Immunological and therapeutic insights in autoimmune autonomic ganglionopathy: What is the position of apheresis in immunotherapy?

Autoimmune autonomic ganglionopathy (AAG) is characterized by various autonomic and extra-autonomic symptoms and is caused by autoantibodies against nicotinic acetylcholine receptors present in the autonomic ganglia (ganglionic acetylcholine receptor, gAChR), requiring immediate and aggressive intervention to prevent the exacerbation of symptoms. However, there is currently no internationally accepted standard of care for the immunotherapy of AAG, including apheresis. Although the rationale for the use of plasma exchange (PLEX) in AAG is strong, whereby pathogenic gAChR antibodies are removed, its overall impact on patient outcomes is not well-established. Based on previous case reports and small case series studies, we provide a comprehensive overview of the challenges and uncertainties surrounding the use of PLEX for the management of AAG and provide current practice recommendations to guide treatment decisions.

Aberrant immunity in the oral cavity-a link with rheumatoid arthritis?

There are well established epidemiological links between rheumatoid arthritis and periodontitis. Recent data have started to shed light on the mechanisms that might underlie the relationship between these two complex diseases. Unravelling the roles of distinct pathways involved in these mechanisms has the potential to yield novel preventative and therapeutic strategies for both diseases. Perhaps most intriguingly, this represents an area where understanding the biology in the oral cavity might reveal fundamental advances in understanding immune regulation and the relationships between the host and microbiome. Here we seek to discuss aspects of the adaptive immune response that might link periodontitis and rheumatoid arthritis.

Subchronic intranasal lipopolysaccharide exposure induces pulmonary autoimmunity and glomerulonephritis in NZBWF1 mice.

Lupus, a systemic autoimmune disease shaped by gene-environment interplay, often progresses to endstage renal failure. While subchronic systemic exposure to bacterial lipopolysaccharide (LPS) triggers autoimmunity and glomerulonephritis in lupus-prone mice, it is unknown if inhaling LPS, which is common in certain occupations, can similarly trigger lupus. Here we determined how subchronic intranasal (IN) LPS instillation influences autoimmunity and glomerulonephritis development in lupusprone NZBWF1 female mice. Briefly, mice were IN-instilled with vehicle or E. coli LPS (0.8 µg/g) twice weekly for 5 wk, followed by necropsy. For systemic comparison, additional cohorts of mice were injected with LPS intraperitoneally (IP) using identical doses/timing. Lungs were assessed for inflammatory and autoimmune responses and then related to systemic autoimmunity and glomerulonephritis. IN/LPS exposure induced in the lung: i) leukocyte infiltration, ii)mRNA signatures for cytokines, chemokines, IFN-regulated, and cell death-related genes, iii) ectopic lymphoid tissue formation, and iv)diverse IgM and IgG autoantibodies (AAbs). Pulmonary effects coincided with enlarged spleens, elevated plasma IgG AAbs, and inflamed IgG-containing kidney glomeruli. In contrast, IP/LPS treatment induced systemic autoimmunity and glomerulonephritis without pulmonary manifestations. Taken together, these preclinical findings suggest the lung could serve as a critical nexus for triggering autoimmunity by respirable LPS in genetically predisposed individuals.

Deletion of the Mitochondrial Membrane Protein Fam210b Is Associated with the Development of Systemic Lupus Erythematosus.

Mitochondrial dysfunction has been increasingly recognized as a trigger for systemic lupus erythematosus (SLE). Recent bioinformatics studies have suggested Fam210b as a significant candidate for the classification and therapeutic targeting of SLE. To experimentally prove the role of Fam210b in SLE, we constructed Fam210b knockout (Fam210b-/-) mice using the CRISPR-Cas9 method. We found that approximately 15.68% of Fam210b-/- mice spontaneously developed lupus-like autoimmunity, which was characterized by skin ulcerations, splenomegaly, and an increase in anti-double-stranded DNA (anti-dsDNA) IgG antibodies and anti-nuclear antibodies(ANA). Single-cell sequencing showed that Fam210b was mainly expressed in erythroid cells. Critically, the knockout of Fam210b resulted in abnormal erythrocyte differentiation and development in the spleens of mice. Concurrently, the spleens exhibited an increased number of CD71+ erythroid cells, along with elevated levels of reactive oxygen species (ROS) in the erythrocytes. The co-culture of CD71+ erythroid cells and lymphocytes resulted in lymphocyte activation and promoted dsDNA and IgG production. In summary, Fam210b knockout leads to a low probability of lupus-like symptoms in mice through the overproduction of ROS in CD71+ erythroid cells. Thus, Fam210b reduction may serve as a novel key marker that triggers the development of SLE.

Macrophage activation and inflammatory priming by anti-MAA antibodies in rheumatoid arthritis.

We studied the effects of rheumatoid arthritis (RA) autoantibodies that target malondialdehyde-acetaldehyde protein adducts (anti-MAA) on inflammation and macrophage functions. We detected a profound reprogramming of gene expressions and the production of chemokines, such as CCL22 and CCL24, in anti-MAA exposed macrophages. Moreover, anti-MAA pretreatment promoted a more inflammatory cytokine profile upon TLR activation. Although anti-MAA are typically multi-reactive, we observed a prominent clonal diversity in inducing macrophage activation. Anti-MAA antibodies were not arthritogenic in mice, but altered a set of cytokine and growth factor encoding genes in the joints. In individuals at risk of RA anti-MAA IgG levels correlated with circulating inflammatory mediators prior to and at arthritis onset. Certain IgG anti-MAA clones may thus contribute to an inflammatory priming of the joint prior to the onset of systemic inflammation via inducing FcγR-mediated macrophage pre-activation and setting the stage for augmented responses to subsequent inflammatory stimuli.

The interference of anti-TSH autoantibody on clinical TSH detection.

Objective: It is well known that macro-thyroid-stimulating hormone (macro-TSH) could interfere with the detection of TSH. The anti-TSH autoantibody is an essential component of macro-TSH. However, the epidemiological characteristics and the clinical interference of the anti-TSH autoantibody are unclear. Methods: In this study, the radioimmunoprecipitation technique was used to detect the anti-TSH autoantibody. Platforms with different detection mechanisms were applied to measure the TSH in patients with the anti-TSH autoantibody. Polyethylene glycol (PEG) precipitation was used to determine the immunoassay interference. Results: The prevalence of the anti-TSH autoantibody in patients with mild subclinical hypothyroidism (SCH) and autoimmune thyroiditis, but normal thyroid function, was 4.78%. All 10 patients with anti-TSH antibodies had autoimmune diseases, with five of them having significant clinical test interference. Conclusion: The appearance of the anti-TSH antibody is not associated with thyroid autoantibodies. The presence of the anti-TSH autoantibody can interfere with the detection of TSH and can affect clinical diagnosis and treatment.

Automated immunoassay of serum NY-ESO-1 and XAGE1 antibodies for predicting clinical benefit with immune checkpoint inhibitor (ICI) in advanced non-small cell lung cancer.

BACKGROUND: NY-ESO-1 and XAGE1 cancer/testis antigens elicit humoral and cellular immune responses in NSCLC patients. We aimed to predict clinical benefit with ICI monotherapy, using an automated immunoassay of NY-ESO-1/XAGE1 antibodies (Abs). METHODS: This study enrolled 99 NSCLC patients who received nivolumab after chemotherapy, including 21 patients harboring EGFR, ALK, or KRAS alterations. The cutoff value (10 units/mL) of NY-ESO-1 and XAGE1 Ab was determined based on Ab levels in non-malignant controls, and NY-ESO-1/XAGE1 Abs in NSCLC were measured before nivolumab. Differences in PFS and OS between the Ab-positive and Ab-negative groups were retrospectively analyzed using Cox regression analysis after applying inverse probability of treatment weighting (IPTW). RESULTS: NY-ESO-1/XAGE1 Abs were positive in 28 NSCLC, who responded more highly to nivolumab than the Ab-negatives (response rate 50.0% vs. 15.5 %, p < 0.0007). The IPTW-adjusted positives and negatives for NY-ESO-1/XAGE1 Abs were 24.5 and 70.2, respectively. The Ab-positives showed longer IPTW-adjusted PFS (HR = 0.59, 95 % CI: 0.39-0.90, p = 0.014) and IPTW-adjusted OS (HR = 0.51, 95 % CI: 0.32-0.81, p = 0.004) than the Ab-negatives. Among NSCLC harboring driver genes, the Ab-positives (n = 10) showed longer PFS (HR = 0.34, 95 % CI: 0.13-0.89, p = 0.029) and OS (HR = 0.27, 95 % CI: 0.098-0.75, p = 0.012) than the Ab-negatives (n = 11). CONCLUSION: Our immunoassay of NY-ESO-1/XAGE1 Abs is probably useful for predicting the clinical benefit with nivolumab in NSCLC, including those harboring driver genes. These results suggest that our immunoassay may be useful in ICI monotherapy for NSCLC.

Development and validation of a TAAbs and TAAs based non-invasive model for diagnosing lung cancer.

Background: Single Tumor-associated autoantibodies (TAAbs) and tumor-associated antigens (TAAs) have been found to have lower diagnostic efficacy in lung cancer. Our objective is to develop and validate a lung cancer prediction model that utilizes TAAbs and TAAs and to enhance the accuracy of lung cancer detection. Methods: 1830 subjects were randomly divided into training and validation sets at a 7:3 ratio for this study. Lasso regression analysis was used to remove collinear variables, whereas univariate logistic regression analysis was employed to identify potential independent risk factors for lung cancer. A diagnostic model was constructed using multivariate logistic analysis. The results were presented as a nomogram and assessed for various performance measures, including area under the curve, calibration curve, and decision curve analysis. Results: The diagnostic model was developed using gender, age, GAGE7, MAGE-A1, CA125, and CEA as variables. The training set had an AUC of 0.787, while the validation set had an AUC of 0.750. The calibration curves of the training and validation sets showed a strong agreement between anticipated and observed values. The nomogram performed better than any individual variable in both the training and validation sets in terms of net benefits for lung cancer detection, according to DCA analysis. Conclusions: This study proposes a diagnostic model for lung cancer that uses TAAbs and TAAs and incorporates individual characteristics. This model can be easily applied to personalized diagnosis.

Disease-specific autoantibody production in the lungs and salivary glands of anti-synthetase syndrome.

Interstitial lung disease is a common complication of anti-synthetase syndrome (ASS), and lymphocytic infiltration is often observed in the lesion. We have recently reported that disease-specific autoantibodies are produced by infiltrating lymphocytes in some autoimmune diseases. Here, we investigate the antigen specificity of B cells in the lung lesions of ASS patients. A total of 177 antibodies were produced from antibody-secreting cells in bronchoalveolar fluid (BALF) of three each of serum anti-Jo-1 and serum anti-EJ antibody-positive patients. Twelve to 30% and 50 to 62% of these antibodies were disease-specific autoantibodies, respectively. These autoantibodies recognized conformational epitopes of the whole self-antigen and had affinity maturations, indicating that self-antigens themselves are the target of humoral immunity. In addition, 100 antibodies were produced from two salivary gland tissues, obtained by chance, of ASS patients. Salivary glands are not generally recognized as lesions of ASS, but unexpectedly, ASS-related autoantibody production was also observed similar to that of BALF. Immunostaining confirmed the presence of ASS-related autoantibody-producing cells in salivary glands. Our results suggest that disease-specific autoantibody production at lesion sites is a common pathogenesis of autoimmune diseases, and that tissue-specific production of autoantibodies can provide insights regarding the distribution of organ manifestations in autoimmune diseases.

Recurrent Cerebral Hemorrhaging with Platelet Dysfunction Accompanied by Anti-glycoprotein VI Autoantibodies in a Patient with TAFRO Syndrome.

Thrombocytopenia, anasarca, fever, renal dysfunction, and organomegaly (TAFRO) syndrome is an inflammatory disorder with an unclear pathogenesis. We herein report a case of TAFRO syndrome in remission in a patient who experienced recurrent intracranial bleeding despite a normal platelet count and coagulation system. A further investigation suggested the presence of anti-glycoprotein VI (GPVI) autoantibodies in the plasma, which induced platelet dysfunction and bleeding tendency. No new bleeding or relapse of TAFRO syndrome occurred after immunosuppressive therapy was initiated. These findings may help elucidate the autoimmune pathogenesis of TAFRO syndrome.

Coexistence of systemic sclerosis and cryopyrin-associated periodic syndrome.

Systemic sclerosis (SSc) and cryopyrin-associated periodic syndrome (CAPS) are distinct clinical entities belonging to the autoimmune and autoinflammatory diseases, respectively. The coexistence of the two entities has rarely been reported and is poorly characterized. Here, we described a case of a 38-year-old Japanese woman diagnosed with anti-centromere antibody-positive SSc and CAPS carrying the pathogenic mutation in the NLRP3 gene, with a detailed autoantibody profile by a high-throughput comprehensive protein array covering approximately 90% of the human transcriptome. The clinical manifestations of the patient were typical of both SSc and CAPS. Comprehensive autoantibody profiling identified 65 autoantibodies in the patient's serum and 78 autoantibodies in the serum of her daughter with CAPS, who carried the same NLRP3 mutation as the patient. SSc-associated autoantibodies (anti-DBT, anti- CENP-B, and anti-CENP-A) and anti-CD320 antibody were detected at high levels only in the patient's serum, while autoantibodies to the following four proteins were detected in the sera of both the patient and her daughter: TRIM21, LIMS1, CLIP4, and KAT2A. The TRRUST enrichment analysis identified NF-κB1 and RelA as overlapping key transcription factors that regulate the genes encoding proteins to which autoantibodies were detected in the patient and her daughter, therefore the autoantibody profile of the patient cannot be solely attributed to SSc, but may also be influenced by CAPS. Although autoimmune and autoinflammatory diseases are considered to be at opposite ends of the immunological spectrum, detailed autoantibody profiling may reveal a unique immunological landscape in an overlapping case of the two entities.

Selenium levels and their association with thyroid autoimmunity and severe preeclampsia in pregnancy: Insights from a prospective ideal breast milk cohort study.

Objective: This study aimed to assess selenium status in South Korean pregnant women and its impact on maternal thyroid function and pregnancy outcomes. Methods: 'Ideal Breast Milk (IBM) Cohort Study' included 367 pregnant women out of 442 participants and categorized into three groups based on plasma selenium levels: deficient (< 70 µg/L), suboptimal (70-99 µg/L), and optimal (≥ 100 µg/L). During the second or third trimester, various blood parameters, including selenium, thyroid-stimulating hormone, free T4, free T3, and anti-thyroid peroxidase antibody levels, were measured. Thyroid parenchymal echogenicity was assessed as another surrogate marker for thyroid autoimmunity using ultrasonography. Results: The median plasma selenium was 98.8 (range: 46.7-206.4) µg/L, and 30 individuals (8%) were categorized as deficient, while 164 (45%) were classified in the suboptimal group. Selenium deficiency was associated with markers of autoimmune thyroiditis, including positive anti-thyroid peroxidase antibody results (13.3 (deficient) vs 4.6 (optimal) %, P = 0.031) and thyroid parenchymal heterogeneity on ultrasound (33.3 (deficient) vs 14.6 (suboptimal) vs 17.3 (optimal) %, P = 0.042), independently of gestational age. The incidence of severe preeclampsia was higher in the group not taking selenium supplements, particularly among those with twin pregnancies, compared to the group taking selenium supplements (0 (selenium supplement) vs 9.0 (no supplement) %, P = 0.015). Conclusion: Pregnant women experience mild selenium deficiency, which can lead to significant health issues including maternal thyroid autoimmunity and obstetrical complications during pregnancy. Guidelines for appropriate selenium intake according to the stage of pregnancy and the number of fetuses are needed.

Altered cytokine and chemokine profile linked to autoantibody and pathogen reactivity in mothers of autistic children.

Maternal autoimmunity, and more specifically, the production of specific maternal autoantibodies, has been associated with altered offspring neurodevelopment. Maternal autoantibody-related (MAR) autism is a subtype of autism that is linked to gestational exposure to certain combinations of autoantibodies to proteins known to be important for fetal neurodevelopment. We wanted to address whether mothers with autism-specific patterns of autoantibodies have a skewed cytokine and chemokine profile during an immune response to infection. To do so, we examined a subset of mothers from the Early Markers for Autism (EMA) study who either produced known patterns of MAR autoantibodies (MAR+) or did not (MAR-). We compared the cytokine/chemokine profiles of MAR+ and MAR- mothers in the context of positive immunoglobulin G (IgG) reactivity to several viral and parasitic agents. We observed that MAR+ mothers have a higher level of proinflammatory cytokine interferon-gamma regardless of IgG status. Additionally, when comparing MAR+ and MAR- mothers in the context of the different pathogens, MAR+ mothers consistently had increases in multiple proinflammatory cytokines and chemokines.

State-of-the-art diagnosis of autoimmune blistering diseases.

Autoimmune blistering disorders (AIBDs) are a heterogeneous group of approximately a dozen entities comprising pemphigus and pemphigoid disorders and dermatitis herpetiformis. The exact diagnosis of AIBDs is critical for both prognosis and treatment and is based on the clinical appearance combined with the detection of tissue-bound and circulating autoantibodies. While blisters and erosions on the skin and/or inspectable mucosal surfaces are typical, lesions may be highly variable with erythematous, urticarial, prurigo-like, or eczematous manifestations. While direct immunofluorescence microscopy (IFM) of a perilesional biopsy is still the diagnostic gold standard, the molecular identification of the major target antigens opened novel therapeutic avenues. At present, most AIBDs can be diagnosed by the detection of autoantigen-specific serum antibodies by enzyme-linked immunosorbent assay (ELISA) or indirect IFM when the clinical picture is known. This is achieved by easily available and highly specific and sensitive assays employing recombinant immunodominant fragments of the major target antigens, i.e., desmoglein 1 (for pemphigus foliaceus), desmoglein 3 (for pemphigus vulgaris), envoplakin (for paraneoplastic pemphigus), BP180/type XVII collagen (for bullous pemphigoid, pemphigoid gestationis, and mucous membrane pemphigoid), laminin 332 (for mucous membrane pemphigoid), laminin ß4 (for anti-p200 pemphigoid), type VII collagen (for epidermolysis bullosa acquisita and mucous membrane pemphigoid), and transglutaminase 3 (for dermatitis herpetiformis). Indirect IFM on tissue substrates and in-house ELISA and immunoblot tests are required to detect autoantibodies in some AIBD patients including those with linear IgA disease. Here, a straightforward modern approach to diagnosing AIBDs is presented including diagnostic criteria according to national and international guidelines supplemented by long-term in-house expertise.

Detection of anti-calreticulin antibody in the sera of Chinese patients with primary Sjögren syndrome.

BACKGROUND: Primary Sjögren syndrome (pSjS) is one of the most prevalent systemic autoimmune diseases and characterized with hyperactivation of B cell and the abundant presence of autoantibodies in sera. The salivary gland epithelial cells (SGECs) release autoantigens to evoke autoimmunity through releasing elevated apoptosis or secreting autoantigen-containing exosomes, thus identifying autoantibodies directly to SGECs might provide insights into disease related biomarkers as well as further elucidating pathogenesis mechanisms. The present study was undertaken to identify autoantibodies to SGECs and to evaluate its clinical values in Chinese pSjS. METHODS: Cell-based indirect immunofluorescence and immunostaining, two-dimensional electrophoresis and liquid chromatograph-tandem mass spectrometry were conducted to identify the autoantibodies to human salivary gland cell line A253 in pSjS sera. Enzyme-linked immunosorbent assay (ELISA) was applied to identify autoantibody titer in pSjS cohort and healthy controls. The prevalence and clinical significance of the identified autoantibodies was further assessed in pSjS population. RESULTS: Anti-calreticulin (CALR) antibody was identified as a new autoantibody directly to SGECs in sera from pSjS patients. Anti-CALR antibody were detected in 37 of 120 pSjS patients (30.83 %) and 1 of 54 healthy controls (1.85 %). It was found in 40.85 % pSjS with anti-SSA positive, 53.85 % with anti-SSB positive, and 14.7 % in sero-negative pSjS. Anti-CALR antibody was associated with clinical manifestations including weight loss(p = 0.045), vasculitis (p = 0.031), and laboratory parameters including erythrocyte sedimentation rate (ESR) (r = 0.056, p = 0.021), Krebs von den Lungen-6 (KL-6) (r = 0.121, p = 0.035), IgG (r = 0.097, p < 0.001), IgG2 (r = 0.142, p = 0.022), IgG3 (r = 0.287, p < 0.001), fibrinogen (r = 0.084, p = 0.016), D-Dimer (r = 0.086, p = 0.012) and fibrinogen degradation production (r = 0.150, p = 0.002). The expression of CALR in salivary glands was related to lymphocytes infiltration into salivary glands in pSjS patients (r = 0.7076, p = 0.0034). CONCLUSION: To our knowledge, this was the first study to investigate the prevalence and clinical significance of anti-CALR antibody in Chinses pSjS patients. The present study identified an autoimmune antibody, anti-CALR antibody, as a good autoimmune biomarker for sero-negative pSjS.

Detection of factor XIII inhibitors in 33 patients with autoimmune factor XIII deficiency in Japan.

Autoimmune factor XIII (FXIII) deficiency (AiF13D) is a rare hemorrhagic disease. The anti-FXIII autoantibodies that cause this disease are classified into three types: type Aa inhibits the heterotetramer assembly and activation of FXIII, type Ab inhibits the enzymatic activity of activated FXIII, and type B enhances the elimination of FXIII from the blood. The former two are FXIII inhibitors and may be lethal if overlooked by conventional functional assays. To reliably detect both types of FXIII inhibitors, a new assay was developed by incorporating 5-(biotinamido)pentylamine (BAPA) into α2-plasmin inhibitor (PI-BAPA assay). This assay was tested on plasma samples from 128 participants, including 60 healthy controls, 35 patients with non-immune acquired FXIII deficiency, and 33 patients with AiF13D (29 with type Aa inhibitors and 4 with type Ab inhibitors). The PI-BAPA assay successfully detected type Aa and Ab inhibitors in 5-step dilution cross-mixing tests between patient and normal plasma. This assay also showed comparable or superior inhibition rates in the 1:1 mixing test compared to conventional ammonia release and amine incorporation assays. Receiver operating characteristic curve analysis confirmed the excellent specificity and sensitivity of this assay for determining inhibition rates, and the assay has already been used for AiF13D diagnosis.

Antibodies in Aseptic Meningitis of Connective Tissue Disorder: A Case Report.

Mixed connective tissue disorder (MCTD) is the first overlap syndrome described with features of overlapping manifestations of at least two other autoimmune rheumatic conditions. It is an autoimmune disease of rarity and is strongly associated with specific antibodies to U1 small nuclear ribonucleoprotein (anti-U1-RNP). This disorder affects almost all organs of the body, and it has varied clinical presentations as it has an autoimmune and inflammatory background, causing heightened immune cell activation. They present more commonly with less fatal symptoms like joint pain, stiffness, and mucocutaneous changes. The majority present initially with Raynaud's phenomenon followed by muscular skeletal involvement and around half of them present with swallowing problems due to esophageal dysmotility. Rarely do they also present with more morbid symptoms of pulmonary hypertension and central nervous system involvement. MCTD on follow-up had a 10 percent association with neurological manifestations as reported by the National Organization for Rare Diseases (NORD), and the most reported diseases were trigeminal neuralgia and aseptic meningitis. Patients presenting with such symptoms and, when treated only with guideline-based antibiotics therapy, would delay the treatment, leading to a poorer prognosis. The following is an interesting case of a young female presenting with a headache, which was masquerading as an underlying undiagnosed connective tissue disorder. Headache is a predominant presentation that has several etiologies in autoimmune disease and meticulous differential diagnosis workup is a must. This case highlights the fact that any persistent atypical, unusual symptom needs to be always considered for further evaluation to arrive at a diagnosis and for a favorable outcome.