Search Results (140)

Neonatal calves possess an immature and naïve immune system and are reliant on the intake of maternal colostrum for the passive transfer of immunoglobulins. Maternal antibodies delivered to the calf via colostrum, are crucial to prevent calfhood diseases and death. Failure of transfer of passive immunity (FTPI) is a condition in which calves do not acquire enough maternal antibodies, mostly in the form of IgG, due to inadequate colostrum quality or delayed colostrum feeding. The diagnosis and risk factors for FTPI have been widely studied in dairy cattle; however, in beef calves, the research interest in the topic is relatively recent, and the most adequate diagnostic and preventative methods are still in development, making it difficult to define recommendations for the assessment and prevention of FTPI in cow–calf operations. The objective of this scoping review is to identify the published literature on best practices for colostrum management and transfer of passive immunity (TPI) in neonatal beef calves. The literature was searched using three electronic databases (CAB Direct, Scopus, and PubMed) for publications from 2003 to 2025. The search process was performed during the period from May to July 2023, and was repeated in January 2025. All screening processes were performed using Covidence systematic review software (Veritas Health Innovation, Melbourne, Australia). A total of 800 studies were initially identified through database searches. After removing duplicates, 346 studies were screened based on their titles and abstracts, leading to the exclusion of 260 studies. The remaining 86 studies underwent full-text screening, and 58 studies were considered eligible for data extraction. Hand-searching the references from published review papers on the subject yielded an additional five studies, bringing the total to 63 included articles. The prevalence of FTPI has been estimated to be between 5.8% and 34.5% in beef calves. Factors studied related to colostrum management include quality and quantity of colostrum intake, the timing and method of colostrum feeding, and the microbial content of the colostrum. Studies on risk factors related to the calf include the topics calf sex, twin status, calf vigor, weight, month of birth, cortisol and epinephrine concentrations, and the administration of nonsteroidal anti-inflammatory drugs to calves after difficult calving. The dam-related risk factors studied include dam body condition score and udder conformation, breed, parity, genetics, prepartum vaccinations and nutrition, calving area and difficulty, and the administration of nonsteroidal anti-inflammatory drugs at C-section. Most importantly for beef systems, calves with low vigor and a weak suckling reflex are at high risk for FTPI; therefore, these calves should be given extra attention to ensure an adequate consumption of colostrum. While serum IgG levels of < 8 g/L or < 10 g/L have been suggested as cutoffs for the diagnosis of FTPI, 16 g/L and 24 g/L have emerged as cutoffs for adequate and optimal serum IgG levels in beef calves. Several field-ready diagnostics have been compared in various studies to the reference standards for measuring indicators of TPI in beef calves, where results often differ between models or manufacturers. Therefore, care must be taken when interpreting these results. Full article

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory disorder primarily affecting adults. The disease in pediatric age is unusual and preferentially affects adolescents. In contrast to adults, who commonly exhibit the involvement of multiple organs simultaneously or sequentially over time, young patients tend to present with a localized disease, typically affecting the orbits. Proptosis, ptosis, diplopia, and restricted eye movement may be observed in these patients. Symptoms are proteiform, and the disease is chronic and indolent with a relapsing–remitting course. Diagnostic criteria have been developed for adults, which may not fully capture the pediatric disease phenotype. If untreated or poorly managed, IgG4-RD can lead to progressive fibrosis and scarring of affected organs, potentially causing irreversible damage. We conducted a narrative review using the IMRAD approach, presenting a nonsystematic analysis of the literature on pediatric IgG4-RD. Original papers, case reports/series, and relevant reviews in English were selected from PubMed, EMBASE, and Web of Science up to January 2024. Keywords included “IgG4-Related Disease” and “pediatric” and, additionally, we presented two original pediatric cases. Our purpose is to offer an overview of IgG4-RD manifestations, and challenges in diagnosing and managing this rare condition in children. Full article

Immunoglobulin G4-related disease (IgG4-RD) is a systemic fibroinflammatory condition marked by tumefactive lesions, IgG4+ plasma cell-rich infiltrates, storiform fibrosis, and obliterative phlebitis. Its multisystem involvement and overlap with malignancies, infections, and immune disorders complicate diagnosis despite recent classification advances. This study summarizes diagnostic challenges, highlights the role of histopathology as per the 2019 classification criteria established by the American College of Rheumatology and the European League Against Rheumatism (ACR/EULAR), and explores emerging tools to improve diagnostic accuracy. ACR/EULAR classification emphasizes three cardinal histopathological features (storiform fibrosis, obliterative phlebitis, or dense lymphoplasmacytic infiltrates) combined with an IgG4+/IgG+ plasma cell ratio >40% and organ-specific IgG4+ thresholds. While serum IgG4 levels are often elevated, their poor specificity necessitates confirmatory biopsy. Diagnostic limitations include sampling variability due to patchy fibrosis, interobserver discrepancies in immunohistochemical interpretation, and differentiation from mimics like lymphoma. Emerging solutions incorporate novel biomarkers (plasmablasts, anti-annexin A11) and advanced techniques (flow cytometry, digital pathology). Future research directions should focus on AI-assisted pattern recognition, multi-omics profiling, and organ-specific criteria refinement. While histopathology remains the diagnostic cornerstone, a multidisciplinary approach integrating clinical, radiological, and laboratory data is vital. Innovations in biomarkers promise improved diagnostic accuracy and personalized care, balancing novel advancements with foundational pathological evaluation. Full article

The number of metabolic dysfunction-associated steatotic liver disease (MASLD) patients is increasing rapidly. More attention has been paid to the relationship between immunity and MASLD. This study explored the roles of serum autoantibodies, immunoglobulins, and complements in MASLD. A total of 182 MASLD patients were investigated and grouped by autoantibody or NAS scores. Correlation between immunology and clinical features was assessed. In addition, metabolic dysfunction-associated steatohepatitis (MASH) models were constructed to verify the findings. Neutrophils were isolated from mice and treated with complement C3 to investigate the association between C3 and neutrophil extracellular traps (NETs). IgG, IgM, and NAS scores in the autoantibody positive group were significantly higher than those in the autoantibody negative group. Antinuclear antibodies (ANA), IgA, IgE, IgG, C3, C4, ALT, and AST were related to MASH. Meanwhile, IgA and C3 correlated with the severity of MASLD. The ROC curve showed that IgA > 2.990 g/L or C3 > 1.115 g/L predicted the presence of MASH. More importantly, IgG, activated C3, and NETs were increased in MASH. C3 stimulation directly induced NET formation in the neutrophils. Immunity systems were activated in MASH and elevated IgG activated C3 to stimulate the production of NETs, thus exacerbating MASH. Full article

Autoimmune pancreatitis is a rare condition of pancreatic inflammation with two classic subtypes. The emergence of a third subtype, ICI-induced pancreatitis, highlights the need for knowledge of each type to ensure accurate diagnosis and treatment. Abbreviations: AIP—Autoimmune pancreatitis; AIP-1—Type 1 autoimmune pancreatitis, also known as lymphoplasmacytic sclerosing pancreatitis (LPSP); AIP-2—Type 2 autoimmune pancreatitis, also referred to as idiopathic duct-centric pancreatitis (IDCP); AIP-3—Type 3 autoimmune pancreatitis, also known as immune checkpoint inhibitor (ICI)-induced autoimmune pancreatitis; IgG4-RD—Immunoglobulin G4-related disease. Full article

Ulcerative colitis (UC) is a major form of inflammatory bowel disease (IBD) characterised by chronic immune-mediated inflammation. While serological biomarkers for IBD diagnosis and differentiation have been explored, autoantibody-based profiling remains underdeveloped. This study aimed to elucidate antibody signatures in manifested and pre-diagnostic UC patients compared to controls using a high-content protein microarray. Serum and plasma samples from manifested and pre-diagnostic UC cohorts were analysed using AIT’s 16k protein microarray, presenting 6369 human proteins. The pre-diagnostic cohort, consisting of 33 UC cases and 33 controls, included longitudinal samples collected before diagnosis, while the severe UC cohort, comprising 49 severe UC patients and 23 controls, included individuals undergoing treatment. Immunoglobulin G (IgG) autoantibody reactivity was assessed to identify differentially reactive antigens (DIRAGs) linked to UC onset, disease progression, and activity. In manifested UC, 691 DIRAGs showed higher reactivity in cases. In the pre-diagnostic cohort, 966 DIRAGs were identified, with 803 antigens exhibiting increased reactivity in cases. Longitudinal analysis revealed 1371 DIRAGs, with 1185 showing increased reactivity closer to diagnosis when comparing samples collected 4–11 months before UC diagnosis to earlier time points 9–24 months prior, highlighting potential early biomarkers. A significant overlap of 286 antigens, corresponding to 41 percent of identified DIRAGs, was observed between severe and pre-diagnostic UC datasets, with an odds ratio of 3.8 and a p-value below 2.2 × 10⁻¹⁶, confirming reliability and biological relevance. Additionally, 21 antigens correlated with simple clinical colitis activity index (SCCAI) scores. Reactome pathway analysis identified 49 pathways associated with DIRAGs in pre-diagnostic UC, distinct from 24 pathways in manifested UC, with an overlap of five key pathways related to protein folding, immune regulation, and viral infection, reflecting differences in disease onset and manifestation. Autoantibody profiling reveals early immune signatures in UC, offering novel biomarkers for preclinical diagnosis and disease monitoring. The overlap between pre-diagnostic and manifested UC antigenic profiles reinforces their biological relevance, linking them to molecular pathology. These findings highlight antibody profiling as an additional omics layer, paving the way for new diagnostic and therapeutic strategies in UC management. Full article

IgG4 is an unusual immunoglobulin (Ig) and is the least component of IgG in humans. It is often asymmetrical and heterobivalent with weak Fc (fragment crystallizable region)-dependent effector function and ineffective complement activation, thus playing an unclear role in immune functions. IgE is an uncommon Ig, being important mostly in allergy and type 2 immunity. There are two rare chronic Ig-related fibroinflammatory diseases, namely IgG4-related disease (IgG4RD) and Kimura disease (KD), characterized by prominent IgG4- or IgE-positive plasma cells in the affected tissues, with or without blood elevations of the same Ig. The etiology of these two Ig-related diseases is unclear, though it appears that the pathogenesis in both is related to polarized Ig heavy chain isotype switching, concomitant with other cellular, cytokine and chemotaxin interactions that culminates in the characteristic pathologic manifestations of inflammation and fibrosis. IgG4RD and KD, despite having overlapping and differing features, may be connected by the similar pathogenetic polarized Ig isotype switching. Full article

Asthma, a chronic airway disease, is marked by allergic inflammation, hyperresponsiveness, and tissue remodeling. Influenza infections in asthma patients can cause severe exacerbations, though the underlying mechanisms remain unclear. This study investigated how pre-existing allergic inflammation affects immune responses to influenza infection in mice exposed to house dust mite (HDM). Mice were repeatedly exposed to HDM, followed by infection with the influenza A virus, and were sacrificed three days post-infection. Plasma was analyzed for HDM-specific immunoglobulins, while lung tissue was used for immune cell flow cytometry and RNA sequencing analysis. HDM exposure induced allergic inflammation, evidenced by more HDM-specific IgE, IgG1, IgG2, eosinophils, neutrophils, Th1, and Th17 cells compared to controls. Upon influenza infection, the effects of HDM and influenza co-infection interacted, showing fewer Th1 cells and regulatory T cells and more Th2 cells compared to mice exposed to the influenza virus alone. Interestingly, RNA-seq analysis revealed less upregulation of Th1-related genes and antiviral pathways in co-exposed mice, suggesting impaired Th1 immunity and antiviral responses. Pre-existing allergic inflammation significantly altered immune responses in mice co-infected with influenza, revealing underdeveloped antiviral responses as early as three days post-infection. These findings may explain the increased susceptibility of patients with asthma to severe viral diseases. Full article

Immune-mediated inflammatory diseases (IMIDs) are characterized by chronic systemic inflammation and multi-organ involvement. Fibrosis formation in IMIDs can cause tissue destruction and subsequently organ malfunction. Fibroblast activation protein inhibitor positron emission tomography/computed tomography (FAPi PET/CT) represents a novel imaging technique that holds great potential to visualize in vivo fibrosis. We here provide an overview of available evidence on FAPi PET/CT imaging to visualize fibrosis in various IMIDs, including interstitial lung diseases, immunoglobulin G4-related diseases, cardiovascular diseases, kidney diseases, and gastrointestinal diseases. FAPi PET/CT imaging demonstrates high sensitivity in detecting early fibrosis, correlating with disease severity, across different IMIDs, showing superiority compared to conventional imaging modalities. Although FAPi PET/CT might be a useful tool to assess fibrosis formation, thereby aiding in grading disease severity and staging, future studies should include larger sample sizes in a broad variety of IMIDs with emphasis on the optimization of imaging protocols to further validate its diagnostic value. Full article

Receptors for the immunoglobulin G constant fraction (FcγRs) are widely expressed in cells of the immune system. Complement-independent phagocytosis prompted FcγR research to show that the engagement of IgG immune complexes with FcγRs triggers a variety of cell host immune responses, such as phagocytosis, antibody-dependent cell cytotoxicity, and NETosis, among others. However, variants of these receptors have been implicated in the development of and susceptibility to autoimmune diseases such as systemic lupus erythematosus. Currently, the knowledge of FcγR variants is a required field of antibody therapeutics, which includes the engineering of recombinant soluble human Fc gamma receptors, enhancing the inhibitory and blocking the activating FcγRs function, vaccines, and organ transplantation. Importantly, recent interest in FcγRs is the antibody-dependent enhancement (ADE), a mechanism by which the pathogenesis of certain viral infections is enhanced. ADEs may be responsible for the severity of the SARS-CoV-2 infection. Therefore, FcγRs have become a current research topic. Therefore, this review briefly describes some of the historical knowledge about the FcγR type I family in humans, including the structure, affinity, and mechanism of ligand binding, FcγRs in diseases such as systemic lupus erythematosus (SLE), and the potential therapeutic approaches related to these receptors in SLE. Full article

Background: Plasma cell myeloma is an incurable malignancy of clonal plasma cells. Recent success in immunotherapeutic strategies has altered the landscape of myeloma treatment. Daratumumab is an anti-CD38 IgG kappa monoclonal antibody that has shown great efficacy in the treatment of myeloma. However, Daratumumab brought with it new challenges in post-therapeutic laboratory assessment, including therapeutic antibody interference with serum protein electrophoresis and serum immunofixation electrophoresis assays. In this study, we highlight the interference identified in post-therapeutic flow cytometry analysis related to bound Daratumumab on normal hematopoietic cells. We also highlight the methods of detection of residual plasma cell neoplasm, post-Daratumumab therapy.: A total of 28 patients with refractory plasma cell myeloma who received Daratumumab (2016–2018) were included in this study. Flow cytometry was performed using 4- or 10-color antibody panels (BD FASC Canto) and analyzed by cluster analysis (Cytopaint Classic software) using four tube panels including VS38c for measurable residual disease (MRD) testing. Pretreatment and post-Daratumumab follow-up bone marrow flow cytometry samples were analyzed. In addition, 10 multiple myeloma patient samples were reflexed to multi-epitope CD38 analysis by flow cytometric analysis of post-Daratumumab residual disease. When discussing CD38 expression, we will refer to CD38 as being detected by conventional reagents. Results: All post-Daratumumab-treated cases (100%) showed negative staining for CD38 using conventional reagents on all plasma cells in the specimens. MRD testing successfully identified small clonal plasma cell populations using VS38C and multi-epitope CD38 (meCD38) antibodies, despite the absence of demonstrable CD38 expression. Additionally, all cases exhibited weak kappa light chain staining on hematogones, attributed to the binding of Daratumumab kappa monoclonal antibody. This interaction can create the appearance of a CD10+ monotypic B-cell population. We also noted diminished CD38 staining on myeloblasts, resulting in an atypical CD34/CD38 staining pattern. This alteration could potentially be misinterpreted as indicative of a myelodysplastic neoplasm (MDS). Furthermore, decreased staining of CD38 was noted on T cells, natural killer (NK) cells, basophils, monocytes, and plasmacytoid dendritic cells. Conclusions: With the emergence of successfully targeted immunotherapies, such as anti-CD38 antibodies, it is important to understand and correctly interpret variations in flow cytometry that may arise from the therapy. Hematogones exhibit high-intensity levels of CD38 expression; thus, Daratumumab binds to them, creating the appearance of kappa expression on all hematogones. Stage I/early stage II hematogones normally lack surface immunoglobulin light chain expression, but in the presence of Daratumumab, they appear to be a CD10(+) monotypic population of B cells. The misinterpretation of these normal cells as a CD10(+) B-cell clone can lead to inaccurate assessment, unnecessary bone marrow immunohistochemical evaluation, and unwarranted anxiety. Additionally, artefacts on various other hematopoietic cells can result in inaccurate assessments of immunophenotypic aberrancy due to binding of the drug. This may lead to the false interpretation of a secondary/therapy-related myeloid neoplasm. This study highlights in detail the interferences that must be considered when assessing residual disease in the era of targeted drug therapies. Full article

Background/Objectives: Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune-related neurological disease that primarily affects the optic nerve and spinal cord. According to current international consensus guidelines for NMOSD, confirming the presence of aquaporin-4 immunoglobulin G antibody (AQP4-IgG) is one of the most important diagnostic criteria because AQP4-IgG is a significant diagnostic biomarker of NMOSD. Several assays are currently available for detecting AQP4-IgG, including cell-based assays (CBAs) and enzyme-linked immunosorbent assays (ELISAs). However, each assay has certain disadvantages, including insufficient sensitivity and specificity, the need for sophisticated techniques, and semi-quantitative results. Methods: We developed a fully automated chemiluminescent enzyme immunoassay (CLEIA) to detect AQP4-IgG (AQP4-CLEIA). This assay utilizes the recombinant antigen purified from the newly generated AQP4-M23 stably expressing Chinese hamster ovary cell line and an anti-AQP4 monoclonal antibody as a calibrator. Results: In analytical performance studies, the assay demonstrates good precision and linearity over the entire measurement range. Moreover, this assay showed no high-dose hook effect and interference from endogenous substances. In clinical validation studies, patients with AQP4-IgG positive NMOSD, multiple sclerosis, or myelin oligodendrocyte glycoprotein antibody-associated disorder and healthy individuals were tested. A cutoff value of 10.0 U/mL was determined by receiver operating characteristic curves based on the results of a microscopic live CBA. The sensitivity and specificity for AQP4-IgG-positive NMOSD were 97.0% and 100.0%, respectively, at the cutoff value. Conclusions: The results suggest that AQP4-CLEIA is a convenient automated method for measuring AQP4-IgG titers in hospitals and clinical laboratories, offering an effective alternative to the gold-standard CBA. Full article

Background and Objectives: Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated, fibroinflammatory, multiorgan disease with an obscure pathogenesis. Findings indicating excessive platelet activation have been reported in systemic sclerosis, which is another autoimmune, multisystemic fibrotic disorder. The immune-mediated, inflammatory, and fibrosing intersections of IgG4-RD and systemic sclerosis raised a question about platelets’ role in IgG4-RD. Materials and Methods: By borrowing transcriptomic data from Nakajima et al. (GEO repository, GSE66465) we sought a platelet contribution to the pathogenesis of IgG4-RD. GEO2R and BRB-ArrayTools were used for class comparisons, and WebGestalt for functional enrichment analysis. During the selection of differentially expressed genes (DEGs), the translationally active but significantly low amount of platelet mRNA was specifically considered. The platelet-specific gene signature derived was used for cluster analysis of patient and control groups. Results: When IgG4-RD patients were compared with controls, 268 DEGs (204 with increased and 64 with decreased expression) were detected. Among these, a molecular signature of 22 platelet-specific genes harbored genes important for leukocyte–platelet aggregate formation (i.e., CLEC1B, GP1BA, ITGA2B, ITGB3, SELP, and TREML1) and extracellular matrix synthesis (i.e., CLU, PF4, PPBP, SPARC, and THBS1). Functional enrichment analysis documented significantly enriched terms related to platelets, including but not limited to “platelet reactivity”, “platelet degranulation”, “platelet aggregation”, and “platelet activation”. During clustering, the 22 gene signatures successfully discriminated IgG4-RD and the control and the IgG4-RD before and after treatment groups. Conclusions: Patients with IgG4-RD apparently display an activated platelet phenotype with a potential contribution to disease immunopathogenesis. If the platelets’ role is validated through further carefully designed research, the therapeutic potentials of selected conventional and/or novel antiplatelet agents remain to be evaluated in patients with IgG4-RD. Transcriptomics and/or proteomics research with platelets should take into account the relatively low amounts of platelet mRNA, miRNA, and protein. Secondary analysis of omics data sets has great potential to reveal new and valuable information. Full article

Cardiovascular disease (CVD) remains a leading global health concern, with atherosclerosis being its principal cause. Standard CVD treatments primarily focus on mitigating cardiovascular (CV) risk factors through lifestyle changes and cholesterol-lowering therapies. As atherosclerosis is marked by chronic arterial inflammation, the innate and adaptive immune systems play vital roles in its progression, either exacerbating or alleviating disease development. This intricate interplay positions the immune system as a compelling therapeutic target. Consequently, immunomodulatory strategies have gained increasing attention, though none have yet reached widespread clinical adoption. Safety concerns, particularly the suppression of host immune defenses, remain a significant barrier to the clinical application of anti-inflammatory therapies. Recent decades have revealed the significant role of adaptive immune responses to plaque-associated autoantigens in atherogenesis, opening new perspectives for targeted immunological interventions. Preclinical models indicate that vaccines targeting specific atherosclerosis-related autoantigens can slow disease progression while preserving systemic immune function. In this context, numerous experimental studies have advanced the understanding of vaccine development by exploring diverse targeting pathways. Key strategies include passive immunization using naturally occurring immunoglobulin G (IgG) antibodies and active immunization targeting low-density lipoprotein cholesterol (LDL-C) and apolipoproteins, such as apolipoprotein B100 (ApoB100) and apolipoprotein CIII (ApoCIII). Other approaches involve vaccine formulations aimed at proteins that regulate lipoprotein metabolism, including proprotein convertase subtilisin/kexin type 9 (PCSK9), cholesteryl ester transfer protein (CETP), and angiopoietin-like protein 3 (ANGPTL3). Furthermore, the literature highlights the potential for developing non-lipid-related vaccines, with key targets including heat shock proteins (HSPs), interleukins (ILs), angiotensin III (Ang III), and a disintegrin and metalloproteinase with thrombospondin motifs 7 (ADAMTS-7). However, translating these promising findings into safe and effective clinical therapies presents substantial challenges. This review provides a critical evaluation of current anti-atherosclerotic vaccination strategies, examines their proposed mechanisms of action, and discusses key challenges that need to be overcome to enable clinical translation. Full article

Background:Bartonella quintana is a body-louse-borne bacterium. Canadian B. quintana disease has been reported primarily in populations experiencing homelessness and in Indigenous communities with limited access to water. We sought to understand the epidemiology of B. quintana in Canada. Methods: This study combined an analysis of laboratory data from Canada’s National Microbiology Laboratory (NML) with a systematic review of the literature. Laboratory data included quantitative polymerase chain reaction (qPCR) cycle threshold values and indirect immunofluorescent antibody titers with the year and province of the sample acquisition. For the systematic review, we searched PubMed, Scopus, Embase, and Web of Science for articles published before 15 July 2024, with terms related to B. quintana in Canada. Results: Thirty-three individuals with qPCR-positive B. quintana were documented in seven provinces and one territory. The number of cases increased over time (p-value = 0.005), with the greatest number of cases being reported in 2022 and 2023. The percent positivity for the B. quintana qPCR performed at the NML increased over time (p-value = 0.036). The median immunoglobulin G titer demonstrated a sustained increase starting in 2017. The systematic review identified fourteen individuals with qPCR-positive B. quintana (none had a qPCR performed at the NML) and seven probable cases of B. quintana disease. Four of these twenty-one individuals from the systematic review died (19%). All fatalities were attributed to endocarditis. Conclusions: The detection of B. quintana disease in seven provinces and one territory suggests that B. quintana has a national distribution. B. quintana disease is increasingly diagnosed in Canada, indicating ongoing transmission across geographic settings. Full article