New Insights into Pediatric Kidney Transplant Rejection Biomarkers: Tissue, Plasma and Urine MicroRNAs Compared to Protocol Biopsy Histology.

The early identification of a subclinical rejection (SCR) can improve the long-term outcome of the transplanted kidney through intensified immunosuppression. However, the only approved diagnostic method is the protocol biopsy, which remains an invasive method and not without minor and/or major complications. The protocol biopsy is defined as the sampling of allograft tissue at pre-established times even in the absence of an impaired renal function; however, it does not avoid histological damage. Therefore, the discovery of new possible biomarkers useful in the prevention of SCR has gained great interest. Among all the possible candidates, there are microRNAs (miRNAs), which are short, noncoding RNA sequences, that are involved in mediating numerous post-transcriptional pathways. They can be found not only in tissues, but also in different biological fluids, both as free particles and contained in extracellular vesicles (EVs) released by different cell types. In this study, we firstly performed a retrospective miRNA screening analysis on biopsies and serum EV samples of 20 pediatric transplanted patients, followed by a second screening on another 10 pediatric transplanted patients' urine samples at one year post-transplant. In both cohorts, we divided the patients into two groups: patients with histological SCR and patients without histological SCR at one year post-transplantation. The isolated miRNAs were analyzed in an NGS platform to identify different expressions in the two allograft states. Although no statistical data were found in sera, in the tissue and urinary EVs, we highlighted signatures of miRNAs associated with the histological SCR state.

Analytical evaluation of a GAD65 antibodies chemiluminescence immunoassay for CSF in neurological syndromes.

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.

Conventional brain MRI features distinguishing limbic encephalitis from mesial temporal glioma.

PURPOSE: Radiological hallmark of autoimmune limbic encephalitis (LE) is a hyperintense signal in MRI T2-weighted images of mesial temporal structures. We aimed to identify conventional magnetic resonance imaging (MRI) features that can help distinguish LE from temporal glioma. METHODS: Brain MRIs of 25 patients affected by antibody-positive autoimmune LE, 24 patients affected by temporal glioma (tumor group), and 5 negative controls were retrospectively blindly evaluated in random order. RESULTS: Ten brain MRIs from the LE group were correctly recognized; one additional patient with mesial temporal hyperintensity with anti-AK5 abs LE was wrongly diagnosed as having a tumor. The brain MRIs of the remaining 14 of the 25 patients with LE were judged negative or, in three cases, showed features not typical for LE. In the tumor group, all MRIs showed pathological alterations diagnosed as tumors in 22/24 cases and as LE in two (2/22, 9%). Unilateral lesions were more common in tumors than in neuroradiologically abnormal LE (96% vs. 18%, p < 0.001). T2/FLAIR hyperintensity of the parahippocampal gyrus was associated more with tumor than with LE (71% vs. 18%) (p = 0,009), as T2/FLAIR hyperintensity of extralimbic structures (p = 0.015), edema (p = 0.041), and mass effect (p = 0.015). Maintenance of gray/white matter distinction was strongly associated with LE (91% vs. 17%, p < 0.001). CONCLUSION: Conventional brain MRI is a fundamental tool in the differential diagnosis between LE and glioma. Bilateral involvement and maintenance of gray/white matter distinction at the cortical/subcortical interface are highly suggestive of LE.

Management of antibody-mediated autoimmune encephalitis in adults and children: literature review and consensus-based practical recommendations.

Autoimmune encephalitis associated with antibodies against neuronal surface targets (NSAE) are rare but still underrecognized conditions that affect adult and pediatric patients. Clinical guidelines have recently been published with the aim of providing diagnostic clues regardless of antibody status. These syndromes are potentially treatable but the choice of treatment and its timing, as well as differential diagnoses, long-term management, and clinical and paraclinical follow-up, remain major challenges. In the absence of evidence-based guidelines, management of these conditions is commonly based on single-center expertise.Taking into account different published expert recommendations in addition to the multicenter experience of the Italian Working Group on Autoimmune Encephalitis, both widely accepted and critical aspects of diagnosis, management and particularly of immunotherapy for NSAE have been reviewed and are discussed.Finally, we provide consensus-based practical advice for managing hospitalization and follow-up of patients with NSAE.

Doublecortin marks a new population of transiently amplifying muscle progenitor cells and is required for myofiber maturation during skeletal muscle regeneration.

Muscle satellite cells are indispensable for muscle regeneration, but the functional diversity of their daughter cells is unknown. Here, we show that many Pax7(+)MyoD(-) cells locate both beneath and outside the basal lamina during myofiber maturation. A large majority of these Pax7(+)MyoD(-) cells are not self-renewed satellite cells, but have different potentials for both proliferation and differentiation from Pax7(+)MyoD(+) myoblasts (classical daughter cells), and are specifically marked by expression of the doublecortin (Dcx) gene. Transplantation and lineage-tracing experiments demonstrated that Dcx-expressing cells originate from quiescent satellite cells and that the microenvironment induces Dcx in myoblasts. Expression of Dcx seems to be necessary for myofiber maturation because Dcx-deficient mice exhibited impaired myofiber maturation resulting from a decrease in the number of myonuclei. Furthermore, in vitro and in vivo studies suggest that one function of Dcx in myogenic cells is acceleration of cell motility. These results indicate that Dcx is a new marker for the Pax7(+)MyoD(-) subpopulation, which contributes to myofiber maturation during muscle regeneration.

Gene Array Analyzer: alternative usage of gene arrays to study alternative splicing events.

Exon arrays are regularly used to analyze differential splicing events. GeneChip Gene 1.0 ST Arrays (gene arrays) manufactured by Affymetrix, Inc. are primarily used to determine expression levels of transcripts, although their basic design is rather similar to GeneChip Exon 1.0 ST Arrays (exon arrays). Here, we show that the newly developed Gene Array Analyzer (GAA), which evolved from our previously published Exon Array Analyzer (EAA), enables economic and user-friendly analysis of alternative splicing events using gene arrays. To demonstrate the applicability of GAA, we profiled alternative splicing events during embryonic heart development. In addition, we found that numerous developmental splicing events are also activated under pathological conditions. We reason that the usage of GAA considerably expands the analysis of gene expression based on gene arrays and supplies an additional level of information without further costs and with only little effort.

A novel cell-based immunofluorescence assay for the detection of autoantibodies to myelin-associated glycoprotein.

Peripheral neuropathy with antibodies to myelin-associated glycoprotein (MAG) is an autoimmune demyelinating disorder of the peripheral nervous system caused by pathogenic IgM recognizing the human natural killer-1 glycoepitope expressed on MAG. This study aimed to analyze the performance of a new indirect immunofluorescence cell-based assay (CBA, EUROIMMUN) for the detection of anti-MAG IgM. Antibody reactivity was determined in sera from 95 patients with clinical and neurophysiological evidence of anti-MAG-associated neuropathy and in control samples from 55 patients with other forms of peripheral neuropathy. Compared to the results of the gold standard method (ELISA, Bühlmann) and using samples at a dilution of 1:100, the CBA had a sensitivity of 98.9% and a specificity of 100% (PPV 100%, NPV 98.2%). In conclusion, the CBA allows the detection of antibodies to MAG using an easy and standardized technique, and it presents a sensitive and specific alternative to the more time-consuming ELISA. Larger studies are needed to address anti-MAG titer monitoring in parallel with clinical activity.

Epidemiology of neuronal surface antibody-mediated autoimmune encephalitis and antibody-based diagnostics.

Epidemiologic data on neuronal surface antibody (NSAb)-associated autoimmune encephalitides (NSAE) are scarce and heterogeneous. We review our 13-year-long biobank-data collection and provide the incidence of NSAE in two Italian provinces (approx. Population of 1,400,000) over a 5-year period (July 2013-June 2018). NSAbs were diagnosed in 75 out of 1179 tested patients (6.4%). The most common NSAbs were anti-LGI1 (30 cases), followed by NMDAR (24). Eleven cases of NSAE were diagnosed in Treviso and Trento provinces with an estimated incidence of 1.54 per 1,000,000 population (LGI1-encephalitis 0.84; C.I. 0.38-1.88). LGI1-E is the most frequent NSAE among adults.

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.

LGI1 and CASPR2 autoimmunity in children: Systematic literature review and report of a young girl with Morvan syndrome.

Leucine-rich glioma-inactivated protein 1 (LGI1) and contactin-associated protein-like 2 (CASPR2) neurological autoimmunity in adults has been associated with various clinical syndromes involving central, peripheral and autonomic nervous system, while data in children is limited. We perform the first systematic literature review on paediatric LGI1 and CASPR2 autoimmunity, with focus on clinical data, in order to contribute to the definition of clinical features of LGI1 and CASPR2 autoimmunity in paediatric age and favour early diagnosis. Additionally, we report the youngest-to-date case of Morvan syndrome. We identified 37 published paediatric cases of LGI1 and/or CASPR2 autoimmunity. Most frequent syndromes were encephalitis in LGI1-positive and isolated epilepsy in CASPR2-positive children, while syndromes with predominant peripheral symptoms were most frequent in double-positive children. With the limitations imposed by the low number of cases, differences to published adult cohorts included: absence of faciobrachial dystonic seizures and hyponatremia in patients with LGI1-positive encephalitis; slightly higher proportion of isolated epilepsy syndromes in CASPR2-positive patients; absence of tumour in the whole cohort.

Sca1-derived cells are a source of myocardial renewal in the murine adult heart.

Although the mammalian heart is one of the least regenerative organs in the body, recent evidence indicates that the myocardium undergoes a certain degree of renewal to maintain homeostasis during normal aging. However, the cellular origin of cardiomyocyte renewal has remained elusive due to lack of lineage tracing experiments focusing on putative adult cardiac precursor cells. We have generated triple-transgenic mice based on the tet-cre system to identify descendants of cells that have expressed the stem cell marker Sca1. We found a significant and lasting contribution of Sca1-derived cells to cardiomyocytes during normal aging. Ischemic damage and pressure overload resulted in increased differentiation of Sca1-derived cells to the different cell types present in the heart. Our results reveal a source of cells for cardiomyocyte renewal and provide a possible explanation for the limited contribution of Sca1-derived cells to myocardial repair under pathological conditions.