Welcome to the Autoimmunity 2021 Congress Calendar

Background and Aims

Genetic variants within/near the interferon regulatory factor 5 (IRF5) locus associate with systemic lupus erythematosus (SLE) across ancestral groups. The major IRF5-SLE risk haplotype is common across populations, yet immune functions for the risk haplotype are undefined.

Methods

Healthy donors carrying the major IRF5-SLE risk haplotype in European Caucasians (rs2004640, rs10954213, rs10488631, and rs142738614 (CGGGG indel)) were identified from the Feinstein Genotype and Phenotype (GaP) Registry after genotyping on the Illumina Human Immunochip. Participants carried either the major IRF5 homozygous risk or non-risk haplotype and had no personal/family history of autoimmune/inflammatory diseases or cancer. Immuno-phenotypes were characterized by ELISA, flow cytometry, ex vivo co-culture and RNA-sequencing.

Results

Contrary to previous studies in B lymphoblastoid cell lines and SLE immune cells, IRF5 genetic variants had little effect on IRF5 protein levels in healthy donors. Instead, we detected basal IRF5 hyper-activation in the myeloid compartment of risk donors that drives an SLE immune-phenotype. Risk donors were ANA positive with anti-Ro and -MPO specificity, had increased circulating plasma cells and plasmacytoid dendritic cells, and enhanced spontaneous NETosis. The IRF5-SLE immune-phenotype was conserved over time and probed mechanistically by ex vivo co-culture, indicating that risk neutrophils are drivers of the global immune-phenotype. RNAseq of risk neutrophils revealed increased IRF5 transcript expression, IFN pathway enrichment and decreased expression of ROS pathway genes.

Conclusions

Altogether, data support that individuals carrying the IRF5-SLE risk haplotype are more susceptible to environmental/stochastic influences that trigger chronic immune activation, predisposing to the development of autoimmune diseases, such as SLE.

Background and Aims

The transcription factor interferon regulatory factor 5 (IRF5) is a central mediator of innate and adaptive immunity. Genetic variations within IRF5 associate with risk of systemic lupus erythematosus (SLE) and mice lacking Irf5 are protected from lupus onset and severity, but how IRF5 functions in the context of SLE disease progression remains unclear.

Methods

Buffy coats were prepared from fresh blood drawn from consented male and female healthy donors and SLE patients. SLE patients fulfilled at least four of the classification criteria for SLE as defined by the ACR. IRF5 activation was determined by imaging flow cytometry on an Amnis Imagestream X Mark II. In vivo studies were performed in NZB/W F1 and MRL/lpr models of murine lupus. IL6 and anti-dsDNA Ig levels were measure by ELISA. Proteinuria was measured by test strip and Bradford protein assay. Serum auto-antibodies were measured by ANA-HEp-2.

Results

In NZB/W F1 mice, we show that murine Irf5 is hyper-activated before clinical onset in a cell type-specific manner. In SLE patients, IRF5 hyper-activation correlated with SLEDAI and dsDNA titers. Treatment of NZB/W F1 and MRL/lpr mice with IRF5 inhibitor attenuated lupus pathology by reducing serum ANA and dsDNA titers, which alleviated kidney pathology and improved overall survival. In ex vivo human studies, inhibitor blocked SLE serum-induced IRF5 activation and reversed basal IRF5 hyper-activation in SLE immune cells.

Conclusions

Altogether, this study provides the first in vivo pre-clinical support for treating SLE patients with an IRF5 inhibitor.

Background and Aims

Autism spectrum disorder (ASD) affects 1 in 59 children in the US and yet, except for rare genetic causes, the etiology in most cases remains unknown. Increased inflammatory proteins and transcripts in the ASD brain reveals an activated innate immune response in a large proportion of cases. This study evaluates for adaptive immune cells and immune cell cytotoxic damage that could drive this innate immune response in ASD.

Methods

The quantity of immune cell subtype infiltrates, cytotoxic cellular debris, tissue loss and fibrosis are compared in ASD and control brains. Standard neuropathology diagnostics methods (histology and immunohistochemistry) are extended with automated image segmentation to quantify pathologic features.

Results

Multifocal perivascular lymphocytic cuffs have increased lymphocyte numbers in ~65% of ASD compared to control brains in males and females, in most brain regions, and in white and grey matter, and leptomeninges. CD3⁺ T-lymphocytes predominate over CD20⁺ B-lymphocytes and CD8⁺ over CD4⁺ T-lymphocytes in the ASD. Importantly, T-lymphocyte numbers correlate to the quantity of astrocyte-derived round membranous blebs, a known cytotoxic reaction to lymphocyte attack and a histologic feature so far unique to ASD. Consistent with an immune cell-mediated injury at perivascular CSF-brain barriers, a subset of white matter vessels has an expanded perivascular space with a jagged contour and increased collagen in ASD. Similar T-lymphocyte and astrocyte bleb pathology is also observed at pial and ependymal surfaces.

Conclusions

The findings suggest dysregulated cellular immunity may target damage of astrocytes at foci along the CSF-brain barrier in ASD.

Background and Aims

The excessive complement activation participated in the development of lupus nephritis (LN). Mesenchymal stem cells (MSCs) exhibit clinical efficacy for severe LN, however, it remains unknown whether MSCs could regulate complement activation. The present study aimed to investigate the dysregulaiton of the complement in LN, examine the effect of MSCs on lupus mice, and explore the possibility of MSCs regulating complement activation as well as the related mechanisms.

Methods

Levels of C5a, C5b-9, and clusterin (CLU) were detected in plasma and renal biopsy specimens. The effect of MSCs and cyclophosphamide was explored on B6.lpr mice. Levels of anti-dsDNA Ab, C3, C5a, C5b-9, and CLU were detected in mice. Histopathological evaluation was performed in renal tissues. Expressions of CLU were detected in MSCs stimulated by interferon-α (IFN-α). MSCs-derived CLU was purified and its functional characteristic was also identified.

Results

Significantly elevated activated complement C5 and decreased CLU were found in LN patients, which were correlated with proteinuria and pathological index. Compared to control mice, the proteinuria, proliferative glomerulonephritis, and depositions of IgG, C3 as well as C5b-9 were significantly reduced in MSCs-treated mice. Meanwhile, plasma C3 and CLU were significantly increased in these mice. Mechanistically, MSCs basally expressed CLU, and IFN-α stimulation promoted MSCs secreting CLU in vitro. Importantly, MSCs-derived CLU effectively inhibited complement C9 polymerization.

Conclusions

Dysregulaiton of complement of C5 was involved in the pathogenesis of LN. Allogeneic MSCs effectively improved the glomerulonephritis in lupus mice by limiting the effect of activated C5 via clusterin, which would be a novel therapeutic target for LN.

Background and Aims

Environmental factors have been shown to play a major role in autoimmune diseases; relatively little attention has been given to food components as possible modifiers of these disorders. We summarize the current body of knowledge related to different mechanisms and associations between food components and autoimmunity.

Methods

Because the conformational fit between food antigens and a host’s self-determinants has been determined for only a few food proteins, we used ELISA to examine the reactivity of affinity-purified disease-specific antibodies with different food antigens, and studied the reaction of monoclonal or polyclonal tissue-specific antibodies with various food antigens and the reaction of food-specific antibodies with human tissue antigens.

Results

Our results showed that antibodies made against different tissue antigens react with many food antigens, and food-specific antibodies react with various tissue antigens. For example, Sm-affinity-purified serum from lupus patients reacted strongly with soy, carrot, spinach and corn. Scl70-purified antibody from scleroderma patients reacted with wheat germ, peas, spinach and corn. Thyroid antibody showed strong reaction with 20 out of 204 tested foods, while amyloid-b peptide reacted with 10. Antibody to pancreatic islet cell reacted with many foods. Conversely, milk, corn, soy, egg, peanut, lectins and agglutinins reacted strongly with many tissue antigens.

Conclusions

We postulated that chemical modification of food proteins by toxicants in food may result in immune reaction against modified food proteins that cross-react with tissue antigens, resulting in autoimmune reactivity. Understanding the relationship between specific foods and autoimmunity can assist practitioners to formulate diets that may help prevent or ameliorate autoimmune disease.

Background and Aims

Introduction: Aluminum salts containing adjuvants, with or without HSA, have been used in vaccines for more than 70 years. The addition of aluminum to viral or bacterial antigens results in neoantigen formation. Increased consumption of processed foods is a major source of aluminum exposure, which makes the gut the main target of inflammation and autoimmunity. About 1% of ingested aluminum accumulates in the skeletal system and the brain, where aluminum induces the cross-linking of Aβ-42 peptide and the formation of amyloid aggregates that is observed in Alzheimer’s disease.

Methods

We used ELISA methodology to measure IgG antibody against HSA-bound aluminum compounds in 94 different sera from healthy controls and patients with rheumatoid arthritis (RA), Crohn’s, celiac, mixed connective tissue and Alzheimer’s disease.

Results

Our results demonstrated that in control groups the mean OD of aluminum-HSA IgG antibody was 0.58. In comparison, the mean level of aluminum-HSA antibody was 0.96 for Crohn’s , 1.0 for celiac, 1.25 for Alzheimer’s, 0.61 for RA, and 0.57 for mixed connective tissue disease. The differences in antibody level against aluminum-HSA were highly significant for Crohn’s, celiac and Alzheimer’s disease, less significant for RA, and insignificant for mixed connective tissue disease.

Conclusions

We demonstrate extensive IgG reactivity against aluminum bound to HSA in the sera of patients with Crohn’s, celiac and Alzheimer’s disease, to a lesser degree with RA, and not in mixed connective tissue disease. We concluded that aluminum ingestion and absorption from the GI tract contributes to some of these diseases.

Background and Aims

It is well established that the humoral immunity in antiphospholipid syndrome (APS) is presented by circulating pathogenic anti-β2GPI autoantibodies. These antibodies play a major role in the disease pathogenesis by targeting mainly domain I of the β2GPI protein. In the current trial, we had orally administered a domain-I derivative of the β2GPI molecule, in order to evaluate a new therapeutic approach: induction of oral tolerance in a mouse model of APS.

Methods

BALB/c mice immunized with β2GPI, were fed with either domain-I, domain-V or complete β2GPI molecule.

Results

β2GPI immunized mice developed experimental APS which were fed with domain-I significantly had decreased fetal loss (p<0.004), a lower size of thrombi (p<0.001) and lower circulating anti-β2GPI Abs in comparison to mice fed with domain-V or PBS (p<0.002). Likewise, Domain-I
fed mice had a lowered inflammatory response, exhibited by decreased expression of inflammatory cytokines (IFNγ, IL-6, IL-17) and elevated production of IL-10 anti-inflammatory cytokine by splenocytes. Moreover, the anti-inflammatory response in the domain-I fed APS mice was associated with alterations in circulating miRNAs, which is associated with immunomodulation of the immune network.

Conclusions

Our results show that DI-β2GPI fed APS mice developed tolerance scenario manifested by a reduction in fetal loss, thrombi size, inhibition of inflammatory cytokine production and upregulation of IL-10 and T regulatory cells. This sequence of events is associated with circulating plasma miRNA related to the immune network. Therefore we propose the DI-β2GPI derivative treatment for patients with APS.

Background and Aims

Applying for ISO 15189 accreditation remains a real challenge for specialized laboratories. In the field of autoimmunity, beside the crucial problem linked to the absence of standardization, laboratories have to manage the analytical performances of the large panel of assays available in the market. The evaluation of such performances involves not only the clinical relevance of the assays but also their measurement precision for which no reference values are available on biorepositories.

Methods

On an initiative of the French EASI (European Autoimmunity Standardization Initiative) group, French diagnostic biomedical laboratories were proposed to participate to a survey aiming to analyze the coefficients of variation (CVs) of intra-run and inter-run variability obtained with assays quantifying 14 different autoantibodies. Two performance goals corresponding to the 90^th percentile and the 50^th percentile defined for three levels of concentration were calculated. The impact on the assay performances of the number of measurements, the nature of the internal quality control (IQC) and the method, were also analyzed.

Results

436 and 651 values of intra-run and inter-run CVs, respectively, were collected. The 50^th percentile performance goals were comprised between 2.9% and 10.7% for the intra-run CVs, and between 2.8% and 13.2% for the inter-run CVs. CVs calculated from 10 values were similar to those obtained from more values. Higher imprecision was observed when the antibody levels of the IQC was lower than 2 fold the positive threshold.

Conclusions

Our results allow proposing some acceptability limits for the performances of the autoimmunity assays, compatible with real life in diagnostic laboratories.

Background and Aims

IgG4 autoimmune diseases are characterized by the presence of antigen-specific autoantibodies of IgG4 subclass, and contain well-characterised diseases such as MuSK myasthenia gravis, pemphigus and thrombotic thrombocytopenic purpura. Recently several new diseases were identified, and by now at least 21 antigens associated with IgG4 subclass are known. The IgG4 subclass is considered as immunologically inert and functionally monovalent The pathogenicity of IgG4 autoantibodies can be validated using our recently published classification system.

Methods

Using literature research, autoimmune diseases associated with IgG4 autoantibodies were identified. Clinical and immunological research data of identified diseases were critically reflected and the pathogenicity of the IgG4 autoantibodies was analysed using the classification system for IgG4 autoantibodies.

Results

As a result, one new class II and six new class III IgG4 autoimmune diseases were identified. New research data allowed a re-classification of Neurofascin-155 antibody associated CIDP as class I IgG4 autoimmune disease. IgG4 autoimmune diseases were found to be restricted to four distinct organs: 1) the central and peripheral nervous system, 2) the kidney, 3) the skin and mucous membranes and 4) the vascular system or soluble antigens in the blood circulation.

Conclusions

In conclusion, there are to date six class I (verified), five class II (likely) and ten class III IgG4 autoimmune diseases, of which five are class IIIa, with insufficient data and five class IIIb, which support pathogenic entities other than IgG4. The pathogenicity of IgG4 in IgG4 autoimmune diseases is associated with blocking of enzymatic activity or protein-protein interaction of their target antigen

Background and Aims

Renal involvement in anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis is associated with significant morbidity and higher mortality rates. This study examined clinical manifestations associated with renal involvement in ANCA-associated vasculitis within a large, international cross-sectional cohort.

Methods

Univariate and multivariate analyses were performed to identify clinical factors associated with renal disease, which was defined as i) a serum-creatinine > 30% above normal and a fall in creatinine-clearance > 25%; or ii) haematuria attributable to active vasculitis.

Results

The study cohort include 1230 patients from 31 countries; 723 (58.8%) presented with renal involvement: microscopic polyangiitis (82.2%), granulomatosis with polyangiitis (58.6%), and eosinophilic granulomatosis with polyangiitis (26.4%). The following clinical and laboratory factors were more common among patients with renal disease: age (p=0.001), fever (p<0.001), fatigue (p=0.005), weight loss (p=0.001), polyarthritis (p=0.036), petechiae/purpura (p=0.022), pulmonary haemorrhage (p=0.014), gastrointestinal symptoms (p=0.002), seizures (p=0.016), lower serum albumin (p<0.001), higher CRP (p=0.038), low serum C3 at baseline (p=0.015), myeloperoxidase- (p<0.001) and proteinase 3-ANCA (p=0.020). The following clinical factors were less common among patients with renal disease: mononeuritis multiplex (p=0.041), proptosis/exophthalmos (p=0.001), nasal polyps, septal defect/perforation (p<0.001 each), respiratory distress/pulmonary fibrosis/asthma (p<0.001), and wheeze/obstructive airway disease (p<0.001).

Conclusions

In this large international study, several clinical and laboratory factors were identified as associated with renal involvement in ANCA-associated vasculitis.

Background and Aims

In Kazakhstan, tocilizumab(TCZ) therapy was first authorized to treat systemic JIA(sJIA) patients in 2011 and, starting from 2014, it has been registered for poly-articular(pJIA) forms as well. TCZ was the only biologic registered in Kazakhstan for JIA therapy until 2015.

Methods

Data from children with JIA (n=81), who received TCZ in the 2011-2016 period, were retrospectively analyzed.

Results

TCZ was administered to 69 patients with sJIA and 12 patients with pJIA. Before TCZ, 53 patients received NSAIDs, DMARDs and glucocorticoids, whereas 28 patients immediately received it in monotherapy, due to the early onset of systemic manifestations.

In 96% of patients with sJIA, fever stopped after the first infusion and the skin manifestations completely resolved within 12 weeks in 85% of them; importantly, the articular involvement improved in all patients by 6 months. At this time point, TCZ was stopped in 23 patients and, eventually, only 3 of them relapsed and needed TCZ again.

As for pJIA, 11 patients reached the stage of inactive disease at 12 weeks of therapy. The ACRpedi 30/50/70/90 criteria at 6 months were fulfilled by 100%,75%,65% and 50% of these patients, respectively. The main factors of unfavorable prognosis resulted to be the disease duration before TCZ (>3 years) and the early onset of poly-articular involvement.

Seven patients had to stop TCZ for allergic reaction or leukopenia; 4 patients developed hepatitis, but needed only temporary suspension. One patient died, because of MAS.

Conclusions

TCZ has changed the JIA management in Kazakhstan/Central Asia and will improve its prognosis in these developing countries.

Background and Aims

Preeclampsia complicates about 10-17% of pregnancies with antiphospholipid syndrome (APS). It is often severe and might occur sometimes at early gestation. The development of preeclampsia before fetal viability is a huge challenge for obstetricians and demands an intensive discussion regarding the therapeutical options.

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Methods

We retrospectively reviewed the data of 7 women with primary APS who developed preeclampsia before 24 weeks of gestation.

Results

Plasma exchange had been performed in four of the cases and two women received corticosteroids. One of the women had received 20 mg of pravastatin daily, starting at 18 weeks of gestation. Neonatal outcome was: live birth in four cases and IUFD in three cases. The main pediatric complications were noted in a 28-week-old premature born boy, who developed severe IRDS and thrombocytopenia. At the present time, the boy continues to have a retarded status.

Conclusions

This retrospective analysis revealed that women with APS can develop severe preeclampsia even before 20 weeks of gestation. Several management options for prolongation of pregnancy such as plasma exchange, pravastatin, LMHW, hydroxychloroquine/HCQ, or TNF-alpha blocker should be discussed with the patients.

Optimal management of preeclampsia before 24 weeks of gestation usually depends on weighing the maternal and fetal complications from expectant management with prolongation of pregnancy versus the predominant fetal and neonatal risks of extreme prematurity from “aggressive” management with immediate delivery.