Novel Nanoparticles Based on N,O-Carboxymethyl Chitosan-Dopamine Amide Conjugate for Nose-to-Brain Delivery

A widely investigated approach to bypass the blood brain barrier is represented by the intranasal delivery of therapeutic agents exploiting the olfactory or trigeminal connections nose-brain. As for Parkinson’s disease (PD), characterized by dopaminergic midbrain neurons degeneration, currently there is no disease modifying therapy. Although several bio-nanomaterials have been evaluated for encapsulation of neurotransmitter dopamine (DA) or dopaminergic drugs in order to restore the DA content in parkinsonian patients, the premature leakage of the therapeutic agent limits this approach. To tackle this drawback, we undertook a study where the active was linked to the polymeric backbone by a covalent bond. Thus, novel nanoparticles (NPs) based on N,O-Carboxymethylchitosan-DA amide conjugate (N,O-CMCS-DA) were prepared by the nanoprecipitation method and characterized from a technological view point, cytotoxicity and uptake by Olfactory Ensheating Cells (OECs). Thermogravimetric analysis showed high chemical stability of N,O-CMCS-DA NPs and X-ray photoelectron spectroscopy evidenced the presence of amide linkages on the NPs surface. MTT test indicated their cytocompatibility with OECs, while cytofluorimetry and fluorescent microscopy revealed the internalization of labelled N,O-CMCS-DA NPs by OECs, that was increased by the presence of mucin. Altogether, these findings seem promising for further development of N,O-CMCS-DA NPs for nose-to-brain delivery application in PD.

The frequency and characteristics of multiple sclerosis misdiagnosis in Latin America: A referral center study in Buenos Aires, Argentina

Objective: Most contemporary data concerning the frequency and causes of multiple sclerosis (MS) misdiagnosis are from North America and Europe with different healthcare system structure and resources than countries in Latin America. We sought to determine the frequency, and potential contributors to MS misdiagnosis in patients evaluated at an MS referral center in Argentina. Methods: The study was a retrospective medical record review. We included patients evaluated at the MS Clinic at Fleni between April 2013 and March 2021. Diagnoses prior to consultation, final diagnoses after consultation, demographic, clinical and paraclinical data, and treatment were extracted and classified. Results: Seven hundred thirty-six patients were identified. Five hundred seventy-two presented with an established diagnosis of MS and after evaluation, misdiagnosis was identified in 89 (16%). Women were at 83% greater risk of misdiagnosis ( p = 0.034). The most frequent alternative diagnoses were cerebrovascular disease, radiological isolated syndrome (RIS), and headache. Seventy-four (83%) of misdiagnosed patients presented with a syndrome atypical for demyelination, 62 (70%) had an atypical brain magnetic resonance imaging (MRI), and 54 (61%) were prescribed disease-modifying therapy. Conclusion: Sixteen percent of patients with established MS were subsequently found to have been misdiagnosed. Women were at higher risk for misdiagnosis. Expert application of the McDonald criteria may prevent misdiagnosis and its associated morbidity and healthcare system cost.

GRK5 Deficiency Causes Mild Cognitive Impairment due to Alzheimer’s Disease

Prevention of Alzheimer’s disease (AD) is a high priority mission while searching for a disease modifying therapy for AD, a devastating major public health crisis. Clinical observations have identified a prodromal stage of AD for which the patients have mild cognitive impairment (MCI) though do not yet meet AD diagnostic criteria. As an identifiable transitional stage before the onset of AD, MCI should become the high priority target for AD prevention, assuming successful prevention of MCI and/or its conversion to AD also prevents the subsequent AD. By pulling this string, one demonstrated cause of amnestic MCI appears to be the deficiency of G protein-coupled receptor-5 (GRK5). The most compelling evidence is that GRK5 knockout (GRK5KO) mice naturally develop into aMCI during aging. Moreover, GRK5 deficiency was reported to occur during prodromal stage of AD in CRND8 transgenic mice. When a GRK5KO mouse was crossbred with Tg2576 Swedish amyloid precursor protein transgenic mouse, the resulted double transgenic GAP mice displayed exaggerated behavioral and pathological changes across the spectrum of AD pathogenesis. Therefore, the GRK5 deficiency possesses unique features and advantage to serve as a prophylactic therapeutic target for MCI due to AD.

Toward a Disease-Modifying Therapy of Alpha-Synucleinopathies: New Molecules and New Approaches Came into the Limelight

The accumulation of the various products of alpha-synuclein aggregation has been associated with the etiology and pathogenesis of several neurodegenerative conditions, including both familial and sporadic forms of Parkinson’s disease (PD) and dementia with Lewy bodies (DLB). It is now well established that the aggregation and spread of alpha-synuclein aggregation pathology activate numerous pathogenic mechanisms that contribute to neurodegeneration and, ultimately, to disease progression. Therefore, the development of a safe and effective disease-modifying therapy that limits or prevents the accumulation of the toxic intermediate products of alpha-synuclein aggregation and the spread of alpha-synuclein aggregation pathology could provide significant positive clinical outcomes in PD/DLB cohorts. It has been suggested that this goal can be achieved by reducing the intracellular and/or extracellular levels of monomeric and already aggregated alpha-synuclein. The principal aim of this review is to critically evaluate the potential of therapeutic strategies that target the post-transcriptional steps of alpha-synuclein production and immunotherapy-based approaches to alpha-synuclein degradation in PD/DLB patients. Strategies aimed at the downregulation of alpha-synuclein production are at an early preclinical stage of drug development and, although they have shown promise in animal models of alpha-synuclein aggregation, many limitations need to be resolved before in-human clinical trials can be seriously considered. In contrast, many strategies aimed at the degradation of alpha-synuclein using immunotherapeutic approaches are at a more advanced stage of development, with some in-human Phase II clinical trials currently in progress. Translational barriers for both strategies include the limitations of alpha-synuclein aggregation models, poor understanding of the therapeutic window for the alpha-synuclein knockdown, and variability in alpha-synuclein pathology across patient cohorts. Overcoming such barriers should be the main focus of further studies. However, it is already clear that these strategies do have the potential to achieve a disease-modifying effect in PD and DLB.

Inadequate Vaccine Responses in Children With Multiple Sclerosis

Objective: Immunizations against Hepatitis B virus (HBV) and Varicella Zoster virus (VZV), are recommended for patients with pediatric onset multiple sclerosis (POMS) and may be required prior to initiation of some disease modifying therapies. However, the efficacy of routine vaccine administration in POMS has never been studied. We sought to assess the humoral mediated vaccine response to HBV and VZV in children with POMS.Methods: A multi-center retrospective chart-based review of 62 patients with POMS was performed. Clinical data and antibody titers against HBV and VZV were collected prior to initiation of disease modifying therapy or steroids and compared to institutional control data, using t-test and chi squared analysis.Results: There were low rates of immunity against both HBV and VZV (33 and 25% respectively) among individuals with POMS. Fifteen individuals (24%) were non-immune to both. Compared to institutional control data, individuals with POMS were significantly less likely to be immune to and HBV (p = 0.003, 95% CI: 0.22–0.75) and VZV (p < 0.001, 95% CI: 0.09–0.39).Interpretation: Individuals with POMS have low rates of antibody-mediated immunity against HBV and VZV, despite receiving the appropriate vaccinations. This suggests an association between POMS and systemic immune dysregulation although further study is needed.

HLA Typing Status of Hospitalized Pediatric Patients with Sickle Cell Disease: Impact of Socioeconomics and an Initiative to Offer Typing to All Patients with Siblings

Background: Hematopoietic stem cell transplant (HSCT) using an HLA-identical sibling donor is a well-established cure for sickle cell disease (SCD). Historically, HSCT was only offered to patients with SCD who had suffered severe complications; however, given improved HSCT outcomes, it is now reasonable to consider HSCT for most patients with SCD who have an HLA-identical sibling. Thus, HLA typing of all full siblings of patients with SCD should be a clinical priority to ensure patients are aware of and have access to this therapeutic option. The primary objectives of this study are to describe the baseline prevalence of HLA typing among a cohort of hospitalized pediatric patients with SCD and to evaluate whether having had HLA typing is associated with certain characteristics. Secondarily, the study describes the acceptability of HLA typing among patients with a healthy (non-SCD) full sibling who had not already had HLA typing at baseline after dedicated outreach to these families. Methods: Between January 1, 2020 and December 31, 2020 a REDCap database of all hospitalized patients with SCD was prospectively maintained. Patient demographic and clinical information was abstracted via retrospective chart review. To evaluate socioeconomic status, a neighborhood area deprivation index (ADI) was determined for each patient using their home address and the Neighborhood Atlas website (https://www.neighborhoodatlas.medicine.wisc.edu/). ADI is a validated ranking (0-100) of Census Block Groups, considering income, education, employment, and housing quality. A higher ADI represents greater socioeconomic disadvantage. As part of a clinical outreach initiative, patients' families who had not already had typing at the time of their hospitalization were contacted to determine if the patient has a healthy full sibling and, if applicable, offer sibling HLA typing. This outreach was originally planned to occur in person at the time of hospitalization or clinic follow-up, but due the COVID-19 pandemic it was paused and when resumed conducted mostly via telephone. Results: During the 52-week study period, 291 patients with SCD were hospitalized at the study pediatric institution. Seventy-one patients (24%) had already completed HLA typing at the time of their first hospitalization during the study period. These patients with HLA typing at baseline were significantly more likely to have a diagnosis of sickle cell anemia (HbSS/HbSβ 0 genotype) and be on disease-modifying therapy (hydroxyurea or chronic transfusion) compared to patients without typing at baseline (Table). Age and sex were not significantly different between patients with and without typing (Table). The group of patients who did not have HLA typing at baseline had a significantly greater ADI (mean 29.7 vs. 24.0, p=.008) and proportion of patients with a high disadvantage ADI score ≥40 (23% vs. 10%, p=.02), Figure. Of the 220 patients with no history of HLA typing, the sibling status of 187 patients was determined via outreach to these families as of July 2021. Among these 187 patients, 81 (43%) reported having a healthy full sibling. Among these 81 patients with siblings, after being offered family HLA typing, 42 (52%) were interested and referred for HLA typing, 29 (36%) were undecided, and 10 (12%) declined typing. Conclusion: Hospitalized pediatric patients with SCD who had already been HLA typed were more likely to have a severe SCD genotype and be on disease-modifying therapy as expected. Patients who had not had HLA typing were more likely to live in a socioeconomically disadvantaged neighborhood. This finding suggests that dedicated outreach to all families regarding HLA typing is needed. Our clinical initiative to offer typing to all hospitalized patients with healthy full siblings was feasible, with a majority of families interested in pursuing HLA typing. Continued work is needed to ensure patients with SCD have equal access to curative therapy regardless of socioeconomic status. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Immunogenicity of Covid-19 Vaccination in Subjects with Myelodysplastic Syndromes

Myelodysplastic syndromes (MDS) represent a spectrum of clonal bone marrow neoplasms from low risk disease through to those transforming into acute myeloid leukaemia. The COVID-19 pandemic has presented a great risk to those with hematological malignancies who are at higher risk of severe disease and death than the general population. Previous studies looking at the immune response to influenza vaccination in those with MDS had shown promising results, with immune responses not differing from those of healthy family members. Whilst some data exist to reassure the MDS community that majority of patients show seroconversion following Covid-19 vaccination, little data exists on their neutralizing capacity or post vaccination T-cell responses in this cohort. In addition, the majority of patients in these studies received BNT162b2 and there is little published data on vaccine response to the ChAdOx1 nCoV-19 vaccine. We have investigated the humoral and T-cell response of 39 patients with MDS two to four weeks following Covid-19 booster vaccination with BNT162b2 or ChAdOx1 nCoV-19 through the SOAP study (Sars-cov-2 fOr cAncer Patients, IRAS project ID:282337). Plasma and PBMCs from MDS cases and healthy controls have been collected, and are being assessed for both humoral and cellular responses to SARS_CoV_2, the alpha (B.1.1.7) and delta (B.1.617.2) variants. Humoral responses will be assessed using ELISA (peptide binding) and functional viral neutralization assays. Cellular responses will be assessed using IFNy ELISPOT and flow cytometry (CD25 and CD69 expression) after 24h peptide stimulation. All data at time point 1 (2 - 4 weeks following booster vaccination) have been collected and will subsequently be collected at 6 months and 12 months post-vaccination. We also report on the safety data for these vaccines within this patient population. Of this cohort 64% were male with a median age of 65 years (range 21-84). 54% received vaccination with ChAdOx1 nCoV-19 and 44% received BNT162b2 (2% unrecorded). The vaccines were well tolerated with no serious adverse events to date. The mean interval between doses was 70.7 days (range 50 - 90 days). 71% of the cohort were receiving no disease modifying therapy at the time of vaccination, half of whom were receiving supportive therapy and the other half no intervention for their MDS. Of those receiving disease modifying therapy; 5 were receiving azacitidine, (1 in conjunction with low-dose cytarabine) and 3 ciclosporin. We will report the largest study of the humoral and T-cell mediated response to the Covid-19 vaccine in MDS patients to date. This will include cellular response to the delta variant and immunogenicity of both the BNT162b2 and ChAdOx1 nCoV-19 vaccines. Given the vulnerability of these patients to severe disease, investigating the immune response to the vaccines begins to build an evidence base for advising MDS patients on their ongoing risk of infection during the pandemic and going forward. The SOAP study will reassess the immune response at 6 and 12 months post-vaccination to continue to investigate post-vaccine immunity in this cohort. Disclosures Kulasekararaj: F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Speakers Bureau; Apellis: Consultancy; Akari: Consultancy, Honoraria, Speakers Bureau; Biocryst: Consultancy, Honoraria, Speakers Bureau; Achilleon: Consultancy, Honoraria, Speakers Bureau; Alexion: Consultancy, Honoraria, Speakers Bureau; Ra Pharma: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Alexion, AstraZeneca Rare Disease Inc.: Consultancy, Honoraria, Other: Travel support. Patten: JANSSEN: Honoraria; NOVARTIS: Honoraria; GILEAD SCIENCES: Honoraria, Research Funding; ROCHE: Research Funding; ASTRA ZENECA: Honoraria; ABBVIE: Honoraria.

Progressive Cerebellar Ataxia After Natalizumab Treatment

A 47-year-old woman with a history of relapsing-remitting multiple sclerosis (MS) receiving natalizumab therapy sought a second opinion regarding a recent diagnosis of secondary progressive disease. She was first diagnosed with multiple sclerosis 8 years earlier. While taking natalizumab, she was monitored for the development of antibodies to JC polyoma virus. Nine months before our evaluation, anti-JC polyoma virus antibodies became positive, with an increased index of 1.1. Given sustained remission, she was continued on natalizumab with increased surveillance and a plan to switch to a different disease-modifying therapy after 24 months. Five months later she noted subacute onset of slurred speech and right upper extremity incoordination. Over the next 4 months she continued to have clinical decline. On examination she had moderate ataxic dysarthria and right greater than left appendicular ataxia. She relied on a wheelchair for transportation and required 1-person assist to stand. Reflexes were brisk with bilateral Babinski sign. This patient with relapsing-remitting multiple sclerosis on natalizumab had a new subacute progressive cerebellar syndrome without radiographic evidence of disease activity. Repeated magnetic resonance imaging showed worsening cerebellar atrophy, right sided greater than left sided, and evolving T2 hyperintensity in the brainstem without enhancement or mass effect. JC polyoma virus polymerase chain reaction was positive. The patient was diagnosed with JC polyoma virus granule cell neuronopathy. Natalizumab was discontinued, and she was treated with 4 of 5 planned cycles of plasma exchange. After her 4th cycle, worsening symptoms developed. Magnetic resonance imaging showed gadolinium enhancement in the brainstem supportive of immune reconstitution inflammatory syndrome. She received high-dose intravenous methylprednisolone followed by a prednisone taper. Her disability progression stabilized. JC polyoma virus central nervous system infection, 1 of several infections reported among treated patients with multiple sclerosis, occurs almost exclusively in immunosuppressed patients, including those receiving disease-modifying therapy for multiple sclerosis.