Common Autoantibodies Research Articles

An analytical study on the ocular manifestations of autoimmune blistering skin disorders, in patients attending a tertiary care hospital

Autoimmune blistering skin diseases are a heterogeneous group of diseases that have as their common feature autoantibodies directed against desmosomal structural proteins. They can sometimes affect the eye, with manifestations ranging from mild to potentially vision threatening. To evaluate the spectrum and incidence of ocular manifestations and to analyze whether early ophthalmological examination will be beneficial in reducing ocular morbidity.rn Hospital based analytical study conducted at Coimbatore Medical College and Hospital, Coimbatore, Tamil Nadu. This study involved 100 patients diagnosed with autoimmune blistering skin disorder attending Dermatology and Ophthalmology outpatient department and included a comprehensive ocular examination of the patients. The collected data were analysed with IBM.SPSS statistics software 23.0 Version. To find the association of significance in categorical data the Chi-Square test was used. In the above statistical tool, the probability value .05 was considered as significant level. Autoimmune blistering skin diseases were associated with a significant proportion of ocular manifestations, of which in this study, dry eye and conjunctivitis were the most common. Dry eye and conjunctivitis were the most common ocular manifestations in this study. Though none of the patients had vision threatening manifestations, a comprehensive ocular examination and follow up of these patients is necessary.

Demographic, clinical, laboratory data, prognostic, and treatment features of patients with antisynthetase syndrome: An international, two-center cohort study.

To compare clinical, demographic, laboratory data, prognostic and treatment characteristics of patients with antisynthetase syndrome (ASSD) treated in two different centers of India and Brazil. This international, two-center, retro-prospective cohort study which was conducted at two tertiary rheumatology centers (one in Brazil and one in India) between January 2000 to January 2020 included a total of 115 patients with ASSD (21 males, 94 females; mean age; at disease diagnosis at 40.3; range, 18 to 80 years). Demographic, clinical and laboratory data of the patients were recorded. Clinical involvement was evaluated. Of the patients, 81 were Brazilians and 34 were of Indian origin. The Indian group exhibited a greater delay in diagnosis after the onset of symptoms compared to Brazilian patients (12 vs. 6 months, respectively; p=0.026). Brazilian patients exhibited a significantly higher prevalence of joint and lung involvement, mechanic's hands, and Raynaud's phenomenon. Anti-Jo-1 was the most common autoantibodies in both groups. Systemic arterial hypertension, followed by diabetes mellitus were the most prevalent comorbidities. Concerning previously used drugs, the Indian patients had a larger group of patients treated with antimalarials, whereas the Brazilian group used more azathioprine and intravenous immunoglobulin. A higher proportion of Indian patients was treated with one immunosuppressive drug (70.6%), while the Brazilian group were often treated using two immunosuppressive drugs (33%). Comparison between the severity and prognosis showed that Brazilian group had a higher number of relapses, and during follow-up, the global mortality rates were similar in both groups (6.2% for Brazilian vs. 8.8% for Indian). Brazilian and Indian patients with ASSD have comparable epidemiological characteristics such as age at the time of disease diagnosis, and sex distribution, and autoantibodies. Diagnostic delay is seen in Indian patients, and Brazilians exhibit a higher prevalence of joint and lung involvement, mechanic's hands, Raynaud's phenomenon with a higher number of relapses, although the mortality rate seems to be similar in both groups.

Tinospora Cordifolia (Giloy)-Induced Liver Injury During the COVID-19 Pandemic-Multicenter Nationwide Study From India.

Tinospora cordifolia (Giloy) is an herbal supplement commonly used in the Indian alternative medicine system Ayurveda. This herb has been promoted to the public in India as an immune booster to prevent novel coronavirus disease 2019. However, small reports have recently shown an association between Giloy use and the development of herb‐induced liver injury (HILI) with autoimmune features in some patients. This large retrospective Indian multicenter study spanning 13 centers at nine locations was designed to identify features and outcomes of HILI temporally associated with Giloy use. Chemical and toxicological analyses of retrieved Giloy samples using state‐of‐the‐art methods were also performed. We report 43 patients, of whom more than half were female, with a median time from initial Giloy consumption to symptom onset of 46 days. Patients presented with acute hepatitis, acute worsening of chronic liver disease (CLD, the most common clinical presentation), or acute liver failure. Causality assessment revealed probable liver injury in 67.4%. The most common autoantibody detected was anti‐nuclear antibody. Liver biopsy in a subset revealed HILI associated with autoimmune features and hepatocyte and canalicular cholestasis and neutrophilic and eosinophilic infiltration. Conclusion: Giloy is associated with acute hepatitis with autoimmune features and can unmask autoimmune hepatitis (AIH) in people with silent AIH‐related CLD. Further studies on the safety (and efficacy) of untested but heavily promoted herbals in alternative systems of medicine are an unmet need in the interests of public health and are especially important during this global health emergency.

Association of hidradenitis suppurativa with autoimmune disease and autoantibodies.

ObjectiveThere is thought to be an association between hidradenitis suppurativa (HS) and autoimmune diseases. This retrospective longitudinal cohort study looked to identify whether certain autoimmune diseases or autoantibody specificities are more closely associated with HS than others and whether such associations are related to the severity of HS.MethodsPatients were identified using the SlicerDicer search tool in Epic from 1 January 2010 to 15 August 2020. Search criteria included HS diagnosis by ICD-10 code (L73.2) and at least one visit to the dermatology department. Charts were reviewed to determine HS disease severity, treatment modalities, presence of autoimmune disease and autoantibody positivity.ResultsSix hundred and twenty-seven patients were identified. Most patients were female (75.3%) and had obese BMIs (71.1%), but there were no significant demographic differences between HS patients with and without autoimmune diseases. One hundred and one (16.1%) patients in the total cohort had at least one autoimmune disease, most commonly thyroid disease, lupus, psoriasis and IBD. Two hundred and twelve patients were also tested for the presence of autoantibodies. The most common positive autoantibody, found in 54 patients (28.4%), was ANA. Fifty-four patients with more severe HS disease manifestations required biologic medications to treat their HS. Neither HS severity nor biologic treatment was associated with presence of autoimmune disease or positive autoantibodies.ConclusionIn a large cohort of patients with HS followed longitudinally, autoimmune disorders (especially lupus, psoriasis and IBD) and presence of autoantibodies were more commonly observed than expected in the normal population.

Incidence and Clinical Pattern of Mixed Connective Tissue Disease in Sudanese Patients at Omdurman Military Hospital: Hospital-Based Study.

BackgroundMixed connective tissue disease (MCTD) is a rare autoimmune disease, characterized by the production of specific autoantibody anti-RNP, which presents with varied overlapping symptoms of different connective tissue disorders. The aim of this study is to identify the frequency and patterns of MCTD.MethodsThis is a descriptive cross-sectional hospital-based study conducted at the rheumatology clinic at Omdurman Military Hospital between February 2019 and July 2019. The study included 30 patients and data were collected using a designated questionnaire.ResultsThe study showed that the majority of patients (96.7%) were females and only 3.3% was male. About 30% of the patients aged between 30 and 39 years were the most affected. As a first diagnosis, 10% of the patients had a MCTD fulfilling the Alarcon-Segovia criteria. The remaining 90% of the patients were diagnosed with other diseases before evolving into MCTD. The most common clinical presentation was arthralgia in 100% of the patients, 90% were symmetrically followed by myositis in 70% of the patients, arthritis in 63.3% of the patients, puffy fingers in 63.3% of the patients, and hand swelling in 60% as major musculoskeletal symptoms. Regarding the initial results in immunological profile, the most common positive autoantibodies among the patients were anti-RNP titer in 96.7% of the patients, ANA in 90%, anti-Sm in 50%, RF in 50%, anti-Ds DNA in 46.7%, and anti-Ro in 43.3%.ConclusionThis study showed that MCTD is more common in females, only 10% of patients presented with a fulfilling criteria of the disease at diagnosis, and the rest of the patients presented with other rheumatologic diseases before evolving into MCTD.

Clinico-Pathological Profile of Cutaneous Lupus Erythematosus Patients: A Report from A Tertiary Care Center of Chattogram

Background : Nearly all epidemiologic studies have involved patients with Systemic Lupus Erythematosus (SLE). Few authors have investigated the characteristics of patients with Cutaneous Lupus Erythematosus (CLE). We aim to describe the epidemiologic, clinical, and immunologic characteristics of a series of patients diagnosed with CLE.
 Materials and methods : This is a descriptive retrospective cross-sectional study carried out using the register records of total 218 patients attending the ‘Lupus Clinic’ in Chittagong Medical College Hospital during the period 2010 and 2020. The disease activity and damage of CLE were assessed according to the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI).
 Results : There were 187 females (86%) and 31 males (14%) with the female: male ratio being 6.1:1. The mean age was 28 ± 10.06 (mean ± SD) ranging between 11 and 65 years. The Chronic Cutaneous Lupus Erythematosus (CCLE) patients accounted 154 (71%) followed by Acute Cutaneous Lupus Erythematosus (ACLE) 46 (21%) and Subacute Cutaneous Lupus Erythematosus (SCLE) 18 (8%). On the basis of CLASI score, 91 (42%) patients were in mild form, 85 (39%) in moderate form and 42 (19%) in severe state. In LE specific skin lesions, common manifestation was photosensitivity 198 (91%) followed by discoid rash 154 (71%) and maculo-papular lupus rash 55 (25%). Oral ulcer was seen in 49 (22%) patients and malar rash in 46 (21%) patients. Other observed LE specific skin manifestations were papulo squamous rash 11 (5%), Toxic epidermal necrolysis like lesions 7 (3%) and lichenoid lesions 6 (3%). Among LE nonspecific skin lesions, common manifestation was nonscarring alopecia 123 (56%) followed by Raynaud’s phenomenon 17 (8%) livedo reticularis 17 (8%) Vasculitis 15 (7%) Periungual telangiectasia 7 (3%) erythema multiforme 6 (3%) and leg Ulcer 5 (2%). Antinuclear Antibody (ANA) 132 (61%) was the most common autoantibody followed by anti-ds DNA 91 (42%) anti-Sm antibody 2 (1%) anti-phospholipid antibodies 9 (4%) and anti-RNP 3 (1%). Hematological manifestations were seen in 161 (73.85%) where erythrocyte sedimentation rate was the most common hematological abnormality 161(73.85%) followed by lymphopenia 126 (57.80%) leucopenia 113 (51.80%) thrombocytopenia 107 (49.10%) anemia 92 (42%) monocytopenia 37 (16.97%). Conclusions: CCLE was the most common subtypes of CLE. Patients with different subtypes of CLE have distinct clinical and pathological characteristics. The onset or concurrence of SLE mandates the involvement of other disciplines depending on organ involvement. In the absence of consensus on a definition that makes it possible to differentiate cutaneous forms of LE from SLE, the dermatologist’s role in the correct diagnosis and classification of such patients is fundamental.
 Chatt Maa Shi Hosp Med Coll J; Vol.20 (2); July 2021; Page 79-84

Clinical features, epidemiology, autoantibody status, HLA haplotypes and genetic mechanisms of type 1 diabetes mellitus among children in Qatar

To describe the clinical features, epidemiology, autoantibody status, HLA haplotypes and genetic mechanisms of type 1 diabetes mellitus (T1DM). Patients (0–18 years) with diabetes were recruited. Clinical data was collected, autoantibodies and c-peptide were measured. Whole Genome Sequencing was performed. Genomic data analysis was compared with the known genes linked with T1DM and HLA alleles were studied. 1096 patients had one or more antibody positivity. The incidence of T1DM in 2020 was 38.05 per 100,000 children and prevalence was 249.73. GADA was the most common autoantibody followed by IAA. Variants in GSTCD, SKAP2, SLC9B1, BANK1 were most prevalent. An association of HLA haplotypes DQA1*03:01:01G (OR = 2.46, p value = 0.011) and DQB1*03:02:01G (OR = 2.43, p value = 0.022) was identified. The incidence of T1DM in Qatar is the fourth highest in the world, IA2 autoantibody was the most specific with some patients only having ZnT8 or IA2 autoantibodies thus underlining the necessity of profiling all 4 autoantibodies. The genes associated with T1DM in the Arab population were different from those that are common in the Caucasian population. HLA-DQ was enriched in the Qatari patients suggesting that it can be considered a major risk factor at an early age.

Screening of Organ-Specific Autoantibodies in a Large Cohort of Patients with Autoimmune Thyroid Diseases

Background: Autoimmune diseases tend to cluster in the same individual or in families. Four types of autoimmune polyglandular syndromes (APS) have been described based on the combination of endocrine and/or non-endocrine autoimmune diseases. In particular, type-3 APS is defined by the association of an autoimmune thyroid disease (ATD) and other autoimmune diseases and has a multifactorial etiology. The natural history of autoimmune diseases is characterized by three stages: potential, subclinical, and clinical. Methods: To determine the prevalence of organ-specific autoantibodies (anti-adrenal, anti-ovary [StCA], anti-pituitary [APA], anti-parietal cells [PCA], anti-tissue transglutaminase [tTGAb], anti-mitochondrial [AMA], anti-glutamic acid decarboxylase [GADA], anti-nicotinic acetylcholine receptor) in patients with ATD and to define the stage of the disease in patients with positive autoantibodies. From January 2016 to November 2018, 1502 patients (1302 female; age 52.7 ± 14.7 [mean ± standard deviation] years, range 18-86 years) with ATD (1285/1502 [85.6%] with chronic autoimmune thyroiditis and 217/1502 [14.4%] with Graves' disease) were prospectively enrolled. Results: The most common organ-specific autoantibodies were PCA (6.99%) and GADA (2.83%), while the prevalence of the remaining autoantibodies was ≤1%. All autoimmune diseases, but celiac disease, were predominant at the potential stage. Sex, ATD type, smoking habit, and coexistence of other autoimmune diseases correlated with the susceptibility to develop chronic atrophic gastritis (CAG) or autoimmune diabetes mellitus. Conclusions: The association between ATD and CAG was the most common manifestation of type-3 APS, mainly at the potential stage, that could lead to appropriate follow-up for early detection and timely treatment of the disease.

Multifaceted features of immunoglobulin G anti‐GM1 antibodies in Guillain–Barré syndrome

AbstractImmunoglobulin G (IgG) anti‐GM1 antibodies, the most common autoantibodies in Guillain–Barré syndrome (GBS), have diverse characteristics regarding IgG subclass, complement activation, affinity and fine specificity. In this review, an update on multifaceted aspects of IgG anti‐GM1 antibodies is provided, emphasizing their roles in creating a varying clinical picture of GBS and in developing pure motor neuropathy after antecedent infection. Diversity in IgG subclass and cross‐reactivity, both of which are closely related to the type of antecedent infection, appears to cause the variation in clinical features and severity of the disease. The environment around GM1 expression in neural tissue is thought to interfere with the binding of anti‐GM1 antibodies by modulating the immunoreactive epitope, allowing only anti‐GM1 antibodies with specific fine specificity to bind to the GM1 ganglioside. This might create the characteristic clinical picture of pure motor neuropathy in anti‐GM1‐positive GBS, although GM1 is present equally in motor and sensory nerves. The environment around the GM1 epitope on Campylobacter jejuni, the most frequently identified agent in antecedent infections of GBS, might also be important in creating diversity in the fine specificity of anti‐GM1 antibodies, possibly preventing the development of GBS in most patients with enteritis by the GM1 epitope‐bearing C. jejuni. Because there remains no direct evidence indicative that diversity of anti‐GM1 antibodies is involved in the development of GBS, further study is required.

Establishing the prevalence of common tissue-specific autoantibodies following severe acute respiratory syndrome coronavirus 2infection.

SummaryCoronavirus 19 (COVID‐19) has been associated with both transient and persistent systemic symptoms that do not appear to be a direct consequence of viral infection. The generation of autoantibodies has been proposed as a mechanism to explain these symptoms. To understand the prevalence of autoantibodies associated with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection, we investigated the frequency and specificity of clinically relevant autoantibodies in 84 individuals previously infected with SARS‐CoV‐2, suffering from COVID‐19 of varying severity in both the acute and convalescent setting. These were compared with results from 32 individuals who were on the intensive therapy unit (ITU) for non‐COVID reasons. We demonstrate a higher frequency of autoantibodies in the COVID‐19 ITU group compared with non‐COVID‐19 ITU disease control patients and that autoantibodies were also found in the serum 3–5 months post‐COVID‐19 infection. Non‐COVID patients displayed a diverse pattern of autoantibodies; in contrast, the COVID‐19 groups had a more restricted panel of autoantibodies including skin, skeletal muscle and cardiac antibodies. Our results demonstrate that respiratory viral infection with SARS‐CoV‐2 is associated with the detection of a limited profile of tissue‐specific autoantibodies, detectable using routine clinical immunology assays. Further studies are required to determine whether these autoantibodies are specific to SARS‐CoV‐2 or a phenomenon arising from severe viral infections and to determine the clinical significance of these autoantibodies.

Diagnostic and Predictive Contribution of Autoantibodies Screening in a Large Series of Patients With Primary Immunodeficiencies.

ObjectivesTo evaluate the diagnostic and predictive contribution of autoantibodies screening in patients with primary immunodeficiencies (PIDs).MethodsIn the present study, PID patients and healthy controls have been screened for 54 different autoantibodies. The results of autoantibodies screening in PID patients were correlated to the presence of autoimmune diseases.ResultsA total of 299 PID patients were included in this study with a predominance of antibody deficiencies (27.8%) followed by immunodeficiencies affecting cellular and humoral immunity (26.1%) and complement deficiencies (22.7%). Autoimmune manifestations were present in 82 (27.4%) patients. Autoimmune cytopenia (10.4%) was the most common autoimmune disease followed by gastrointestinal disorders (10.0%), rheumatologic diseases (3.7%), and endocrine disorders (3.3%). Autoantibodies were found in 32.4% of PID patients and 15.8% of healthy controls (P < 0.0005). Anti-nuclear antibodies (ANA) (10.0%), transglutaminase antibody (TGA) (8.4%), RBC antibodies (6.7%), anti-smooth muscle antibody (ASMA) (5.4%), and ASCA (5.0%) were the most common autoantibodies in our series. Sixty-seven out of the 82 patients with autoimmune manifestations (81.7%) were positive for one or more autoantibodies. Eleven out of the 14 patients (78.6%) with immune thrombocytopenia had positive platelet-bound IgM. The frequencies of ASCA and ANCA among patients with IBD were 47.4% and 21.0% respectively. All patients with celiac disease had TGA-IgA, while six out of the 11 patients with rheumatologic diseases had ANA (54.5%). Almost one third of patients (30/97) with positive autoantibodies had no autoimmune manifestations. ANA, rheumatoid factor, ASMA, anti-phospholipid antibodies and ANCA were often detected while specific AID was absent. Despite the low positive predictive value of TGA-IgA and ASCA for celiac disease and inflammatory bowel disease respectively, screening for these antibodies identified undiagnosed disease in four patients with positive TGA-IgA and two others with positive ASCA.ConclusionThe present study provides valuable information about the frequency and the diagnostic/predictive value of a large panel of autoantibodies in PIDs. Given the frequent association of some AIDs with certain PIDs, screening for corresponding autoantibodies would be recommended. However, positivity for autoantibodies should be interpreted with caution in patients with PIDs due to their low positive predictive value.

Association between human leukocyte antigens (HLAs) and human neutrophil antigens (HNAs) and autoimmune neutropenia of infancy in Danish patients.

BackgroundAutoimmune neutropenia of infancy (AIN) is a frequent cause of neutropenia in children. The disease is caused by antibodies against epitopes on the immunoglobulin G (IgG) Fc receptor type 3b (FcγIIIb). We investigated the possible association of human neutrophil antigens (HNA), human leukocyte antigen (HLA)‐DR, and HLA‐DQ alleles with AIN and the association of these genotypes with the presence of autoantibodies.MethodsEighty AIN cases with a median age of 13.5 months were included. Controls were healthy unrelated Danish blood donors. Anti‐HNA‐1a autoantibodies were detected using a flow cytometric granulocyte immunofluorescence test (Flow‐GIFT) with phenotyped donor cells for detection of antibody specificity. Molecular determination of HNA genotypes was determined using real‐time polymerase chain reaction (q‐PCR). High‐resolution HLA‐DRB1 and HLA‐DQB1 were determined by next‐generation sequencing.ResultsAntibodies against HNA‐1a were detected in 51% (n = 41) of AIN patients, and anti‐HNA‐1b was detected in 3% (n = 2) of cases. In 46% of cases, the antibodies were anti‐FcγIIIb‐reactive. FCGR3B*01+,*02‐,*03‐ was more common (odds ratio, 6.70; P < .0001), and FCGR3B*01‐,*02+,*03‐ was less common (odds ratio, 0.30; P < .0001) among AIN cases. HNA‐1a antibodies were significantly more frequent among AIN cases with the FCGR3B*01+,*02‐,*03‐ genotype (odds ratio, 3.86; P < .007). The HLA‐DRB1*14 ‐ HLA‐DQB1*05:03 haplotype was significantly more common (odds ratio, 7.44; P < .0001) in AIN patients.ConclusionThe HLA haplotype HLA‐DRB1*14 ‐ DQB1*05:03 is associated with Danish AIN cases. Among Danish AIN patients, anti‐HNA‐1a is the most common autoantibody, and the antibody is more common in cases with the FCGR3B*01+,*02‐,*03‐ genotype.

SARS-CoV-2 infection as a trigger of autoimmune response.

Currently, few evidences have shown the possible involvement of autoimmunity in patients affected by coronavirus disease 2019 (COVID‐19). In this study, we elucidate whether severe acute respiratory syndrome coronavirus disease 2 (SARS‐CoV‐2) stimulates autoantibody production and contributes to autoimmunity activation. We enrolled 40 adult patients (66.8 years mean age) admitted to Alessandria Hospital between March and April 2020. All the patients had a confirmed COVID‐19 diagnosis and no previously clinical record of autoimmune disease. Forty blood donors were analyzed for the same markers and considered as healthy controls. Our patients had high levels of common inflammatory markers, such as C reactive protein, lactate dehydrogenase, ferritin, and creatinine. Interleukin‐6 concentrations were also increased, supporting the major role of this interleukin during COVID‐19 infection. Lymphocyte numbers were generally lower compared with healthy individuals. All the patients were also screened for the most common autoantibodies. We found a significant prevalence of antinuclear antibodies, antineutrophil cytoplasmic antibodies, and ASCA immunoglobulin A antibodies. We observed that patients having a de novo autoimmune response had the worst acute viral disease prognosis and outcome. Our results sustain the hypothesis that COVID‐19 infection correlates with the autoimmunity markers. Our study might help clinicians to: (a) better understand the heterogeneity of this pathology and (b) correctly evaluate COVID‐19 clinical manifestations. Our data explained why drugs used to treat autoimmune diseases may also be useful for SARS‐CoV‐2 infection. In addition, we highly recommend checking patients with COVID‐19 for autoimmunity markers, mainly when deciding on whether to treat them with plasma transfer therapy. Study Highlights WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC? ☑ Recent data sustain the idea that autoimmune phenomena exist in patients with coronavirus disease 2019 (COVID‐19), but other investigations are necessary to define the possible link between severe acute respiratory syndrome coronavirus disease 2 (SARS‐CoV‐2) infection and autoimmune disease onset. WHAT QUESTION DID THIS STUDY ADDRESS? ☑ In this monocentric study, we demonstrated how SARS‐CoV‐2 infection could be associated with an autoimmune response and development of autoantibodies. WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE? ☑ Patients with COVID‐19 having an increased level of inflammatory markers and strong autoantibodies positivity (i.e., antinuclear antibodies and antineutrophil cytoplasmic antibodies) presented the worst clinical outcome. HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE? ☑ These results suggest that the drugs normally used to treat autoimmune diseases should also be considered during SARS‐CoV‐2, improving public health. In addition, before starting a transfer plasma therapy, it is important to also evaluate the autoimmunity conditions of the patients with COVID‐19. Transferring antibodies or trying to neutralize them should be done with precaution. It is possible that the risk of developing or increasing the autoimmune response may enhance.

PM-Scl and Th/To in systemic sclerosis: a comparison of different autoantibody assays.

To compare test characteristics of the Euroimmun line blot assay with other assays for two uncommon autoantibody specificities in systemic sclerosis(SSc). Patients from the Johns Hopkins Scleroderma Center were assayed routinely using the Euroimmun platform. Patients positive for anti-Th/To (N= 73) and anti-PM-Scl (PM75 and/or PM100; N= 290) by Euroimmun were compared with SSc patients negative for these autoantibodies. For Th/To antibodies, the comparison assay was immunoprecipitation (IP), performed using 4 Th/To complex components: POP1, RPP40, RPP30, and RPP25. For anti-PM-Scl, IPs were performed with PM100 and PM75. Different Euroimmun cut-offs for assigning antibody positive status (≥ 15/+, ≥ 36/++, ≥ 71/+++) were examined. Kappa statistics were calculated to determine agreement between assays. The best performing thresholds for defining anti-PM-Scl positivity were both PM75 and PM100 ≥ 15/+ on Euroimmun, corresponding to a kappa statistic of 0.79, sensitivity 72% and specificity 100%. For anti-Th/To, kappa values were lower for all comparisons (κ< 0.5). Given the high sensitivity of defining anti-Th/To by ≥ 15/+ (91-95%), a potential approach is to use Euroimmun screening (15/+ cut-off), followed by confirmatory IP. Given the increasing utilization of Euroimmun and the importance of comparing data across cohorts, continued use of this platform is warranted, acknowledging discordance with IP for some specificities. For these, using a two-step approach (Euroimmun to maximize sensitivity, confirmatory assay to increase specificity) is suggested. • For less common SSc autoantibody specificities, some discordances exist between IP and Euroimmun LIA. • The best performing thresholds for defining anti-PM-Scl positivity were both PM75 and PM100≥15/+ on Euroimmun. • For Th/To, a two-step approach (Euroimmun to maximize sensitivity, confirmatory assay to increase specificity) is suggested.

The Absence of Islet Autoantibodies in Clinically Diagnosed Older-Adult Onset Type 1 Diabetes Suggests an Alternative Pathology, Advocating for Routine Testing in This Age Group

Objective: Islet autoantibodies at diagnosis are not well studied in older-adult onset (>30years) type 1 diabetes due to difficulties of accurate diagnosis. We used a type 1 diabetes genetic risk score (T1DGRS) to identify type 1 diabetes aiming to evaluate the prevalence and pattern of autoantibodies in older-adult onset type 1 diabetes. Methods: We used a 30 variant T1DGRS in 1866 white-European individuals to genetically confirm a clinical diagnosis of new onset type 1 diabetes. We then assessed the prevalence and pattern of GADA, IA2A and ZnT8A within genetically consistent type 1 diabetes across three age groups ( 30years (n=588)). Findings: In autoantibody positive cases T1DGRS was consistent with 100% type 1 diabetes in each age group. Conversely in autoantibody negative cases, T1DGRS was consistent with 93%(56/60) of 30years having type 1 diabetes. Restricting analysis to genetically consistent type 1 diabetes showed similar proportions of positive autoantibodies across age groups (92% 30years)[p=0.87]. GADA was the most common autoantibody in older-adult onset type 1 diabetes, identifying 95% of autoantibody positive cases versus 72% in those <18years. Interpretation: Older adult-onset type 1 diabetes has identical rates but different patterns of positive autoantibodies to childhood onset. In clinically suspected type 1 diabetes in older-adults, absence of autoantibodies strongly suggests non-autoimmune diabetes. Our findings suggest the need to change guidelines from measuring islet autoantibodies where there is diagnostic uncertainty to measuring at least GADA in all suspected adult type 1 diabetes cases. Funding Statement: NJT is funded by a Wellcome Trust funded GW4 PhD (220601/Z/20/Z). M.N.W. is supported by the Wellcome Trust Institutional Support Fund (WT097835MF). KAP is a Wellcome Trust fellow (219606/Z/19/Z) and the genetic risk score analysis in ADDRESS-2 was funded by Diabetes wellness Research foundation pump priming grant. ADDRESS-2 is co-funded by Diabetes UK (grant numbers 09-0003919, 15-005234 & 19/0006119) and the Juvenile Diabetes Research Foundation (grant numbers 9-2010-407 & 3-SRA-2015-35-A-N), supported by the NIHR Clinical Research Network and hosted by Imperial College London. S.M. is currently supported by a Future Leaders Mentorship award from the European Federation for the Study of Diabetes. NO is supported by the National Institute for Health Research (NIHR) Biomedical Research Centre based at Imperial College London. DJ is funded by the NIHR CRN. Declaration of Interests: We declare no competing interest. Ethics Approval Statement:Ethics for the ADDRESS2 study was granted by the South Central – Berkshire NHS Research Ethics Committee on the 03/10/2010, ref: 10/H0505/85. Ethics for monogenic testing in the ADDRESS2 cohort by the East of England – Essex Research Ethics Committee on the 14/7/2016, ref 16/EE/0306

Latent rheumatic, thyroid and phospholipid autoimmunity in hospitalized patients with COVID-19

Autoimmune responses mediated by autoantibodies have been observed in SARS-CoV-2 infection. Herein, we evaluate the presence of rheumatic, thyroid and phospholipid autoantibodies in sera samples from 120 adult hospitalized patients with COVID-19 in comparison to pre-pandemic samples from 100 healthy individuals. In addition, to estimate the frequency of these autoantibodies in COVID-19, a meta-analysis of selected articles was conducted. Hospitalized patients with COVID-19 had latent autoimmunity characterized by a high frequency of anti-thyroid peroxidase antibodies, rheumatoid factor (RF), anti-cyclic citrullinated peptide third generation antibodies, antinuclear antibodies (ANAs), IgM anti-β2-glycoprotein I (β2GP1) and IgM anti-cardiolipin antibodies. The meta-analysis confirmed our results, with RF and ANAs being the most common autoantibodies. In addition, cluster analysis revealed that those patients with high frequency of RF, IgM anti-β2GP1 antibodies and ANAs had a longer hospital stay, required more vasopressors during hospitalization, and were more likely to develop critical disease. These data suggest that latent autoimmunity influences the severity of COVID-19, and support further post-COVID studies in order to evaluate the development of overt autoimmunity.

Autoimmune rheumatic diseases: One or many diseases?

Until the etiopathogenic factor(s) of autoimmune and autoinflammatory rheumatic disorders will be identified, their classification into entities will continue. However, their similar clinical manifestations, overlapping syndromes, evolution from one entity into another, as well as common autoantibody responses, suggest that autoimmune and autoinflammatory disorders may constitute distinct pathophysiologic processes on the basis of a different genetic background. Prognosis and effective therapeutic regimens are mostly based on the clinico-pathologic severity of the involved tissues or organs and not on the disease label.

Cancer in Systemic Sclerosis: Analysis of Antibodies Against Components of the Th/To Complex.

The aim of this study is to describe 4 of the most common autoantibodies against components of the Th/To complex: human POP1 (hPOP1), RPP25, RPP30, and RPP40. We report their prevalence and clinical characteristics in a systemic sclerosis (SSc) population, and determine whether these specificities are associated with cancer. A case-control study was performed using data from the Johns Hopkins Scleroderma Center Cohort. A total of 804 adult patients with SSc were included; 401 SSc patients with no history of cancer after at least 5 years of disease were compared to 403 SSc patients who ever had a history of cancer. Antibodies against hPOP1, RPP25, RPP30, and RPP40 were assayed by immunoprecipitation of 35 S-methionine-labeled proteins generated by in vitro transcription/translation. Demographic and clinical characteristics were compared between groups. Of 804 patients, 67 (8.3%) had antibodies against any component of the Th/To complex. Patients with antibodies to any component were significantly more likely to have limited cutaneous disease, less likely to have tendon friction rubs, and more likely to have findings consistent with interstitial lung disease or pulmonary hypertension. Patients with antibodies against hPOP1, RPP25, RPP30, and/or RPP40 were significantly less likely to develop cancer within 2 years of SSc onset (0% versus 11% of antibody-negative patients; P = 0.009). SSc patients who produce autoantibodies to components of the Th/To complex have a clinical phenotype characterized by limited cutaneous disease and pulmonary involvement. Our findings show that the presence of any Th/To autoantibody may have a protective effect against contemporaneous cancer.

Comparison of clinical and immunological features between clinically amyopathic dermatomyositis and typical dermatomyositis

OBJECTIVE To study the differences between clinically amyopathic dermatomyositis (CADM) and typical dermatomyositis (DM) on clinical and immunological features. METHODS By collecting clinical data of 106 CADM patients and 158 DM patients from January 2010 to June 2019 in the department of Rheumatology and Immunology, Peking University People's Hospital, the clinical characteristics and immunological features in the two groups were compared, and the distribution characters and the clinical meanings of myositis autoantibodies were discussed in the two groups respectively. Myositis autoantibodies were measured by immunoblotting according to the manufacturers' instructions. RESULTS In the aspects of clinical manifestations, CADM presented more with onset of interstial lung diseases (ILD) compared with DM (20.7% vs. 7.6%, P=0.002), and CADM-ILD was more likely to be acute ILD (58.3% vs. 26%, P < 0.001), and there were no differences between CADM and DM in cutaneous manifestations, accompanied with connective tissue disease (CTD) and malignancy. In CADM, the positive rate of rheumatoid factors and antinuclear antibodies was lower in DM. The most common myositis specific autoantibodies (MSAs) in CADM were anti-MDA5 (36%), anti-PL-7 (11.2%) and anti-TIF-1γ (10.1%). The most common MSAs in DM were anti-Jo-1 (19.2%), anti-TIF-1γ (11.5%) and anti-MDA5 (11.5%). Anti-MDA5 was correlated with acute ILD and skin ulceration both in CADM and DM; in CADM, skin ulceration was not associated with the titer of anti-MDA5; while in DM, skin ulceration was associated with high titer of anti-MDA5. In DM, anti-TIF-1γ was correlated with heliotrope eruption, V/shawl neck sign, perionychia erythma and malignancy, and higher rate of malignancy was seen in all titers of the anti-TIF-1γ positive patients. In CADM, anti-TIF1-γ showed no correlation with clinical manifestations. The most common myositis associated autoantibody was anti-Ro-52 both in CADM and DM. In CADM, anti-Ro-52 was associated with Raynaud's phenomenon and chronic ILD, while in DM, anti-Ro-52 was associated with mechanic's hands, noninfectious fever and accompanied CTD. CONCLUSION Compared with DM, ILD is more likely to be acute in CADM. It is different between CADM and DM about the distribution of myositis autoantibodies and the clinical significance of the same myositis antibody, and the clinical significance of some myositis antibodies is related to titers.

Diagnostic Value of Structural and Functional Neuroimaging in Autoimmune Epilepsy.

Epilepsy is a common nervous system disease, which affects about 70 million people all over the world. In 2017, the International League Against Epilepsy (ILAE) considered immune factors as its independent cause, and the concept of autoimmune epilepsy (AE) was widely accepted. Early diagnosis and timely treatment can effectively improve the prognosis of the disease. However, due to the diversity of clinical manifestations, the expensive cost of autoantibody detection, and the increased prevalence in Western China, the difficulty for clinicians in early diagnosis and treatment has increased. Fortunately, convenient and fast imaging examinations are expected to help even more. The imaging manifestations of AE patients were characteristic, especially the combined application of structural and functional neuroimaging, which improved the diagnostic value of imaging. In this paper, several common autoantibodies associated with AE and their structure and function changes in neuroimaging were reviewed to provide help for neurologists to achieve the goal of precision medicine.