OAC usage within 3 months post stroke.

Human T-bet governs the generation of a distinct subset of CD11chighCD21low B cells

High-level expression of the transcription factor T-bet characterizes a phenotypically distinct murine B cell population known as "age-associated B cells" (ABCs). T-bet-deficient mice have reduced ABCs and impaired humoral immunity. We describe a patient with inherited T-bet deficiency and largely normal humoral immunity including intact somatic hypermutation, affinity maturation and memory B cell formation in vivo, and B cell differentiation into Ig-producing plasmablasts in vitro. Nevertheless, the patient exhibited skewed class switching to IgG1, IgG4, and IgE, along with reduced IgG2, both in vivo and in vitro. Moreover, T-bet was required for the in vivo and in vitro development of a distinct subset of human B cells characterized by reduced expression of CD21 and the concomitantly high expression of CD19, CD20, CD11c, FCRL5, and T-bet, a phenotype that shares many features with murine ABCs. Mechanistically, human T-bet governed CD21^loCD11c^hi B cell differentiation by controlling the chromatin accessibility of lineage-defining genes in these cells: FAS, IL21R, SEC61B, DUSP4, DAPP1, SOX5, CD79B, and CXCR4. Thus, human T-bet is largely redundant for long-lived protective humoral immunity but is essential for the development of a distinct subset of human CD11c^hiCD21^lo B cells.

[The relationship between fasting blood glucose level and thromboembolism events in patients with non-valvular atrial fibrillation]

Objective: To explore the relationship between fasting blood glucose level and thromboembolism events in patients with non-valvular atrial fibrillation (NVAF). Methods: This was an observational study based on data from a multicenter, prospective Chinese atrial fibrillation registry cohort, which included 18 703 consecutive patients with atrial fibrillation (AF) in 31 hospitals in Beijing from August 2011 to December 2018. Patients were divided into 5 groups according to status of comorbid diabetes and fasting glucose levels at admission: normal blood glucose (normal glucose group), pre-diabetes group, strict glycemic control group, average glycemic control group and poor glycemic control group. Patients were followed up by telephone or outpatient service every 6 months. The primary follow-up endpoint was thromboembolic events, including ischemic stroke and systemic embolism. The secondary endpoint was the composite endpoint of cardiovascular death and thromboembolic events. Kaplan-Meier survival analysis and multifactorial Cox regression were used to analyze the correlation between fasting glucose levels and endpoint events. Results: The age of 18 703 patients with NVAF was (63.8±12.0) years, and there were 11 503 (61.5%) male patients. There were 11 877 patients (63.5%) in normal blood glucose group, 2 023 patients (10.8%)in pre-diabetes group, 1 131 patients (6.0%) in strict glycemic control group, 811 patients in average glycemic control group and 2 861 patients(4.3%) in poor glycemic control group. Of the 4 803 diabetic patients, 1 131 patients (23.5%) achieved strict glycemic control, of whom 328 (29.0%) were hypoglycemic (fasting blood glucose level<4.4 mmol/L at admission). During a mean follow-up of (51±23) months (up to 82 months), thromboembolic events were reported in 984 patients (5.3%). The survival curve analysis of Kaplan Meier showed that the incidence rates of thromboembolic events in normal glucose group, pre-diabetes group, strict glycemic control group, average glycemic control group and poor glycemic control group were 1.10/100, 1.41/100, 2.09/100, 1.46/100 and 1.71/100 person-years, respectively (χ²=53.0, log-rank P<0.001). The incidence rates of composite endpoint events were 1.86/100, 2.17/100, 4.08/100, 2.58/100, 3.16/100 person-years (χ²=72.3, log-rank P<0.001). The incidence of thromboembolic events and composite endpoint events in the other four groups were higher than that in the normal blood glucose group (P<0.001). Multivariate Cox regression analysis showed that compared with normal glucose group, the risk of thromboembolism increased in pre-diabetes group(HR=1.23, 95%CI 1.00-1.51, P=0.049), strict glycemic control group(HR=1.32, 95%CI 1.06-1.65, P=0.013) and poor glycemic control group(HR=1.26, 95%CI 1.01-1.58, P=0.044). Conclusion: Both high or low fasting glucose may be an independent risk factor for thromboembolic events in patients with NVAF.

[Efficacy and safety of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation and hypertrophic cardiomyopathy]

Objective: To evaluate the efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOAC) in patients with atrial fibrillation (AF) and hypertrophic cardiomyopathy (HCM). Methods: This study was a prospective cohort study. The data of this study were based on the Chinese Atrial Fibrillation Registry (CAFR) Study, which was a prospective, multicenter registry study. The CAFR Study enrolled inpatients and outpatients with AF from 31 hospitals. Patients with AF and HCM were selected from August 2011 to December 2018. The patients were divided into NOAC-treated group and warfarin-treated group. General clinical data, echocardiographic results and treatment options were collected and compared between the two groups. Patients were followed up every 6 months; outcome events included effective endpoint events(thromboembolism)and safety endpoint events(major bleeding). The incidence of endpoint events in both groups was calculated and compared. Cox proportional hazards regression models and Kaplan-Meier survival analysis were performed to determine the association between NOAC use and endpoint events. Results: A total of 393 patients were included (average age: (60.5±11.8) years, 252 men (64.1%)). There were 133 (34.0%) patients in the NOAC-treated group and 260 (66.0%) patients in the warfarin-treated group. Compared with the warfarin-treated group, the patients in the NOAC-treated group had a higher proportion of paroxysmal AF, catheter ablation of AF, a lower proportion of hypertension, ischemic stroke/transient ischemic attack (TIA), lower heart rate, lower usage rate of angiotensin-converting enzyme inhibitors(ACEI)/angiotensin receptor blockers(ARB), β-blockers, non-dihydropyridine calcium channel blockers(NDH-CCB)(P<0.05). There were no significant differences on the echocardiographic results, including interventricular septal thickness, left ventricular posterior wall thickness, left ventricular end-diastolic diameter, left atrial diameter, left ventricular ejection fraction(P>0.05). After a follow-up of 42 (24, 60)months, the incidence rates of thromboembolism were 1.63 and 2.10 events per 100 person-years for NOAC-and warfarin-treated group, and those of major bleeding were 0.66 and 1.03 events per 100 person-years. Kaplan-Meier survival analysis showed survival rates free from endpoint events were similar between NOAC-treated group and warfarin-treated group(thromboembolism-free survival comparison, P=0.476; major bleeding-free survival comparison, P=0.855). Cox multivariate regression analysis revealed that there was no significant difference on risk of thromboembolism(HR=1.21, 95%CI: 0.42-3.50, P=0.720) and major bleeding(HR=1.50, 95%CI: 0.27-8.41, P=0.642) between NOAC-treated and warfarin-treated group. Conclusion: Patients with AF and HCM can be safely and effectively treated with NOAC.

Hyper-IgE Syndrome due to an Elusive Novel Intronic Homozygous Variant in DOCK8

Rare, biallelic loss-of-function mutations in DOCK8 result in a combined immune deficiency characterized by severe and recurrent cutaneous infections, eczema, allergies, and susceptibility to malignancy, as well as impaired humoral and cellular immunity and hyper-IgE. The advent of next-generation sequencing technologies has enabled the rapid molecular diagnosis of rare monogenic diseases, including inborn errors of immunity. These advances have resulted in the implementation of gene-guided treatments, such as hematopoietic stem cell transplant for DOCK8 deficiency. However, putative disease-causing variants revealed by next-generation sequencing need rigorous validation to demonstrate pathogenicity. Here, we report the eventual diagnosis of DOCK8 deficiency in a consanguineous family due to a novel homozygous intronic deletion variant that caused aberrant exon splicing and subsequent loss of expression of DOCK8 protein. Remarkably, the causative variant was not initially detected by clinical whole-genome sequencing but was subsequently identified and validated by combining advanced genomic analysis, RNA-seq, and flow cytometry. This case highlights the need to adopt multipronged confirmatory approaches to definitively solve complex genetic cases that result from variants outside protein-coding exons and conventional splice sites.

[The Chinese expert recommendations on the clinical use of dronedarone]

Dronedarone, a class Ⅲ antiarrhythmic drug, is a deiodinated benzofuran derivative of amiodarone. It has similar antiarrhythmic effects with amiodarone, but much lesser adverse effects than amiodarone, particularly in those outside the heart. It is suggested to use dronedarone for the rhythm control of atrial fibrillation/flutter, for it has been shown to prevent the recurrence of atrial fibrillation/flutter and reduce rehospitalization in patients with paroxysmal or persistent atrial fibrillation/flutter. Dronedarone is not recommended for the rhythm control in patients with long-term persistent atrial fibrillation or permanent atrial fibrillation, and atrial flutter or atrial fibrillation patients with reduced ejection fraction. Liver function, electrolyte tests and an electrocardiogram should be performed before and after the drug initiation. Potential interactions with other kinds of drugs have to be taken into consideration as well.

Intrinsic Defects in B Cell Development and Differentiation, T Cell Exhaustion and Altered Unconventional T Cell Generation Characterize Human Adenosine Deaminase Type 2 Deficiency

PURPOSE

Deficiency of adenosine deaminase type 2 (ADA2) (DADA2) is a rare inborn error of immunity caused by deleterious biallelic mutations in ADA2. Clinical manifestations are diverse, ranging from severe vasculopathy with lacunar strokes to immunodeficiency with viral infections, hypogammaglobulinemia and bone marrow failure. Limited data are available on the phenotype and function of leukocytes from DADA2 patients. The aim of this study was to perform in-depth immunophenotyping and functional analysis of the impact of DADA2 on human lymphocytes.

METHODS

In-depth immunophenotyping and functional analyses were performed on ten patients with confirmed DADA2 and compared to heterozygous carriers of pathogenic ADA2 mutations and normal healthy controls.

RESULTS

The median age of the patients was 10 years (mean 20.7 years, range 1-44 years). Four out of ten patients were on treatment with steroids and/or etanercept or other immunosuppressives. We confirmed a defect in terminal B cell differentiation in DADA2 and reveal a block in B cell development in the bone marrow at the pro-B to pre-B cell stage. We also show impaired differentiation of CD4⁺ and CD8⁺ memory T cells, accelerated exhaustion/senescence, and impaired survival and granzyme production by ADA2 deficient CD8⁺ T cells. Unconventional T cells (i.e. iNKT, MAIT, Vδ2⁺ γδT) were diminished whereas pro-inflammatory monocytes and CD56^bright immature NK cells were increased. Expression of the IFN-induced lectin SIGLEC1 was increased on all monocyte subsets in DADA2 patients compared to healthy donors. Interestingly, the phenotype and function of lymphocytes from healthy heterozygous carriers were often intermediate to that of healthy donors and ADA2-deficient patients.

CONCLUSION

Extended immunophenotyping in DADA2 patients shows a complex immunophenotype. Our findings provide insight into the cellular mechanisms underlying some of the complex and heterogenous clinical features of DADA2. More research is needed to design targeted therapy to prevent viral infections in these patients with excessive inflammation as the overarching phenotype.

The expansion of human T-bethighCD21low B cells is T cell dependent

Accumulation of human CD21low B cells in peripheral blood is a hallmark of chronic activation of the adaptive immune system in certain infections and autoimmune disorders. The molecular pathways underpinning the development, function, and fate of these CD21low B cells remain incompletely characterized. Here, combined transcriptomic and chromatin accessibility analyses supported a prominent role for the transcription factor T-bet in the transcriptional regulation of these T-bethighCD21low B cells. Investigating essential signals for generating these cells in vitro established that B cell receptor (BCR)/interferon-γ receptor (IFNγR) costimulation induced the highest levels of T-bet expression and enabled their differentiation during cell cultures with Toll-like receptor (TLR) ligand or CD40L/interleukin-21 (IL-21) stimulation. Low proportions of CD21low B cells in peripheral blood from patients with defined inborn errors of immunity (IEI), because of mutations affecting canonical NF-κB, CD40, and IL-21 receptor or IL-12/IFNγ/IFNγ receptor/signal transducer and activator of transcription 1 (STAT1) signaling, substantiated the essential roles of BCR- and certain T cell–derived signals in the in vivo expansion of T-bethighCD21low B cells. Disturbed TLR signaling due to MyD88 or IRAK4 deficiency was not associated with reduced CD21low B cell proportions. The expansion of human T-bethighCD21low B cells correlated with an expansion of circulating T follicular helper 1 (cTfh1) and T peripheral helper (Tph) cells, identifying potential sources of CD40L, IL-21, and IFNγ signals. Thus, we identified important pathways to target autoreactive T-bethighCD21low B cells in human autoimmune conditions, where these cells are linked to pathogenesis and disease progression.

[Safety and effectiveness of left atrial appendage occlusion in patients with atrial fibrillation and end-stage renal disease undergoing long-term hemodialysis]

Objective: To evaluate the safety and effectiveness of left atrial appendage occlusion (LAAO) in patients with atrial fibrillation and end-stage renal disease undergoing long-term hemodialysis. Methods: Six patients with AF and end-stage renal disease(ESRD)on long term hemodialysis who underwent LAAO from March 2017 to March 2021 in Beijing Anzhen Hospital were enrolled. Baseline characteristics such as age, sex, types of arrhythmia, stroke and bleeding score, and continuous dialysis time were collected. Four patients underwent LAAO, two patients underwent the combined procedure of catheter ablation and LAAO. Perioperative treatment and serious complications were recorded. Transesophageal echocardiography was repeated at 45 days and 60 days after the procedure. Telephone follow-up was conducted at 3, 6 and 12 months after the procedure, and every 6 months thereafter. Thromboembolism and major bleeding events and survival were evaluated. Results: The average age was (66.7±17.0) years old, and 5 were male (5/6). There were 4 patients with paroxysmal AF (4/6), and 2 patients with persistent AF (2/6). The mean CHA₂DS₂-VASc score was (4.8±1.5), and the HAS-BLED score was (3.5±1.4). The duration of hemodialysis was 2.6 (1.1, 8.3) years. Successfully Watchman implantation was achieved in all patients. There were no severe perioperative complications, and no device related thrombosis or leaks were observed by transesophageal echocardiography. During a mean of 22.0 (12.0, 32.0) months follow-up, there was no thromboembolism or major bleeding events. A total of 2 patients died, one from sudden cardiac death, and another one from heart failure. Conclusions: LAAO may be a safe and effective therapeutic option for prevention of thromboembolism in patients with atrial fibrillation and end-stage renal disease undergoing long-term hemodialysis, further studies with larger patient cohort are needed to confirm our results.