Occurrence Of Autoantibodies Research Articles

Effect of Leishmania infantum infection on B cell lymphopoiesis and memory in the bone marrow and spleen.

Visceral leishmaniasis (VL) is characterized by an uncontrolled infection of internal organs such as the spleen, liver and bone marrow (BM) and can be lethal when left untreated. No effective vaccination is currently available for humans. The importance of B cells in infection and VL protective immunity has been controversial, with both detrimental and protective effects described. VL infection was found in this study to increase not only all analyzed B cell subsets in the spleen but also the B cell progenitors in the BM. The enhanced B lymphopoiesis aligns with the clinical manifestation of polyclonal hypergammaglobulinemia and the occurrence of autoantibodies. In line with earlier reports, flow cytometric and microscopic examination identified parasite attachment to B cells of the BM and spleen without internalization, and transformation of promastigotes into amastigote morphotypes. The interaction appears independent of IgM expression and is associated with an increased detection of activated lysosomes. Furthermore, the extracellularly attached amastigotes could be efficiently transferred to infect macrophages. The observed interaction underscores the potentially crucial role of B cells during VL infection. Additionally, using immunization against a fluorescent heterologous antigen, it was shown that the infection does not impair immune memory, which is reassuring for vaccination campaigns in VL endemic areas.

Comparative Analysis of Laboratory-Scale Immunoglobulin G Purification Methods from Human Serum.

Immunoglobulin G (IgG) purification is a critical process for evaluating its role in autoimmune diseases, which are defined by the occurrence of autoantibodies. Affinity chromatography with protein G is widely considered to be the optimal technique for laboratory-scale purification. However, this technique has some limitations, including the exposure of IgG to low pH, which can compromise the quality of the purified IgG. Here, we show that alternative methods for IgG purification are possible while maintaining the quality of IgG. Different techniques for IgG purification from serum were evaluated and compared with protein G-based approaches: Melon Gel, caprylic acid-ammonium sulfate (CAAS) precipitation, anion-exchange chromatography with diethylamino ethyl (DEAE) following ammonium sulfate (AS) precipitation, and AS precipitation alone. The results demonstrated that the purification yield of these techniques surpassed that of protein G. However, differences in the purity of IgG were observed using GeLC-MS/MS. The avidity of purified IgG against selected targets (SARS-CoV-2 and topoisomerase-I) was similar between purified IgG obtained using all techniques and unpurified sera. Our work provides valuable insights for future studies of IgG function by recommending alternative purification methods that offer advantages in terms of yield, time efficiency, cost-effectiveness, and milder pH conditions than protein G.

Variations in the interferon and TLR3 genes may be associated with susceptibility to systemic lupus erythematosus and its clinical presentation

The study aimed to explore the pontential impact of 10 polymorphisms within IFN-α, IFN-β1, IFN-γ and TLR3 genes on SLE phenotype and susceptibility and to study the relationship between specific genotypes and clinics. Whole blood samples from SLE patients and healthy controls was obtained. DNA was extracted from the peripheral blood by the QIAamp DNA Blood Mini Kit (Qiagen). The quality and quantity of isolated DNA was estimated by the Quawell Q5000 spectrophotometer. We genotyped SLE patients and healthy subjects using real-time PCR (QuantStudio 5 thermocycler). The study suggests that IFN-γ rs2069705, IFN-γ rs2069718 and IFN-α rs3758236 polymorphisms have a protective role in SLE. We observed relations between TLR3 rs3775292, IFN-β1 rs7873167, IFN-γ rs2069705, TLR3 rs3775291 and TLR3 rs5743305 polymorphisms and clinical picture of SLE patients. We found associations between the IFN-α rs3758236, IFN-γ rs2069705, IFN-γ rs2069718, IFN-γ rs1861493 and IFN-β1 rs10964831 polymorphisms and the clinical manifestation of the SLE and/or its comorbidities. We perceived links between IFN-γ rs2069705, IFN-γ rs2069718, IFN-γ rs1861493, TLR3 rs3775291, TLR3 rs3775292 and TLR3 rs5743305 polymorphisms and the occurrence of autoantibodies. Our study presented the relationship between IFN and TLR gene polymorphisms with SLE susceptibility, phenotype and autoantibodies profile. This study propose that polymorphisms within interferons and TLR3 genes can be engaged in the SLE pathogenesis and course.

Prevalence of a large panel of systemic autoantibodies in the Bavarian adult population.

Autoimmune diseases commonly feature the presence of specific humoral autoantibodies. However, the prevalence of a large panel of systemic autoantibodies has never been assessed in the general population. We, therefore, described the prevalence of about 50 humoral systemic autoantibodies in a sample of the general Bavarian adult population. Non-fasting venous serum samples from 331 participants were analyzed for 7 autoantibody screening tests (nuclear, cytoplasmic, and mitotic ANA, ANCA, cANCA and pANCA, anti-ENA autoantibodies) and 44 different monospecific humoral non-organ specific/systemic autoantibodies using indirect immunofluorescence tests, ELISAs, and line blots. In order to assess associations between sex, age, BMI, education level, smoking status and the presence of systemic autoantibodies, logistic regression analyses were conducted. At least one screening test was positive in 29.9% of the participants, and 42.3% of the participants were seropositive for at least one monospecific autoantibody. The most frequently found monospecific autoantibodies were rheumatoid factor (35.6%), ß2-glycoprotein 1 IgM (4.8%), and cardiolipin IgG (1.8%). Only few associations between sex, age, BMI, education, smoking status and autoantibody frequencies were observed. Systemic autoantibodies are common in the general Bavarian population, and largely independent of sex, age, BMI, education, or smoking status. The study results may give orientation to clinicians about the occurrence of autoantibodies in the population, not (yet) associated with clinical symptoms.

Serum profiling identifies CCL8, CXCL13, and IL-1RA as markers of active disease in patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a clinically heterogeneous disease that presents a challenge for clinicians. To identify potential biomarkers for diagnosis and disease activity in SLE, we investigated a selected yet broad panel of cytokines and autoantibodies in patients with SLE, healthy controls (HC), and patients with other autoimmune diseases (AIDs). Serum samples from 422 SLE patients, 546 HC, and 1223 other AIDs were analysed within the frame of the European PRECISESADS project (NTC02890121). Cytokine levels were determined using Luminex panels, and autoantibodies using different immunoassays. Of the 83 cytokines analysed, 29 differed significantly between patients with SLE and HC. Specifically, CCL8, CXCL13, and IL-1RA levels were elevated in patients with active, but not inactive, SLE versus HC, as well as in patients with SLE versus other AIDs. The levels of these cytokines also correlated with SLE Disease Activity Index 2000 (SLEDAI-2K) scores, among five other cytokines. Overall, the occurrence of autoantibodies was similar across SLEDAI-2K organ domains, and the correlations between autoantibodies and activity in different organ domains were weak. Our findings suggest that, upon validation, CCL8, CXCL13, and IL-1RA could serve as promising serum biomarkers of activity in SLE.

Immunogenic lipid oxidation by oxidative stress in young people and the risk of early atherogenic endotelial dysfunction

Abstract Introduction The high presence of oxygen free radicals and low antioxidant enzymes values, trigger oxidative stress imbalance and lipid oxidation, with immunogenic potential, thus the occurrence of autoantibodies, with endothelial lesional effect, accelerating the onset of early atherogenesis. A high oxidative stress level in young people may also be involved in the development of non-lesional cardiac arrhythmias. Purpose Assessment of early atherogenic risk in young people with cardiac arrhythmias, with and without dyslipidemia, by determining oxidative stress profile, through specific antioxidant biomarkers (superoxide dismutase – SOD, glutathione peroxidase – GPx, and total antioxidant status – TAS), in relation to the development of lipid oxidation (oxidized low density lipoprotein – oxLDL) and autoantibodies anti-oxidized lipoprotein – anti-oxLDL), with a role in endothelial dysfunction. Patients and methods The research was conducted on 120 young subjects, 18–45 years old, divided into three equal groups: two groups (I, II) – subjects who presented non-lesional cardiac arrhythmic manifestations, 40 of them with dyslipidemia, 40 without dyslipidemia and a control group. SOD, GPx, TAS, as well as the lipid profile, oxLDL and anti-oxLDL antibodies were determined, in serum. Electrocardiogram and investigations were performed, in order to exclude a pre-existing cardiovascular pathology or conditions that may alter oxidative status and lipid profile. Results A decrease of antioxidant enzymes – SOD and GPx, as well as TAS was found, in patients with cardiac arrhythmias, with and without dyslipidemia. It was associated with an increased oxLDL level, as well as with the occurrence of anti-oxLDL autoantibodies. Compared to controls, both in arrhythmic patients with and without dyslipidemia, the mean values were reduced at 62–64% of the SOD activity, 68–74% of GPx and 52–54% of TAS, with increased mean values for oxLDL up to 206% in those with dyslipidemia and 161% in those without. OxLDL autoantibodies were also increased, 176% – 140%. Highly statistical correlations (p<0.001) were found between decreased SOD, GPx, TAS and increased oxLDL and anti-oxLDLox autoantibodies. The decrease of oxidative stress biomarkers was also correlated with the presence of non-lesional cardiac arrhythmias. Conclusions 1. Decreased antioxidant level is associated with accelerated lipid oxidation and the occurrence of anti-oxLDL autoantibodies. 2. Increased values of oxLDL and anti-oxLDL autoantibodies promote the onset of early endothelial lesions, triggering subclinical atherosclerosis. 3. The presence of oxidative stress associates the occurrence of non-lesional arrrhythmias in young people, as well as the risk of autoimmunity through anti-oxLDL antibodies. 4. Oxidized LDL increased to 206% and anti-oxLDL autoantibodies to 176% in both dyslipidemic and non-dyslipidemic patients, trigger a highly increased atherogenic risk. Funding Acknowledgement Type of funding sources: None.

Microvascular capillaroscopic abnormalities and occurrence of antinuclear autoantibodies in patients with sarcoidosis

We described nailfold videocapillaroscopy (NVC) findings and estimated the prevalence of serum anti-nuclear (ANA) and extractable nuclear antigen autoantibodies (ENA) in a cohort of sarcoidosis patients, comparing them with adequate healthy controls (HCs) and with primary Raynaud’s phenomenon patients (PRPs). NVC findings were also correlated with the occurrence of autoantibodies, current treatment, laboratory parameters, variables of lung function and whole-body imaging data. Twenty-six patients with sarcoidosis were assessed through NVC, laboratory parameters, pulmonary function tests, chest-X ray and 18- fluorodeoxyglucose positron emission tomography/computed tomography. The NVC parameters and ANA/ENA dosage were recorded also in 30 PRPs and 30 HCs. Sarcoidosis patients showed a higher rate of capillary dilations and nonspecific abnormalities and a lower mean capillary absolute number than PRPs and HCs (p < 0.01 for all comparisons). The prevalence of ANA positivity was higher in patients with sarcoidosis compared with PRPs and HCs (p < 0.02 for both), whereas ENA positivity was detected in one sarcoidosis patient (Ro52). Among sarcoidosis patients, the mean capillary absolute number negatively correlated with the C-reactive protein concentrations and was positively associated with the forced vital capacity percentage. Instead, a negative correlation was detected between serum ACE levels and the presence of capillary dilations (all p < 0.05). Our findings suggest a microvascular involvement in sarcoidosis whose investigation by NVC might be useful for the follow-up of patients displaying RP. Autoantibody positivity in sarcoidosis might suggest autoimmune implications in the disease or the production of autoantibodies reactive to tissue damage.

Occurrence of autoantibodies against skin proteins in patients with hereditary epidermolysis bullosa predisposes to development of autoimmune blistering disease.

Skin blistering disorders are associated with inherited defects in proteins involved in the dermal-epidermal adhesion or autoantibodies targeting those proteins. Although blistering in hereditary epidermolysis bullosa (EB) is pathogenetically linked to genetic deficiency of distinct proteins of the epidermis or the dermal-epidermal junction, circulating autoantibodies against these proteins have also been identified in EB patients. So far, autoantibodies have been considered bystanders in EB and active pathogenicity of them in EB has not been disclosed. In sera of a cohort of 258 EB patients, we found by ELISA in 22% of the patients autoantibodies against the bullous pemphigoid antigen BP180. The titers correlated negatively with collagen VII skin expression and positively with disease severity. Among those patients, we identified six (2.33%) with clinical features of an autoimmune bullous disorder (AIBD) and positive indirect immunofluorescence (IIF) staining. In literature, we found four more cases of EB patients developing disease-aggravating AIBD. Co-existence of these two rare skin disorders suggests that EB patients have a predisposition for the development of AIBD. Our work highlights that EB patients with increased itch or blister formation should be evaluated for additional AIBD and repeated screening for changes in autoantibody titers and skin-binding specificities is advised.

The Spectrum of Autoantibodies in Adult Patients With Idiopathic Pulmonary Hemosiderosis: A Brief Review of the Literature.

While autoimmune antibodies or autoantibodies have been reported sporadically in adult patients with idiopathic pulmonary hemosiderosis (IPH), their true prevalence is unknown. The question as to whether any difference exists between antibody-positive and negative patients has not been explored. The primary objective of this paper was to assess the spectrum of autoantibody testing and its positivity rate. The other objectives included a comparative analysis of demographics, symptom onset, clinical manifestations, and differences in clinical outcomes between antibody-positive (cohort A) and negative (cohort B) patients. To that end, we conducted a retrospective review of the relevant published literature. Multiple databases were searched to retrieve studies published between 1990 and 2022.A total of 35 studies, involving 38 patients, were identified. Five of these patients had a positive autoantibody. Patients in cohort A were older and more likely to be male. The frequencies of testing for these antibodies were as follows: antineutrophil cytoplasmic antibody (ANCA): 37/38 (97.4%), antinuclear antibody (ANA): 31/38 (81.6%), and anti-glomerular basement membrane antibody (anti-GBM): 30/38 (78.9%); 5/38 (13.2%) patients tested positive for an autoantibody, and two of these patients were positive for ANA, two for antithyroid antibody, and one patient tested positive for ANCA, rheumatoid factor (RF), and granulocyte monocyte-colony stimulating factor (GM-CSF) antibody. There was no difference between the cohorts regarding their clinical presentations, recurrence risks, and survival.The occurrence of autoantibodies is uncommon in adult IPH patients. This is in contrast with the pediatric IPH patient population, where the prevalence is much higher (26.4% vs. 13.2%), and the antibodies are more diverse. Unlike pediatric patients, adult patients with autoantibodies do not necessarily have worse outcomes.

Species-specific accumulation of ceramides in cerebrospinal fluid from encephalomyeloradiculoneurpathy patients associated with peripheral complement activation: A pilot study

Glycolipids are now known to be rapidly converted to mediators for inflammatory reactions or to signaling molecules that control inflammatory events in the nervous system. The present study aimed to explore whether disturbed glycolipids metabolism in the nervous system is present in patients with a neuroinflammatory disorder, encephalo-myelo-radiculo-neuropathy (EMRN), because most EMRN patients have been reported to exhibit autoantibodies against neutral glycolipids. Although molecular pathogenesis of this disorder remains unknown, we tried to search the immunochemical abnormalities in this disorder. ELISA for activated peripheral C5 complement and mass spectrometry analysis of cerebrospinal fluid clearly disclosed a significant upregulation of active C5 complement, C5a levels in sera as well as a significant accumulation of species-specific ceramides but not sphingomyelin in cerebrospinal fluid from EMRN patients. Furthermore, we confirmed the occurrence of anti-neutral glycolipids antibodies in all EMRN patients.Thus, the present study might indicate the pathophysiology of this disorder is the dysregulation of glycolipids metabolism and abnormal production of autoantibodies against neutral glycolipids resulting in the abnormal complement activation, although molecular basis for these sphingolipids dysregulation and the occurrence of autoantibodies against glycolipids remains to be elucidated at present. The present study implicates a new therapeutic strategy employing anti-ceramide and/or anti-complement therapy for this disorder.

Autoantibodies against complement component C1q in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is the archetype of a systemic autoimmune disease, but the multifaceted pathogenic mechanisms leading to inflammation and organ damage are not fully understood. Homozygous deficiency of complement C1q, the first component of the classical pathway of complement, is strongly associated with the development of SLE, thus pointing at a primarily protective role of C1q. However, while most SLE patients do not have hereditary C1q deficiency, there is indirect evidence for the importance of C1q in the inflammatory processes of the disease, including hypocomplementemia as a result of activation via the classical pathway, deposition of C1q in affected tissues and the occurrence of autoantibodies against C1q (anti‐C1q). The growing body of knowledge on anti‐C1q led to the establishment of a biomarker that is used in the routine clinical care of SLE patients. Exploring the binding characteristics of anti‐C1q allows to understand the mechanisms, that lead to the expression of relevant autoantigenic structures and the role of genetic as well as environmental factors. Lastly, the analysis of the pathophysiological consequences of anti‐C1q is of importance because C1q, the target of anti‐C1q, is a highly functional molecule whose downstream effects are altered by the binding of the autoantibody. This review summarises current study data on anti‐C1q and their implications for the understanding of SLE.

Correction to: Atopic dermatitis and autoimmunity: the occurrence of autoantibodies and their association with disease severity.

Two of the references included in this review concern antigens derived from the fungus Malassezia globosa that have also been found in human sweat.

A Three-Part, Randomised Study to Investigate the Safety, Tolerability, Pharmacokinetics and Mode of Action of BC 007, Neutraliser of Pathogenic Autoantibodies Against G-Protein Coupled Receptors in Healthy, Young and Elderly Subjects.

Background and ObjectiveBC 007 is a substance with a novel and innovative mode of action for the first-time causal treatment of chronic heart failure, associated with the occurrence of autoantibodies against the β1-adrenoceptor, and other diseases of mostly the heart and vascular system, being accompanied by the occurrence of functionally active agonistic autoantibodies against G-protein-coupled receptors (fGPCR-AAb). The proposed mechanism of action of BC 007 is the neutralisation of these pathogenic autoantibodies which stimulate the respective receptor. To evaluate the safety, tolerability, pharmacokinetics and mode of action of BC 007, single intravenous infusions of increasing concentration were given to healthy young males and healthy elderly autoantibody-negative and autoantibody-positive participants of both sexes.MethodsThis study was subdivided into three parts. Part A was a single-centre, randomised, double-blind, placebo-controlled safety and tolerability study including healthy young male autoantibody-negative Whites (N = 23) and Asians (N = 1), testing doses of 15, 50 and 150 mg BC 007 (Cohorts 1–3) and elderly male and female Whites (N = 8), testing a dose of 150 mg BC 007 (Cohort 4), randomly assigned in a 3:1 ratio to BC 007 or placebo. Open-label Part B included fGPCR-AAb-positive subjects (50 and 150 mg BC 007, Cohorts 1 and 2, respectively). Open-label Part C included fGPCR-AAb-positive subjects for testing doses of 300, 450, 750, 1350 mg and 1900 mg BC 007. Lower doses were either given as an infusion or divided into a bolus plus infusion up to a dose of 300 mg followed by a constant bolus of 150 mg up to a dose of 750 mg, while at doses of 1350 mg and 1900 mg it was a slow infusion with a constant infusion rate. Infusion times increased with increasing dose from 20 min (15, 50 or 150 mg) to 40 min (300, 450 or 750 mg), 75 min (1350 mg) and 105 min (1900 mg).ResultsThe mean observed BC 007 area under the concentration–time curve (AUC0–24) increased with increasing dose in a dose proportional manner (slope estimate of 1.039). No serious adverse events were observed. Drug-related adverse events were predominantly the expected mild-to-moderate increase in bleeding time (aPTT), beginning with a dose of 50 mg, which paralleled the infusion and returned to normal shortly after infusion. fGPCR-AAb neutralisation efficiency increased with increasing dose and was achieved for all subjects in the last cohort.ConclusionBC 007 is demonstrated to be safe and well tolerated. BC 007 neutralised fGPCR-AAb, showing a trend for a dose-response relationship in elderly healthy but fGPCR-AAb-positive subjects.ClinicalTrials.gov Registration NumberNCT02955420.

Vaccine immune response, autoimmunity and morbidity after neonatal blood exchange transfusion

IntroductionA blood exchange transfusion (BET) is most commonly performed to treat severe neonatal haemolytic disease. A distinct form of blood transfusion adverse reaction is transfusion-related immunomodulation. The purpose of our retrospective single-centre case-control cohort study was to investigate whether a blood exchange transfusion in the neonatal period provokes immunomodulation and affects humoral immune response to vaccination, morbidity and occurrence of autoantibodies. MethodsStudy subjects were 74 apparently healthy children, who were born at term as appropriate for gestational age and received four doses of diphtheria and tetanus toxoid vaccine. Forty-one received BET due to neonatal hemolytic disease and no other blood product afterwards, while 33 did not receive any blood products. Analysis of diphtheria, tetanus and autoimmune antibodies was performed and their medical records were analyzed for infectious, allergic, cancerous and autoimmune diseases. ResultsA clearly exaggerated immune response to diphtheria (1.016 IU/mL, 95% confidence interval (CI) 0.662–1.369 IU/mL vs. 0.515 IU/mL, 95% CI 0.363 to 0.626 IU/mL, P = 0.011) and slightly exaggerated immune response to tetanus vaccine (1.798 IU/mL, 95% CI 1.180–2.416 IU/mL vs. 1.036 IU/mL, 95% CI 0.398–1.673 IU/mL, P = non-specific) were observed in BET subjects. A propensity towards autoimmunity (25.8% vs. 12.5%, P = non-specific) was observed in BET subjects. However, BET in the neonatal period did not influence the occurrence of bacterial, childhood viral diseases with exception of varicella (43.9% vs. 21.2%, P = 0.040), autoimmune and cancer diseases. ConclusionBET impacted humoral immune response to diphtheria and tetanus vaccine and occurrence of autoimmune antibodies, but did not affect morbidity and the occurrence of autoimmune diseases. These effects could be related to massive antigenic load of BET and an accelerated priming of immune cells and consequent immunomodulation.

Effect of antithyroid drugs on the occurrence of antibodies against type 2 deiodinase (DIO2), which are involved in hyperthyroid Graves’ disease influencing the therapeutic efficacy

Graves' disease is an organ-specific autoimmune disease with hyperthyroidism, diffuse goiter and autoantibodies against TSH receptor, thyroid peroxidase (TPO) and/or thyroglobulin (Tg). Graves' hyperthyroidism is characterized by T3 dominance due to the conversion of T4 into T3 through type 1 and 2 deiodinase enzymes (DIO1, DIO2). Methimazole (MMI) and propylthiouracil (PTU) therapies inhibit thyroid hormone synthesis blocking the activity of deiodinase and TPO enzymes. The study investigated the occurrence of autoantibodies against DIO2 peptides (cys- and hom-peptides) with the effect of antithyroid drugs on their frequencies in 78 patients with Graves' disease and 30 controls. In hyperthyroidism, the presence of DIO2 peptide antibodies was as follows: 20 and 11 cases out of 51 for cys- and hom-peptide antibodies, respectively, of whom 8 cases possessed antibodies against both peptides. Antithyroid drugs differently influenced their frequencies, which were greater in PTU than in MMI (3/6 vs 13/45 cases, P < 0.016 for cys- and 0/6 vs 2/45 cases for hom-peptide antibodies). Antibodies against both peptides demonstrated more reduced levels of anti-TPO (P < 0.003) and anti-Tg antibodies (P < 0.002) compared with those without peptide antibodies. PTU compared with MMI increased the levels of TSH receptor antibodies (32.5 UI/l vs 2.68IU/l, P < 0.009). MMI treatment led to more reduced FT3 levels and FT3/FT4 ratios in hyperthyroid Graves' ophthalmopathy (P < 0.028 for FT3, P < 0.007 for FT3/FT4 ratio). In conclusion, the presence of DIO2 peptide antibodies is connected to Graves' hyperthyroidism influencing the levels of antibodies against TPO, Tg and TSH receptor, as well as the therapeutic efficacy of antithyroid drugs.

Stabilized Cyclic Peptides as Scavengers of Autoantibodies: Neutralization of Anticitrullinated Protein/Peptide Antibodies in Rheumatoid Arthritis.

The occurrence of autoantibodies is a hallmark of rheumatoid arthritis, specifically those autoantibodies targeting proteins containing the arginine-derived amino acid citrulline. There is strong evidence showing that the occurrence of anticitrullinated protein/peptide antibodies (ACPA) are involved in disease progression, and ACPA was recently shown to induce pain in animals. Here, we explore a novel concept useful for research, diagnostics, and possibly therapy of autoimmune diseases, namely, to directly target and neutralize autoantibodies using peptide binders. A high-affinity peptide-based scavenger of ACPA was developed by grafting a citrullinated epitope derived from human fibrinogen into a naturally occurring stable peptide scaffold. The best scavenger comprises the truncated epitope α-fibrinogen, [Cit573]fib(566-580), grafted into the scaffold sunflower trypsin inhibitor-1, SFTI-1. The final peptide demonstrates low nanomolar apparent affinity and superior stability.

Functional and phenotypic analysis of basophils allows determining distinct subtypes in patients with chronic urticaria.

Chronic urticaria (CU) is a frequent skin disease characterized by relapsing appearance of pruritic hives. While clinical symptoms are due to the release of histamine by cutaneous mast cells, the underlying pathophysiology is still unknown. However, previous studies indicate that basophils might be of relevance. Besides, the occurrence of autoantibodies against IgE or its receptor, FcεRI, and the therapeutic efficacy of anti-IgE antibodies imply that IgE-mediated mechanisms also play an important role in CU. Reactivity of CU patients' peripheral blood basophils (n=60) to specific anti-FcεRI and IgE-independent fMLP stimulation was determined by basophil activation test in comparison with patients suffering from IgE-mediated allergic rhinitis (n=10) and healthy controls (n=10). In addition, immunoglobulin receptor (FcεRI, FcγRII) expression and surface bound antibodies (IgE, IgG) were quantified on basophils. Furthermore, the autoreactive capacity of CU sera was evaluated and urticaria-related symptoms were assessed by both UCT and CU-Q2 oL. Stimulating CU patients' basophils via FcεRI, we identified three distinct immunologic phenotypes. One subgroup of patients' basophils reacted to FcεRI stimulation, whereas the others had anti-FcεRI nonreactive basophils. Among the latter, a subgroup with pronounced basopenia was identified. Of note, this group was characterized by augmented serum-induced basophil activation, increased levels of autoantibodies against thyroid peroxidase, and also exhibited the strongest disease impact on their quality of life. Patients with CU can be categorized into three immunologic subgroups based on their basophil reactivity and frequency. These phenotypes are associated with different clinical characteristics, pointing to basophils as important players in CU pathophysiology.

The occurrence of autoantibodies in patients with chronic HCV infection, including patients dialyzed and after kidney transplantation.

IntroductionThere are reports suggesting that hepatitis C virus (HCV) may stimulate the autoimmune process. Studies have been undertaken to evaluate the occurrence and type of autoantibodies in HCV-infected patients with and without immunosuppression. Results were analyzed according to HCV genotype, intensity of inflammation and liver fibrosis stage.Material and methodsThe study included 105 patients chronically infected with HCV, including 25 with immunological suppression administered for kidney disease or kidney transplantation. Blood samples were tested by immunoblotting for the presence of AMA-M2, SLA/LP, LKM-1, LC1, anti-F-actin, anti-desmin, anti-myosin, anti-gp210 and anti-sp100 autoantibodies, and ANA. All the patients were scored for autoimmune hepatitis.ResultsAutoantibodies were detected in 32.5% of patients without immunosuppression and in 16% with immunosuppression. Single types of autoantibodies were identified in 26% of patients. The most frequent ones were ANA (19%) and AMA-M2 (5.7%). The presence of antibodies in patients with genotype 1 was significantly higher in comparison to their occurrence in genotype 3. Autoimmune hepatitis was not diagnosed in any of the patients. Immunoglobulin G level was significantly higher in patients with detectable autoantibodies, compared to patients without antibodies (1.89 vs. 1.28 g/dl, p < 0.001). No correlation between fibrosis stage or intensity of inflammatory state and the frequency of antibodies was found.ConclusionsThe antibodies are significantly more frequent in patients without immunosuppression and in patients infected with genotype 1 than genotype 3. The presence of these autoantibodies is not associated with the development of autoimmune hepatitis. Higher level of immunoglobulin G in the serum correlates with the presence of autoantibodies.

Ethylmercury and Hg2+ induce the formation of neutrophil extracellular traps (NETs) by human neutrophil granulocytes.

Humans are exposed to different mercurial compounds from various sources, most frequently from dental fillings, preservatives in vaccines, or consumption of fish. Among other toxic effects, these substances interact with the immune system. In high doses, mercurials are immunosuppressive. However, lower doses of some mercurials stimulate the immune system, inducing different forms of autoimmunity, autoantibodies, and glomerulonephritis in rodents. Furthermore, some studies suggest a connection between mercury exposure and the occurrence of autoantibodies against nuclear components and granulocyte cytoplasmic proteins in humans. Still, the underlying mechanisms need to be clarified. The present study investigates the formation of neutrophil extracellular traps (NETs) in response to thimerosal and its metabolites ethyl mercury (EtHg), thiosalicylic acid, and mercuric ions (Hg(2+)). Only EtHg and Hg(2+) triggered NETosis. It was independent of PKC, ERK1/2, p38, and zinc signals and not affected by the NADPH oxidase inhibitor DPI. Instead, EtHg and Hg(2+) triggered NADPH oxidase-independent production of ROS, which are likely to be involved in mercurial-induced NET formation. This finding might help understanding the autoimmune potential of mercurial compounds. Some diseases, to which a connection with mercurials has been shown, such as Wegener's granulomatosis and systemic lupus erythematosus, are characterized by high prevalence of autoantibodies against neutrophil-specific auto-antigens. Externalization in the form of NETs may be a source for exposure to these self-antigens. In genetically susceptible individuals, this could be one step in the series of events leading to autoimmunity.

Antinuclear antibodies defining autoimmunity pathways

Immunofluorescent imaging has been a powerful technique in helping to identify intracellular nuclear and cytoplasmic molecules which are target antigens of autoantibodies in systemic autoimmune disorders. Patterns of staining can be correlated with molecules engaged in specific cellular functions and distributed in distinct cellular domains. Different autoimmune disorders have different profiles of autoantibodies, and immunodiagnostics has become an important adjunct in differential diagnosis. An important finding that has eluded explanation is the presence of autoantibodies to many different antigens, manifested strikingly in systemic lupus erythematosus. In cancer, the occurrence of autoantibodies to tumor-associated antigens is not uncommon and a characteristic feature is also the presence of multiple autoantibodies. The targeted tumor-associated antigens are either oncogene or tumor suppressor gene products or their coactivators, which are altered or mutated and driving the autoimmune response. Most cancer cells have between two and eight mutated genes before oncogenic transformation occurs, initiating a process called synthetic lethality in tumorigenesis pathways. These observations beg the question of whether there are similar mechanisms in systemic lupus erythematosus and other disorders driving autoimmunity pathways. Targeting molecules that are synthetic lethal to each other is in the forefront of the search for anticancer therapy, and this could also be an objective in systemic autoimmune disorders.