Remodeling Articular Immune Homeostasis with an Efferocytosis-inspired Nanoimitator Mitigates Rheumatoid Arthritis

Massive intra-articular infiltration of the pro-inflammatory macrophages is a prominent feature of rheumatoid arthritis (RA) lesions, which are thought to underlie articular immune dysfunction, severe synovitis and ultimate joint erosion. Here we report an efferocytosis-inspired nanoimitator (EINI) for in situ targeted reprogramming of the synovial inflammatory macrophages (SIMs) and thus thwarting their autoimmune attack and reinstating articular immune homeostasis, which mitigates RA. The EINI consisted of a drug-based core with an oxidative stress-responsive phosphatidylserine (PtdSer) corona and a shell of P-selectin-blocking motif, low molecular weight heparin (LMWH). When systemically administrated, the LMWH on the EINI first bound to P-selectin overexpressed on endothelium in subsynovial capillaries, which functioned as an antagonist disrupting neutrophils synovial trafficking. Due to the high dysregulation of the synovial microvasculature, the EINI subsequently enriched in joint synovium where the shell was exfoliated upon the reactive oxygen species stimulation, and PtdSer corona was then exposed. In an efferocytosis-like manner, the PtdSer-coroneted core was in turn phagocytosed by SIMs, which synergistically terminated the SIMs-initiated pathological cascades and serially reconstructed the intra-articular immune homeostasis, conferring a chondroprotection effect. These findings demonstrate that SIMs can be precisely remodeled via the efferocytosis-mimetic strategy, which holds great potential for RA treatment.

A gene-centric approach to biomarker discovery identifies transglutaminase 1 as an epidermal autoantigen

Autoantigen discovery is a critical challenge for the understanding and diagnosis of autoimmune diseases. While autoantibody markers in current clinical use have been identified through studies focused on individual disorders, we postulated that a reverse approach starting with a putative autoantigen to explore multiple disorders might hold promise. We here targeted the epidermal protein transglutaminase 1 (TGM1) as a member of a protein family prone to autoimmune attack. By screening sera from patients with various acquired skin disorders, we identified seropositive subjects with the blistering mucocutaneous disease paraneoplastic pemphigus. Validation in further subjects confirmed TGM1 autoantibodies as a 55% sensitive and 100% specific marker for paraneoplastic pemphigus. This gene-centric approach leverages the wealth of data available for human genes and may prove generally applicable for biomarker discovery in autoimmune diseases.

Similarities Between Bacterial GAD and Human GAD65: Implications in Gut Mediated Autoimmune Type 1 Diabetes

A variety of islet autoantibodies (AAbs) can predict and possibly dictate eventual type 1 diabetes (T1D) diagnosis. Upwards of 75% of those with T1D are positive for AAbs against glutamic acid decarboxylase (GAD65), a producer of gamma-aminobutyric acid (GABA) in human pancreatic beta cells. Interestingly, bacterial populations within the human gut also express GAD65 and produce GABA. Evidence suggests that dysbiosis of the microbiome may correlate with T1D pathogenesis and physiology. Therefore, autoimmune linkages between the gut microbiome and islets susceptible to autoimmune attack need to be further elucidated. Utilizing silico analyses, we show here that 25 GAD sequences from different human gut bacterial sources show sequence and motif similarities to human beta cell GAD65. Our motif analyses determined that a majority of gut GAD sequences contain the pyroxical dependent decarboxylase domain of human GAD65 which is important for its enzymatic activity. Additionally, we showed overlap with known human GAD65 T-cell receptor epitopes which may implicate the immune destruction of beta cells. Thus, we propose a physiological hypothesis in which changes in the gut microbiome in those with T1D result in a release of bacterial GAD, thus causing miseducation of the host immune system. Due to the notable similarities, we found between humans and bacterial GAD, these deputized immune cells may then go on to target human beta cells leading to the development of T1D.

Immunogenetic, Molecular and Clinical Determinants of Clonal Evolution in Aplastic Anemia and Paroxysmal Nocturnal Hemoglobinuria

Despite therapeutic successes, AA patients (pts) exhibit a much higher risk of leukemic evolution than the general population. Secondary myeloid neoplasia (sMN) remains the most serious AA complication with major therapeutic and prognostic implications. Historically, multiple theories have been proposed as to the origin of leukemic evolution. For instance, sMN may be the consequence of a relentless autoimmune attack producing a maladaptive response to immunosuppression (IST). Alternatively, occurrence of leukemogenic drivers may be an event setting in motion initially successful and overshooting tumor surveillance reactions. Finally, sMN pathogenesis may be related to either CHIP evolution or acceleration of its progression. Each of these theories is supported by clinical-molecular features (e.g. HLA mutations, secondary PNH evolution, somatic mutations at presentation etc.). Here, we took advantage of a multicentric cohort of pts with AA (n=1010; to our knowledge the largest yet explored) and primary MN (n=3599) to define immunogenetic, iatrogenic and molecular determinants of MN progression. Among AA pts (M:F ratio 0.98; median age 34 years, IQR 20-54, median follow-up 89 months), the 5 and 10 years cumulative incidences of sMN were 6% and 11% respectively, with a median time to progression of 56 months (IQR 23-96). Analysis of available data showed that younger pts (<40 years, HR=0.27 [95%CI 0.1-0.5] p<.001), IST responders (HR=0.36 [95%CI 0.1-0.8] p=.01) and moderate AA (HR=0.33 [95%CI 0.1-0.8] p=.02) had lower risk of malignant evolution. MDS was the most frequent diagnosis at progression (80%), followed by AML (17%, of which 71% MRC subtype) and MPN (3%). Whereas only 27% of MDS pts were classified as EB-1/2, high-risk R-IPSS scores (>3.5) were observed in 59% (vs 43% in pMDS, p=.02) due to the enrichment in poor/very poor cytogenetic risk groups. In particular, chr.7 abnormalities were the most frequent (54%, of which 88% were del7). By comparison, del7/7q was present in 8% of pMN cases (p<.001). Among treated pts, chemotherapy was administered to 37%, HMA to 63% and, overall 36% received HSCT. Disease progression was the main cause of death (42%). When compared to pMN, sMN had poorer survival outcomes (p=.01) especially among del7/7q carriers (p=.004). At the time of AA onset only 18% of pts harbored somatic myeloid mutations with their presence/absence not influencing evolution, whereas mutations were found in 81% of sMN (1.7 mutations/patient, n=86/101). No difference in mutational burden was observed according to presence/absence of del7/7q, which constituted the founder lesion in 60% of cases, when the analysis was possible. ASXL1 (24% vs 14%, p=.01), RUNX1 (21% vs 11%, p=.008), SETBP1 (14% vs 3%, p<.001) and U2AF1 (13% vs 6%, p=.01) mutations were more frequent in sMN, while TET2 (8% vs 26%, p<.001) and SF3B1 (1% vs 12%, p<.001) were less common as compared to pMN. Del7/7q pts were enriched in SETBP1 (22% vs 4% in pMN, p<.001), ASXL1 (29% vs 12%, p=.007) and RUNX1 (29% vs 12%, p=.003) lesions while TP53 mutations were by far less common (5% vs 31%, p<.001).Remarkably, CUX1 hits at AA onset heralded malignant progression (p<.001) and longitudinal analysis showed their loss in patients who eventually acquired del7/7q. In aggregate, the low CUX1 expression in 70% of primary del7/7q MDS and its function in DNA repair, may argue for a role of CUX1/chr.7 during AA to MN progression. 1 When we studied immune-selected somatic events, PIGA mutations were the most frequent lesions at AA onset (33%). However, only 5% of cases at MN evolution (p<.001) had PNH clones, consistent with a reciprocal expansion of PNH clones/evolution to secondary PNH in non-progressors, and clonal sweeping in sMN. HLA class I/II mutations or loss were instead identified at a similar rate in AA and sMN (~27%) pts. No HLA alleles were identified as harbingers of malignant evolution, which instead associated with a lower HLA class II evolutionary divergence (HR=2 [95%CI 1-4] p=.03) possibly hampering efficacious surveillance responses. 2 AA malignant evolution is characterized by an orchestra of molecular events with an invariant genomic signature (e.g. CUX1, SETBP1, ASXL1). Immunogenetic and immune escape mechanisms may also play a role in shaping the fate of individual patients' trajectories towards PNH vs sMN progression, which may be considered a maladaptive escape event resulting from a bottlenecked hematopoiesis. Disclosures Sebert: BMS: Consultancy; Abbvie: Consultancy. Patel: Apellis: Consultancy, Other: educational talks, Speakers Bureau; Alexion: Consultancy, Other: educational talks, Speakers Bureau. Voso: Celgene: Consultancy, Research Funding, Speakers Bureau; Novartis: Speakers Bureau. Calado: Novartis Brasil: Honoraria; Alexion Brasil: Consultancy; AA&MDS International Foundation: Research Funding; Agios: Membership on an entity's Board of Directors or advisory committees; Instituto Butantan: Consultancy; Team Telomere, Inc.: Membership on an entity's Board of Directors or advisory committees. Peffault De Latour: Novartis: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Amgen: Research Funding; Alexion Pharmaceuticals: Consultancy, Honoraria, Research Funding; Apellis Pharmaceuticals Inc: Consultancy, Honoraria; Swedish Orphan Biovitrum AB: Consultancy, Honoraria. Maciejewski: Regeneron: Consultancy; Alexion: Consultancy; Novartis: Consultancy; Bristol Myers Squibb/Celgene: Consultancy.

Challenge of coexisting type 2 diabetes mellitus and insulinoma: a case report

Background Insulinomas are rare clinical entities, but concurrent diabetes mellitus is even more uncommon, and the combination is easily missed. Recurrent hypoglycemia could be misconstrued as improved glycemic control. We present an unusual patient with type 2 diabetes and neuroglycopenia, with apparent improved glycemic control due to an insulinoma. Case presentation A 54-year-old mixed ancestry man with a positive family history of type 2 diabetes mellitus was diagnosed with type 2 diabetes mellitus and hypertension 8 years prior to admission. He presented with episodes of abnormal behavior and hypoglycemia. Inappropriately high insulin and C-peptide concentrations were identified at the time of hypoglycemia. Despite poor adherence to his diabetic treatment, he had no target organ damage relating to diabetes, and his hemoglobin A1c (HbA1c) was 5.3%. A diagnosis of insulinoma was made, and he was started on diazoxide, with endoscopic ultrasound revealing a possible lesion in the pancreatic tail measuring 12 mm × 12 mm. A fine-needle aspiration biopsy could not be performed due to overlying splenic arteries and the risk of vascular perforation. An intraoperative ultrasound confirmed a 15 mm × 10 mm tumor in the pancreatic tail, necessitating a partial pancreatectomy and splenectomy, which were curative. A well-differentiated intermediate grade 2 pancreatic neuroendocrine tumor producing insulin was confirmed on histopathology. Conclusions Recurrent, progressive hypoglycemia and improved glycemic control in a diabetic, without an alternative explanation, may suggest an insulinoma. Insulinomas that exist with type 1 diabetes mellitus, particularly malignant insulinomas, must have escaped autoimmune attack through lack of autoantigen expression. Computed tomography on its own may be insufficiently sensitive for diagnosis of insulinomas, whereas endoscopic and intraoperative ultrasonography may improve the identification of the culprit lesion.

The Immunoregulatory Role of the Signal Regulatory Protein Family and CD47 Signaling Pathway in Type 1 Diabetes

BackgroundThe pathogenesis of type 1 diabetes (T1D) involves complex genetic susceptibility that impacts pathways regulating host immunity and the target of autoimmune attack, insulin-producing pancreatic β-cells. Interactions between risk variants and environmental factors result in significant heterogeneity in clinical presentation among those who develop T1D. Although genetic risk is dominated by the human leukocyte antigen (HLA) class II and insulin (INS) gene loci, nearly 150 additional risk variants are significantly associated with the disease, including polymorphisms in immune checkpoint molecules, such as SIRPG.Scope of ReviewIn this review, we summarize the literature related to the T1D-associated risk variants in SIRPG, which include a protein-coding variant (rs6043409, G>A; A263V) and an intronic polymorphism (rs2281808, C>T), and their potential impacts on the immunoregulatory signal regulatory protein (SIRP) family:CD47 signaling axis. We discuss how dysregulated expression or function of SIRPs and CD47 in antigen-presenting cells (APCs), T cells, natural killer (NK) cells, and pancreatic β-cells could potentially promote T1D development.Major ConclusionsWe propose a hypothesis, supported by emerging genetic and functional immune studies, which states a loss of proper SIRP:CD47 signaling may result in increased lymphocyte activation and cytotoxicity and enhanced β-cell destruction. Thus, we present several novel therapeutic strategies for modulation of SIRPs and CD47 to intervene in T1D.

New classification of autoimmune neuropathies based on target antigens and involved domains of myelinated fibres

Autoimmune neuropathies are named by eponyms, by descriptive terminology or because of the presence of specific antibodies and are traditionally classified, on the basis of pathology and electrophysiology, as primary demyelinating or axonal. However, autoimmune disorders targeting specific molecules of the nodal region, although not showing pathological evidence of demyelination, can exhibit all the electrophysiological changes considered characteristic of a demyelinating neuropathy and acute neuropathies with antiganglioside antibodies, classified as axonal and due to nodal dysfunction, can present with reversible conduction failure and prompt recovery that appear contradictory with the common view of an axonal neuropathy. These observations bring into question the concepts of demyelinating and axonal nerve conduction changes and the groundwork of the classical dichotomous classification.We propose a classification of autoimmune neuropathies based on the involved domains of the myelinated fibre and, when known, on the antigen. This classification, in our opinion, helps to better systematise autoimmune neuropathies because points to the site and molecular target of the autoimmune attack, reconciles some contrasting pathological and electrophysiological findings, circumvents the apparent paradox that neuropathies labelled as axonal may be promptly reversible and finally avoids taxonomic confusion and possible misdiagnosis.

Revisiting the Antigen-Presenting Function of β Cells in T1D Pathogenesis

Type 1 diabetes (T1D) is characterized by the unresolved autoimmune inflammation and islet β cell destruction. The islet resident antigen-presenting cells (APCs) including dendritic cells and macrophages uptake and process the β cell-derived antigens to prime the autoreactive diabetogenic T cells. Upon activation, those autoreactive T cells produce copious amount of IFN-γ, TNF-α and IL-1β to induce β cell stress and death. Autoimmune attack and β cell damage intertwine together to push forward this self-destructive program, leading to T1D onset. However, β cells are far beyond a passive participant during the course of T1D development. Herein in this review, we summarized how β cells are actively involved in the initiation of autoimmune responses in T1D setting. Specifically, β cells produce modified neoantigens under stressed condition, which is coupled with upregulated expression of MHC I/II and co-stimulatory molecules as well as other immune modules, that are essential properties normally exhibited by the professional APCs. At the cellular level, this subset of APC-like β cells dynamically interacts with plasmacytoid dendritic cells (pDCs) and manifests potency to activate autoreactive CD4 and CD8 T cells, by which β cells initiate early autoimmune responses predisposing to T1D development. Overall, the antigen-presenting function of β cells helps to explain the tissue specificity of T1D and highlights the active roles of structural cells played in the pathogenesis of various immune related disorders.

Case Report: Opsoclonus-Myoclonus Syndrome Associated With Contactin-Associated Protein-Like 2 and Acetylcholine Receptor Autoantibodies in the Setting of Non-Small Cell Lung Carcinoma

Opsoclonus myoclonus syndrome (OMS) is a rare immune-mediated paraneoplastic or para/-post-infectious syndrome characterized by “dancing” eye movements, myoclonus, and ataxia. Neuropsychiatric symptoms have also been reported. Without treatment, OMS may progress to further neurological impairment and even death. Autoimmune attack of CNS structures in OMS is most commonly mediated by anti-Ri (also known as ANNA2) IgG antibodies, with additional findings implicating antibodies targeting various neurotransmitter receptors. Prompt immunotherapy and neoplasm treatment may result in improvement. We report a novel association of Contactin-Associated Protein-Like 2 (Caspr2) antibodies occurring in association with paraneoplastic OMS. While breast cancer and small cell lung cancer (SCLC) are more commonly associated with OMS among adults, we characterize a novel association between Caspr2 antibody in a patient with mixed non-small cell and small cell lung carcinoma.

Hashimoto’s thyroiditis worsens ovaries in polycystic ovary syndrome patients compared to Anti-Müllerian hormone levels

Background The human ovary is the target of autoimmune attack in cases of autoimmune disorders, which can cause ovarian dysfunction. Due to the higher prevalence of Hashimoto’s Thyroiditis (HT) in Polycystic Ovary Syndrome (PCOS) patients, we aimed to evaluate ovarian reserve and the effect of autoimmune exposure time on ovarian reserve in PCOS patients with HT by Anti-Müllerian hormone (AMH) levels. Methods Forty-six PCOS patients and 46 PCOS with HT diagnosed patients who are between 18 and 35 years old were recruited for this study. Detailed medical histories were obtained from all participants. Polycystic ovary image was evaluated and antral follicles were counted by transvaginal ultrasound. Modified Ferriman Gallwey score, body mass index, waist/hip ratio of the patients were examined. Hormonal, biochemical profiles and AMH levels of the patients were evaluated during the early follicular phase. The data of both groups were statistically analyzed with SPSS 18.0. Results 20 (43.5%) patients in the PCOS group were fertile, 8 (17.4%) patients in the PCOS + HT group were fertile, fertility rate was significantly lower in PCOS + HT group. The mean AMH value was 8.8 ± 8.8 in the PCOS + HT group and 12.4 ± 8.1 in the PCOS group and it was significantly lower in the PCOS + HT group (p = 0.043). AMH values were significantly negatively correlated with anti-thyroid peroxidase antibody (anti-TPO) level and the duration of HT. There was a significant positive correlation between the anti-TPO level and the duration of HT. Conclusıon We pointed out that the coexistence of PCOS and HT, two prevalent diseases of reproductive age, further diminished ovarian reserve. More exposure of the ovaries to autoantibodies can cause ovarian destruction, similar to the thyroid gland like HT. Because of all these close relations with PCOS and thyroid dysfunctions, we recommend evaluating both thyroid autoantibodies and hormone levels in PCOS patients at the first visit. Patients with PCOS + HT should be monitored more closely to determine the fertility treatment options and control premature ovarian failure (POF) table.