Systemic lupus erythematosus (SLE) is a clinically heterogeneous, systemic autoimmune disease characterized by autoantibody formation. Previously published genome-wide association studies (GWAS) have ...investigated SLE as a single phenotype. Therefore, we conducted a GWAS to identify genetic factors associated with anti-dsDNA autoantibody production, a SLE-related autoantibody with diagnostic and clinical importance. Using two independent datasets, over 400,000 single nucleotide polymorphisms (SNPs) were studied in a total of 1,717 SLE cases and 4,813 healthy controls. Anti-dsDNA autoantibody positive (anti-dsDNA +, n = 811) and anti-dsDNA autoantibody negative (anti-dsDNA -, n = 906) SLE cases were compared to healthy controls and to each other to identify SNPs associated specifically with these SLE subtypes. SNPs in the previously identified SLE susceptibility loci STAT4, IRF5, ITGAM, and the major histocompatibility complex were strongly associated with anti-dsDNA + SLE. Far fewer and weaker associations were observed for anti-dsDNA - SLE. For example, rs7574865 in STAT4 had an OR for anti-dsDNA + SLE of 1.77 (95% CI 1.57-1.99, p = 2.0E-20) compared to an OR for anti-dsDNA - SLE of 1.26 (95% CI 1.12-1.41, p = 2.4E-04), with p(heterogeneity)<0.0005. SNPs in the SLE susceptibility loci BANK1, KIAA1542, and UBE2L3 showed evidence of association with anti-dsDNA + SLE and were not associated with anti-dsDNA - SLE. In conclusion, we identified differential genetic associations with SLE based on anti-dsDNA autoantibody production. Many previously identified SLE susceptibility loci may confer disease risk through their role in autoantibody production and be more accurately described as autoantibody propensity loci. Lack of strong SNP associations may suggest that other types of genetic variation or non-genetic factors such as environmental exposures have a greater impact on susceptibility to anti-dsDNA - SLE.
Paraneoplastic optic neuropathy (PON) is relatively uncommon, and the visual outcomes and prognosis of this disease have not been well documented. The aim of this study was to investigate the ...clinical features and prognosis of antibody-mediated PON.
Clinical data were retrospectively collected from hospitalised patients diagnosed with PON at the Neuro-Ophthalmology Department at the Chinese People's Liberation Army General Hospital from January 2015 to June 2017.
A total of seven patients (four females and three males, 13 involved eyes) were included with a mean age of 56.28±11.32 years (36-70 years). Simultaneous or early sequential bilateral eye involvement (5/7, 71.4%) was common in the patients with PON. Severe vision loss (≤0.1) was seen in 76.9% (10/13) of the eyes. There were 13 eyes in the acute phase of the disease, and six eyes presented with optic disc oedema. All patients had definite evidence of paraneoplastic-associated antibodies (three with serum positive for antiamphilphysin, one for anti-PNMA2 (Ma2/Ta), one for anti-Yo, one for anti-Ma2 and one for anti-CV2). All of the serum samples were negative for myelin oligodendrocyte glycoprotein antibody and two patients companied with seropositive for the aquaporin-4 antibody. Five patients had history of primary malignancy, including thyroid cancer, type B thymoma, testicular seminoma, cervical cancer and lung carcinoma. Two patients had positive paraneoplastic syndrome antibodies (anti-Yo and antiamphiphysin), but the solid tumour had not been found through a PET scan. Visual acuity in 9/13 (69.2%) eyes was below 0.1, and all of the patients survived to the follow-up with no metastatic lesions.
PON is relative rare, with a predominance of bilateral involvement and more with a poor visual prognosis. Paraneoplastic antibody testing can contribute to the diagnosis of PON, distinct from other types of optic neuropathies, which can help doctors to find the primary cancer earlier to guide further treatment.
Background
Serum anti‐myenteric autoantibodies define autoimmune achalasia and tissue MMP‐9 activity may locally process autoantigenic proteins in the muscle of the lower esophageal sphincter (LES) ...of achalasia patients.
Methods
Biopsies of the LES muscle from 36 achalasia patients, 6 esophagogastric junction outflow obstruction (EGJOO) patients, and 16 transplant donors (TD) were compared in a blind cross‐sectional study. Histological characteristics such as inflammation, fibrosis, presence of ganglion cells, cells of Cajal, GAD65, PNMA2, S‐100, P substance, and MMP‐9 proteoforms in tissue were assessed by H&E and Picrosirius Red staining and immunohistochemistry analysis. Anti‐neuronal antibodies, onconeural antigens, recoverin, SOX‐1, titin, zic4, GAD65, and Tr were evaluated by immunoblot/line assay.
Key Results
Tissue of achalasia patients had heterogeneous inflammatory infiltrates with fibrosis and contrasting higher levels of activated MMP‐9, as compared with EGJOO and TD. Moreover, lower ganglion cell percentages and cell of Cajal percentages were determined in esophageal tissues of achalasia patients versus TD. The tissues of achalasia versus EGJOO patients had higher GAD65 and PNMA2 protein expression. Unexpectedly, these proteins were absent in TD tissue. S‐100 and P substance had similar expression levels in tissues of achalasia patients versus TD and EGJOO. Most of the achalasia sera had anti‐GAD65 (83%) and anti‐PNMA2 (90%) autoantibodies versus EGJOO (17% and 33%, respectively) and healthy volunteers (10% and 0%, respectively).
Conclusions and Inferences
Tissue‐specific ectopic expression of GAD65 and PNMA/Ta2 and active MMP‐9, associated with the presence of specific autoantibodies directed against these proteins, might participate in the pathophysiology of achalasia triggering and/or perpetuating autoimmune disease.
Tissue‐specific ectopic expression of GAD65 and PNMA/Ta2 and active MMP‐9, associated with the presence of specific autoantibodies directed against these proteins, might participate in the pathophysiology of achalasia triggering and/or perpetuating autoimmune disease.
Aims/hypothesis
Autoantibodies that precede type 1 diabetes frequently develop in early childhood and target distinct beta cell proteins. The aim of this study was to determine the heterogeneity of ...islet autoantibody development and fate.
Methods
The ages of development of insulin autoantibodies (IAA) and GAD autoantibodies (GADA), followed by multiple islet autoantibodies and progression to diabetes were examined in 2,441 children participating in two German birth cohorts.
Results
In 218 children who developed islet autoantibodies, the first islet autoantibody-positive sample was characterised by single IAA in 80 (37%), multiple islet autoantibodies in 68 (31%) and single GADA in 63 (29%) children. Of the children who were single antibody positive at seroconversion, 35 (44%) IAA-positive and 15 (24%) GADA-positive children developed multiple islet autoantibodies. Single persistent antibodies had heterogeneous affinities; GADA were also heterogeneous in their binding to N-terminally truncated GAD65 and in an ELISA. Progression to diabetes occurred in >50% of children within 10 years in all groups that developed multiple islet autoantibodies and in 44% of children with persistent single high-affinity IAA or persistent single GADA that were positive in both a radiobinding assay and ELISA. The earliest autoantibody development was seen in children with single IAA that progressed to multiple islet autoantibodies or in those with persistent high-affinity single IAA, with a sharp peak in incidence observed at age 9 months. The peak incidence occurred at age 2 years for children who underwent seroconversion directly to multiple islet autoantibodies and at 5 years for children who first seroconverted to GADA and subsequently developed other autoantibodies. Seroconversion to low-affinity IAA or persistent single GADA occurred at a low incidence after the age of 9 months.
Conclusions/interpretation
Children of different ages have differing susceptibilities to autoimmunisation against specific beta cell autoantigens.
Severe acute exacerbations (AE) of idiopathic pulmonary fibrosis (IPF) are medically untreatable and often fatal within days. Recent evidence suggests autoantibodies may be involved in IPF ...progression. Autoantibody-mediated lung diseases are typically refractory to glucocorticoids and nonspecific medications, but frequently respond to focused autoantibody reduction treatments. We conducted a pilot trial to test the hypothesis that autoantibody-targeted therapies may also benefit AE-IPF patients.
Eleven (11) critically-ill AE-IPF patients with no evidence of conventional autoimmune diseases were treated with therapeutic plasma exchanges (TPE) and rituximab, supplemented in later cases with intravenous immunoglobulin (IVIG). Plasma anti-epithelial (HEp-2) autoantibodies and matrix metalloproteinase-7 (MMP7) were evaluated by indirect immunofluorescence and ELISA, respectively. Outcomes among the trial subjects were compared to those of 20 historical control AE-IPF patients treated with conventional glucocorticoid therapy prior to this experimental trial.
Nine (9) trial subjects (82%) had improvements of pulmonary gas exchange after treatment, compared to one (5%) historical control. Two of the three trial subjects who relapsed after only five TPE responded again with additional TPE. The three latest subjects who responded to an augmented regimen of nine TPE plus rituximab plus IVIG have had sustained responses without relapses after 96-to-237 days. Anti-HEp-2 autoantibodies were present in trial subjects prior to therapy, and were reduced by TPE among those who responded to treatment. Conversely, plasma MMP7 levels were not systematically affected by therapy nor correlated with clinical responses. One-year survival of trial subjects was 46+15% vs. 0% among historical controls. No serious adverse events were attributable to the experimental medications.
This pilot trial indicates specific treatments that reduce autoantibodies might benefit some severely-ill AE-IPF patients. These findings have potential implications regarding mechanisms of IPF progression, and justify considerations for incremental trials of autoantibody-targeted therapies in AE-IPF patients.
ClinicalTrials.gov NCT01266317.
A role for B cells in autoimmune diseases is now clearly established both in mouse models and humans by successful treatment of multiple sclerosis and rheumatoid arthritis with anti‐CD20 monoclonal ...antibodies that eliminate B cells. However, the underlying mechanisms by which B cells promote the development of autoimmune diseases remain poorly understood. Here, we review evidence that patients with autoimmune disease suffer from defects in early B‐cell tolerance checkpoints and therefore fail to counterselect developing autoreactive B cells. These B‐cell tolerance defects are primary to autoimmune diseases and may result from altered B‐cell receptor signaling and dysregulated T‐cell/regulatory T‐cell compartment. As a consequence, large numbers of autoreactive naive B cells accumulate in the blood of patients with autoimmune diseases and may promote autoimmunity through the presentation of self‐antigen to T cells. In addition, new evidence suggests that this reservoir of autoreactive naive B cells contains clones that may develop into CD27−CD21−/lo B cells associated with increased disease severity and plasma cells secreting potentially pathogenic autoantibodies after the acquisition of somatic hypermutations that improve affinity for self‐antigens.
Summary Background Autoimmunity might be associated with or implicated in sleep and neurodegenerative disorders. We aimed to describe the features of a novel neurological syndrome associated with ...prominent sleep dysfunction and antibodies to a neuronal antigen. Methods In this observational study, we used clinical and video polysomnography to identify a novel sleep disorder in three patients referred to the Sleep Unit of Hospital Clinic, University of Barcelona, Spain, for abnormal sleep behaviours and obstructive sleep apnoea. These patients had antibodies against a neuronal surface antigen, which were also present in five additional patients referred to our laboratory for antibody studies. These five patients had been assessed with polysomnography, which was done in our sleep unit in one patient and the recording reviewed in a second patient. Two patients underwent post-mortem brain examination. Immunoprecipitation and mass spectrometry were used to characterise the antigen and develop an assay for antibody testing. Serum or CSF from 298 patients with neurodegenerative, sleep, or autoimmune disorders served as control samples. Findings All eight patients (five women; median age at disease onset 59 years range 52–76) had abnormal sleep movements and behaviours and obstructive sleep apnoea, as confirmed by polysomnography. Six patients had chronic progression with a median duration from symptom onset to death or last visit of 5 years (range 2–12); in four the sleep disorder was the initial and most prominent feature, and in two it was preceded by gait instability followed by dysarthria, dysphagia, ataxia, or chorea. Two patients had a rapid progression with disequilibrium, dysarthria, dysphagia, and central hypoventilation, and died 2 months and 6 months, respectively, after symptom onset. In five of five patients, video polysomnography showed features of obstructive sleep apnoea, stridor, and abnormal sleep architecture (undifferentiated non-rapid-eye-movement non-REM sleep or poorly structured stage N2, simple movements and finalistic behaviours, normalisation of non-REM sleep by the end of the night, and, in the four patients with REM sleep recorded, REM sleep behaviour disorder). Four of four patients had HLA-DRB1*1001 and HLA-DQB1*0501 alleles. All patients had antibodies (mainly IgG4) against IgLON5, a neuronal cell adhesion molecule. Only one of the 298 controls, who had progressive supranuclear palsy, had IgLON5 antibodies. Neuropathology showed neuronal loss and extensive deposits of hyperphosphorylated tau mainly involving the tegmentum of the brainstem and hypothalamus in the two patients studied. Interpretation IgLON5 antibodies identify a unique non-REM and REM parasomnia with sleep breathing dysfunction and pathological features suggesting a tauopathy. Funding Fondo de Investigaciones Sanitarias, Centros de Investigación Biomédica en Red de enfermedades neurodegenerativas (CIBERNED) and Respiratorias (CIBERES), Ministerio de Economía y Competitividad, Fundació la Marató TV3, and the National Institutes of Health.
Aims/hypothesis
Islet autoantibodies, in addition to elevated blood glucose, define type 1 diabetes. These autoantibodies are detectable for a variable period of time before diabetes onset. Thus, the ...occurrence of islet autoantibodies is associated with the beginning of the disease process. The age at, and order in, which autoantibodies appear may be associated with different genetic backgrounds or environmental exposures, or both.
Methods
Infants with
HLA-DR
high-risk genotypes (
DR3/4
,
DR4/4
,
DR4/8
and
DR3/3
) were enrolled and prospectively followed with standardised autoantibody assessments quarterly throughout the first 4 years of life and then semi-annually thereafter.
Results
Autoantibodies appeared in 549/8,503 (6.5%) children during 34,091 person-years of follow-up. Autoantibodies at 3 (0.1%) and 6 (0.2%) months of age were rare. Of the 549, 43.7% had islet autoantibodies to insulin (IAA) only, 37.7% had glutamic acid decarboxylase autoantibodies (GADA) only, 13.8% had both GADA and IAA only, 1.6% had insulinoma antigen-2 only and 3.1% had other combinations. The incidence of IAA only peaked within the first year of life and declined over the following 5 years, but GADA only increased until the second year and remained relatively constant. GADA only were more common than IAA only in
HLA-DR3/3
children but less common in
HLA-DR4/8
children.
Conclusions/interpretation
Islet autoantibodies can occur very early in life and the order of appearance was related to
HLA-DR-DQ
genotype.
B lymphocytes acquire self-reactivity as an unavoidable byproduct of antibody gene diversification in the bone marrow and in germinal centers (GCs). Autoreactive B cells emerging from the bone marrow ...are silenced in a series of well-defined checkpoints, but less is known about how self-reactivity that develops by somatic mutation in GCs is controlled. Here, we report the existence of an apoptosis-dependent tolerance checkpoint in post-GC B cells. Whereas defective GC B cell apoptosis has no measurable effect on autoantibody development, disruption of post-GC apoptosis results in accumulation of autoreactive memory B cells and plasma cells, antinuclear antibody production, and autoimmunity. The data presented shed light on mechanisms that regulate immune tolerance and the development of autoantibodies.
Summary Several CNS disorders associated with specific antibodies to ion channels, receptors, and other synaptic proteins have been recognised over the past 10 years, and can be often successfully ...treated with immunotherapies. Antibodies to components of voltage-gated potassium channel complexes (VGKCs), NMDA receptors (NMDARs), AMPA receptors (AMPARs), GABA type B receptors (GABAB Rs), and glycine receptors (GlyRs) can be identified in patients and are associated with various clinical presentations, such as limbic encephalitis and complex and diffuse encephalopathies. These diseases can be associated with tumours, but they are more often non-paraneoplastic, and antibody assays can help with diagnosis. The new specialty of immunotherapy-responsive CNS disorders is likely to expand further as more antibody targets are discovered. Recent findings raise many questions about the classification of these diseases, the relation between antibodies and specific clinical phenotypes, the relative pathological roles of serum and intrathecal antibodies, the mechanisms of autoantibody generation, and the development of optimum treatment strategies.
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