Tissue-based Assays Research Articles

Retrospective study evaluating the genomic landscape of anal squamous cell carcinoma using liquid biopsy.

8 Background: Advanced-stage squamous cell carcinoma of the anus (aSCCA) is a rare malignancy. Diagnostic biopsies are often inadequate for tissue-based genomic profiling, thus genomic profiles are largely unexplored in this setting. We assessed liquid biopsy NGS results of aSCCA patients (pts) and described genomic profiles by age and sex. To our knowledge, we are the first to describe genetic alterations by liquid biopsy in this patient population. Methods: Pts with aSCCA who underwent circulating tumor DNA (ctDNA) NGS with Guardant360 assays from 2017 to 2024 were included. Frequency of alterations were assessed based on sex and age (18-49 years (yrs), ≥50 yrs). Co-occurrence patterns were assessed using cBioPortal. Demographics were extracted from test requisition forms. Statistical analyses via two sided t-tests were performed with significance defined as p<0.05. Results: 646 pts with aSCCA had non-synonymous ctDNA alterations detected; 69.2% (N=447) were female and 30.8% (N=199) male. Median age was 66 yrs (32-94) with 9.9% (N=64) <50 yrs and 90.1% (N=582) ≥50 yrs. Most frequently altered genes were PIK3CA (17.3%), TP53 (9.8%), ATM (7.8%), EGFR (4.3%), and BRCA2 (4.2%). More unique genes were altered in ≥50 yrs cohort [53 mutations, 38 genes with copy number amplification (CNA)] vs <50 yrs cohort (30 mutations, 66 CNA). Most frequent genes altered in <50 yrs cohort were TP53 (17.6%), PIK3CA (13.2%), EGFR (11.0%), APC (4.4%), and MET (4.4%). PIK3CA (16.7%), TP53 (12.2%), ATM (8.8%), BRCA2 (5.5%), and EGFR (3.4%) were most frequent in ≥50 yrs cohort. More genes were altered in females (64 mutations, 32 CNA) vs. males (56 mutations, 41 CNA). Most frequent alterations in females were PIK3CA E545K (3.4%), PIK3CA CNA (2.8%), PIK3CA E542K (1.9%), and ATM CNA (1.0%) vs in male pts being PIK3CA E545K (4.8%), PIK3CA CNA (3.3%), PIK3CA E542K (3.3%), EGFR CNA (1.6%), TERT promoter (1.0%). Overall, PIK3CA and TP53 alterations were mutually exclusive (odds ratio 0.43, p<0.001). Conclusions: Liquid biopsy is feasible in patients with aSCCA. Most frequently detected alterations and CNAs were in PIK3CA and TP53 in aSCCA which is consistent with prior studies evaluating aSCCA tumor NGS in tissue-based assays. Alterations varied across age and sex. PIK3CA E545K and E542K alterations were detected frequently in this population and have on-label therapies for non-aSCCA indications which may be a source for clinical consideration in this cancer type in the future. This data illustrates the importance of liquid biopsy NGS to also screen for clinical trial enrollment in a disease which is poorly responsive to standard therapy. Additional research is warranted to further elucidate genomic profiles for clinical applications of this rare tumor.

Analytical and Clinical Validation of the Plasma-Based Guardant360 CDx Test for Assessing HER2 (ERBB2) Mutation Status in Patients with Non-Small-Cell Lung Cancer for Treatment with Trastuzumab Deruxtecan in DESTINY-Lung01/02.

This study demonstrates the analytical and clinical validity of the approved (United States and Japan) plasma-based Guardant360 companion diagnostic (CDx) test for selecting patients with human epidermal growth factor receptor 2 (HER2 [ERBB2])-mutated (HER2m) non-small-cell lung cancer (NSCLC) for trastuzumab deruxtecan (T-DXd) treatment. Concordance between the Guardant360 CDx test and the plasma-based AVENIO ctDNA Expanded Kit Assay (AVENIO), as well as the tissue-based clinical trial assays (CTAs) was investigated. Clinical utility was assessed by comparing T-DXd clinical efficacy results of patients in DESTINY-Lung01/02 who tested positive for HER2 mutations using the Guardant360 CDx test to benchmark efficacy results from DESTINY-Lung01/02. Finally, concordance between the Guardant360 CDx test and the tissue-based Oncomine Dx Target (ODxT) test was explored. High concordance was observed between the Guardant360 CDx test versus AVENIO [positive percent agreement (PPA), 98.8%; negative percent agreement (NPA), 91.5%] and CTAs (DESTINY-Lung01 Cohort 2-PPA, 91.0%; NPA, 100%; DESTINY-Lung02 arm 1-PPA, 86.0%; NPA, 100%). Confirmed objective response rates were similar in patients with HER2m NSCLC identified by the Guardant360 CDx test and by CTAs. There was a high level of agreement between the Guardant360 CDx test and the ODxT test. The Guardant360 CDx test demonstrated analytical and clinical validity for identifying patients with HER2m NSCLC for T-DXd therapy; results support plasma-based testing when tissue-based testing is not feasible.

Novel Meningoencephalomyelitis Associated With Vimentin IgG Autoantibodies

ImportanceAutoantibodies targeting astrocytes, such as those against glial fibrillary acidic protein (GFAP) or aquaporin protein 4, are crucial diagnostic markers for autoimmune astrocytopathy among central nervous system (CNS) autoimmune disorders. However, diagnosis remains challenging for patients lacking specific autoantibodies.ObjectiveTo characterize a syndrome of unknown meningoencephalomyelitis associated with an astrocytic autoantibody.Design, Setting, and ParticipantsThis retrospective case series study included samples collected from April 2021 to May 2024 at a tertiary referral hospital among patients with uncharacterized CNS autoimmune disorders and similar clinical and radiological features. Single-cell RNA sequencing (scRNA-seq) was performed on cerebrospinal fluid (CSF) cells of 2 index patients to identify the putative target antigen of the clonally expanded B cells. A comprehensive screening for additional patients was conducted using blinded cell-based and tissue-based assay. Candidate patients were followed up for a median (range) duration of 23 (5-31) months.ExposuresscRNA-seq, autoantibody characterization, and testing.Main Outcomes and MeasuresDetection of the autoantibody and characterization of the associated autoimmune meningoencephalomyelitis.ResultsFourteen candidate patients (10 [71%] female; median [IQR] age, 33 [23-41] years) were identified. Initially, CSF from 2 female patients with unknown encephalomyelitis showed astrocytic reactivity on rat tissue but was negative for GFAP IgG. A total of 17 of 37 clonally expanded B cell clonotypes (46%) in their CSF expressed IgG autoantibodies targeting the astrocytic intermediate filament protein vimentin. Subsequent screening identified 12 additional patients. These 14 patients shared a unique clinical profile characterized by relapsing courses and symptoms prominently involving the cerebellum, brainstem, and corticospinal tract (CST). All patients also exhibited elevated CSF protein and cells, intrathecal immunoglobulin synthesis, and magnetic resonance imaging (MRI) showing bilateral lesions on CST. Notably, 8 of 12 patients (67%) who received first-line immunotherapy at their first episode responded well. At the last follow-up, 11 patients (79%) experienced significant disability (modified Rankin Scale ≥3).Conclusions and RelevanceIn this case series, autoantibodies targeting the astrocytic intermediate filament protein vimentin were identified in patients with previously undifferentiated meningoencephalomyelitis and common radiographic features.

Comprehensive genomic profiling for advanced hepatocellular carcinoma in clinical practice.

Although several therapeutic agents show efficacy in advanced hepatocellular carcinoma (HCC), biomarkers such as comprehensive genomic profiling (CGP) for the selection of second-line treatments after immunotherapy have not been established. We evaluated the value of CGP for the treatment decision in patients with HCC. We retrospectively studied 52 patients with advanced HCC who received CGP tests at three tertiary hospitals between February 2022 and November 2023. Genomic profiles were obtained using one of three CGP tests; 49 and 3 patients were evaluated using tissue-based and blood-based assay, respectively. The impact of CGP results on subsequent treatment selection in clinical practice and correlations between representative gene alterations and patient characteristics or responses to immunotherapy were evaluated. The most frequently observed variants were TERT mutations, followed by CTNNB1, TP53, ARID1A, and MYC mutations. Potentially druggable gene alterations were observed in 45 patients (87%), and 34 patients (65%) were recommended to receive treatments based on specific gene alterations by a molecular tumor board. Treatments were covered by health insurance in 13 patients (25%). Five patients (10%) received the recommended treatment by the date of data cut-off. There were no differences in the efficacy of immunotherapy with respect to mutation status in hTERT, CTNNB1, TP53, ARID1A, and MYC. The results of the present study suggested that druggable gene alterations may provide useful information not only in proposing alternative treatment after standard of care but also in selecting second-line targeted treatments after immunotherapy for patients with advanced HCC.

Frequency of anti-MOG antibodies in serum and CSF of patients with possible autoimmune encephalitis: Results from a Brazilian multicentric study

IntroductionMOGAD encephalitis and ADEM share several clinical features with autoimmune encephalitis (AE) associated with antineuronal antibodies (ANeA); nonetheless, treatment and prognosis differ. Anti-MOG antibodies (abs) are not routinely tested in possible AE, and epidemiological studies on MOGAD encephalitis are scarce. ObjectivesTo determine the frequency of anti-MOG abs in the serum and CSF in a cohort of possible AE and to compare the clinical characteristics of MOGAD patients and those with seropositive AE. Methods481 patients with possible AE from the Brazilian Autoimmune Encephalitis Network underwent tissue-based assay and cell-based assay (CBA) for ANeA. Anti-MOG abs were assessed in serum and CSF with in-house CBA. Clinical and laboratory characteristics of MOGAD and seropositive AE patients were compared. ResultsOf the 481 patients, 87 (18 %) had ANeA, and 17 (3.5 %) had anti-MOG abs. Three AE patients with anti-MOG abs and ANeA were excluded from further analysis. Anti-MOG abs were detected in 4 (1.2 %) of the 328 adults and 10 (6.5 %) of the 153 children. Of the 14 patients with MOGAD, nine had ADEM (mostly children), and five had encephalitis (including three adults). Only one patient with ADEM had anti-MOG abs exclusively in CSF. All patients with MOGAD encephalitis were seropositive for anti-MOG abs, and three had normal brain MRI. Patients with MOGAD had fewer behavioral changes (MOGAD 21 % x AE 96 %, p ≤ 0.0001) and movement disorders (MOGAD 42 % x AE 81 %, p = 0.0017) and more demyelinating symptoms, such as myelitis and optic neuritis (MOGAD 14 % x AE 0 %, p = 0.013). ConclusionApproximately 3.5 % of patients with possible AE harbor anti-MOG abs, and 0.9 % of the adults had MOGAD encephalitis. Anti-MOG abs were more frequent than other ANeAs regularly tested in AE. We provide evidence that MOGAD is a differential diagnosis in possible AE, even in adult patients with normal brain MRI, and that serum anti-MOG should be considered as an add-on diagnostic tool in AE among adults and pediatric patients.

IGLON5 Frequency in Idiopathic REM Sleep Behavior Disorder: A Multicenter Study.

Idiopathic/isolated REM sleep behavior disorder (iRBD) has been strongly linked to neurodegenerative synucleinopathies such as Parkinson disease, dementia with Lewy bodies, and multiple system atrophy. However, there have been increasing reports of RBD as a presenting feature of serious and treatable autoimmune syndromes, particularly IGLON5. This study's objective was to investigate the frequency of autoantibodies in a large cohort of participants with iRBD. Participants were enrolled in the North American Prodromal Synucleinopathy cohort with polysomnography-confirmed iRBD, free of parkinsonism and dementia. Plasma samples were systematically screened for the autoantibodies IGLON5, DPPX, LGI1, and CASPR2 using plasma IgG cell-based assay. Positive or equivocal results were confirmed by repeat testing, plus tissue-based indirect immunofluorescence assay for IGLON5. Of 339 samples analyzed, 3 participants (0.9%) had confirmed positive IGLON5 autoantibodies in the cell-based assay, which were confirmed by the tissue-based assay. An additional participant was positive for CASPR2 with low titer by cell-based assay only (of lower clinical certainty). These cases exhibited a variety of symptoms including dream enactment, cognitive decline, autonomic dysfunction, and motor symptoms. In 1 IGLON5 case and the CASPR2 case, evolution was suggestive of typical synucleinopathy, suggesting the possibility that findings were incidental. However, 2 participants with IGLON5 died before diagnosis was clinically suspected, with a final clinical picture highly suggestive of autoimmune disease. Our finding that nearly 1% of a large iRBD cohort may have a serious but potentially treatable autoantibody syndrome has important clinical implications. In particular, it raises the question of whether autoantibody testing for IGLON-5-IgG should be widely implemented for participants with iRBD, considering the difficulty in diagnosis of autoimmune diseases, their response to treatment, and the potential for rapid disease progression. However, any routine testing protocol will also have to consider costs and potential adverse effects of false-positive findings. NCT03623672.

Defining the optimal setting for transcriptomic analyses on blood samples for response prediction in immunotherapy-treated NSCLC patients

Transcriptomic profiling of blood immune cells offers a promising alternative to invasive, sampling bias-prone tissue-based biomarker assays for predicting immune checkpoint inhibitor (ICI) therapy response in non-small cell lung cancer (NSCLC) patients. However, the optimal analytical approach to identify systemic correlates of response still needs to be explored. We collected peripheral blood mononuclear cells and whole blood (WB) samples from 33 ICI-treated NSCLC patients before ICI treatment and at the first response evaluation. After bulk polyadenylated RNA-sequencing, we assessed differences in gene expression profiles between non-responders and responders using differential expression analysis, single sample gene set enrichment analysis (ssGSEA), and cell type deconvolution. We evaluated gene expression values, ssGSEA scores, and deconvolved cell type proportions to distinguish non-responders from responders via ROC curve (AUC) analysis, training a logistic regression classification model. Gene expression values and deconvolved proportions yielded the best results with WB samples after treatment (AUC = 0.87 and 0.85, respectively). Overall, ssGSEA scores showed superior classification performance across all sample types and timepoints (AUC > 0.7). In conclusion, transcriptomic analysis through ssGSEA demonstrated the best performance as a non-invasive biomarker for predicting clinical benefit in ICI-treated NSCLC patients, with gene expression and deconvolution on post-treatment WB samples also showing promising results.

PET Imaging of Breast Cancer: Current Applications and Future Directions.

As molecular imaging use expands for patients with breast cancer, it is important for breast radiologists to have a basic understanding of molecular imaging, including PET. Although breast radiologists may not directly interpret such studies, basic knowledge of molecular imaging will enable the radiologist to better direct diagnostic workup of patients as well as discuss diagnostic imaging with the patient and other treating physicians. Several new tracers are now available to complement imaging glucose metabolism with FDG. Because it provides a noninvasive assessment of disease status across the whole body, PET offers specific advantages over tissue-based assays. Paired with targeted therapy, molecular imaging has the potential to guide personalized treatment of breast cancer, including guiding dosing during drug trials as well as predicting and assessing clinical response. This review discusses the current established applications of FDG, which remains the most widely used PET radiotracer for malignancy, including breast cancer, and highlights potential areas for expanded use based on recent research. It also summarizes research to date on the U.S. Food and Drug Administration (FDA)-approved PET tracer 16α-18F-fluoro-17β-estradiol (FES), which targets ER, including the current guidelines from the Society of Nuclear Medicine and Molecular Imaging on the appropriate use of FES-PET/CT for breast cancer as well as areas of active investigation for other potential applications. Finally, the review highlights several of the most promising novel PET tracers that are poised for clinical translation in the near future.

Autoimmune Encephalitis and Paraneoplastic Neurological Syndromes with Progressive Supranuclear Palsy-like Manifestations.

Advances in diagnostic procedures have led to an increasing rate of diagnosis of autoimmune encephalitis or paraneoplastic neurological syndrome (AE/PNS) among patients with progressive supranuclear palsy (PSP)-like manifestations. In this narrative review, we first discuss the clinical characteristics of AE/PNS in comparison to those of PSP, followed by a discussion of diagnosis and treatment. The antibodies involved in these conditions include anti-IgLON5, -Ma2, and -Ri antibodies, each of which has a characteristic clinical presentation. The steps in the diagnosis of AE/PNS in patients with PSP-like manifestations include (i) suspicion of AE/PNS based on clinical presentations atypical of PSP and (ii) antibody detection measures. Methods used to identify antibodies include a combination of tissue-based assays and confirmatory tests. The primary confirmatory tests include cell-based assays and immunoblotting. Treatments can be divided into immunotherapy and tumor therapies, the former of which includes acute and maintenance therapies. One of the major challenges of diagnosis is that existing reports on PSP-like patients with AE/PNS include only case reports, with the majority discussing antibodies other than anti-IgLON5 antibody. As such, more patients need to be evaluated to establish the relationship between antibodies and PSP-like manifestations.

Long-Term Outcomes in Antibody-Negative Autoimmune Encephalitis: A Retrospective Study.

To characterize the long-term outcomes of patients with "possible only" or "probable" autoimmune encephalitis (AE). Despite comprising one-third of AE cases, antibody-negative cases lacking typical AE-defining features are understudied. We conducted a retrospective analysis of adult patients evaluated at a tertiary center neuroimmunology practice from 2006 to 2020, meeting diagnostic criteria for "possible only" or "probable but antibody-negative" AE, with at least one year of follow-up. All patients underwent neural antibody testing. Forty-five patients (median age, 61 years [range, 20-88]; female, 21 [47%]) were included, with a median follow-up of 36 months (range, 12-174). A change in diagnosis was noted in six additional patients, who were excluded from further analysis, with only two receiving a non-autoimmune diagnosis during follow-up. The majority (41/45 [91%]) presented with significant disability (modified Rankin Scale [mRS] ≥3) at baseline. CSF was inflammatory in 20/44 (45%) and MRI was abnormal in 21/45 (47%). Unclassified neural-specific IgG staining on tissue-based assay was detected in five (11%). Two cases (4%) had a paraneoplastic cause. The median time from onset to immunotherapy initiation was two months (range, 0-21), resulting in at least partial improvement in all 44 (98%) treated cases. Clinical relapses occurred in 14/45 (31%). At last follow-up, the most common symptoms were memory dysfunction (31/45 [69%]), attention deficits (17/45 [38%]), gait instability (13/45 [29%]), and visuospatial dysfunction (10/45 [22%]). Most patients achieved independence (median mRS, 2 [range, 0-6]); however, 11 patients had poor neurological outcome (mRS ≥3). Higher mRS score and gait assistance requirement at three months were predictive of poor outcome (P ≤0.01). Despite significant disability at initial stages, patients with antibody-negative but clinically presumed AE show potential for improvement with immunotherapy, highlighting the importance of early intervention. Early functional status and gait assistance requirements may assist in predicting long-term prognosis.

Performance Assessment of the New EUROLINE Neurologic Syndrome 15 Ag (IgG) for the Determination of Autoantibodies Associated with Neurological Disorders.

Here, we assess the performance of the new EUROLINE Neurologic Syndrome 15 Ag (IgG) which expands the EUROLINE Paraneoplastic Neurologic Syndrome 12 Ag by adding CDR2L (together with CDR2 targeted by anti-Yo), AK5, and Neurochondrin (NCDN). Many paraneoplastic as well as non-paraneoplastic autoantibodies (AAbs) have been described in neurological disorders in the last decade. By integrating the associated antigens into existing assays, the diagnostic work-up of patients is being improved and diagnostic gaps reduced. Sensitivity of each AAb was analyzed using a total of 194 clinically and diagnostically pre-characterized samples (Table 1). Specificity of each AAb was investigated using a minimum of 100 sera from healthy blood donors. Using the EUROLINE Neurologic Syndrome 15 Ag, autoantibody positivity was confirmed in 89-100% of samples. In particular, all samples for which clinical and tissue-based indirect immunofluorescence assay pre-characterization indicated anti-Yo positivity were anti-CDR2 and -CDR2L double positive. Anti-AK5 was determined in serum and cerebrospinal fluid (CSF) with a sensitivity of 90 and 100%, respectively, and anti-NCDN with a sensitivity of 100%. The individual specificities were ≥99%. This kit is a tool for the qualitative in vitro determination of AAbs against a large panel of 15 different neuronal autoantigens to support the diagnosis of neurologic syndromes. The parallel detection of anti-CDR2 and anti-CDR2L (both anti-Yo) increases the diagnostic significance, as double positivity is strongly related to paraneoplastic cerebellar degeneration.[Table: see text].

Long-term outcomes in antibody-negative autoimmune encephalitis: a retrospective study.

Despite constituting one-third of suspected autoimmune encephalitis (AE) patients, antibody-negative cases without typical AE features are understudied. We aim to characterize the clinical phenotypes and long-term outcomes of "possible only" and "probable" AE cases. We conducted a retrospective analysis of adult patients evaluated at Mayo Clinic's Autoimmune Neurology Clinic (01/01/2006-12/31/2020), meeting diagnostic criteria for "possible only" or "probable but antibody-negative" AE, with ≥ 1year of follow-up. All patients underwent neural antibody testing. Among fifty-one patients, six had a change in diagnosis (non-autoimmune, 2) and were excluded from further analysis. Forty-five patients were analyzed [median age, 61years (range 20-88); female, 21 (47%); median follow-up, 36months (range 12-174)]. A nadir modified Rankin Scale (mRS) ≥ 3 was recorded in 41/45 (91%). CSF was inflammatory in 20/44 (45%) and MRI had encephalitic changes in 21/45 (47%). Unclassified neural-specific IgG staining on tissue-based assay was detected in five (11%). Two patients (4%) had paraneoplastic causation. Relapses (> 3months from onset) were noted in 14 (31%). Memory dysfunction (69%), attention deficits (38%), and gait instability (29%) were the most frequent at the last follow-up. Most patients (76%) were independent at the last follow-up and only two required an assistive device to ambulate; 11 patients (24%) had poor neurological outcome (mRS ≥ 3). Higher mRS score and gait assistance requirement at 3months were predictive of poor outcome (P ≤ 0.01). Despite significant disability at initial disease stages, most antibody-negative AE patients regain independent functioning. Early functional status and gait assistance requirements may predict long-term prognosis.

Clinical characteristics of double negative atypical inflammatory demyelinating disease: A prospective study.

This study aimed to investigate the clinical characteristics and predictors of relapse in double negative atypical inflammatory demyelinating disease (IDD) and to explore potential antigenic targets by tissue-based assays (TBA) using rat brain indirect immunofluorescence. We compared the clinical, laboratory, and MRI data of double negative atypical IDD with other IDD patients. Serum samples were collected for TBA. The predictors of relapse were examined over a minimum of 24 months follow-up. In our cohort of 98 patients with double negative atypical IDD, there was no significant female predominance (58.2%, 57/98). The lesions primarily affected the spinal cord and brain stem, with fewer cases of involvement in the area postrema (5.1%, 5/98) and longitudinally extensive transverse myelitis (43.9%, 43/98). A total of 62.5% (50/80) patients tested positive for anti-astrocyte antibodies based on rat brain TBA. Over a median duration of 39.5 months, 80 patients completed the entire follow-up, and 47.5% (38/80) patients exhibited monophasic course. A total of 36% (18/50) patients positively for anti-astrocyte antibodies had a monophasic course, which is significantly lower than patients negatively for anti-astrocyte antibodies (66.7%, 20/30) (p = 0.008). The presence of anti-astrocyte antibodies (hazard ratio (HR), 2.243; 95% CI, 1.087-4.627; p = 0.029) and ≥4 cerebrum lesions at first attack (HR, 2.494; 95% CI, 1.224-5.078; p = 0.012) were risk factors for disease relapse, while maintenance immunotherapy during remission (HR, 0.361; 95% CI, 0.150-0.869; p = 0.023) was protective factor. Double negative atypical IDD are unique demyelinating diseases with a high relapse rate. Maintenance immunotherapy is helpful to the prevention of relapse, particularly in patients with anti-astrocyte antibodies or ≥4 cerebrum lesions at first attack.

Evaluation of Methodologies in Anti-nephrin Autoantibody Detection.

Recent studies discovered the prominent presence of anti-nephrin autoantibodies in minimal change disease, steroid-sensitive nephrotic syndrome and/or post-transplant recurrent focal segmental glomerulosclerosis (FSGS). However, widely different, and often unconventional autoantibody detection methods were used among these studies, making it challenging to assess the pathogenic role for the antibodies. Here we examined methods of conventional ELISA, magnetic on-beads ELISA, immunoprecipitation-immunoblotting (IP-IB), and cell- and tissue-based antibody assays with 127 plasma samples of kidney and non-kidney diseases. On the antigen side, we compared commercially available recombinant human nephrin extracelluar domain (ECD) produced from human or mouse cell lines, as well as lab-made full length, ECD, and series of ECD truncates for measuring autoantibody reactivity and specificity. Surprisingly, different assay methods and different antigen preparations led to observation of assay-specific false-positive and false-negative results. In general, a set of tests that combines magnetic beads-enhanced ELISA, followed by IP-IB, and epitope mapping showed the most robust results for anti-nephrin autoantibodies, detected in two primary FSGS patients among all cases tested. It is interesting to note that cell/tissue-based results, also supported by antigen truncation studies, clearly suggest steric hindrance of reactive epitopes, as in full length nephrin that forms compact self-associated complexes. In conclusion, anti-nephrin positivity is rare among the tested patients (2/127), including those with FSGS (2/42), and autoantibody results can be affected by the choice of detection methods.

Development of a first-in-class antibody and a specific assay for α-1,6-fucosylated prostate-specific antigen

Prostate-specific antigen (PSA) levels are widely used to screen for prostate cancer, yet the test has poor sensitivity, specificity and predictive value, which leads to overdiagnosis and overtreatment. Alterations in the glycosylation status of PSA, including fucosylation, may offer scope for an improved biomarker. We sought to generate a monoclonal antibody (mAb) targeting α-1,6-fucosylated PSA (fuc-PSA) and to develop a tissue-based immunological assay for fuc-PSA detection. Immunogens representing fuc-PSA were used for immunisation and resultant mAbs were extensively characterised. The mAbs reacted specifically with fuc-PSA-specific glycopeptide, but not with aglycosylated PSA or glycan without the PSA peptide. Reactivity was confirmed using high-throughput surface plasmon resonance spectroscopy. X-ray crystallography investigations showed that the mAbs bound to an α-helical form of the peptide, whereas the native PSA epitope is linear. Protein unfolding was required for detection of fuc-PSA in patient samples. Peptide inhibition of fuc-PSA mAbs was observed with positive screening reagents, and target epitope specificity was observed in formalin-fixed, paraffin-embedded tissue samples. This research introduces a well-characterised, first-in-class antibody targeting fuc-PSA and presents the first crystal structure of an antibody demonstrating glycosylation-specific binding to a peptide.

Progressive encephalomyelitis with rigidity and myoclonus: a pediatric case report and literature review

BackgroundProgressive encephalomyelitis with rigidity and myoclonus (PERM) is a rare and life-threatening autoimmune disease of the central nervous system. So far, only ten cases of PERM have been reported in children worldwide, including the one in this study.Case presentationWe report a case of an 11-year-old boy with PERM with an initial presentation of abdominal pain, skin itching, dysuria, urinary retention, truncal and limb rigidity, spasms of the trunk and limbs during sleep, deep and peripheral sensory disturbances, and dysphagia. A tissue-based assay using peripheral blood was positive, demonstrated by fluorescent staining of mouse cerebellar sections. He showed gradual and persistent clinical improvement after immunotherapy with intravenous immunoglobulin, steroids, plasmapheresis and rituximab.ConclusionsWe summarized the diagnosis and treatment of a patient with PERM and performed a literature review of pediatric PERM to raise awareness among pediatric neurologists. A better comprehension of this disease is required to improve its early diagnosis, treatment, and prognosis.

Brazilian consensus recommendations on the diagnosis and treatment of autoimmune encephalitis in the adult and pediatric populations.

Autoimmune encephalitis (AIE) is a group of inflammatory diseases characterized by the presence of antibodies against neuronal and glial antigens, leading to subacute psychiatric symptoms, memory complaints, and movement disorders. The patients are predominantly young, and delays in treatment are associated with worse prognosis. With the support of the Brazilian Academy of Neurology (Academia Brasileira de Neurologia, ABN) and the Brazilian Society of Child Neurology (Sociedade Brasileira de Neurologia Infantil, SBNI), a consensus on the diagnosis and treatment of AIE in Brazil was developed using the Delphi method. A total of 25 panelists, including adult and child neurologists, participated in the study. The panelists agreed that patients fulfilling criteria for possible AIE should be screened for antineuronal antibodies in the serum and cerebrospinal fluid (CSF) using the tissue-based assay (TBA) and cell-based assay (CBA) techniques. Children should also be screened for anti-myelin oligodendrocyte glucoprotein antibodies (anti-MOG). Treatment should be started within the first 4 weeks of symptoms. The first-line option is methylprednisolone plus intravenous immunoglobulin (IVIG) or plasmapheresis, the second-line includes rituximab and/or cyclophosphamide, while third-line treatment options are bortezomib and tocilizumab. Most seizures in AIE are symptomatic, and antiseizure medications may be weaned after the acute stage. In anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis, the panelists have agreed that oral immunosuppressant agents should not be used. Patients should be evaluated at the acute and postacute stages using functional and cognitive scales, such as the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA), the Modified Rankin Scale (mRS), and the Clinical Assessment Scale in Autoimmune Encephalitis (CASE). The present study provides tangible evidence for the effective management of AIE patients within the Brazilian healthcare system.

Easy recognition and high autoimmune hepatitis specificity of smooth muscle antibodies giving an actin microfilament immunofluorescent pattern on embryonal vascular smooth muscle cells.

Smooth muscle antibodies (SMA) with anti-microfilament actin (MF-SMA) specificity are regarded as highly specific markers of type 1 autoimmune hepatitis (AIH-1) but their recognition relying on immunofluorescence of vessel, glomeruli, and tubules (SMA-VGT pattern) in rodent kidney tissue, is restricted by operator-dependent interpretation. A gold standard method for their identification is not available. We assessed and compared the diagnostic accuracy for AIH-1 of an embryonal aorta vascular smooth muscle (VSM) cell line-based assay with those of the rodent tissue-based assay for the detection of MF-SMA pattern in AIH-1 patients and controls. Sera from 138 AIH-1 patients and 295 controls (105 primary biliary cholangitis, 40 primary sclerosing cholangitis, 50 chronic viral hepatitis, 20 alcohol-related liver disease, 40 steatotic liver disease, and 40 healthy controls) were assayed for MF-SMA and SMA-VGT using VSM-based and rodent tissue-based assays, respectively. MF-SMA and SMA-VGT were found in 96 (70%) and 87 (63%) AIH-1 patients, and 2 controls (P < 0.0001). Compared with SMA-VGT, MF-SMA showed similar specificity (99%), higher sensitivity (70% vs 63%, P = ns) and likelihood ratio for a positive test (70 vs 65). Nine (7%) AIH-1 patients were MF-SMA positive despite being SMA-VGT negative. Overall agreement between SMA-VGT and MF-SMA was 87% (kappa coefficient 0.870, [0.789-0.952]). MF-SMA were associated with higher serum γ-globulin [26 (12-55) vs 20 g/l (13-34), P < 0.005] and immunoglobulin G (IgG) levels [3155 (1296-7344) vs 2050 mg/dl (1377-3357), P < 0.002]. The easily recognizable IFL MF-SMA pattern on VSM cells strongly correlated with SMA-VGT and has an equally high specificity for AIH-1. Confirmation of these results in other laboratories would support the clinical application of the VSM cell-based assay for reliable detection of AIH-specific SMA.

Trace elements alone or in mixtures associated with unconventional natural gas exploitation affect rat fetal steroidogenesis and testicular development in vitro

Biomonitoring studies have shown that pregnant women living in regions of unconventional natural gas (UNG) exploitation have higher levels of trace elements. Whether developmental endocrine disruption can be expected at these exposure levels during pregnancy is unclear. In this study, we aimed to test the impact of five trace elements alone or in mixtures using in vitro cell- and tissue-based assays relevant to endocrine disruption and development. Manganese, aluminum, strontium, barium, and cobalt were tested at concentrations including those representatives of human fetal exposure. Using transactivation assays, none of the tested elements nor their mixture altered the human estrogen receptor 1 or androgen receptor genomic signalling. In the rat fetal testis assay, an organ culture system, cobalt (5 μg/l), barium (500 μg/l) and strontium (500 μg/l) significantly increased testosterone secretion. Cobalt and strontium were associated with hyperplasia and/or hypertrophy of fetal Leydig cells. Mixing the five elements at concentrations where none had an effect individually stimulated testosterone secretion by the rat fetal testis paralleled by the significant increase of 3β-hydroxysteroid dehydrogenase protein level in comparison to the vehicle control. The mechanisms involved may be specific to the fetal testis as no effect was observed in the steroidogenic H295R cells. Our data suggest that some trace elements in mixture at concentrations representative of human fetal exposure can impact testis development and function. This study highlights the potential risk posed by UNG operations, especially for the most vulnerable populations, pregnant individuals, and their fetus.

Enfortumab vedotin plus pembrolizumab in the treatment of locally advanced or metastatic bladder cancer of variant histology: A phase II study.

TPS4615 Background: Bladder cancers of variant histology (BCVH) account for up to 25% of bladder cancer incidence and affected patients (pts) usually have poor outcomes. The treatment options are limited due to the underrepresentation or exclusion of BCVH pts from trials for locally advanced or metastatic urothelial cancer (mUC). Enfortumab vedotin (EV) is an antibody-drug conjugate specific for Nectin-4. In the EV 302 Phase III trial, EV+pembrolizumab (pembro) significantly prolonged overall survival (OS) compared to platinum-based chemotherapy in mUC (HR 0.47, 95% CI 0.38-0.58) and was recently FDA-approved as standard of care in 1L mUC. Translational studies from our center show Nectin-4 expression in many BCVH pts and data support immune-checkpoint inhibitor (ICI) activity in subsets of these pts. We hypothesize the presence of clinical activity of this combination in BCVH. Therefore, we designed this trial to assess the efficacy and safety of EV+pembro in locally advanced or metastatic BCVH (mBCVH). Methods: This is a Phase II, open-label, single-center trial at the Winship Cancer Institute of Emory University (NCT05756569) for pts with mBCVH. Pts will receive pembro 200mg IV on Day 1 and EV 1.25mg/Kg IV on Days 1 and 8 of a 21-day cycle for up to two years. The eligibility criteria include histologically confirmed variant histology or non-urothelial bladder cancer of epithelial origin including squamous cell carcinoma and adenocarcinoma (according to the WHO 2016 Classification), ECOG 0-1, and any line of therapy. Pts with neuroendocrine bladder cancer, non-epithelial cancers (e.g. sarcoma, lymphoma), prior ICI and/or EV treatment are excluded. Overall response rate (ORR) per RECIST 1.1 is the primary outcome and will be tested using Simon's two-stage design (n=25). The first interim analysis is planned after 15 patients. The desirable target is ORR≥30% relative to a null hypothesis of ORR ≤10%. This statistical design yields a type I error rate of 0.05 and a power of 80% for a true ORR≥30%. Key secondary outcomes include OS, progression-free survival, duration of response, and incidence of adverse events per CTCAE v5.0. Correlative biomarker analyses using blood- and tissue-based assays will be conducted during screening and at disease progression. The trial is currently open for enrollment. Clinical trial information: NCT05756569 .