Relevance of genetic testing in the gene-targeted trial era: the Rostock Parkinson's disease study.

Estimates of the spectrum and frequency of pathogenic variants in Parkinson's disease (PD) in different populations are currently limited and biased. Furthermore, although therapeutic modification of several genetic targets has reached the clinical trial stage, a major obstacle in conducting these trials is that PD patients are largely unaware of their genetic status and, therefore, cannot be recruited. Expanding the number of investigated PD-related genes and including genes related to disorders with overlapping clinical features in large, well-phenotyped PD patient groups is a prerequisite for capturing the full variant spectrum underlying PD and for stratifying and prioritizing patients for gene-targeted clinical trials. The Rostock Parkinson's disease (ROPAD) study is an observational clinical study aiming to determine the frequency and spectrum of genetic variants contributing to PD in a large international cohort. We investigated variants in 50 genes with either an established relevance for PD or possible phenotypic overlap in a group of 12 580 PD patients from 16 countries [62.3% male; 92.0% White; 27.0% positive family history (FH+), median age at onset (AAO) 59 years] using a next-generation sequencing panel. Altogether, in 1864 (14.8%) ROPAD participants (58.1% male; 91.0% White, 35.5% FH+, median AAO 55 years), a PD-relevant genetic test (PDGT) was positive based on GBA1 risk variants (10.4%) or pathogenic/likely pathogenic variants in LRRK2 (2.9%), PRKN (0.9%), SNCA (0.2%) or PINK1 (0.1%) or a combination of two genetic findings in two genes (∼0.2%). Of note, the adjusted positive PDGT fraction, i.e. the fraction of positive PDGTs per country weighted by the fraction of the population of the world that they represent, was 14.5%. Positive PDGTs were identified in 19.9% of patients with an AAO ≤ 50 years, in 19.5% of patients with FH+ and in 26.9% with an AAO ≤ 50 years and FH+. In comparison to the idiopathic PD group (6846 patients with benign variants), the positive PDGT group had a significantly lower AAO (4 years, P = 9 × 10-34). The probability of a positive PDGT decreased by 3% with every additional AAO year (P = 1 × 10-35). Female patients were 22% more likely to have a positive PDGT (P = 3 × 10-4), and for individuals with FH+ this likelihood was 55% higher (P = 1 × 10-14). About 0.8% of the ROPAD participants had positive genetic testing findings in parkinsonism-, dystonia/dyskinesia- or dementia-related genes. In the emerging era of gene-targeted PD clinical trials, our finding that ∼15% of patients harbour potentially actionable genetic variants offers an important prospect to affected individuals and their families and underlines the need for genetic testing in PD patients. Thus, the insights from the ROPAD study allow for data-driven, differential genetic counselling across the spectrum of different AAOs and family histories and promote a possible policy change in the application of genetic testing as a routine part of patient evaluation and care in PD.

The Rostock International Parkinson's Disease (ROPAD) Study: Protocol and Initial Findings.

BACKGROUND: Genetic stratification of Parkinson's disease (PD) patients facilitates gene-tailored research studies and clinical trials. The objective of this study was to describe the design of and the initial data from the Rostock International Parkinson's Disease (ROPAD) study, an epidemiological observational study aiming to genetically characterize ~10,000 participants. METHODS: Recruitment criteria included (1) clinical diagnosis of PD, (2) relative of participant with a reportable LRRK2 variant, or (3) North African Berber or Ashkenazi Jew. DNA analysis involved up to 3 successive steps: (1) variant (LRRK2) and gene (GBA) screening, (2) panel sequencing of 68 PD-linked genes, and (3) genome sequencing. RESULTS: Initial data based on the first 1360 participants indicated that the ROPAD enrollment strategy revealed a genetic diagnostic yield of ~14% among a PD cohort from tertiary referral centers. CONCLUSIONS: The ROPAD screening protocol is feasible for high-throughput genetic characterization of PD participants and subsequent prioritization for gene-focused research efforts and clinical trials. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

LIPAD (LRRK2/Luebeck International Parkinson's Disease) Study Protocol: Deep Phenotyping of an International Genetic Cohort.

Background: Pathogenic variants in the Leucine-rich repeat kinase 2 (LRRK2) gene are the most common known monogenic cause of Parkinson's disease (PD). LRRK2-linked PD is clinically indistinguishable from idiopathic PD and inherited in an autosomal dominant fashion with reduced penetrance and variable expressivity that differ across ethnicities and geographic regions. Objective: To systematically assess clinical signs and symptoms including non-motor features, comorbidities, medication and environmental factors in PD patients, unaffected LRRK2 pathogenic variant carriers, and controls. A further focus is to enable the investigation of modifiers of penetrance and expressivity of LRRK2 pathogenic variants using genetic and environmental data. Methods: Eligible participants are invited for a personal or online examination which comprises completion of a detailed eCRF and collection of blood samples (to obtain DNA, RNA, serum/plasma, immune cells), urine as well as household dust. We plan to enroll 1,000 participants internationally: 300 with LRRK2-linked PD, 200 with LRRK2 pathogenic variants but without PD, 100 PD patients with pathogenic variants in the GBA or PRKN genes, 200 patients with idiopathic PD, and 200 healthy persons without pathogenic variants. Results: The eCRF consists of an investigator-rated (1 h) and a self-rated (1.5 h) part. The first part includes the Movement Disorder Society Unified Parkinson's Disease Rating, Hoehn &Yahr, and Schwab & England Scales, the Brief Smell Identification Test, and Montreal Cognitive Assessment. The self-rating part consists of a PD risk factor, food frequency, autonomic dysfunction, and quality of life questionnaires, the Pittsburgh Sleep Quality Inventory, and the Epworth Sleepiness as well as the Hospital Anxiety and Depression Scales. The first 15 centers have been initiated and the first 150 participants enrolled (as of March 25th, 2021). Conclusions: LIPAD is a large-scale international scientific effort focusing on deep phenotyping of LRRK2-linked PD and healthy pathogenic variant carriers, including the comparison with additional relatively frequent genetic forms of PD, with a future perspective to identify genetic and environmental modifiers of penetrance and expressivity Clinical Trial Registration:ClinicalTrials.gov, NCT04214509.

Immune responses in mice after immunization with antigens from different stages of the parasite Schistosoma mansoni.

Mice responses to immunization with Schistosoma mansoni antigens were investigated. Priming with cercarial antigen preparation (CAP) induced significant (P < 0.05) IgM, IgG, IgG2a, IgG2b, and IgA increases, while booster caused a significant IgG1 increase. A soluble worm antigen preparation (SWAP) caused significant IgG elevation. Priming with soluble egg antigen (SEA) caused significant IgM and IgG2a increases, while booster induced significant IgM, IgG and IgA increases. CAP-immunized mice sera (IMS) recognized CAP peptides ranging from 23-78 kDa. SWAP-IMS recognized SWAP peptides ranging from 40-75 kDa. SEA-IMS recognized SEA peptides ranging from 33-101 kDa. The cross-reactive peptides among the 3 antigens were identified. CAP caused significant increases in mesenteric lymph nodes (MLNs) CD(4,8)+, B lymphocytes, CD8+ thymocytes, CD4+ T and B splenocytes. SWAP priming caused significant increases in MLNs CD(4,8)+ thymocytes and B splenocytes. SWAP booster caused significant increases in MLNs CD8+ T and B lymphocytes, CD(4,8)+ thymocytes and CD4+ T and B splenocytes. SEA caused significant increase in CD4+ T cells.

Rapid Large-Scale COVID-19 Testing During Shortages.

The Coronavirus disease 2019 (COVID-19) pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) has resulted in economic and social lockdowns in most countries all over the globe. Early identification of infected individuals is regarded as one of the most important prerequisites for fighting the pandemic and for returning to a 'New Normal'. Large-scale testing is therefore crucial, but is facing several challenges including shortage of sample collection tools and of molecular biological reagents, and the need for safe electronic communication of medical reports. We present the successful establishment of a holistic SARS-CoV-2 testing platform that covers proband registration, sample collection and shipment, sample testing, and report issuing. The RT-PCR-based virus detection, being central to the platform, was extensively validated: sensitivity and specificity were defined as 96.8% and 100%, respectively; intra-run and inter-run precision were <3%. A novel type of sample swab and an in-house-developed RNA extraction system were shown to perform as good as commercially available products. The resulting flexibility guarantees independence from the current bottlenecks in SARS-CoV-2 testing. Based on our technology, we offered testing at local, national, and global levels. In the present study, we report the results from approx. 18,000 SARS-CoV-2 tests in almost 10,000 individuals from a low-frequency SARS-CoV-2 pandemic area in a homogenous geographical region in north-eastern Germany for a period of 10 weeks (21 March to 31 May 2020). Among the probands, five SARS-CoV-2 positive cases were identified. Comparative analysis of corresponding virus genomes revealed a diverse origin from three of the five currently recognized SARS-CoV-2 phylogenetic clades. Our study exemplifies how preventive SARS-CoV-2 testing can be set up in a rapid and flexible manner. The application of our test has enabled a safe maintenance/resume of critical local infrastructure, e.g., nursing homes where more than 5000 elderlies and caretakers got tested. The strategy outlined by the present study may serve as a blueprint for the implementation of large-scale preventive SARS-CoV-2 testing elsewhere.

Cross-reactivity of Schistosoma mansoni-Fasciola gigantica influenced by saponins.

The aim of the present work was to investigate the Schistosoma mansoni and Fasciola gigantica cross-reactivity between adult worms and egg homogenates of the parasites. Immunoprophylactic effects of crude Schistosoma mansoni worms and egg antigens mixed with or without saponins extracted from Atriplex nummularia were studied followed by challenge with 80 cercariae of Schistosoma mansoni. Our results showed that post 1st immunization with schistosome egg antigens (SEA) there was a significant change (P approximately 0.05) in the IgM levels against Fasciola egg homogenate (FgEH) without saponins. Post 2nd immunization with SEA mixed with saponins the levels of IgM increased significantly (P approximately 0.05) against Fasciola worm homogenate (FgWH) as compared with a non-immunized group. Post 2nd immunization the level of IgG was significantly elevated (P approximately 0.05) by SEA mixed with saponins against FgWH. Post 2nd immunizations with SEA mixed with saponins showed a significant change (P approximately 0.05) in IgG levels against FgEH. These results clearly demonstrated that there is a cross-reactivity between Schistosoma mansoni eggs and Fasciola gigantica worms and eggs. Saponins were found to be immunostimulatory adjuvants in our study.

Escherichia coli shares T- and B-lymphocyte epitopes with Schistosoma mansoni.

BACKGROUND: In this study, we tested the cross-reaction between crude Escherichia coli antigen (ECA) and 3 crude Schistosoma mansoni antigens. METHODOLOGY: The schistosomal antigens used were cercarial antigen preparation (CAP), soluble worm antigen preparation (SWAP), and soluble egg antigen (SEA). Four groups each of 3 mice received 2 intraperotineal immunizations with the above-mentioned antigens at a two-week interval. The dose of the ECA was 20 microg/100 microl PBS/mouse and that of any of the used schistosomal antigens was 50 microg/100 microl PBS/mouse. IgM and IgG reactivities and cross-reactivities were tested in individual immunized mice sera (IMS) against the above-mentioned antigens by ELISA and Western blotting. The changes in the B, CD4+ and CD8+ -T cells' counts post immunization were recorded. RESULTS: Priming with ECA caused significant increases in IgM (P<0.05) against CAP and SWAP, while both priming and boosting with ECA caused a significant elevation in the IgG only against SWAP. Priming and boosting with ECA or schistosomal antigens caused significant increases in IgM against ECA. Priming with ECA or SWAP caused significant elevation in IgG against ECA. In Western blotting, ECA-IMS recognized 16, 33, 38 and 94 kDa ECA peptides that cross-reacted with CAP-IMS. ECA peptides at 30 and 38 kDa cross-reacted among ECA, SWAP and SEA-IMS. CAP peptides at 40, 71, 85 and 97 kDa cross-reacted with ECA-IMS. A 59 kDa SWAP peptide cross-reacted with ECA. SEA peptides at approximately 55, 96 and 101 kDa cross-reacted with ECA-IMS. Immunization with ECA, CAP, SWAP or SEA caused significant increases in mesentric lymph nodes (MLN)-CD4+, CD8+ -T cells and MLN-B cells. For thymocytes, CD4+ -T cells significantly increased upon immunization with ECA and SWAP while CD8+-T cells significantly increased upon immunization with SWAP. CONCLUSION: It is necessary to include E. coli antigens as controls while establishing schistosomal antigens-based diagnostic tests to ensure the specificity of the detected immune responses. Characterization of the cross-reactive ECA antigens with protective potential against S. mansoni infection remains a future research objective.