Epidemiology of seropositive myasthenia gravis in Sardinia: A population-based study in the district of Sassari.

INTRODUCTION/AIMS: The global incidence and prevalence of myasthenia gravis (MG) range between 6-31/million and 10-37/100,000, respectively. Sardinia is a high-risk region for different immune-mediated disorders, but the epidemiology of MG remains unclear. We determined the epidemiology of MG with acetylcholine receptor (AChR)-immunoglobulin G (IgG) and muscle-specific tyrosine kinase (MuSK)-IgG in the district of Sassari (North-Western Sardinia; population, 325,288). METHODS: From the laboratory of the University Hospital of Sassari (reference for AChR/MuSK-IgG testing in Sardinia since 1998) and the main neurology units in Sardinia, we retrospectively identified MG patients with (1) AChR-IgG and/or MuSK-IgG positivity by radioimmunoprecipitation assay; and (2) residency in the district of Sassari. Incidence (January 2010-December 2019) and prevalence (December 31, 2019) were calculated. RESULTS: A total of 202 patients were included (incident, 107; prevalent, 180). Antibody specificities were AChR (n = 187 [93%]) and MuSK (n = 15 [7%]). The crude MG incidence (95% confidence interval) was 32.6 (26.8-39.2)/million, while prevalence was 55.3 (47.7-63.9)/100,000. After age-standardization to the world population, incidence decreased to 18.4 (14.3-22.5)/million, while prevalence decreased to 31.6 (26.1-37.0)/100,000. Among incident cases, age strata (years) at MG onset were: <18 (2%), 18-49 (14%), 50-64 (21%), and ≥65 (63%). DISCUSSION: Sardinia is a high-risk region for MG, with a prevalence that exceeds the European threshold for rare disease. Identification of the environmental and genetic determinants of this risk may improve our understanding of disease pathophysiology.

Validity and reliability of the Questionnaire of Olfactory Disorders for Italian-speaking patients with olfactory dysfunction.

Objective: To translate and validate an Italian version of the Questionnaire of Olfactory Disorders (IT-QOD). Materials and methods: This is a prospective, multicentre study that involved patients with olfactory dysfunction (OD). Both cases and controls underwent administration of the IT-QOD, Sino-Nasal Outcome Test-22 (SNOT-22) and psychophysical evaluation of orthonasal and retronasal olfactory function. Results: The IT-QOD was administered to 96 patients and 38 controls. The Cronbach's alpha exceeded 0.90, indicating satisfactory internal consistency. The test-retest reliability was found to be high for both parosmia (rs = 0.944) and life quality (rs = 0.969). Patients with OD had significantly higher IT-QOD scores compared to healthy individuals (p < 0.001), indicating strong internal validity. The external validity was also satisfactory, as shown by the significant correlation with SNOT-22 (rs = -0.54) and the threshold, discrimination, and identification score (rs = -0.63). Conclusions: The IT-QOD was demonstrated to be reliable and valid to assess the impact of OD on the quality of life of Italian-speaking patients.

A top-down proteomic approach reveals a salivary protein profile able to classify Parkinson's disease with respect to Alzheimer's disease patients and to healthy controls.

Parkinson's disease (PD) is a complex neurodegenerative disease with motor and non-motor symptoms. Diagnosis is complicated by lack of reliable biomarkers. To individuate peptides and/or proteins with diagnostic potential for early diagnosis, severity and discrimination from similar pathologies, the salivary proteome in 36 PD patients was investigated in comparison with 36 healthy controls (HC) and 35 Alzheimer's disease (AD) patients. A top-down platform based on HPLC-ESI-IT-MS allowed characterizing and quantifying intact peptides, small proteins and their PTMs (overall 51). The three groups showed significantly different protein profiles, PD showed the highest levels of cystatin SA and antileukoproteinase and the lowest of cystatin SN and some statherin proteoforms. HC exhibited the lowest abundance of thymosin ß4, short S100A9, cystatin A, and dimeric cystatin B. AD patients showed the highest abundance of α-defensins and short oxidized S100A9. Moreover, different proteoforms of the same protein, as S-cysteinylated and S-glutathionylated cystatin B, showed opposite trends in the two pathological groups. Statherin, cystatins SA and SN classified accurately PD from HC and AD subjects. α-defensins, histatin 1, oxidized S100A9, and P-B fragments were the best classifying factors between PD and AD patients. Interestingly statherin and thymosin ß4 correlated with defective olfactory functions in PD patients. All these outcomes highlighted implications of specific proteoforms involved in the innate-immune response and inflammation regulation at oral and systemic level, suggesting a possible panel of molecular and clinical markers suitable to recognize subjects affected by PD.

Unraveling the prognostic significance and molecular characteristics of tumor-infiltrating B lymphocytes in clear cell renal cell carcinoma through a comprehensive bioinformatics analysis.

Introduction: Clear cell renal cell carcinoma (ccRCC) is a prevalent subtype of kidney cancer that exhibits a complex tumor microenvironment, which significantly influences tumor progression and immunotherapy response. In recent years, emerging evidence has underscored the involvement of tumor-infiltrating B lymphocytes (TIL-Bs), a crucial component of adaptive immunity, and their roles in ccRCC as compared to other tumors. Therefore, the present study endeavors to systematically explore the prognostic and molecular features of TIL-Bs in ccRCC. Methods: Initially, xCell algorithm was used to predict TIL-Bs in TCGA-KIRC and other ccRCC transcriptomic datasets. The Log-Rank test and Cox regression were applied to explore the relationship of B-cells with ccRCC survival. Then, we used WGCNA method to identify important modules related to TIL-Bs combining Consensus subcluster and scRNA-seq data analysis. To narrow down the prospective biomarkers, a prognostic signature was proposed. Next, we explored the feature of the signature individual genes and the risk-score. Finally, the potential associations of signature with clinical phenotypes and drugs were investigated. Results: Preliminary, we found ccRCC survival was negatively associated with TIL-Bs, which was confirmed by other datasets. Afterwards, ten co-expression modules were identified and a distinct ccRCC cluster was subsequently detected. Moreover, we assessed the transcriptomic alteration of B-cell in ccRCC and a relevant B-cell subtype was also pinpointed. Based on two core modules (brown, red), a 10-gene signature (TNFSF13B, SHARPIN, B3GAT3, IL2RG, TBC1D10C, STAC3, MICB, LAG3, SMIM29, CTLA4) was developed in train set and validated in test sets. These biomarkers were further investigated with regards to their differential expression and correlation with immune characteristics, along with risk-score related mutations and pathways. Lastly, we established a nomogram combined tumor grade and discovered underlying drugs according to their sensitivity response. Discussion: In our research, we elucidated the remarkable association between ccRCC and B-cells. Then, we detected several key gene modules, together with close patient subcluster and B-cell subtype,which could be responsible for the TIL-Bs in ccRCC. Moreover, we proposed a 10-gene signature and investigated its molecular features from multiple perspectives. Overall, understanding the roles of TIL-Bs could aid in the immunotherapeutic approaches for ccRCC, which deserve further research to clarify the implications for patient prognosis and treatment.

Non-demyelinating disorders mimicking and misdiagnosed as NMOSD: a literature review.

BACKGROUND: Differentiating neuromyelitis optica spectrum disorder (NMOSD) from its mimics is crucial to avoid misdiagnosis, especially in the absence of aquaporin-4-IgG. While multiple sclerosis (MS) and myelin oligodendrocyte glycoprotein-IgG associated disease (MOGAD) represent major and well-defined differential diagnoses, non-demyelinating NMOSD mimics remain poorly characterized. METHODS: We conducted a systematic review on PubMed/MEDLINE to identify reports of patients with non-demyelinating disorders that mimicked or were misdiagnosed as NMOSD. Three novel cases seen at the authors' institutions were also included. The characteristics of NMOSD mimics were analyzed and red flags associated with misdiagnosis identified. RESULTS: A total of 68 patients were included; 35 (52%) were female. Median age at symptoms onset was 44 (range, 1-78) years. Fifty-six (82%) patients did not fulfil the 2015 NMOSD diagnostic criteria. The clinical syndromes misinterpreted for NMOSD were myelopathy (41%), myelopathy + optic neuropathy (41%), optic neuropathy (6%), or other (12%). Alternative etiologies included genetic/metabolic disorders, neoplasms, infections, vascular disorders, spondylosis, and other immune-mediated disorders. Common red flags associated with misdiagnosis were lack of cerebrospinal fluid (CSF) pleocytosis (57%), lack of response to immunotherapy (55%), progressive disease course (54%), and lack of magnetic resonance imaging gadolinium enhancement (31%). Aquaporin-4-IgG positivity was detected in five patients by enzyme-linked immunosorbent assay (n = 2), cell-based assay (n = 2: serum, 1; CSF, 1), and non-specified assay (n = 1). CONCLUSIONS: The spectrum of NMOSD mimics is broad. Misdiagnosis frequently results from incorrect application of diagnostic criteria, in patients with multiple identifiable red flags. False aquaporin-4-IgG positivity, generally from nonspecific testing assays, may rarely contribute to misdiagnosis.

Autoimmune encephalitis misdiagnosis and mimics.

The diagnosis of autoimmune encephalitis (AE) requires reasonable exclusion of other conditions. The aim of this study is to characterize mimickers and misdiagnoses of AE, thus we performed an independent PubMed search for mimickers of AEs or patients with alternative neurological disorders misdiagnosed as AE. Fifty-eight studies with 66 patients were included. Neoplastic (n = 17), infectious (n = 15), genetic (n = 13), neurodegenerative (n = 8), and other neurological (n = 8) or systemic autoimmune (n = 5) disorders were misdiagnosed as AE. The lack of fulfillment of diagnostic criteria for AE, atypical neuroimaging findings, non-inflammatory CSF findings, non-specific autoantibody specificities and partial response to immunotherapy were major confounding factors.

Antibody Response to HERV-K and HERV-W Envelope Epitopes in Patients with Myasthenia Gravis.

Myasthenia gravis is an antibody-mediated autoimmune neurological disorder characterized by impaired neuromuscular junction transmission, resulting in muscle weakness. Recently, the involvement of Human Endogenous Retroviruses (HERVs) in the pathophysiology of different immune-mediated and neurodegenerative diseases, such as multiple sclerosis, has been demonstrated. We aimed to investigate potential immune system involvement related to humoral responses targeting specific epitopes of HERV-K and HERV-W envelope proteins in myasthenia gravis. Myasthenia gravis patients were recruited in the Neurology Unit, while healthy controls were selected from the Blood Transfusion Center, both affiliated with AOU Sassari. Highly immunogenic antigens of HERV-K and HERV-W envelope proteins were identified using the Immune Epitope Database (IEDB) online tool. These epitopes were utilized in enzyme-linked immunosorbent assays (ELISA) to detect autoantibodies in serum directed against these sequences. The study involved 39 Healthy Donors and 47 MG patients, further categorized into subgroups based on the presence of autoantibodies: MG-AchR Ab+ (n = 17), MG-MuSK Ab+ (n = 7), double seronegative patients (MG-DSN, n = 18), MG-LRP4 Ab + (n = 4), and one patient with no antibodies data (n = 1). Our findings revealed high levels of autoantibodies in myasthenia gravis patients directed against the HERV-K-env-su(19-37), HERV-K-env-su(109-126), HERV-K-env-su(164-186), HERV-W-env(93-108), HERV-W-env(129-14), and HERV-W-env(248-262) epitopes. Notably, these results remained highly significant even when patients were subdivided into MG-AchR Ab+ and MG-DSN subgroups. Correlation analysis further revealed significant positive associations between the antibody levels against HERV-K and HERV-W families in patients, suggesting a synergistic action of the two HERVs in the pathology context since this correlation is absent in the control group. This study marks the first identification of a specific humoral response directed against defined epitopes of HERV-K and HERV-W envelope proteins in myasthenia gravis patients. These findings lay the foundation for future investigations aimed at elucidating the molecular mechanisms driving this immune response. The detection of these autoantibodies suggests the potential for novel biomarkers, especially within the MG-DSN patient subgroup, addressing the need for new biomarkers in this population.

Relationship between risk and protective factors and clinical features of Parkinson's disease.

BACKGROUND: Non-genetic risk factors play a relevant role in Parkinson's disease (PD) development but the relationship between these factors and PD clinical features is unknown. OBJECTIVE: The aim of the present multicenter study was to investigate possible relationship between risk factors and clinical motor and non-motor features in a large sample of PD patients. METHODS: Six hundred ninety-four patients with PD participated. Patients underwent a clinical evaluation assessing motor symptoms and motor complications as well as non-motor symptoms severity. Information regarding pharmacological treatment was also collected. Risk and protective factors were previously identified in the present population and included coffee consumption, cigarette smoking, and physical activity as protective factors and a family history of PD, dyspepsia, exposure to toxic agents and general anesthesia as risk factors. Multiple regression models were used to investigate the relationship between risk factors and clinical variables. RESULTS: Coffee consumption predicted older age at onset (B: 0.527; CI: 0.195; 0.858) and milder motor symptom severity (B: 1.383; CI: 2.646; -0.121). Non-motor symptom severity was more severe in patients with dyspepsia before PD (B: 13.601; CI 5.019; 22.182) and milder in patients who performed physical activity before PD (B: 11.355; CI: 16.443; -6.266). We found no relationship between risk factors and motor complications, motor subtype and pharmacological treatment. CONCLUSIONS: Risk and protective factors of PD development may influence PD clinical features. This finding may represent the first step in the development of new preventive approaches able to delay disease onset and mitigate the extent of clinical manifestations.

Rasagiline Withdrawal Syndrome in Parkinson's Disease.

Parkinson's disease (PD) patients using dopamine agonists can develop withdrawal symptoms, referred to as dopamine agonist withdrawal syndrome (DAWS), under dose tapering or discontinuation of these drugs. DAWS includes a severe stereotypical cluster of psychiatric and psychological symptoms encompassing severe mood and anxiety disturbances, autonomic symptoms, as well as generalized pain and drug cravings. However, symptoms of withdrawal of dopamine replacement therapies (DRT) are not simply limited to dopamine agonists tapering, as observed in PD patients on deep brain stimulation after dopaminergic drugs withdrawal related to surgery. To date, no DRT-related withdrawal syndrome has been described in PD patients who discontinue rasagiline, an irreversible inhibitor of monoamine oxidase-B (MAO-B). Here we report three PD patients who developed a severe withdrawal syndrome after rasagiline suspension. The syndrome was mainly characterized by prominent psychiatric disorders (depression, anxiety with panic attacks, dysphoria, and agitation) associated with fatigue, generalized pain, and autonomic manifestations (closely resembling symptoms of DAWS). In our opinion, this report suggests the importance of closely monitoring PD patients undergoing rasagiline suspension for withdrawal symptoms and provides interesting points of reflection on the role of rasagiline and other MAO-B inhibitors in mood disorders.

Effect of Different Disease-Modifying Therapies on Humoral Response to BNT162b2 Vaccine in Sardinian Multiple Sclerosis Patients.

Objectives: Vaccination against COVID-19 is highly recommended to patients affected by multiple sclerosis (MS); however, the impact of MS disease-modifying therapies (DMTs) on the immune response following vaccination has been only partially investigated. Here, we aimed to elucidate the effect of DMTs on the humoral immune response to mRNA-based anti-SARS-CoV-2 vaccines in MS patients. Methods: We obtained sera from 912 Sardinian MS patients and 63 healthy controls 30 days after the second dose of BNT162b2 vaccine and tested them for SARS-CoV-2 response using anti-Spike (S) protein-based serology. Previous SARS-CoV-2 infection was assessed by anti-Nucleocapsid (N) serology. Patients were either untreated or undergoing treatment with a total of 13 different DMTs. Differences between treatment groups comprised of at least 10 patients were assessed by generalized linear mixed-effects model. Demographic and clinical data and smoking status were analyzed as additional factors potentially influencing humoral immunity from COVID-19 vaccine. Results: MS patients treated with natalizumab, teriflunomide, azathioprine, fingolimod, ocrelizumab, and rituximab showed significantly lower humoral responses compared to untreated patients. We did not observe a statistically significant difference in response between patients treated with the other drugs (dimethyl fumarate, interferon, alemtuzumab and glatiramer acetate) and untreated patients. In addition, older age, male sex and active smoking were significantly associated with lower antibody titers against SARS-CoV-2. MS patients previously infected with SARS-CoV-2 had significantly higher humoral responses to vaccine than uninfected patients. Conclusion: Humoral response to BNT162b2 is significantly influenced by the specific DMTs followed by patients, as well as by other factors such as previous SARS-CoV-2 infection, age, sex, and smoking status. These results are important to inform targeted strategies to prevent clinically relevant COVID-19 in MS patients.

TDP-43 and HERV-K Envelope-Specific Immunogenic Epitopes Are Recognized in ALS Patients.

The human endogenous retrovirus-K (HERV-K) and TAR DNA-binding protein 43 (TDP-43) have been associated with the pathophysiology of amyotrophic lateral sclerosis (ALS). Given these findings, we investigated the humoral response against HERV-K envelope surface (env-su) glycoprotein antigens and TDP-43 in the plasma of ALS patients and healthy controls (HCs). The measured levels of Abs against the different epitopes' fragments were significantly elevated in ALS patients, both in long-survivor (LS) and newly diagnosed (ND) patients, compared to HCs. We observed a positive correlation between HERV-K and TDP-43 antibodies (Abs) levels, which seemed to strengthen with disease progression, that was not found in HCs. The TDP-43 and HERV-K epitopes identified in this study are highly immunogenic and recognized by the humoral response of ALS patients. Increased circulating levels of Abs directed against specific HERV-K- and TDP-43-derived epitopes could serve as possible biomarkers.

Risk factors of Parkinson disease: Simultaneous assessment, interactions, and etiologic subtypes.

OBJECTIVE: To perform a simultaneous evaluation of potential risk/protective factors of Parkinson disease (PD) to identify independent risk/protective factors, to assess interaction among factors, and to determine whether identified risk factors predict etiologic subtypes of PD. METHODS: We designed a large case-control study assessing 31 protective/risk factors of PD, including environmental and lifestyle factors, comorbid conditions, and drugs. The study enrolled 694 patients with PD and 640 healthy controls from 6 neurologic centers. Data were analyzed by logistic regression models, additive interaction models, and cluster analysis. RESULTS: The simultaneous assessment of 31 putative risk/protective factors of PD showed that only coffee consumption (odds ratio [OR] 0.6; 95% confidence interval [CI] 0.4-0.9), smoking (OR 0.7, 95% CI 0.6-0.9), physical activity (OR 0.8, 95% CI 0.7-0.9), family history of PD (OR 3.2, 95% CI 2.2-4.8), dyspepsia (OR 1.8, 95% CI 1.3-2.4), and exposure to pesticides (OR 2.3, 95% CI1.3-4.2), oils (OR 5.6, 95% CI 2.3-13.7), metals (OR 2.8, 95% CI 1.5-5.4), and general anesthesia (OR 6.1, 95% CI 2.9-12.7) were independently associated with PD. There was no evidence of interaction among risk/protective factors, but cluster analysis identified 4 subtypes with different risk factor profiles. In group 1, all patients had a family history of PD, while dyspepsia or exposure to toxic agents was present in 30% of patients. In groups 2 and 3, a family history of PD was lacking, while exposure to toxic agents (group 2) and dyspepsia (group 3) played major roles. Group 4 consisted of patients with no risk factors. CONCLUSIONS: This study demonstrated that 9 factors independently modify PD risk by coexisting in the same patient rather than interacting with others. Our study suggests the need for future preventive strategies aimed at reducing the coexistence of different risk factors within the same participant.

Treatment of benign essential blepharospasm with finasteride: a case report.

We report the case of a 75-year-old man with a 35-year history of benign essential blepharospasm, which was poorly responsive to botulinum toxin. The patient had also developed Parkinson disease over the past 2 years. After his condition was diagnosed as benign prostatic hypertrophy, he started finasteride (FIN, 5 mg/d) treatment. During the following month, he experienced a significant attenuation of the severity of his dystonic symptoms; this improvement remained stable for the course of the therapy, with no notable adverse effect and no alterations of the symptoms of Parkinson disease. Discontinuation of FIN led to an abrupt exacerbation of symptoms, which was promptly reversed by resumption of the therapy. This case highlights the possibility that FIN may represent a useful therapeutic option in the treatment of certain clusters of benign essential blepharospasm.

Genetic analysis for five LRRK2 mutations in a Sardinian parkinsonian population: importance of G2019S and R1441C mutations in sporadic Parkinson's disease patients.

Mutations in the LRRK2 gene are the most common known cause of familial and sporadic Parkinson's disease (PD). Few studies performed to date to assess frequency of these mutations are actually only representative of specific areas. Here we study the frequency and clinical phenotype of LRRK2 G2019S, I2020T and R1441C/G/H mutations in 356 Sardinian patients with idiopathic PD and 208 controls. Seventeen additional subjects, relatives of PD mutated probands, were enrolled. Eight patients were mutated in heterozygosis for LRRK2 gene (2.3%): six carried the G2019S (1.7%) and two the R1441C (0.6%) mutation. Three PD patients G2019S carriers (50%) were detected in two contiguous villages comprising 3921 inhabitants while the other three (50%) were identified in the remaining population of 796,079 inhabitants. Only one mutated proband had a family history of PD. LRRK2 G2019S and R1441C mutations associated with PD were not an uncommon mutation in a Sardinian population, especially in sporadic PD patients. The detection of the G2019S variant in ten unaffected relatives confirms a reduced penetrance of the underlying mutation and might explain its prevalence among patients with sporadic PD. These findings may provide new insights into the importance of studies of frequency of LRKK2 mutations in PD patients originating from small ethnically homogeneous populations.