Serum Organ-Specific Anti-Heart and Anti-Intercalated Disk Autoantibodies as New Autoimmune Markers of Cardiac Involvement in Systemic Sclerosis: Frequency, Clinical and Prognostic Correlates.

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.

Antibodies against SARS-CoV-2 Time Course in Patients and Vaccinated Subjects: An Evaluation of the Harmonization of Two Different Methods.

The time course of antibodies against SARS-CoV-2 is not yet well elucidated, especially in people who underwent a vaccination campaign. In this study, we measured the antibodies anti-S1 and anti-RBD with two different methods, both in patients and in vaccinated subjects. One hundred and eight specimens from 48 patients with COVID-19 (time from the onset of symptoms from 3 to 368 days) and 60 specimens from 20 vaccinated subjects (collected after 14 days from the first dose, 14 days and 3 months after a second dose of Comirnaty) were evaluated. We used an ELISA method that measured IgG against anti-Spike 1, and a chemiluminescence immunoassay that measured IgG anti-RBD. In the patients, the antibodies concentrations tended to decline after a few months, with both the methods, but they persisted relatively high up to nearly a year after the symptoms. In the vaccinated subjects, the antibodies were already detectable after the first dose, but after the booster, they showed a significant increase. However, the decrease was rapid, given that 3 months after the second vaccination, they were reduced to less than a quarter. The conversion of the results into BAU units improves the relationship between the two methods. However, in the vaccinated subjects, there was no evidence of proportional error after the conversion, while in the patients, the difference between the two methods remained significant.

Evaluation of peripherin in biofluids of patients with motor neuron diseases.

Peripherin (PRPH), a type III intermediate filament, assembles with neurofilaments in neurons of the peripheral nervous system, including lower motor neurons (LMN). To evaluate the role of PRPH in LMN degeneration, we assessed PRPH and neurofilament light chain (NfL) in cerebrospinal fluid (CSF) and serum of 91 patients with motor neuron diseases (MND) and 69 controls. Overall, we found PRPH to be more concentrated in serum than in CSF. Serum PRPH resulted significantly increased in MND patients but it was unrelated to CSF-NfL or survival in the amyotrophic lateral sclerosis (ALS) subset. PRPH might represent a marker of LMN involvement.

A Novel Circulating MicroRNA for the Detection of Acute Myocarditis.

BACKGROUND: The diagnosis of acute myocarditis typically requires either endomyocardial biopsy (which is invasive) or cardiovascular magnetic resonance imaging (which is not universally available). Additional approaches to diagnosis are desirable. We sought to identify a novel microRNA for the diagnosis of acute myocarditis. METHODS: To identify a microRNA specific for myocarditis, we performed microRNA microarray analyses and quantitative polymerase-chain-reaction (qPCR) assays in sorted CD4+ T cells and type 17 helper T (Th17) cells after inducing experimental autoimmune myocarditis or myocardial infarction in mice. We also performed qPCR in samples from coxsackievirus-induced myocarditis in mice. We then identified the human homologue for this microRNA and compared its expression in plasma obtained from patients with acute myocarditis with the expression in various controls. RESULTS: We confirmed that Th17 cells, which are characterized by the production of interleukin-17, are a characteristic feature of myocardial injury in the acute phase of myocarditis. The microRNA mmu-miR-721 was synthesized by Th17 cells and was present in the plasma of mice with acute autoimmune or viral myocarditis but not in those with acute myocardial infarction. The human homologue, designated hsa-miR-Chr8:96, was identified in four independent cohorts of patients with myocarditis. The area under the receiver-operating-characteristic curve for this novel microRNA for distinguishing patients with acute myocarditis from those with myocardial infarction was 0.927 (95% confidence interval, 0.879 to 0.975). The microRNA retained its diagnostic value in models after adjustment for age, sex, ejection fraction, and serum troponin level. CONCLUSIONS: After identifying a novel microRNA in mice and humans with myocarditis, we found that the human homologue (hsa-miR-Chr8:96) could be used to distinguish patients with myocarditis from those with myocardial infarction. (Funded by the Spanish Ministry of Science and Innovation and others.).

Possible clinical role of MOG antibody testing in children presenting with acute neurological symptoms.

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.

Evidence From Family Studies for Autoimmunity in Arrhythmogenic Right Ventricular Cardiomyopathy: Associations of Circulating Anti-Heart and Anti-Intercalated Disk Autoantibodies With Disease Severity and Family History.

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.

Free light chains and heavy/light chains in monitoring POEMS patients.

BACKGROUND: POEMS syndrome is defined by Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal gammopathy and Skin changes. The vascular endothelial growth factor (VEGF) appears to play a key role in the pathogenesis of the syndrome, and its concentrations are deemed to correlate to disease activity. The aim of the present study was to verify whether other biochemical markers including serum free light chains (FLC) and heavy/light chains (HLC) would be of value in monitoring POEMS patients. METHODS: Fifty-three serum samples were collected from seven POEMS patients at diagnosis and during a follow-up period (range 14-56 months). VEGF was measured using an ELISA method, while FLC and HLC concentrations were measured using Binding Site reagents on a BNII (Siemens) nephelometer. RESULTS: At diagnosis all patients presented high VEGF concentrations, while the κ/λFLC ratio (FLCr) was within the reference range. Four patients had abnormal HLC, HLCκ/HLCλ (HLCr) and FLC values. The relationship between the trend of VEGF and both HLC and FLC during the follow-up was analysed by means of Cohen's κ coefficient. VEGF and HLC values displayed a significant κ-Cohen (0.537, p=0.002) in all chemotherapy-responder patients while in non-responders it did not. Conversely, in both responders and non-responders, VEGF and FLC values did not attain a significance on κ-Cohen analysis. In three out of four responders HLCr values increased, thus reflecting an improved clinical condition. CONCLUSIONS: The findings made in the present study indicate that HLC, either as intact immunoglobulin or as HLCr, may provide useful information, particularly in identifying responders and confirm that the role of FLC is unreliable in monitoring patients with POEMS syndrome.

Prevalence of antinuclear antibodies in schoolchildren during puberty and possible relationship with musculoskeletal pain: a longitudinal study.

OBJECTIVE: The role of antinuclear antibodies (ANA) in children has still to be elucidated. The aim of our study was to evaluate the prevalence and persistence of ANA in schoolchildren during the puberty switch, and the possible relationship with chronic noninflammatory musculoskeletal pain (MSP). METHODS: Children aged 8-13 years and attending 4 public schools underwent a clinical examination, focusing on pubertal stage and presence of chronic noninflammatory MSP. Laboratory tests to determine the autoantibody-profile were also performed. Subjects with ANA positivity (titer ≥ 1:80) and/or chronic noninflammatory MSP were re-evaluated 3 years later. RESULTS: Two hundred sixty-one subjects enrolled in the study and 12.3% were ANA-positive, equally distributed in terms of sex and pubertal status. Three years later, in the group of patients studied for chronic noninflammatory MSP (n = 67), ANA positivity significantly increased from 13.4% to 44.8%. In the ANA-positive cohort at baseline (n = 28), 92.9% of subjects were confirmed as being ANA-positive with a significantly increased titer. No association between ANA positivity and chronic noninflammatory MSP was found. CONCLUSION: ANA prevalence and titers increase during puberty, especially in females, but have no relationship with chronic noninflammatory MSP. This finding may be related to the complex hormonal changes during the puberty switch period and opens new insights into autoimmunity.

Serum free light chain reference values: a critical approach.

OBJECTIVES: The clinical usefulness of serum free light chain (FLC) measurement in the management of patients with plasma cell proliferative disorders has been reported in several papers, and most clinical studies use the reference ranges declared by the manufacturer. The aim of the present study was to evaluate the reproducibility of FLCs immunoassay and to validate the reference range, before introducing it in routine setting. DESIGN AND METHODS: Internal quality control materials and a pool of fresh serum samples were used to evaluate imprecision; 162 fresh sera from healthy blood donors were analyzed to evaluate the reference range for FLCs. In order to verify the κ/λ FLC ratio, 43 sera from patients with polyclonal hypergammaglobulinemia were tested. The FLC immunoassay was performed using a nephelometer with the Freelite reagents. RESULTS: The imprecision studies performed using a serum pool tested with two different lots of reagents showed a mean CV of 16.09% for κFLC and of 16.72% for λFLC. Lower CV%s and different mean values were found by calculating the results from each specific lot separately, while different results were obtained using the control materials provided by the manufacturer. In reference subjects, the 2.5-97.5th percentiles were found to be 4.52-22.33 and 4.84-21.88mg/L for κFLC and λFLC, respectively. The range for κ/λ ratio (0.65-2.36) was validated with the values obtained from subjects with polyclonal hypergammaglobulinemia. In retesting 15 samples from blood donor subjects with a different lot of reagents, mean bias percentages of 17.60 for κFLC and 15.26 for λFLC were obtained. CONCLUSIONS: These findings confirm the lot-to-lot variability of the FLC assays also in the measurement of polyclonal light chains, as well as the need to carefully validate the reference values.