Prevalence Of Autoantibodies Research Articles

Autoantibody screening of plasma and peritoneal fluid of patients with endometriosis.

Are there specific autoantibody profiles in patients with endometriosis that are different from those in controls? This study did not reveal a significantly higher prevalence of autoantibodies in the studied groups of patients. Various inflammatory factors are postulated to be involved in the pathomechanisms of endometriosis, and a potential link exists with autoimmune diseases, which may also play an important role. As the diagnosis of endometriosis remains invasive, it can only be confirmed using laparoscopy with histopathological examination of tissues. Numerous studies have focused on identifying useful biomarkers to confirm the disease, but without unequivocal effects. Autoantibodies are promising molecules that serve as potential prognostic factors. A multicentre, cross-sectional study was conducted over 18 months (between 2018 and 2019), at eight Departments of Obstetrics and Gynaecology in several cities across Poland on 137 patients undergoing laparoscopic examination for the diagnosis of endometriosis. During laparoscopy, we obtained plasma samples from 137 patients and peritoneal fluid (PF) samples from 98 patients. Patients with autoimmune diseases were excluded from the study. Autoantibody profiling was performed using HuProt v3.1 human proteome microarrays. We observed no significant differences in the expression of autoantibodies in the plasma or PF between the endometriosis and control groups. The study revealed that in the PF of women with Stage II endometriosis, compared with other stages, there were significantly higher reactivity signals for ANAPC15 and GABPB1 (adj. P < 0.016 and adj. P < 0.026, respectively; logFC > 1 in both cases). Comparison of the luteal and follicular phases in endometriosis patients revealed that levels of NEIL1 (adj. P < 0.029), MAGEB4 (adj. P < 0.029), and TNIP2 (adj. P < 0.042) autoantibody signals were significantly higher in the luteal phase than in the follicular phase in PF samples of patients with endometriosis. No differences were observed between the two phases of the cycle in plasma or between women with endometriosis and controls. Clustering of PF and plasma samples did not reveal unique autoantibody profiles for endometriosis; however, comparison of PF and plasma in the same patient showed a high degree of concordance. Although this study was performed using the highest-throughput protein array available, it does not cover the entire human proteome and cannot be used to study potentially promising post-translational modifications. Autoantibody levels depend on numerous factors, such as infections; therefore the autoantibody tests should be repeated for more objective results. Although endometriosis has been linked to different autoimmune diseases, it is unlikely that autoimmune responses mediated by specific autoantibodies play a pivotal role in the pathogenesis of this inflammatory disease. Our study shows that in searching for biomarkers of endometriosis, it may be more efficient to use higher-throughput proteomic microarrays, which may allow the detection of potentially new biomarkers. Only research on such a scale, and possibly with different technologies, can help discover biomarkers that will change the method of endometriosis diagnosis. This study was funded by a grant from the Polish Ministry of Health (grant no. 6/6/4/1/NPZ/2017/1210/1352). It was also funded by the Estonian Research Council (grant PRG1076) and the Horizon 2020 Innovation Grant (ERIN; grant no. EU952516), Enterprise Estonia (grant no. EU48695), and MSCA-RISE-2020 project TRENDO (grant no. 101008193). The authors declare that there is no conflict of interest. N/A.

The prevalence of diabetes and thyroid related autoantibodies in Sri Lankan children with type 1 diabetes and their unaffected siblings - The utility of a new screening assay.

There is limited information about diabetes and thyroid related autoantibodies in children with type 1 diabetes (T1D) or their siblings in Sri Lanka. To assess in T1D children and their unaffected siblings the prevalence of autoantibodies to (1) glutamic acid decarboxylase (GADA), insulinoma associated antigen-2 (IA-2A) and zinc transporter 8 (ZnT8A) using 3 Screen ICA™ (3-Screen) and individual ELISA assays; (2) insulin (IAA); and (3) thyroid peroxidase (TPOA), thyroglobulin (TgA) and the TSH receptor (TSHRA). We selected - (a) consecutive T1D children, and (b) their unaffected siblings of both sexes, from the T1D Registry at Lady Ridgeway Hospital, Colombo. The median age (IQR) of 235 T1D children and 252 unaffected siblings was 11 (8.4, 13.2) and 9 (5.4, 14.9) years respectively, and the duration of T1D was 23 (7, 54) months. (1) T1D children (a) 79.1% were 3-Screen positive; (b) all 3-Screen positives were individual antibody positive (GADA in 74%; IA-2A 31.1%; ZnT8A 38.7%); (c) and were younger (p=0.01 vs 3-Screen negatives); (d) multiple autoantibodies were present in 45.1%; (e) IA-2A (p=0.002) and ZnT8A (p=0.006) prevalence decreased with T1D duration. (f) TPOA and TgA prevalence was higher in T1D children compared to unaffected siblings (28%, p=0.001 and 31%, p=0.004, respectively). (2) Unaffected siblings (a) 6.3% were 3-Screen positive (p=0.001 vs T1D), and 2.4% were positive for IAA; (b) four subjects had two diabetes related autoantibodies, one of whom developed dysglycaemia during follow-up. The 3-Screen assay, used for the first time in Sri Lankan T1D children and their siblings as a screening tool, shows a high prevalence of T1D related Abs with a high correlation with individual assays, and is also a helpful tool in screening unaffected siblings for future T1D risk. The higher prevalence of thyroid autoantibodies in T1D children is consistent with polyglandular autoimmunity.

High prevalence of autoantibodies in children after COVID-19 infection of differing levels of severity

Autoantibodies, hallmarks of autoimmune disorders, have been described in individuals who have had COVID-19. We evaluated for autoantibodies in children after SARS-CoV-2 infection, including children who developed multisystem inflammatory syndrome in children (MIS-C).

Long-term outcome of thyroid abnormalities in patients with severe Covid-19.

We have previously observed thyroid dysfunction, i.e. atypical thyroiditis (painless thyrotoxicosis associated with non-thyroidal illness syndrome), in patients with severe acute respiratory syndrome coronavirus 2 disease (Covid-19). This study aimed to analyse the evolution of thyroid dysfunction over time. One hundred eighty-three consecutive patients hospitalised for severe Covid-19 without known thyroid history were studied at hospital admission (baseline). Survivors were offered 12-month longitudinal follow-up including assessment of thyroid function, autoantibodies and ultrasound scan (US). Patients showing US focal hypoechoic areas suggestive of thyroiditis (focal hypoechogenicity) also underwent thyroid 99mTc or 123I uptake scan. At baseline, after excluding from TSH analysis, 63 out of 183 (34%) Covid-19 patients commenced on steroids before hospitalisation, and 12 (10%) showed atypical thyroiditis. Follow-up of 75 patients showed normalisation of thyroid function and inflammatory markers and no increased prevalence of detectable thyroid autoantibodies. Baseline US (available in 65 patients) showed focal hypoechogenicity in 28% of patients, of whom 82% had reduced thyroid 99mTc/123I uptake. The presence of focal hypoechogenicity was associated with baseline low TSH (P = 0.034), high free-thyroxine (FT4) (P = 0.018) and high interleukin-6 (IL6) (P = 0.016). Focal hypoechogenicity persisted after 6 and 12 months in 87% and 50% patients, respectively, but reduced in size. After 9 months, thyroid 99mTc/123I uptake partially recovered from baseline (+28%) but was still reduced in 67% patients. Severe Covid-19 induces mild transient thyroid dysfunction correlating with disease severity. Focal hypoechogenicity, associated with baseline high FT4, IL6 and low TSH, does not seem to be related to thyroid autoimmunity and may persist after 1 year although decreasing in size. Long-term consequences seem unlikely.

Role of the autoantibodies and IL-1 cytokine in the pathogenesis diabetes mellitus

Diabetes mellitus is a complex multifactorial and heterogeneous syndrome characterized by hyperglycemia resulting from inadequate insulin secretion and/or insulin action. T lymphocytes and macrophages appear to play an important role in mediating ß-cell damage and causing Type 1 diabetes.A case-control study is done during the period from Feb., 2011, through the end of Feb. 2012. The study enrolled 90 diabetic patients divided into three groups Type 1, Type2 and LADA ( 30 patients in each group) who attended in Al Zahraa Teaching Hospital in Al-Kut city &amp; 25 non diabetic as a control to determine the prevalence of islet cell autoantibodies, glutamic acid decarboxylase autoantibodies (ICAs&amp; GADAs) and measured (IL-1Α α , IL-4, IL17, TNF α, IFN γ) as well as the frequency of HLA DR was measured in diabetic patients and non-diabetic control with no family history of diabetes. Serological tests for GADA &amp; ICA (by using ELISA) have been done for all sera of the study groups. Dual set ELISA technique is used for estimating the cytokines levels in the sera of all study groups while DNA extracted from whole blood from all study groups and these DNA were used to detected the HLA DR allele by using HISTO SPOT SSO system.According to the results of this study, Type 1 diabetic patients had higher frequency of GADA 65 autoantibodies compared with other study groups, as eighteen of them (60%) showed GADA positive in comparison to 6.6 % in type 2 DM, 56.7% in LADA and 0% in control group. Furthermore, twenty of type 1 diabetic patients which represent (66.7%) were ICA positive in comparison to 33.33% in type 2 DM, 70% in LADA and 4% in control group. Statistical analysis showed highly significant difference.Analysis of the serum sample showed that IL-1 α levels has been elevated significantly in the sera of Type 1(635.8± 685 pg./ml), type 2 (625.5± 55.86 pg./ml) and LADA (383.2± 533.5 pg./ml) diabetics patients positive autoantibodies in comparison with other groups type 1, type 2 and LADA diabetics patients negative autoantibodies and healthy control (60±35.21 pg. /ml)

T-cell infiltrate intensity is associated with delayed response to treatment in late acute cellular rejection in pediatric liver transplant recipients.

Late acute cellular rejection (ACR) is associated with donor-specific antibodies (DSA) development, chronic rejection, and allograft loss. However, accurate predictors of late ACR treatment response are lacking. ACR is primarily T-cell mediated, yet B cells and plasma cells (PC) also infiltrate the portal areas during late ACR. To test the hypothesis that the inflammatory milieu is associated with delayed response (DR) to rejection therapy, we performed a single-center retrospective case-control study of pediatric late liver ACR using multiparameter immunofluorescence for CD4, CD8, CD68, CD20, and CD138 to identify immune cell subpopulations. Pediatric liver transplant recipients transplanted at <17 years of age and treated for biopsy-proven late ACR between January 2014 and 2019 were stratified into rapid response (RR) and DR based on alanine aminotransferase (ALT) normalization within 30 days of diagnosis. All patients received IV methylprednisolone as an initial rejection treatment. Immunofluorescence was performed on archived formalin-fixed paraffin embedded (FFPE) liver biopsy tissue. Liver biopsies from 60 episodes of late ACR in 54 patients were included in the analysis, of which 33 were DR (55%). Anti-thymocyte globulin was only required in the DR group. The frequency of liver-infiltrating CD20+ and CD8+ lymphocytes and the prevalence of autoantibodies were higher in the DR group. In univariate logistic regression analysis, serum gamma-glutamyl transpeptidase (GGT) level at diagnosis, but not ALT, Banff score or presence of DSA, predicted DR. Higher serum GGT level, presence of autoantibodies, and increased CD8+ T-cell infiltration portends DR in late ACR treatment in children.

Predictors and clinical complications associated with antiphospholipid antibodies in sickle cell disease.

Although a higher prevalence of antiphospholipid autoantibodies (aPL) has been observed in some cohorts of sickle cell disease (SCD) patients, the clinical risk factors for the development of aPL and its associated complications remain unclear. In a retrospective study of 63 SCD patients, a lower hemoglobin concentration and higher white blood cell count were independently associated with an elevated aPL. SCD patients with elevated aPL had increased pregnancy complications (≥3 miscarriages, preterm delivery, pre-eclampsia) and venous thrombotic events. Our findings suggest that SCD may predispose to the generation of aPL and that aPL itself may contribute to the vasculopathy of SCD. Prospective testing for aPL is warranted in patients with SCD.

Antiphospholipid antibodies in pulmonary embolism treated with direct oral anticoagulants: Prevalence data from unselected consecutive patients

BackgroundDirect oral anticoagulants (DOACs) are the first-choice treatment option for the prevention of the recurrence of venous thrombosis in patients with pulmonary embolism (PE); however, their effect in patients with antiphospholipid syndrome (APS) is challenged. Therefore, the prevalence of antiphospholipid autoantibodies in patients with PE is noteworthy. ObjectivesTo determine the prevalence of unselected patients presenting with PE who meet the criteria for APS based on elevated levels of anticardiolipin (aCL) and anti-β2-glycoprotein I (aβ2GPI) antibodies. MethodsConsecutive patients with PE, in whom DOACs were primarily initiated, were tested for aCL and aβ2GPI. If the levels were elevated, the tests were repeated after 12 weeks for APS diagnosis. Laboratory results and patient characteristics were retrospectively collected from a laboratory information system and electronic patient journal entries over a 2-year period. ResultsThe prevalence of APS based on consistently elevated levels of aCL or aβ2GPI was 3.7% (10 of 267 patients). Three patients were double positive. In 11 out of 21 patients (52%) with initially elevated values, the levels of the antibodies normalized after 12 weeks. The patient characteristics were largely similar in those with APS and those without APS; however, patients with APS tended to be older and more likely to receive antithrombotic treatment at the time of PE. ConclusionWe found a relatively low prevalence of APS based on aCL or aβ2GPI. The high rate of normalized levels of the antibodies after 12 weeks reaffirms the need for repeated tests for APS diagnosis. Older patients more frequently met the criteria for APS. Determining the effectiveness of DOACs in non–triple-positive patients with APS following venous thromboembolism is important to further determine the feasibility of unselected tests in patients with PE.

Characteristics of patients with juvenile dermatomyositis from 2001-2021 at a tertiary care center.

Juvenile dermatomyositis (JDM) is the most common inflammatory myopathy in the pediatric population and can represent a medical emergency. However, many features of JDM remain poorly understood, disease presentation is highly variable, and predictors of disease course have yet to be identified. This retrospective chart review included 47 JDM patients seen at a tertiary care center over a 20-year period. Characteristics such as demographics, clinical signs and symptoms, antibody positivity, dermatopathology features, and treatments were recorded. All patients had evidence of cutaneous involvement, whereas 88.4% experienced muscle weakness. Constitutional symptoms and dysphagia were commonly present. The most frequent cutaneous findings were Gottron papules, heliotrope rash, and nailfold changes. Anti-TIF1? was the most prevalent myositis-specific autoantibody. Management involved systemic corticosteroids in nearly all cases. Strikingly, the dermatology department was only involved in the care of four in every ten (19/47) patients. Prompt recognition of the strikingly reproducible skin findings present in JDM can improve disease outcomes in this population. This study highlights the need for increased education of such pathognomonic findings as well as more multidisciplinary care. In particular, a dermatologist should be involved in the care of patients presenting with muscle weakness and skin changes.

Scleroderma specific autoantibodies in rheumatoid arthritis and Sjögren's syndrome patients with interstitial lung disease: Prevalence and associations

Systemic sclerosis (SSc) has been classically linked to interstitial lung disease (ILD) development, often in association with specific SSc autoantibodies. In the present report, we aimed to estimate the prevalence of SSc autoantibodies in 60 seropositive RA and 41 primary SS patients complicated or not by ILD. SSc autoantibodies were determined in patients’ sera by a commercial immunoblot assay. RA ILD patients displayed higher frequency of SSc-specific antibodies at strong titers compared to RA-with no lung involvement (25% vs 3.1%, p = 0.01)[OR 95% CI:10.9 (1.2–94.5)], with no differences detected between primary SS groups. These data indicate that many seropositive RA ILD patients probably represent an overlap RA/SSc entity, requiring tailored diagnostic and therapeutic approach.

Abstract 161

Objective: To determine the prevalence of disease specific auto-antibodies: anti-glutamic acid decarboxylase (anti-GAD), anti-zinc transporter (anti-ZnT8), anti-islet cell (AICA), insulin autoantibody (IAA), and other organ specific autoantibodies: anti-thyroid peroxidase (anti-TPO) and IgA anti-tissue transglutaminase (anti-tTG) in children with T1D. To evaluate correlation between antibodies positivity and clinical parameters related to T1D. Methods: 300 insulin requiring children, with onset of diabetes between 6 months and 18 years of age, attending the T1D clinic of our institute between Jan-19 and Apr-22, were enrolled. T1D was diagnosed as per the ISPAD criteria, coupled with documentation of insulinopenia (fasting C-peptide &lt;0.6 ng/ml). Children with secondary, neonatal, monogenic and drug induced diabetes were excluded. 272 patients were included in the analysis. Continuous and categorical data are presented as mean ± SD and frequency (%), respectively. Pearson’s coefficient was used to determine correlation between the various parameters. Results: Mean age of our cohort was 10.5 ± 4 years, with 53.3% girls. Mean age at diagnosis was 7.4 ± 3.9 years, with 3.1 ± 3.2 years being the mean duration of diabetes.12.5% children were hypothyroid and 15.1% had celiac disease. Anti-GAD, anti-ZnT8, AICA and IAA antibodies were present in 58.5%, 32.3%, 32% and 16.9% children, respectively. 22.1% patients were antibody negative. At least two antibodies were present in 27.6%. Three antibodies were present in 11%, and 3.3% had all four auto-antibodies positive. The presence of anti-TPO and IgA anti-tTG was seen in 28.3% and 13.6%, respectively. Age at diagnosis positively correlated with anti-GAD positivity, and negatively correlated with IAA positivity. Duration of diabetes negatively correlated with T1D antibodies positivity, multiple antibodies positivity, and anti-GAD, anti-ZnT8 and AICA positivity. There was no gender difference observed. Presence of nephropathy and retinopathy negatively correlated to anti-GAD positivity. Anti-TPO positivity was more common in the female children. Presence of IgA anti-tTG negatively correlated with age of T1D onset, and positively correlated to duration of diabetes. Conclusion: Children diagnosed at younger age are more likely to be anti-GAD positive, while those diagnosed at older age are more likely to demonstrate IAA positivity. Positivity for multiple auto-antibodies, and anti-GAD, anti-ZnT8 and AICA decreases with increasing duration of diabetes. Girls are more likely to develop anti-TPO positivity, while IgA anti-tTG positivity is seen in older children and those with longer duration of diabetes.

IgG autoantibodies against ACE2 in SARS-CoV-2 infected patients.

How frequently autoantibodies against angiotensin-converting enzyme 2 (ACE2) occur in patients infected by SARS-CoV-2 is understudied and limited to investigations on a small sample size. The presence of these antibodies may contribute to the long-lasting effects of COVID-19 observed in some individuals, particularly if IgG-class antibodies would emerge in patients. This study assessed the prevalence of IgG autoantibodies against ACE2 in 1139 patients infected with SARS-CoV-2 and examined their relationship with severity, demographic characteristics, and status of vaccination against influenza. The overall prevalence of anti-ACE IgG antibodies in our cohort was 1.5%. Most of these individuals were men (76.5%) and underwent mild COVID-19, but some severe and asymptomatic cases were also observed. Patients with severe infection had twofold higher titers than mild and asymptomatic cases. Age, comorbidities, and influenza vaccination status were not related to antibody prevalence. The prevalence of IgG anti-SARS-CoV-2 antibodies (against nucleocapsid protein and S2 subunit, but not against receptor-binding domain) was higher in the subset with ACE2 autoantibodies. Further research is required to understand the potential spectrum and duration of effects of IgG autoantibodies against ACE2 in patients after SARS-CoV-2 infection, particularly concerning long COVID-19.

Prevalence of Antineutrophil Cytoplasmic Antibodies and Antinuclear Antibodies in Patients with Pulmonary Tuberculosis: A Tertiary Care Center Experience from North India.

Tuberculosis (TB) can have manifestations closely mimicking autoimmune diseases. The prevalence of autoantibodies in TB varies among different populations. To study the prevalence of anti-neutrophilic cytoplasmic antibodies (ANCA) and antinuclear antibodies (ANA) in pulmonary tuberculosis (PTB). This was a cross-sectional, observational study. Subjects with microbiologically confirmed PTB, either via smear or culture positivity on sputum or bronchoalveolar lavage (BAL) fluid, or positive rapid diagnostic tests were included. ANCA against proteinase-3 (PR3), myeloperoxidase (MPO), lactoferrin, and elastase were tested using an enzyme-linked immunosorbent assay (ELISA). ANA was detected using indirect immunofluorescence (IIF). Eighty-nine subjects with a median [interquartile range (IQR)] age of 28 (20-46) years, 67.4% males, were recruited. Eighty-one subjects had microbiological confirmation on sputum examination, and eight required examination of BAL fluid. Sera were drawn from 62 treatment-naïve subjects, the rest (27) were on antitubercular therapy (ATT). Eighty-six (96.6%) subjects tested positive for anti-elastase antibody, seven of which were also positive for anti-PR3. None were positive for anti-MPO and anti-lactoferrin. Six (6.7%) subjects tested positive for ANA. None of the subjects had features of underlying connective tissue disease or vasculitis. PTB patients showed a high prevalence of anti-elastase and a low prevalence of ANA and anti-PR3 antibodies. ANCA positivity should be interpreted with caution in TB endemic areas. The role of anti-elastase antibodies in differentiating TB from ANCA-associated vasculitis (AAV) needs further research.

Antineuronal Autoantibodies in the Cerebrospinal Fluid and Serum From 106 Patients With Recent-Onset Depression Compared With 106 Individually Matched Healthy Control Subjects

No large studies have investigated the prevalence of cerebrospinal fluid antineuronal autoantibodies in isolated depression. In this case-control study comparing 106 patients with isolated depression (ICD-10 code F32) with 106 healthy control subjects, cerebrospinal fluid and serum samples were tested for 7 immunoglobulin G autoantibodies using commercial fixed cell-based assays. To explore validity of methods, positive samples were retested twice by cell-based assays and once by tissue-based assays (monkey cerebellum). The prevalence of any of the antineuronal autoantibodies in cerebrospinal fluid was 0.0% in both groups and the seroprevalence was 0.9% in both groups, based on consistent findings in cell-based assays. However, all samples were negative by the tissue-based assay. Evaluation of antineuronal autoantibodies in cerebrospinal fluid cannot be recommended routinely for patients with isolated depression of moderate severity. Future studies of isolated depression should consider much larger sample sizes and evaluation of antineuronal autoantibodies using modalities other than commercial kits.

Autoantibody profile in sarcoidosis, analysis from the GRADS sarcoidosis cohort.

BackgroundSarcoidosis, a multi-systemic granulomatous disease, is a predominantly T-cell disease but evidence for a role for humoral immunity in disease pathogenesis is growing. Utilizing samples from the Genomic Research in Alpha-1 anti-trypsin Deficiency and Sarcoidosis (GRADS) study, we examined the prevalence of autoantibodies in sarcoidosis patients with pulmonary-only and extra-pulmonary organ involvement compared to normal controls.Study design and methodsWe analyzed serum samples from sarcoidosis patients who participated in the GRADS study utilizing an autoantigen microarray platform for both IgM and IgG antibodies. The cohort included sarcoidosis patients with pulmonary-only disease (POS, n = 106), sarcoidosis patients with extra-pulmonary disease (EPS, n = 120) and a normal control cohort (NC, n = 101). Organ involvement was assessed following a standardized format across all GRADS participating centers.ResultsSarcoidosis patients overall had increased levels of IgM and IgG autoantibodies compared to normal controls. In addition, several autoantibodies were elevated in the POS and EPS cohorts compared to the NC cohort. Differences in autoantibody levels were also noted between the POS and the EPS cohorts. When comparing organ involvement with sarcoidosis, bone, spleen and ear, nose and throat involvement had higher IgM expression than other organs.ConclusionSarcoidosis patients have elevated IgM and IgG autoantibody levels compared to normal controls. In addition, individuals with pulmonary as well as additional organ involvement had higher IgM expression. Further research is needed focusing on specific organ-autoantibody pairs and role of autoantibodies in disease pathogenesis.

A retrospective study of prevalence and pattern of international consensus on ANA patterns among patients with hepatitis C virus infection.

BackgroundA previous study reported a 30% prevalence of various autoantibodies among patients with hepatitis C virus (HCV) infection. The International Consensus on Anti-Nuclear Antibody (ANA) Patterns was recently introduced to classify ANA patterns based on immunoassay on HEp-2 cells. There is no previous report with this newly developed classification to evaluate patients with HCV infection. The study aims to study the prevalence and pattern of ANA patterns among HCV-infected patients.MethodsWe retrospectively analyzed the medical records of patients with HCV infection from September 2020 to June 2021 at our institution. A positive ANA is defined as a titer of more than 1:320. We compared patient features among the positive and negative groups.ResultsOverall, 258 patients were enrolled—184 patients with negative ANA and 74 patients (28.7%) with positive ANA. The mean age was 67.3 in ANA positive group and 61.2 ANA negative group. Female was prominent with ANA positive and accounted for 63.5%. The most detected ANA pattern was AC-1(homogeneous) (25.9%), followed by AC-4(fine speckled) (25.2%) and AC-21(anti-mitochondrial antibody) (9.6%). In ANA positive group, we found a trend of lower HCV viral load (5.72 log10 IU/ML vs. 6.02 log10 IU/ML), lower alanine aminotransferase level (39.5 U/L vs. 44 U/L), and higher advanced fibrosis (F3 and F4) (38.5% vs. 26.1%). In addition, higher positive ANA (more than 1:640) is significantly associated with lower estimated glomerular filtration rate (eGFR) (77.76 vs. 87.94 mL/min/1.73 m2, P = 0.044).ConclusionsA high prevalence (28.7%) of ANA was found in patients with chronic hepatitis C. The presence of positive ANA is not related to the severity of their hepatic manifestation. However, higher positive ANA was significantly associated with lower eGFR.

PREVALENCE OF ANTI-NUCLEAR ANTIBODY IN THE INDIAN POPULATION: A TERTIARY REFERENCE LABORATORY STUDY

Background: Autoimmune diseases are known to be the third leading cause of fatality and morbidity amongst the population of industrialized world. They account for 3-9% of health burden in general people, but information regarding prevalence of autoantibodies and autoimmune diseases in developing nations is scarce. To study the prevalence of Anti-nuclear antibodies, Aim: the total number and distribution of different tests used in the diagnosis of anti-nuclear antibody amongst Indian population, and correlate the ndings from these tests with the clinical characteristics of the patients. Retrospective data was evaluated from a Global Reference Method: Diagnostic Laboratory in Mumbai, for a period of 6 years. This included a total of 285095 cases tested for ANA. ANA-IFA and ANA-ELISA were the screening tests used while ANA-ELISA Prole and ANA Blot were the conrmatory tests. ANA by IFA was the most preferred Results: screening test (88.73%) and ANA by Blot was the most preferred Conrmatory test (67.13%) based on their sensitivity and positive predictive value respectively. ANA-IFA showed positivity of 36.48% and ANA by ELISA test had positivity of 11.46%. In conrmatory testing, ANA Blot showed a positivity of 31.90% and ELISA Prole had 23.36% positivity. Females showed signicantly higher positivity for both the screening test and Conrmatory tests than males (p&lt;0.001). Screening by ANA IFA and Conrmatory by Conclusion: ANA Blot was the most preferred tests in our study population. These tests were found to be better for diagnosis, sub-syndrome categorization, prognosis, clinical follow-up and therapeutic strategies in various autoimmune disorders.

Prevalence of Myositis-Specific Autoantibodies and Myositis-Associated Autoantibodies in COVID-19 Patients: A Pilot Study and Literature Review.

Coronavirus disease 2019 (COVID-19) infection has been linked to numerous autoimmune manifestations. Neither the mechanism nor the etiology of this association has been fully explored or elucidated. Prior studies have detected myositis in patients with proven COVID-19 infection, suggesting a relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the development of myositis. Studies have reported elevated levels of autoimmune antibodies, including myositis-specific autoantibodies (MSAs) and myositis-associated autoantibodies (MAAs), in patients with COVID-19 infection, however the prevalence is not well documented. Our objective was to assess the prevalence of MSAs and MAAs in COVID-19 patients compared with unaffected subjects. Serum samples from 74 unvaccinated, polymerase chain reaction (PCR)-positive COVID-19 infected patients were compared with serum samples from 41 healthy, unaffected individuals. All serum samples were tested for MSA and MAA reactivity. Within the COVID-19-positive group, six (8.1%) patients exhibited MSA/MAA positivity, compared with only one (2.4%) individual from the control group. Although a higher prevalence of MSA/MAA positivity was observed within the COVID-19 infected group, the difference did not reach statistical significance (p=0.223). The autoantibodies detected in this study have a unique association with dermatomyositis and other inflammatory myopathies, and may play a role in COVID-19-associated myopathy. This article was previously presented as an abstract at Jacobs School of Medicine and Biomedical Sciences Research Day on June 3rd, 2022.

OA29 Blotting-based assays under-detected TIF1-gamma and NXP2 autoantibodies compared to immunoprecipitation in Juvenile Dermatomyositis cohorts

Introduction/BackgroundThe rare heterogenous autoimmune disease Juvenile Dermatomyositis (JDM) relies on prognostic tools including myositis specific antibodies (MSA) and myositis associated antibodies (MAA) to guide early treatment and reduce the risks of poor outcome. However, there is an emerging concern regarding the inter-assay validity due to the current lack of a standardised protocol for MSA/MAA screening across healthcare centres. Among available MSA/MAA screening assays, most laboratories prefer using immunoblot over immunoprecipitation, due to its practicality and lower cost. Notably, blotting-based assays were reported to have reduced specificity at detecting certain MSA/MAA subgroups.Description/MethodA total of 472 JDM patients recruited via UK Juvenile Dermatomyositis Cohort and Biomarker Study (JDCBS) were included in this study. For immunoprecipitation cohort, the sera of 383 JDM-diagnosed patients were determined at the University of Bath using radio-labelled protein immunoprecipitation, and 140kDa bands were confirmed with ELISA for NXP2 or MDA5. For immunoblot cohort (n = 89), MSA/MAA results were obtained from the patients’ records at the centre of care. The immunoprecipitation group and immunoblot group were investigated for the frequency of each autoantibody subgroup within each cohort. The objective was to determine the sensitivity of each assay in detecting myositis relevant antibodies (MSA/MAA) in the context of JDM.Discussion/ResultsOverall, the majority of patients were female, and self-identified as white. Specifically, in immunoprecipitation cohort, 70.9% of the patients were female, while 77.1% of the patients self-identified as white. In the immunoblot cohort, 72.7% of the patient were female, while 65.9% self-identified as white.Regarding MSA/MAA status in each cohort, 225 out of 383 (58%) immunoprecipitation samples were positive for at least 1 myositis relevant autoantibody (MSA/MAA). In the immunoblot cohort the proportion was 53% (47 out of 89 samples). Despite the similar gender and ethnicity distribution, the frequencies of autoantibody subgroups varied between two cohorts. In descending order, the 3 most common MSAs detected by immunoprecipitation group were anti-TIF1γ (18.1%), anti-NXP2 (15.8%) and anti-MDA5 (5.9%). On the contrary, anti-MDA5 (15.5%) was the most prevalent autoantibody detected by immunoblot, followed by anti-TIF1γ (11.3%) and anti-NXP2 (9.3%), respectively.The prevalence of more than one myositis relevant autoantibodies detected in a patient was rare in both cohorts. Specifically, when excluding anti-Ro52, a MAA that is not detected with immunoprecipitation, 2.2% of the total patients in immunoblot cohort had more than 1 MSA/MAA. This rate is lower in immunoprecipitation cohort, as only 0.5% of the patients in this cohort were determined to be positive for more than one autoantibody subgroup. When accounting for anti-Ro52 in immunoblot cohort, 7 out of 8 anti-Ro52 positive patients were also positive for anti-MDA5, making up 7.9% of immunoblot cohort.Key learning points/ConclusionThe variance between autoantibody frequencies detected by each method suggested that immunoprecipitation and immunoblot assays do not perform equally for all MSA and MAA. The lower detection of anti-TIF1γ in immunoblot is consistent with previous reports. Additionally, a potential reduction of sensitivity in anti-NXP2 detection using immunoblot is observed for the first time. Higher rate of anti-MDA5 in immunoblot cohort might reflect the earlier pre-treatment samples compared to the samples tested in immunoprecipitation cohort, as the titre of anti-MDA5 was reported to decrease with treatment. As MSA/MAA status are interpreted by clinicians to classify JDM patients into homogenous subgroups for more focused treatment plans, the reliability of autoantibody screening process is an issue of interest. Further investigations are necessary to characterise the sensitivity and specificity of each method.

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.