Ferenc Sipos

The possible association between monoclonal gammopathy and autoimmune/immune-mediated diseases has received increasing attention in recent years. Several observational studies have reported an increased prevalence of monoclonal gammopathy in certain autoimmune conditions, particularly primary Sjögren’s syndrome, rheumatoid arthritis, and systemic lupus erythematosus. However, recent population-based screening data from the iStopMM study found no significant association between autoimmune disease and screen-detected MGUS after adjustment for age and sex, suggesting that ascertainment bias may partly explain associations observed in clinically identified cohorts. The underlying mechanisms may include chronic antigen stimulation, sustained B-cell activation, germinal-center dysregulation, increased T follicular helper cell activity, and BAFF/APRIL-, IL-6-, NF-κB-, and STAT3-mediated signaling pathways. Based on current evidence, the relationship between monoclonal gammopathy and autoimmunity can be interpreted according to four potentially overlapping models: monoclonal gammopathy may serve as a marker of chronic immune activation, develop as a consequence of persistent autoimmune inflammation, act as a pathogenetic factor through the direct effects of the monoclonal immunoglobulin or the underlying clonal B-cell/plasma-cell population, or represent a coincidental finding related to factors such as age, genetic background, or increased diagnostic surveillance. This review summarizes the major epidemiological, pathogenetic, and clinical evidence supporting these interpretations and discusses their potential diagnostic, prognostic, and therapeutic implications. Finally, we highlight key directions for future research, including longitudinal single-cell and spatial omics approaches, further characterization of the BAFF/APRIL axis, and investigation of PANoptosis as a potential link between chronic inflammation and clonal plasma-cell disorders.

Trained immunity is a concept that is currently in development and refers to the long-term functional reprogramming of innate immune cells in response to microbial or inflammatory stimuli. This process serves a dual purpose in the gastrointestinal tract, contributing to chronic inflammatory conditions like inflammatory bowel disease and maintaining host defense. The production of pro-inflammatory mediators is augmented by epigenetic and metabolic changes that are induced by the persistent activation of innate immune cells, which is triggered by microbial components and damage-associated signals. Although this increased responsiveness may initially be protective, sustained activation leads to tissue damage, epithelial barrier dysfunction, and chronic inflammation. These mechanisms are significant contributors to colorectal carcinogenesis, particularly in colitis-associated cancer. Through the activation of oncogenic signaling pathways, the establishment of a pro-tumorigenic microenvironment, and an increase in oxidative stress, trained immunity also influences tumor development. Additionally, the systemic reprogramming of hematopoietic progenitor cells has the potential to exacerbate inflammation and facilitate the progression of tumors. The identification of epigenetic and metabolic biomarkers associated with trained immunity can lead to novel diagnostic opportunities. Targeting metabolic and epigenetic pathways, as well as regulating the intestinal microbiota, is a promising therapeutic approach that could enhance the effectiveness of treatments for colorectal cancer while minimizing adverse effects on the immune system. Nevertheless, it is necessary to maintain a delicate equilibrium to suppress pathological inflammation without compromising protective immune responses. In general, trained immunity may represent a potentially relevant mechanistic link between chronic inflammation and colorectal cancer; however, its role remains context-dependent and not yet fully defined.

The long-lasting, varied, and complicated nature of immune system issues in autoimmune disorders continues to make treatment difficult. Although standard immunosuppressive and biologic therapies have enhanced disease management, they infrequently provide enduring remission and often result in cumulative damage. Due to this, stem cell treatment has emerged as a potential alternative that aims to restore immunological homeostasis rather than maintain long-term immune suppression. This editorial review provides a comprehensive overview of the current evidence, unmet requirements, and future directions in the field, summarizing the primary contributions of the Special Issue “Stem Cell Therapy for Autoimmune Diseases”. We examine the conceptual distinction between immune reset, as demonstrated by hematopoietic stem cell transplantation, and immune modulation, which is facilitated by mesenchymal stromal cells and their secretome. Systemic sclerosis, neuroimmunological disorders, inflammatory bowel disease, and type 1 diabetes exhibit disease-specific clinical experiences that underscore both context-dependent limitations and therapeutic potential. Meanwhile, an urgent need to address persistent issues such as incomplete immune reconstitution, autoreactive memory cell-driven relapse, a lack of predictive biomarkers, safety concerns, and complex ethical and regulatory problems is addressed. This review concludes by offering perspectives on the future development of this approach, highlighting standardization, biomarker-driven patient selection, and next-generation techniques, including extracellular vesicles and genetically modified cells. This overview marks stem cell therapy as a crucial area of research for the treatment of autoimmune disorders.

PANoptosis is an integrated form of regulated cell death that combines pyroptosis, apoptosis, and necroptosis through a coordinated molecular platform known as the PANoptosome. Autophagy, in parallel, maintains immune homeostasis by controlling cellular stress responses. Although both pathways are essential for innate and adaptive immunity, their functional interplay has only recently been explored. This review summarizes current knowledge on the bidirectional relationship between PANoptosis and autophagy, with emphasis on how autophagy can restrain PANoptotic signaling or, under certain conditions, promote inflammatory cell death. We discuss cell-type-specific aspects of this crosstalk in macrophages, dendritic cells, monocytes, neutrophils, T cells, and B cells, focusing on key PANoptosis mediators and autophagy-related proteins. We then examine how dysregulated autophagy and exaggerated PANoptotic signaling contribute to chronic inflammation and tissue damage in immune-mediated inflammatory disease, including systemic lupus erythematosus, rheumatoid arthritis, Sjögren’s syndrome, psoriasis, and inflammatory bowel disease. Finally, we outline shared molecular principles that position the autophagy–PANoptosis axis as a fundamental immunoregulatory mechanism and a promising source of therapeutic targets in chronic inflammatory and autoimmune disorders.

Common variable immunodeficiency (CVID) is the most prevalent symptomatic primary immunodeficiency, characterised by impaired antibody production, immune dysregulation, and a broad spectrum of clinical manifestations. Gastrointestinal involvement is frequent, affecting up to 20% of patients and significantly contributing to morbidity and mortality. Among infectious triggers, norovirus plays a particularly important role, as persistent infection may drive chronic inflammation and contribute to the development of CVID‐associated enteropathy, a severe non‐infectious complication marked by chronic diarrhoea, malabsorption, and weight loss. The pathogenesis is multifactorial, involving impaired humoural immunity, absent mucosal IgA, and aberrant T‐ and B‐cell interactions, resulting in defective viral clearance and sustained mucosal injury. Although viral eradication has been shown to induce clinical and histological improvement, no standardized therapeutic strategy currently exists. Intravenous or subcutaneous immunoglobulin replacement fails to adequately protect against gastrointestinal infections, and off‐label antivirals such as ribavirin, nitazoxanide, or interferon alpha have yielded inconsistent results. Oral administered immunoglobulin preparations have shown variable efficacy in case reports, reflecting differences in viral genotypes, host susceptibility, and donor antibody repertoires. In this review, we summarise current knowledge on the epidemiology, pathogenesis, clinical features, and diagnostic considerations of CVID‐associated enteropathy linked to chronic norovirus infection, with a special focus on therapeutic aspects. We also present our experience with a patient successfully treated with immunoglobulin therapy administered via nasogastric tube, leading to clinical remission, nutritional recovery, and viral clearance. Recognising norovirus as a key etiological factor in CVID enteropathy emphasises the need to conduct systematic studies and evidence‐based therapeutic approaches.

The examination of PANoptosis in colorectal cancer is particularly important, as many tumor cells can evade apoptotic cell death while continuing to proliferate through inflammatory mediators and creating an immunosuppressive environment. The PANoptosome functions as a regulatory complex that unites proteins governing pyroptotic, apoptotic, and necroptotic pathways, rather than allowing distinct death pathways to compete. The expression and functional status of key molecules within the PANoptosome, such as ZBP1, RIPK1, RIPK3, CASP8, and ASC, may influence tumor viability and immune detection. The tumorigenic impact of PANoptosis is complex and predominantly manifests through chronic inflammation, immune response modulation, and changes in the tumor microenvironment. PANoptosis also aids in the defense against colon cancer by directly eradicating tumor cells and modifying the cellular environment. The expression profile of PANoptosis components may possess prognostic and predictive significance. The therapeutic ramifications of PANoptosis in colorectal cancer are now being investigated through many avenues. It provides an opportunity to develop targeted therapeutic techniques. In contrast, it may also be pertinent in conjunction with immunotherapy, as PANoptosis signifies an immunogenic type of cell death and may consequently enhance the anti-tumor immune response. A thorough comprehension of how these parameters influence PANoptosis is crucial for practical implementation.

Schnitzler syndrome is a unique autoinflammatory disease, of which 747 cases have been described worldwide to date. The main features of the syndrome are a triad of recurrent urticaria, monoclonal IgM gammopathy, systemic inflammation associated with recurrent fever, joint and bone pain, and atypical bone remodeling (osteosclerosis). The abnormal activation of the NLRP3 inflammasome produces IL-1, which drives the disease pathology, but it also involves IL-6 and IL-18. Unlike other autoinflammatory diseases, Schnitzler syndrome lacks evidence of the gene divergence causing the abnormal activation of NLRP3. However, mutations in the MEFV and MYD88 genes can be associated with the development of the disease. Due to its rarity, diagnosing the disease can be a challenging task. IL-1 inhibitors (i.e., anakinra, canakinumab, and rilonacept) are prominent in the treatment of the disease, but the IL-6 receptor inhibitor tocilizumab and the Bruton’s tyrosine kinase inhibitor ibrutinib are also promising alternatives. In this summary article, we aim to provide a comprehensive overview of the clinical and molecular background of the disease and potential therapeutic targets, based on the cases reported so far. We diagnosed a patient who, to the best of our knowledge, represents the 748th documented case of this specific pathology. In the context of this patient, we would also like to draw attention to the potential pathogenic role of two novel gene mutations (variants of the MEFV gene “c.2084A>G” and the F2 gene “3′UTR c.*97G>A”).

CD133 protein expression is observable in differentiated cells, stem cells, and progenitor cells within normal tissues, as well as in tumor tissues, including colorectal cancer cells. The CD133 protein is the predominant cell surface marker utilized to detect cancer cells exhibiting stem cell-like characteristics. CD133 alters common abnormal processes in colorectal cancer, such as the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) and Wnt/β-catenin pathways. Autophagy is a cellular self-digestion mechanism that preserves the intracellular milieu and plays a dual regulatory role in cancer. In cancer cells, apoptosis is a critical cell death mechanism that can impede cancer progression. CD133 can modulate autophagy and apoptosis in colorectal cancer cells via several signaling pathways; hence, it is involved in the regulation of these intricate processes. This can be an explanation for why CD133 expression is associated with enhanced cellular self-renewal, migration, invasion, and survival under stress conditions in colorectal cancer. The purpose of this review article is to explain the complex relationship between the CD133 protein, apoptosis, and autophagy. We also want to highlight the possible ways that CD133-mediated autophagy may affect the apoptosis of colorectal cancer cells. Targeting the aforementioned mechanisms may have a significant therapeutic role in eliminating CD133-positive stem cell-phenotype colorectal cancer cells, which can be responsible for tumor recurrence.

Tuft cells are more than guardian chemosensory elements of the digestive tract. They produce a variety of immunological effector molecules in response to stimulation; moreover, they are essential for defense against protozoa and nematodes. Beyond the description of their characteristics, this review aims to elucidate the potential pathogenic and therapeutic roles of colonic tuft cells in inflammatory bowel disease and colorectal cancer, focusing on their primarily immunomodulatory action. Regarding inflammatory bowel disease, tuft cells are implicated in both maintaining the integrity of the intestinal epithelial barrier and in tissue repair and regeneration processes. In addition to maintaining intestinal homeostasis, they display complex immune-regulatory functions. During the development of colorectal cancer, tuft cells can promote the epithelial-to-mesenchymal transition, alter the gastrointestinal microenvironment, and modulate both the anti-tumor immune response and the tumor microenvironment. A wide variety of their biological functions can be targeted for anti-inflammatory or anti-tumor therapies; however, the adverse side effects of immunomodulatory actions must be strictly considered.