Clinical Reviews in Allergy & Immunology最新文献

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a multifactorial inflammatory condition characterized by persistent sinus inflammation and tissue remodeling. Epithelial-derived alarmins, including thymic stromal lymphopoietin (TSLP), interleukin-33 (IL-33), and interleukin-25 (IL-25), are critical mediators that initiate and amplify immune responses in CRSwNP. These alarmins are secreted by stressed or damaged nasal epithelial cells in response to environmental insults, such as allergens, microbial infections, pollutants, and proteases. Once released, they orchestrate immune cell activation and amplify inflammatory pathways. Targeting epithelial-derived alarmins has emerged as a promising therapeutic strategy for CRSwNP, with several biologics, including TSLP and IL-33 inhibitors, showing encouraging clinical outcomes. This review focuses on the role of epithelial-derived alarmins in CRSwNP, examining their expression patterns, regulatory mechanisms, and contributions to inflammation, evaluating the current progress in alarmin-targeted therapies, and exploring future research directions to optimize their clinical application.

The palatine tonsils, positioned at the aerodigestive crossroads, serve as immunological sentinels orchestrating frontline defense through coordinated surveillance of inhaled and ingested antigens. As secondary lymphoid organs, palatine tonsils bridge innate and adaptive immunity via specialized microanatomical domains. Recent paradigm shifts now position the tonsils as dual-function immunological entities: while essential for pathogen surveillance and mucosal immunity, their dysregulated immune responses may paradoxically drive systemic inflammation. Concurrently, emerging evidence demonstrates therapeutic implications of tonsillar modulation, particularly through precision interventions such as tonsillectomy. This review examines recent advances in tonsillar anatomy and histology while critically evaluating novel insights into their pathogenic involvement in autoimmune diseases and other extra-tonsillar disorders. Furthermore, we analyze evolving perspectives on tonsil-targeted therapies as potential disease-modifying strategies. The synthesis underscores the tonsils' evolving status from regional lymphoid tissue to systemic immunomodulatory organ, bridging mucosal defense mechanisms with systemic inflammatory pathogenesis.

Patients with hereditary alpha-tryptasemia (HαT) have been shown not only to be more prone to anaphylaxis but also to more severe reactions. The relationship between hypermobility, gastroparesis, gastroesophageal reflux disease (GERD), postural orthostatic tachycardia syndrome (POTS), and HαT has been variably described in the literature although no causal biochemical or genetic link has been identified. Herein, we sought to describe the clinical presentation, treatment, and co-morbidities of patients diagnosed with HαT within the Penn State Health System. Through a retrospective cross-sectional chart review, we report  the clinical and therapeutic characteristics of patients who tested positive for HαT genotypes (2α3β, 3α2β) within Penn State Health. Twenty-six percent of patients within our cohort had co-occurring diagnoses of hypermobility (7, 26.9%), or POTS (7, 26.9%) while more than half of patients had GERD (15, 57.7%). Anaphylaxis was reported among 7 (26.9%) with the average number of anaphylactic episodes per patient prior to HαT identification being less than one. Patients with triplication had higher prevalence of hypermobility and POTS and were more likely to receive treatment with omalizumab or cromolyn. Co-morbid hypermobility, POTS and GERD in patients with flushing, urticaria, or anaphylaxis should warrant further investigation for HαT.

Hemophagocytic lymphohistiocytosis (HLH) is a severe and life-threatening hyperinflammatory disorder characterized by dysregulated immune activation, primarily driven by excessive stimulation of cytotoxic lymphocytes (CTLs) and macrophages. This uncontrolled immune response leads to cytokine-induced tissue damage and multiorgan dysfunction. HLH presents a significant clinical challenge due to its rapid progression and high mortality rate. In adult patients, current first-line treatment strategies, adapted from pediatric protocols such as HLH-94 and HLH-2004, achieve complete disease resolution in only approximately 50% of cases. The urgent need for more effective therapeutic options is underscored by the lack of targeted treatments and the persistent high mortality associated with HLH. However, the pathophysiology of HLH remains complex and incompletely understood, involving multiple immune dysregulations, diverse etiologies, and variable clinical presentations, making drug development particularly challenging. Drawing from recent advancements, this review provides a translational perspective on the immunopathological mechanisms underlying HLH, highlighting emerging therapeutic targets and novel treatments currently under clinical investigation. By synthesizing these insights, we aim to identify key opportunities for the development of innovative therapies to improve patient outcomes.

Obstetric antiphospholipid syndrome (OAPS) is an autoimmune disorder characterized by antiphospholipid antibody-mediated inflammatory environment at the maternal-fetal interface. It leads to significant complications, including pre-fetal or fetal demise, preeclampsia, and placental insufficiency. Pregnancy leads to significant changes in the immune profile that facilitate fetal tolerance while ensuring protection from infections. A controlled inflammation at the maternal-fetal interface is essential during implantation as trophoblasts need to invade the endometrial lining. However, excessive inflammation can disrupt this balance and contribute to pregnancy-related complications. Consequently, the increased activation of the innate immune system is counteracted by the tolerogenic responses of the adaptive immune system. There is a shift from T helper (Th) 1 to Th2 responses from the first to the third trimester of pregnancy. This is associated with a decrease in lymphopoiesis, together with a prolonged B cell lifespan. Thus, during pregnancy, antibody-producing B cells are prone to activation, potentially leading to a loss of tolerance. Changes in B cell function, antigen presentation, and antibody affinity are seen in women with antiphospholipid syndrome. It is essential to understand the defects in B cell regulation in OAPS as they are likely to induce a breach in immune homeostasis. Herein, we will review the role of B cell tolerance in OAPS, including a discussion of potential novel therapeutic effects to improve maternal and fetal health.

Allergic asthma is a chronic respiratory disorder driven by a T helper type 2 (Th2)-mediated immune response that involves eosinophils and mast cell recruitment to affected tissues, eliciting inflammatory cytokines and IgE production. Typical symptoms in more severe cases include wheezing, shortness of breath, chest tightness, persistent coughing, excessive mucus production, and airway hyperresponsiveness. Current therapies, which focus on suppressing the immune system, mitigate the symptoms but are generally insufficient to address the disease. Mycobacterium bovis bacillus Calmette-Guérin (BCG) platform, initially developed as an attenuated vaccine for tuberculosis (TB), induces a potent T helper type 1 (Th1) polarized immune response, making it a promising candidate for treating Th2-dominant conditions, such as allergic asthma, ultimately alleviating the symptoms. BCG can be genetically modified to express antigens of other pathogens or immunogenic proteins, such as IL-12p70. In this review, we examine the potential of BCG as a novel therapeutic platform for allergic asthma, focusing on its ability to modulate the immune response via IL-12.

The mechanisms underlying immune tolerance induction during sublingual immunotherapy (SLIT) of seasonal allergic rhinitis (SAR) remain insufficiently understood. This study aimed to investigate the molecular and immunological process involved in SLIT. RNA sequencing (RNA-seq) and bioinformatics analyses were performed to examine the functions of differentially expressed genes (DEGs) in leukocytes from 11 SAR patients at three time points: baseline, peak pollen phase (PPP), and end-of-treatment. Patients received a 4-month SLIT course with Artemisia annua (A. annua) extract (n = 5) or placebo (n = 6). Plasma cytokine levels were measured in a validation cohort of 15 SAR patients (9 in the SLIT group and 6 in the placebo group) using Luminex assays. The results showed that A. annua SLIT inhibited the upregulation of IL-17A-associated pathways and the expression of inflammatory mediators, including CXCL1, CCL7, and PLPP3, while enhancing myeloid immune cell function by increasing the expression of CD36, TYROBP, FCGR1A, and FCER1G. Additionally, A. annua SLIT reactivated myeloid immune cell-associated genes that were downregulated during PPP and significantly reduced IL-17A and GRO-β levels in plasma, compared to the placebo group. These findings suggest that A. annua SLIT alleviates SAR by modulating IL-17A pathways, reducing inflammatory responses, and enhancing myeloid immune cell function.

Allergic rhinitis (AR) is a common inflammatory condition affecting millions globally. Emerging evidence suggests a potential link between AR and suicidality; however, this association remains underexplored compared to other atopic diseases. This systematic review and meta-analysis aimed to investigate the association between AR and the risks of suicidal ideation, attempts, and death. Following PRISMA guidelines, we conducted a systematic search across PubMed, Embase, PsycINFO, Cochrane databases, Web of Science, Scopus, CINAHL, and Google Scholar. A total of 590 studies were screened, with 9 eligible cross-sectional studies involving 1,604,962 participants included. Data on suicidal ideation, suicide attempts, and death were synthesized using random-effects meta-analyses. Odds ratios (ORs) were calculated with 95% confidence intervals (CIs). The risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist, and evidence was graded using the GRADE framework. AR was not significantly associated with suicidal ideation (OR: 1.12, 95% CI: 0.97-1.30; 1,101,819 participants from 7 studies). However, AR patients demonstrated an elevated risk of suicide attempts (OR: 1.25, 95% CI: 1.00-1.57; 1,554,297 participants from 5 studies) and suicide death (OR: 1.65, 95% CI: 1.46-1.86; 478,244 participants from 2 studies). This meta-analysis highlights an association between allergic rhinitis and increased risk of suicide attempts and death. However, due to the cross-sectional nature of included studies, causality cannot be inferred.

Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by microvasculopathy, extensive fibrosis, and autoantibodies. The disease affects mostly the female sex. In this review, we highlight sex bias in clinical manifestations in SSc, and the pathophysiological changes underlying this bias. Male sex is associated with the diffuse cutaneous form of the disease, digital ulcers, interstitial lung disease, and worse prognosis. These clinical differences can be attributed to sex hormones and sex chromosomes, as females differ from males in sex hormones (estrogens in females, androgens in males) and sex chromosomes (XX in females, XY in males). Estrogens in females generally have immunostimulatory and profibrotic effects, and androgens have immunosuppressive effects. The X-chromosome contains many immunity-related genes, but the double dose of X-linked genes in females is avoided by random inactivation of one X-chromosome (XCI). However, many X-linked immunity-related genes, including toll-like receptor (TLR)7, TLR8 and Bruton's tyrosine kinase (BTK), escape XCI resulting in a biallelic expression with pathophysiological implications. Also, autosomal genes are differentially expressed between sexes. Therefore, sex should be included in future studies on SSc to aid in forming predictive algorithms and helping therapeutic decisions in this difficult-to-treat disease.

Although alopecia areata (AA) is recognized as a hair loss disorder stemming from the dysregulation of cutaneous immune homeostasis, its precise pathogenesis still remains elusive. The collapse of hair follicle (HF) immune privilege (IP), leading to immune cell-mediated attack on the hair follicle, is currently the widely accepted fundamental mechanism of AA. Among the immune cells studied in this context, CD8⁺ T cells and regulatory T (Treg) cells are relatively well-researched, but the direct involvement of macrophages in the disease process has been less frequently demonstrated. In this review, we summarize various previous studies on macrophages and hypothesize the immune mechanisms by which macrophages contribute to the pathogenesis of AA. This exploration provides new insights for future research and potential clinical treatments.