Background:Commercial line immunoassays (LIAs) are used to detect myositis-specific and myositis-associated autoantibodies (MSAs/MAAs) in patients with suspected idiopathic inflammatory myopathy (IIM). However, performance consistency with LIAs remains challenging. We evaluated the appropriateness, clinical consistency, and diagnostic performance of MSA/MAA LIA testing in real-life clinical practice. Methods:Between January and December 2024, eight Italian laboratories performed 1,127 MSA/MAA LIA determinations (Euroline Myopathies 16 Ags plus cN-1A). LIA appropriateness was defined as concordance between the clinical information provided and the MSA/MAA request; clinical consistency was defined as agreement between the IIM diagnosis and LIA results; and diagnostic performance was defined as the reliability of LIA in confirming an IIM diagnosis. Results:MSA/MAA positivity was observed with 564/1,127 (50.1%) LIA requests. LIA appropriateness and consistency were 31.6% and 51.3%, respectively. Of the 1,127 LIA requests, 666 (59.1%) included a clinical diagnosis. The appropriateness and consistency of the 666 LIA reports were 53.4% and 86.8%, respectively. Among the 666 patients, 337 (50.6%) were diagnosed as having IIM, and 329 (49.4%) were diagnosed as having a non-IIM disease. In patients with IIM, 288/337 (85.4%) received true-positive MSA/MAA LIA results, whereas 105/329 (31.9%) of patients with non-IIM disease received false-positive results (P<0.001). Significant positive odds ratios were observed for anti-Jo-1, anti-MDA5, anti-PM-Scl-75/100, and MSA-associated anti-Ro52 antibodies (P<0.001). Conclusions:With increasing MSA/MAA requests for suspected IIM, LIA testing can help identify certain antibodies in real-life scenarios. The appropriateness of the request and the clinical information provided mainly influence the LIA diagnostic performance.

Autoimmune hepatitis (AIH) is a liver disease of unknown cause characterized by hypergammaglobulinemia, typical or compatible liver histology, the absence of viral hepatitis and the production of autoantibodies. Anti-smooth muscle antibodies (SMAs) detected with indirect immunofluorescence (IIF) in rodent tissues are not disease specific, whereas antibodies directed to the filamentous form of actin (F-actin) are specifically involved in AIH-1. As solid-phase immunoassays (SPAs) specifically targeting F-actin, such as enzyme-linked immunosorbent assay (ELISA), have already been included in recent guidelines, in this study, we evaluated the diagnostic performance of an immunoblotting SPA for F-actin. We selected 86 samples positive for SMA by IIF (titre≥1∶40) and/or for anti-F-actin by ELISA (≥20 units); the patients were divided into 3 groups: AIH-1 (n=14), other liver disorders (n=38) and other nonliver-related conditions (n=34). The samples were tested with an immunoblot SPA (European Autoimmune Liver Diseases 9 Ag plus F-actin, Euroimmun, Germany); the qualitative results were converted into numeric intensity values via EurolineScan software. Immunoblotting revealed 16 positive samples (19%), and ELISA revealed 24 (28%); among them, 7/16 (44%) and 11/24 (46%) had AIH-1. The diagnostic performance metrics were as follows: sensitivity (50%); specificity (87.5%); positive predictive value (PPV), 43.8%; negative predictive value (NPV), 90%; and accuracy (81.4%) and equal to those of ELISA. The mean values were greater in the AIH-1 group; the receiver operating characteristic curve (ROC) had an area under curve (AUC) of 0.77 and was not different from that of the ELISA (0.82); the agreement was 81.4%, with a Cohens kappa of 0.49.Immunoblotting might be a reliable assay for the identification of anti-F-actin antibodies, and given its high specificity, its implementation in a clinical laboratory might confirm the specific diagnosis of AIH-1 in patients with IIF-detected SMA.

Objectives Anti-nuclear antibodies (ANA) testing on indirect immunofluorescence (IIF) has been for a long time the gold standard assay in the diagnosis of rheumatic diseases; more recently different solid phase assays (SPA) have been recommended to increase specificity of positive results. The best combination of the different assays should both reduce the time to diagnosis and the costs of testing. Methods Serum samples from 995 unselected outpatients were analysed simultaneously using IIF and a fluorescent enzyme SPA as initial screening test. Any IIF or SPA positive sample was further analysed for individual antibody specificities and three algorithm models with different timelines were adopted. The cost-effectiveness assessment was performed by calculating the total number of positive patients and the cost of diagnosis for each algorithm. Results IIF and SPA were both positive in 112 (11.3 %) patients, and both negative in 597 (60 %) patients; 257 results (25.8 %) were conflicting between the two methods. The three algorithms resulted in a different number of positive patients and had a different cost per single diagnosis: the combined algorithm revealed the highest number of positive patients with a lower cost per diagnosis than the traditional one. Conclusions The combined approach of two different methods ensures the highest reliability of ANA screening test; however, specific appropriate SPA testing might be chosen according to IIF pattern as recommended in International guidelines. Each clinical laboratory should carefully evaluate its diagnostic algorithm for ANA testing on the volume and type of requests, eventually designing new cost-effective reimbursement models based on patients outcomes.

Antibodies against glutamic acid decarboxylase (anti-GAD) are a valuable diagnostic tool to detect severe autoimmune conditions as type 1 diabetes mellitus (T1DM) and anti-GAD related neurological disorders, having the latter more often anti-GAD concentrations in serum multiple times higher than in the former. Automated immunoassays, either with ELISA or chemiluminescent technology, are validated for diagnostic use in serum with analytical ranges suitable for T1DM diagnosis. In a patient presenting with a suspected autoimmune ataxia, anti-GAD testing on an automated chemiluminescent immunoassay (CLIA) resulted in slightly abnormal concentrations in serum (39.2 KIU/L) and very high concentrations in CSF (>280 KIU/L), thus prompting to proceed to serum dilutions to exclude a false negative result and a misdiagnosis. Different dilutions of serum resulted in nonlinear concentrations with endpoint result of 276,500 KIU/L at dilution 1:1000. CSF dilution was instead linear with endpoint result of 4050 KIU/L. In this case report we found that anti-GAD testing in CSF was essential to establish the clinical diagnosis and to suspect hook-effect in serum due to the excess of autoantibodies in this severe autoimmune condition.

Background: The usefulness of myositis-specific autoantibodies (MSAs) and myositis-associated autoantibodies (MAAs) for the assessment of idiopathic inflammatory myopathies (IIMs) is acknowledged, but laboratory standardization remains a challenge. We detected MSAs/MAAs by multi-analytic line immunoassay (LIA) and particle-based multi-analyte technology (PMAT) in a multicenter cohort of patients with IIMs. Methods: We tested the sera from 411 patients affected with definite IIM, including 142 polymyositis (PM), 147 dermatomyositis (DM), 19 cancer-associated myositis, and 103 overlap myositis syndrome (OM), and from 269 controls. MSAs/MAAs were determined by 16Ags LIA in all sera, and anti-HMGCR by ELISA in 157/411 IIM sera and 91/269 control sera. The analytical specificity of LIA/HMGCR ELISA was compared with that of PMAT in 89 MSA+ IIM sera. Results: MSAs/MAAs were positive in 307/411 (75%) IIM patients and 65/269 (24%) controls by LIA (Odds Ratio 9.26, 95% CI 6.43–13.13, p < 0.0001). The sensitivity/specificity of individual MSAs/MAAs were: 20%/100% (Jo-1), 3%/99.3% (PL-7), 4%/98.8% (PL-12), 1%/100% (EJ), 0.7%/100% (OJ), 9%/98% (SRP), 5.6%/99.6% (TIF1γ), 4.6%/99.6% (MDA5), 8%/96% (Mi-2), 1.5%/98% (NXP2), 1.7%/100% (SAE1), 4%/92% (Ku), 8.5%/99% (PM/Scl-100), 8%/96% (PM/Scl-75), and 25.5%/79% (Ro52). Anti-HMGCR was found in 8/157 (5%) IIM patients and 0/176 (0%) controls by ELISA (p = 0.007). Concordance between LIA/HMGCR ELISA and PMAT was found in 78/89 (88%) samples. Individual MSAs detected by LIA were associated with IIM subsets: Jo-1 with PM and OM, PL-12 with OM, Mi-2, TIF1γ, and MDA5 with DM, SRP with PM, and PM/Scl-75/100 with OM (p < 0.001 for all). Conclusions: Since MSAs are mostly mutually exclusive, multi-specific antibody profiling seems effective for a targeted clinical-serologic approach to the diagnosis of IIMs.

Abstract Objectives Antibodies against glutamic acid decarboxylase isoform 65 (GAD-Ab) have been found in different severe neurological conditions associated with altered synthesis of γ-aminobutyric acid (GABA). Serum GAD-Ab can be found in up to 90 % of patients with Type 1 Diabetes mellitus (T1DM), mostly at relatively low concentrations, while high concentrations of GAD-ab are thought to be more frequently associate to a neurological condition, with levels 100-folds higher than those found in T1DM. Although CSF testing is recommended when suspecting a GAD-associated neurological syndrome, no commercial immunoassay is validated for this use and no cut-off is internationally recognized to support the diagnosis. Methods In this study we validated CSF testing of GAD-Ab on an automated chemiluminescence (CLIA) immunoassay that had previously shown good agreement with ELISA on serum. Results We tested 43 CSF from patients with typical GAD-associated neurological disorders and patients with other neurological conditions, identifying a clinical cut-off of 18 kIU/L that discriminated GAD-disease with an area under the curve (AUC) of 0.921. CLIA showed good analytical performances on repeatability and recovery tests in CSF and confirmed an excellent agreement with ELISA. Conclusions GAD-Ab associated neurological disorders are rare but CSF testing for GAD-Ab is a common request for neurologists when suspecting an insidious autoimmune central nervous system disease. CLIA platforms are expected to be increasingly adopted in clinical laboratories due to their flexibility and reliability, therefore studies on decisional levels should be implemented for improving the interpretation and utilization of laboratory data.

Aims: The role of inflammation markers in myocarditis is unclear. We assessed the diagnostic and prognostic correlates of C-reactive protein (CRP) at diagnosis in patients with myocarditis. Methods and results: We retrospectively enrolled patients with clinically suspected (CS) or biopsy-proven (BP) myocarditis, with available CRP at diagnosis. Clinical, laboratory and imaging data were collected at diagnosis and at follow-up visits. To evaluate predictors of death/heart transplant (Htx), a machine-learning approach based on random forest for survival data was employed. We included 409 patients (74% males, aged 37 ± 15, median follow-up 2.9 years). Abnormal CRP was reported in 288 patients, mainly with CS myocarditis (p < 0.001), recent viral infection, shorter symptoms duration (p = 0.001), chest pain (p < 0.001), better functional class at diagnosis (p = 0.018) and higher troponin I values (p < 0.001). Death/Htx was reported in 13 patients, of whom 10 had BP myocarditis (overall 10-year survival 94%). Survival rates did not differ according to CRP levels (p = 0.23). The strongest survival predictor was LVEF, followed by anti-nuclear auto-antibodies (ANA) and BP status. Conclusions: Raised CRP at diagnosis identifies patients with CS myocarditis and less severe clinical features, but does not contribute to predicting survival. Main death/Htx predictors are reduced LVEF, BP diagnosis and positive ANA.

Objectives The reported prevalence of TSH-receptor (TSHR) autoantibodies (TRAb) in patients with chronic thyroiditis (CT) range from 0 to 48%. The objective was to study the prevalence of TRAb in patients with CT and hypothyroidism and to correlate it with gender, age, thyroid dimensions, TSH levels, and autoimmune diseases. Methods The study comprised 245 patients with CT and hypothyroidism (median age 42 years, 193 females, 52 males) and 123 Italian healthy subjects matched for sex and age as controls. TRAb were tested with ELISA using a >2.5 IU/L cut off for positivity. TSHR blocking (TBAb) and TSHR stimulating autoantibodies (TSAb) were measured in 12 TRAb-positive patients using bioassays with Chinese hamster ovary (CHO) cells expressing wild-type or R255D-mutated TSHR. Results TRAb positivity was found in 32/245 (13.1%) patients and significantly correlated (p<0.05) with TSH levels. TRAb positivity was significantly higher in males vs. females (p=0.034), in females 16-45 years of age vs. >45 years of age (p<0.05) and in patients with reduced vs. normal/increased thyroid dimensions (p<0.05). Linear regression analysis showed a correlation between TRAb concentrations with age (p<0.05) and TRAb concentrations with TSH (p<0.01). In bioassay with TSHR-R255D all 12 patients tested were TBAb-positive while 33% were also TSAb-positive suggesting the presence of a mixture of TRAbs with different biological activities in some patients. Conclusions TRAb have been found in patients with CT and hypothyroidism. A mixture of TBAb and TSAb was found in some patients and this may contribute to the pathogenesis of thyroid dysfunction during the course of the disease.

Aims Outcome predictors in myocarditis are not well defined; we aimed at identifying predictors of death, heart transplantation (HTx) and relapse before the introduction of immunosuppression. Methods and results From 1992 to 2012, 466 consecutive patients (68% male, mean age 37 +/- 17 years, single centre recruitment, median follow-up 50 months) were included, of whom 216 had clinically suspected and 250 biopsy-proven myocarditis. Serum anti-heart (AHA) and anti-intercalated disk (AIDA) autoantibodies were measured by indirect immunofluorescence. Univariable and multivariable analyses of clinical and diagnostic features at diagnosis were performed. Survival free from death or HTx at 10 years was 83% in the whole study population and was lower in biopsy-proven versus clinically suspected myocarditis (76% vs. 94%, p < 0.001). Female gender (hazard ratio [HR] 2.7, 95% confidence interval [CI] 1.1-6.5), fulminant presentation (HR 13.77, 95% CI 9.7-261.73), high-titre organ-specific AHA (HR 4.2, 95% CI 1.2-14.7) and anti-nuclear antibodies (ANA) (HR 5.2, 95% CI 2.1-12.8) were independent predictors of death or HTx; higher echocardiographic left ventricular ejection fraction (LVEF) at diagnosis was protective, with a 0.93-fold risk reduction for each 1% LVEF increase (95% CI 0.89-0.96). History of myocarditis at diagnosis (HR 8.5, 95% CI 3.5-20.7) was an independent predictor of myocarditis relapse at follow-up; older age was protective (HR 0.95, 95% CI 0.91-0.99). Predictors of death, HTx and relapse did not differ in biopsy-proven versus clinically suspected myocarditis. Conclusions Young age and a previous myocarditis were independent relapse predictors; female gender, fulminant onset, lower LVEF at presentation and high-titre organ-specific AHA and ANA were independent predictors of death and HTx, suggesting that autoimmune features predict worse prognosis.

Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) differ for triggers, mode of start, associated symptoms, evolution, and biochemical traits. Therefore, serious attempts are underway to partition them into subgroups useful for a personalized medicine approach to the disease. Here, we investigated clinical and biochemical traits in 40 ME/CFS patients and 40 sex- and age-matched healthy controls. Particularly, we analyzed serum levels of some cytokines, Fatty Acid Binding Protein 2 (FAPB-2), tryptophan, and some of its metabolites via serotonin and kynurenine. ME/CFS patients were heterogeneous for genetic background, trigger, start mode, symptoms, and evolution. ME/CFS patients had higher levels of IL-17A (p = 0.018), FABP-2 (p = 0.002), and 3-hydroxykynurenine (p = 0.037) and lower levels of kynurenine (p = 0.012) and serotonin (p = 0.045) than controls. Changes in kynurenine and 3-hydroxykynurenine were associated with increased kynurenic acid/kynurenine and 3-hydroxykynurenine/kynurenine ratios, indirect measures of kynurenine aminotransferases and kynurenine 3-monooxygenase enzymatic activities, respectively. No correlation was found among cytokines, FABP-2, and tryptophan metabolites, suggesting that inflammation, anomalies of the intestinal barrier, and changes of tryptophan metabolism may be independently associated with the pathogenesis of the disease. Interestingly, patients with the start of the disease after infection showed lower levels of kynurenine (p = 0.034) than those not starting after an infection. Changes in tryptophan metabolites and increased IL-17A levels in ME/CFS could both be compatible with anomalies in the sphere of energy metabolism. Overall, clinical traits together with serum biomarkers related to inflammation, intestine function, and tryptophan metabolism deserve to be further considered for the development of personalized medicine strategies for ME/CFS.

Background: Sarcoidosis is an immune-mediated disease. Cardiac involvement, a granulomatous form of myocarditis, is under-recognized and prognostically relevant. Anti-heart autoantibodies (AHAs) and anti-intercalated disk autoantibodies (AIDAs) are autoimmune markers in nonsarcoidosis myocarditis forms. Objective: The aim was to assess serum AHAs and AIDAs as autoimmune markers in cardiac sarcoidosis. Methods: This is a cross-sectional study on AHA and AIDA frequency in: 29 patients (aged 46 ± 12, 20 male) with biopsy-proven extracardiac sarcoidosis and biopsy-proven or clinically suspected and confirmed by 18-fluorodeoxyglucose positron emission tomography and/or cardiovascular magnetic resonance (CMR) cardiac involvement; 30 patients (aged 44 ± 11, 12 male) with biopsy-proven extracardiac sarcoidosis without cardiac involvement (no cardiac symptoms, normal 12-lead electrocardiogram, echocardiography and CMR), and control patients with noninflammatory cardiac disease (NICD) (n = 160), ischemic heart failure (IHF) (n = 141) and normal blood donors (NBDs) (n = 270). Sarcoidosis patients were recruited in two recruiting tertiary centers in the USA and Italy. AHAs and AIDAs were detected by indirect immunofluorescence on the human myocardium and skeletal muscle. Results: AHA and AIDA frequencies were higher in sarcoidosis with cardiac involvement (86%; 62%) than in sarcoidosis without cardiac involvement (0%; 0%), NICD (8%; 4%), IHF (7%; 2%) and NBD (9%; 0%) (p = 0.0001; p = 0.0001, respectively). Sensitivity and specificity for cardiac sarcoidosis were 86% and 92% for positive AHAs and 62% and 98% for positive AIDAs, respectively. AIDAs in cardiac sarcoidosis were associated with a higher number of involved organs (p = 0.04). Conclusions: Serum AHAs and AIDAs provide novel noninvasive diagnostic autoimmune markers for cardiac sarcoidosis.

BACKGROUND:Heart involvement (HInv) in systemic sclerosis (SSc) may relate to myocarditis and is associated with poor prognosis. Serum anti-heart (AHA) and anti-intercalated disk autoantibodies (AIDA) are organ and disease-specific markers of isolated autoimmune myocarditis. We assessed frequencies, clinical correlates, and prognostic impacts of AHA and AIDA in SSc.METHODS:The study included consecutive SSc patients (n = 116, aged 53 ± 13 years, 83.6% females, median disease duration 7 years) with clinically suspected heart involvement (symptoms, abnormal ECG, abnormal troponin I or natriuretic peptides, and abnormal echocardiography). All SSc patients underwent CMR. Serum AHA and AIDA were measured by indirect immunofluorescence in SSc and in control groups of non-inflammatory cardiac disease (NICD) (n = 160), ischemic heart failure (IHF) (n = 141), and normal blood donors (NBD) (n = 270). AHA and AIDA status in SSc was correlated with baseline clinical, diagnostic features, and outcome.RESULTS:The frequency of AHA was higher in SSc (57/116, 49%, p < 0.00001) than in NICD (2/160, 1%), IHF (2/141, 1%), or NBD (7/270, 2.5%). The frequency of AIDA was higher (65/116, 56%, p < 0.00001) in SSc than in NICD (6/160, 3.75%), IHF (3/141, 2%), or NBD (1/270, 0.37%). AHAs were associated with interstitial lung disease (p = 0.04), history of chest pain (p = 0.026), abnormal troponin (p = 0.006), AIDA (p = 0.000), and current immunosuppression (p = 0.01). AHAs were associated with death (p = 0.02) and overall cardiac events during follow-up (p = 0.017).CONCLUSIONS:The high frequencies of AHA and AIDA suggest a high burden of underdiagnosed autoimmune HInv in SSc. In keeping with the negative prognostic impact of HInv in SSc, AHAs were associated with dismal prognosis.

The differential diagnosis between acquired inflammatory demyelinating syndromes of the central nervous system (CNS), such as multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD) and acute disseminated encephalomyelitis (ADEM) can be very challenging at onset. Apart from cerebrospinal fluid oligoclonal bands and anti-aquaporin-4 antibodies (AQP4-Ab), definite diagnostic biomarkers are lacking. Anti-myelin oligodendrocyte glycoprotein antibodies (MOG-Abs) have been increasingly described in children with AQP4-seronegative NMOSD, ADEM and other inflammatory demyelinating CND syndromes; despite partial overlaps with AQP4-Ab disease, a novel "MOG-Ab-disorder" phenotype has been suggested. In this study, we tested the presence of MOG-Ab and AQP4-Ab in 57 children at first onset of acute neurological symptoms; three clinical subgroups were identified: 12 patients had acquired inflammatory demyelinating CNS syndromes, 11 had other autoimmune/immune-mediated disorders of the central and peripheral nervous system and 34 had non-immune-mediated CNS disorders. MOG-Abs were found positive only in a subset of cases in the subgroup with acquired inflammatory demyelinating CNS syndromes (in 2/12 patients, both with non-MS phenotype) and in none of the patients with other autoimmune and immune-mediated disorders of the central and peripheral nervous system or with non-immune-mediated disorders of the CNS.Data from the literature review support clinical and analytical observations.

Background: Serum anti-heart autoantibodies (AHAs) and anti-intercalated disk autoantibodies (AIDAs) are autoimmune markers in myocarditis. Myocarditis has been reported in arrhythmogenic right ventricular cardiomyopathy (ARVC). To provide evidence for autoimmunity, we searched for AHAs and AIDAs in ARVC. Methods: We studied: 42 ARVC probands, 23 male, aged 42, interquartile range 33-49, 20 from familial and 22 nonfamilial pedigrees; 37 clinically affected relatives (ARs), 24 male aged 35, interquartile range 18-46; and 96 healthy relatives, 49 male, aged 27, interquartile range 17-45. Serum AHAs and AIDAs were tested by indirect immunofluorescence on human myocardium and skeletal muscle in 171 of the 175 ARVC individuals and in controls with noninflammatory cardiac disease (n=160), ischemic heart failure (n=141), and healthy blood donors (n=270). Screening of 5 desmosomal genes was performed in probands; when a sequence variant was identified, cascade family screening followed, blind to immunologic results. Results: AHA frequency was higher (36.8%) in probands, ARs (37.8%), and healthy relatives (25%) than in noninflammatory cardiac disease (1%), ischemic heart failure (1%), or healthy blood donors (2.5%; P=0.0001). AIDA frequency was higher in probands (8%, P=0.006), in ARs (21.6%, P=0.00001), and in healthy relatives (14.6%, P=0.00001) than in noninflammatory cardiac disease (3.75%), ischemic heart failure (2%), or healthy blood donors (0.3%). AHA-positive status was associated with higher frequency of palpitation (P=0.004), implantable cardioverter defibrillator implantation (P=0.021), lower left ventricular ejection fraction (P=0.004), AIDA-positive status with both lower right ventricular and left ventricular ejection fractions (P=0.027 and P=0.027, respectively). AHA- and/or AIDA-positive status in the proband and at least one of the respective relatives was more common in familial (17/20, 85%) than in sporadic (10/22, 45%) pedigrees (P=0.007). Conclusions: The presence of AHAs and AIDAs provides evidence of autoimmunity in the majority of familial and in almost half of sporadic ARVC. In probands and in ARs, these antibodies were associated with features of disease severity. Longitudinal studies are needed to clarify whether they may predict ARVC development in healthy relatives or if they be a result of manifest ARVC.

Myocarditis is an infectious or autoimmune inflammatory disease of the myocardium; diagnosis relies on the exclusion of an acute coronary syndrome, and is confirmed by endomyocardial biopsy (EMB). Prognosis is highly variable, outcome predictors are not well defined. To identify clinical, imaging and immunological predictors of death, heart transplantation (HTx) and relapse in patients with myocarditis in the pre-immunosuppression era. From 1993 to 2012 we consecutively enrolled 466 patients (68% male, mean age 37±17 years), 216 with clinically suspected and 250 with EMB-proven myocarditis. All patients underwent coronary angiogram and transthoracic echocardiogram, 44% of patients underwent cardiac magnetic resonance (CMR). Circulating auto-antibodies were measured in patients' sera by indirect immunofluorescence. All patients were prospectively followed-up at the local Cardio-immunology outpatient clinic. After a median follow-up of 50 months (IQR 25–75), 366 patients (79%) were alive, while 42 (9%) were dead or underwent HTx; 58 were lost to follow-up. Ten-year survival free from death or HTx was overall 83%, but was lower in patients with EMB-proven myocarditis (76% vs 94% in patients with clinically suspected myocarditis, p<0.001). On univariate analysis, predictors of death and HTx were female gender (p=0.003), previous myocarditis (p=0.03), heart failure on presentation and advanced NYHA class (p<0.001, respectively), histological diagnosis of giant-cell myocarditis (p=0.002), positivity for anti-heart antibodies (AHA, p=0.04), anti-cardiac endothelial cell (AECA, p=0.002) and anti-nucleus antibodies (ANA, p=0.003). On multivariate analysis, female gender (HR 2.69, p=0.02), lower left ventricular ejection fraction on echocardiogram (p<0.001), positivity for high-titre organ-specific AHA (HR 4.1, p=0.02) and for ANA (HR 5.1, p<0.001) were independent predictors of death and HTx. Seventy-seven patients had relapsing myocarditis; on univariate analysis, young age (p<0.001), previous myocarditis (p<0.001), symptoms preceding diagnosis (p=0.004), positivity for anti-intercalated disk autoantibody (AIDA, p=0.02), and presence of diffuse late gadolinium enhancement (LGE) on CMR (p<0.001) were predictors of relapse. On multivariate analysis young age (p=0.02) and previous myocarditis (HR 8.4, p<0.001) were independent predictors of relapse. Predictors of death, HTx and relapse, respectively, did not differ when considering separately patients with EMB-proven myocarditis and those with clinically suspected myocarditis. In the pre-immunosuppressive era, young age and a previous episode of myocarditis were independent predictors of relapse, female gender, left ventricular dysfunction at presentation and high-titre organ-specific AHA and ANA were independent predictors of death and HTx, suggesting that autoimmune features in myocarditis predict worse prognosis. Type of funding source: None

We investigated the SARS-CoV-2 specific antibody titers in 133 asymptomatic healthcare providers working at the Department of Laboratory Medicine of our tertiary center. A commercial chemiluminescence immunoassay, validated according to the ISO15189 standard requirements, was used. All the enrolled healthcare professionals underwent, simultaneously to the blood sampling, a nasopharyngeal swab for molecular testing with quantitative reverse-transcriptase-based polymerase chain reaction (RT-PCR). An overall positiveness of 5.25% was found. We strongly promote a wide use of validated serologic assays in asymptomatic, healthy individuals, as a crucial information for epidemiological surveillance.

Background Autoimmune polyendocrinopathy-candidiasis-ectodermal-dystrophy (APECED) or autoimmune polyglandular syndrome type 1 (APS-1) is a rare autosomal recessive genetic disease due to mutations in theAIRE(AutoImmune REgulator) gene. The clinical diagnosis is classically based on the presence of at least two of the three main components: chronic mucocutaneous candidiasis, hypoparathyroidism and primary adrenal insufficiency. Patients often suffer from other endocrine or non-endocrine autoimmune conditions throughout life. APECED etiopathogenesis is mediated by T lymphocytes. Autoantibodies against proteins of the affected organs are found in the serum of APECED patients as well as neutralizing antibodies against cytokines. We report here the clinical and genetic characteristics of 45 Indian APECED patients in comparison to Finnish, Sardinian, Turkish and North/South American cohorts from their published results. We also report a new case of APECED of Indian origin, a 2-year old child suffering from chronic mucocutaneous candidiasis since the age of 8 months, with confirmatoryAIREhomozygous mutation c.274C > T (p.R92W). Conclusion With the inherent limitations of a retrospective study, analysis of Indian APECED patients suggested that compared to classic criteria, application of Ferre/Lionakis criteria validated in North/South American patients could help in earlier diagnosis in 3 of 8 (37.5%) patients for whom adequate information for evaluation was available.

Abstract Background Cardiovascular magnetic resonance (CMR) is an accurate diagnostic tool providing detailed myocardial tissue characterization. Correlates of late gadolinium enhancement (LGE) with clinical and diagnostic features are poorly defined in endomyocardial biopsy (EMB)-proven myocarditis. Purpose We sought to identify clinical, laboratory and imaging correlates of LGE in patients with EMB-proven myocarditis. Methods We analyzed our prospective cohort of patients with EMB-proven myocarditis (n=366) to identify patients who underwent CMR (n=154, aged 39±13, 108 males). Presence of LGE was qualitatively assessed. CMR and EMB were performed in all cases at the time of hospitalization. Clinical, laboratory, and imaging features at diagnosis were analyzed to identify correlates of LGE presence. Results Demographic characteristics (age, gender), cardiovascular risk factors (hypertension, diabetes) and cardiovascular therapy did not differ between patients with and without LGE. Patients with history of myocarditis tended to have a higher prevalence of LGE (25 vs 4 patients, p=0.07). There was a trend towards a higher prevalence of LGE in patients presenting with heart failure or acute coronary syndrome (p=0.07) as opposed to those presenting with arrhythmias. Patients with LGE were more symptomatic in the 6 months preceding diagnosis (palpitations, p=0.03, chest pain p=0.02). Clinical left and right ventricular systolic dysfunction at presentation were more common in patients with LGE (p=0.02, p=0.02 respectively). LGE presence failed to distinguish patients according to EMB findings (active vs. borderline myocarditis) (p=0.66) or to the histological type of myocarditis. Troponin I levels were higher in patients with LGE (p=0.03). There was no difference in bi-ventricular volumes and function, as assessed both by echocardiography and heart catheterization. There was no correlation between anti-heart antibodies and LGE presence, nor were patients with LGE more likely to receive immunosuppressive therapy; however, response to immunosuppression tended to be more common in patients without LGE (13/13 vs 29/38 patients, p=0.09). The rate of heart transplant, death and myocarditis relapse did not differ between patients with and without LGE. Conclusions Presence of LGE on CMR was associated with longer symptom duration before diagnosis, presentation with heart failure and higher troponin release, but failed to correlate with specific EMB features or myocarditis aetiopathogenetic markers. Acknowledgement/Funding None