Anti-neurochondrin antibody as a biomarker in primary autoimmune cerebellar ataxia-a case report and review of the literature

BACKGROUND AND PURPOSE

Neuronal autoantibodies can support the diagnosis of primary autoimmune cerebellar ataxia (PACA). Knowledge of PACA is still sparce. This article aims to highlight the relevance of anti-neurochondrin antibodies and possible therapeutical consequences in people with PACA.

METHODS

This is a case presentation and literature review of PACA associated with anti-neurochondrin antibodies.

RESULTS

A 33-year-old man noticed reduced control of the right leg in May 2020. During his first clinic appointment at our institution in September 2021, he complained about gait imbalance, fine motor disorders, tremor, intermittent diplopia and slurred speech. He presented a pancerebellar syndrome with stance, gait and limb ataxia, scanning speech and oculomotor dysfunction. Within 3 months the symptoms progressed. An initial cerebral magnetic resonance imaging, June 2020, was normal, but follow-up imaging in October 2021 and July 2022 revealed marked cerebellar atrophy (29% volume loss). Cerebrospinal fluid analysis showed lymphocytic pleocytosis of 11 x 10³ /L (normal range 0-4) and oligoclonal bands type II. Anti-neurochondrin antibodies (immunoglobulin G) were detected in serum (1:10,000) and cerebrospinal fluid (1:320, by cell-based indirect immunofluorescence assay and immunoblot, analysed by the EUROIMMUN laboratory). After ruling out alternative causes and neoplasia, diagnosis of PACA was given and immunotherapy (steroids and cyclophosphamide) was started in January 2022. In March 2022 a stabilization of disease was observed.

CONCLUSION

Cerebellar ataxia associated with anti-neurochondrin antibodies has only been described in 19 cases; however, the number of unrecognized PACAs may be higher. As anti-neurochondrin antibodies target an intracellular antigen and exhibit a mainly cytotoxic T-cell-mediated pathogenesis, important therapeutic implications may result. Because of the severe and rapid clinical progression, aggressive immunotherapy was warranted. This case highlights the need for rapid diagnosis and therapy in PACA, as stabilization and even improvement of symptoms are attainable.

Evaluating nanobiomaterial-induced DNA strand breaks using the alkaline comet assay

Due to their unique chemical and physical properties, nanobiomaterials (NBMs) are extensively studied for applications in medicine and drug delivery. Despite these exciting properties, their small sizes also make them susceptible to toxicity. Whilst nanomaterial immunotoxicity and cytotoxicity are studied in great depth, there is still limited data on their potential genotoxicity or ability to cause DNA damage. In the past years, new medical device regulations, which came into place in 2020, were developed, which require the assessment of long-term NBM exposure; therefore, in recent years, increased attention is being paid to genotoxicity screening of these materials. In this article, and through an interlaboratory comparison (ILC) study conducted within the Horizon 2020 REFINE project, we assess five different NBM formulations, each with different uses, namely, a bio-persistent gold nanoparticle (AuNP), an IR-780 dye-loaded liposome which is used in deep tissue imaging (LipImage™815), an unloaded PACA polymeric nanoparticle used as a drug delivery system (PACA), and two loaded PACA NBMs, i.e. the cabazitaxel drug-loaded PACA (CBZ-PACA) and the NR668 dye-loaded PACA (NR668 PACA) for their potential to cause DNA strand breaks using the alkaline comet assay and discuss the current state of genotoxicity testing for nanomaterials. We have found through our interlaboratory comparison that the alkaline comet assay can be suitably applied to the pre-clinical assessment of NBMs, as a reproducible and repeatable methodology for assessing NBM-induced DNA damage.

Implementation and Initial Analysis of a Laboratory-Based Weekly Biosurveillance System, Provence-Alpes-Côte d'Azur, France

We describe the implementation of an automated infectious disease surveillance system that uses data collected from 210 microbiologic laboratories throughout the Provence-Alpes-Côte d’Azur region in France. Each week, these facilities report bacterial species that have been isolated from patients in their area. An alarm is triggered whenever the case count for a bacterial species infection exceeds 2 SDs of the historical mean for that species at the participating laboratory. At its inception in July 2013, the system monitored 611 bacterial species. During July 1, 2013–March 20, 2016, weekly analyses of incoming surveillance data generated 34 alarms signaling possible infectious disease outbreaks; after investigation, 14 (41%) of these alarms resulted in health alerts declared by the regional health authority. We are currently improving the system by developing an Internet-based surveillance platform and extending our surveillance to include more laboratories in the region.

Cytotoxicity of Poly(Alkyl Cyanoacrylate) Nanoparticles

Although nanotoxicology has become a large research field, assessment of cytotoxicity is often reduced to analysis of one cell line only. Cytotoxicity of nanoparticles is complex and should, preferentially, be evaluated in several cell lines with different methods and on multiple nanoparticle batches. Here we report the toxicity of poly(alkyl cyanoacrylate) nanoparticles in 12 different cell lines after synthesizing and analyzing 19 different nanoparticle batches and report that large variations were obtained when using different cell lines or various toxicity assays. Surprisingly, we found that nanoparticles with intermediate degradation rates were less toxic than particles that were degraded faster or more slowly in a cell-free system. The toxicity did not vary significantly with either the three different combinations of polyethylene glycol surfactants or with particle size (range 100–200 nm). No acute pro- or anti-inflammatory activity on cells in whole blood was observed.

Advances in nanomedicines for malaria treatment

Malaria is an infectious disease that mainly affects children and pregnant women from tropical countries. The mortality rate of people infected with malaria per year is enormous and became a public health concern. The main factor that has contributed to the success of malaria proliferation is the increased number of drug resistant parasites. To counteract this trend, research has been done in nanotechnology and nanomedicine, for the development of new biocompatible systems capable of incorporating drugs, lowering the resistance progress, contributing for diagnosis, control and treatment of malaria by target delivery. In this review, we discussed the main problems associated with the spread of malaria and the most recent developments in nanomedicine for anti-malarial drug delivery.

Nanocarriers for intravenous injection--the long hard road to the market

Nanodispersed drug delivery systems for the intravenous injection have successfully overcome the hurdle of drug approval in the European Union and the United States. Although there is a need for highly advanced nanocarrier devices they have not been the result of a rational formulation design but were developed as stand-alone products in a long chain of case-by-case studies. This review focuses on aspects in development, composition, and manufacture of these innovative dosage forms that are relevant for the translation into new drug products.