Author Profile

Michael Orth

Affiliation: Department of Neurology, University of Ulm, Ulm, Germany

Recent Posts

Age-at-onset in Huntington disease

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Background: In Huntington disease, the accurate determination of age-at-onset is critical to identify modifiers and therapies that aim to delay it.

Methods: Retrospective data from the European Huntington’s Disease Network’s REGISTRY. Data (age, gender, CAG repeat length, parent affected, and Unified Huntington’s Disease Rating Scale motor score, total functional capacity) from at least three visits in 423 REGISTRY participants were included. Data based extrapolations of individual age-at-onset using generalized linear mixed models based on individual slopes of motor score or total functional capacity, and predictions using the Langbehn, or Ranen formula, were compared with clinicians’ estimates.

Results: Concordance was best for the calculated onset using the REGISTRY UHDRS longitudinal motor scores. For total functional capacity, the investigator’s estimate was 4 years before the data derived age-at-onset. The concordance of predictions of probability of age-at-onset was ±20 years (difference in 25%tile).

Conclusions: Estimating or predicting age-at-onset in Huntington disease may be inaccurate. It can be useful to 1) add in the manifest population motor score regression derived age-at-onset as additional motor onset and 2) add total functional capacity regression derived age-at-onset for the onset of functional impact of Huntington disease when patients are in mid- to late-stage.

Abnormal peripheral chemokine profile in Huntington’s disease

Huntington’s disease (HD) is an inherited neurodegenerative disorder characterized by both neurological and systemic abnormalities. Immune activation is a well-established feature of the HD brain and we have previously demonstrated a widespread, progressive innate immune response detectable in plasma throughout the course of HD. In the present work we used multiplex ELISA to quantify levels of chemokines in plasma from controls and subjects at different stages of HD. We found an altered chemokine profile tracking with disease progression, with significant elevations of five chemokines (eotaxin-3, MIP-1β, eotaxin, MCP-1 and MCP-4) while three (eotaxin-3, MIP-1β and eotaxin) showed significant linear increases across advancing disease stages. We validated our results in a separate sample cohort including subjects at different stages of HD. Here we saw that chemokine levels (MCP-1 and eotaxin) correlated with clinical scores. We conclude that, like cytokines, chemokines may be linked to the pathogenesis of HD, and that immune molecules may be valuable in tracking and exploring the pathogenesis of HD.

Observing Huntington’s Disease: the European Huntington’s Disease Network’s REGISTRY

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Background: Huntington’s disease (HD) is a rare triplet repeat (CAG) disorder. Advanced, multi-centre, multi-national research frameworks are needed to study simultaneously multiple complementary aspects of HD. This includes the natural history of HD, its management and the collection of clinical information and biosamples for research.
Methods: We report on cross-sectional data of the first 1766 participants in REGISTRY, the European Huntington’s Disease Network’s (EHDN), multi-lingual, multi-national prospective observational study of HD in Europe. Data collection (demographics, phenotype, genotype, medication, co-morbidities, biosamples) followed a standard protocol.
Results: Phenotype, and the HD genotype, of manifest HD participants across different European regions was similar. Motor onset was most common (48%) with a non-motor onset in more than a third of participants. Motor signs increased, and cognitive abilities and functional capacity declined as the disease burden (CAGn-35.5) X age) increased. A life-time history of behavioural symptoms was common, but the behavioural score was not related to disease burden. One fifth of participants had severe psychiatric problems, e.g. suicidal ideation and attempts, and/or irritability/aggression, with psychosis being less common. Participants on anti-dyskinetic medication had a higher motor and lower cognitive score, were older, and more prone to physical trauma. A higher motor and a lower cognitive score predicted more advanced disease.
Conclusions: The unparalleled collection of clinical data and biomaterials within the EHDN’s REGISTRY can expedite the search for disease modifiers (genetic and environmental) of age at onset and disease progression that could be harnessed for the development of novel treatments.