Insights into the Value of Lyso-Gb1 as a Predictive Biomarker in Treatment-Naïve Patients with Gaucher Disease Type 1 in the LYSO-PROOF Study.

Gaucher disease (GD) is a rare autosomal recessive disorder arising from bi-allelic variants in the GBA1 gene, encoding glucocerebrosidase. Deficiency of this enzyme leads to progressive accumulation of the sphingolipid glucosylsphingosine (lyso-Gb1). The international, multicenter, observational "Lyso-Gb1 as a Long-term Prognostic Biomarker in Gaucher Disease"-LYSO-PROOF study succeeded in enrolling a cohort of 160 treatment-naïve GD patients from diverse geographic regions and evaluated the potential of lyso-Gb1 as a specific biomarker for GD. Using genotypes based on established classifications for clinical presentation, patients were stratified into type 1 GD (n = 114) and further subdivided into mild (n = 66) and severe type 1 GD (n = 48). Due to having previously unreported genotypes, 46 patients could not be classified. Though lyso-Gb1 values at enrollment were widely distributed, they displayed a moderate and statistically highly significant correlation with disease severity measured by the GD-DS3 scoring system in all GD patients (r = 0.602, p < 0.0001). These findings support the utility of lyso-Gb1 as a sensitive biomarker for GD and indicate that it could help to predict the clinical course of patients with undescribed genotypes to improve personalized care in the future.

HAE patient self-sampling for biomarker establishment.

BACKGROUND: Hereditary Angioedema (HAE) is a genetic disorder that leads to frequent angioedema attacks in various parts of the body. In most cases it is caused by pathogenic variants in the SERPING1 gene, coding for C1-Inhibitor (C1-INH). The pathogenic variants in the gene result in reduced C1-INH levels and/or activity, which causes aberrant bradykinin production and enhanced vascular permeability. The standard-of-care diagnostic test is performed biochemically via measuring C1-INH level and activity as well as the C4 level. This, however, does not allow for the diagnosis of HAE types with normal C1-INH. There is an urgent need to identify and characterize HAE biomarkers for facilitating diagnostics and personalizing the treatment. The Hereditary Angioedema Kininogen Assay (HAEKA) study aims to measure the dynamics of cleaved High Molecular Weight Kininogen (HKa) and other metabolite levels during the angioedema and non-angioedema state of the disease. The metabolites will be analyzed and verified by liquid chromatography ion mobility high resolution mass spectrometry (LC/IM-QToF MS) of dried blood spot (DBS) cards upon the study completion. The study design is truly innovative: 100 enrolled participants provide blood samples via DBS: (1) every 3 months within 2 years during regular study site visits and (2) by at-home self-sampling during HAE attacks via finger pricking. We are presenting a project design that permits clinical study activities during pandemic contact restrictions and opens the door for other clinical studies during COVID-19. RESULTS: As of October 2020, there are 41 patients from 5 sites in Germany enrolled. 90 blood samples were collected during the regular visits, and 19 of the participants also performed self-sampling during the HAE attacks from which a total of 286 attack blood samples were collected. Participating patients rate the study procedures as easy to implement in their daily lives. The concept of home self-sampling is effective, reproducible, and convenient especially in times of contact restrictions due to the COVID-19 pandemic. CONCLUSIONS: It is the hope that the HAEKA study will complete in 2023, reveal biomarker(s) for monitoring HAE disease activity, and may help to avoid HAE attacks via applying medication prior to the symptom onset.

C26-Ceramide as highly sensitive biomarker for the diagnosis of Farber Disease.

Farber disease (FD) is a rare autosomal recessive disease caused by mutations in the acid ceramidase gene (ASAH1). Low ceramidase activity results in the accumulation of fatty substances, mainly ceramides. Hallmark symptoms at clinical level are periarticular nodules, lipogranulomas, swollen and painful joints and a hoarse voice. FD phenotypes are heterogeneous varying from mild to very severe cases, with the patients not surviving past their first year of life. The diagnostic aspects of FD are poorly developed due to the rarity of the disease. In the present study, the screening for ceramides and related molecules was performed in Farber affected patients (n = 10), carriers (n = 11) and control individuals (n = 192). This study has the highest number of enrolled Farber patients and carriers reported to present. Liquid chromatography multiple reaction mass spectrometry (LC/MRM-MS) studies revealed that the ceramide C26:0 and especially its isoform 1 is a highly sensitive and specific biomarker for FD (p < 0.0001). The new biomarker can be determined directly in the dried blood spot extracts with low sample consumption. This allows for easy sample preparation, high reproducibility and use in high throughput screenings.

Quality of care and mortality among patients with stroke: a nationwide follow-up study.

BACKGROUND: The relationship between process and outcome measures among patients with stroke is unclear. OBJECTIVES: To examine the association between quality of care and mortality among patients with stroke in a nationwide population-based follow-up study. METHODS: Using data from The Danish National Indicator Project, a quality improvement initiative with participation of all Danish hospital departments caring for patients with stroke, we identified 29,573 patients hospitalized with stroke between January 13, 2003 and October 31, 2005. Quality of care was measured in terms of 7 specific criteria: early admission to a stroke unit, early initiation of antiplatelet or oral anticoagulant therapy, early examination with computed tomography/magnetic resonance imaging scan, and early assessment by a physiotherapist, an occupational therapist, and of nutritional risk. Data on 30- and 90-day mortality rates were obtained through the Danish Civil Registration System. RESULTS: Six of 7 of these criteria were associated with lower 30- and 90-day mortality rates. Adjusted mortality rate ratios corrected for clustering by department ranged from 0.41 to 0.83. We found indication of an inverse dose-response relationship between the number of quality of care criteria met and mortality; the lowest mortality rate was found among patients whose care met all criteria compared with patients whose care failed to meet any criteria (ie, adjusted 30-day mortality rate ratios: 0.45, 95% confidence interval: 0.24-0.66). When analyses were stratified by age and sex, the dose-response relationship was found in all subgroups. CONCLUSIONS: Higher quality of care during the early phase of stroke was associated with substantially lower mortality rates.