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Helen Tremlett

Publications and source records attributed to Helen Tremlett.

10 recordsLinked to original sources
PubMed2026

Disease-modifying therapy uptake in a pediatric-onset multiple sclerosis population, British Columbia, Canada.

BACKGROUND: The treatment of pediatric-onset multiple sclerosis (POMS) is evolving as disease-modifying therapies (DMTs) undergo pediatric clinical trials. However, most DMTs remain off-label in children resulting in barriers to access and variability in treatment patterns across jurisdictions. The aim of this study was to describe trends in DMT uptake in POMS in British Columbia, Canada. METHODS: We utilized linked clinical and administrative datasets to identify MS with onset <18&#xa0;years-of-age and assess DMT uptake from dispensed prescriptions between January 1, 1996 and March 1, 2020 in British Columbia, Canada. RESULTS: Of 173 POMS cases (median follow-up&#xa0;=&#xa0;11.5&#xa0;years), 32 (18%) filled a DMT prescription <18&#xa0;years-of-age; 76 (44%) did so at any age. Moderate-efficacy therapies (beta-interferons/glatiramer acetate/teriflunomide/dimethyl fumarate) were the initial DMT in 60 cases (79%) overall, however by the end of follow-up a high-efficacy therapy was the most recent DMT dispensed for 52/76 cases (68%). After 2016, anti-CD20 monoclonal antibodies became the most common DMT class dispensed. CONCLUSIONS: Moderate-efficacy therapies were the more common initial DMT dispensed for individuals with POMS, but more than two-thirds eventually received a high-efficacy therapy. Only a minority of POMS cases were first dispensed a DMT under age 18&#xa0;years.

Disease modifying therapies↗
PubMed2026

Proportionality-based association metrics in count compositional data.

Compositional data comprise vectors that describe the constituent parts of a whole. Data arising from various -omics platforms such as 16S and RNA sequencing are compositional in nature. In this kind of data, correlations between features on raw counts have no meaningful interpretation. Metrics of proportionality were formulated to address this problem. However, an inherent bias arises when these metrics are calculated empirically on count-based measures due to variability in read depths. We quantify the bias introduced by empirically calculating proportionality-based association metrics in count data. Additionally, we propose a means of estimating these metrics within a logit-normal multinomial model in pursuit of more accurate estimates. The model-based estimates are shown to outperform empirical estimates in simulated data and are applied to a mouse embryonic stem cell single-cell sequencing dataset, as well as a pediatric-onset multiple sclerosis metagenomic dataset.

Animals↗
PubMed2006

Is late-onset multiple sclerosis associated with a worse outcome?

OBJECTIVE: To describe the characteristics of late-onset multiple sclerosis (MS) (LOMS, 50+ years) vs adult-onset MS (AOMS, 16 to <50 years) and examine prognosis and associated risk factors. METHODS: Patients with definite MS, onset prior to July 1988, registered with a BCMS clinic before July 1998, with at least one Expanded Disability Status Scale (EDSS) score, were selected from the longitudinal population-based British Columbian (BC) MS database. Clinical and demographic characteristics were compared between LO and AOMS. Progression was measured as time to reach sustained EDSS 6 and potential risk factors examined were sex, disease course (primary progressive [PP] vs relapsing [R]), and onset symptoms. RESULTS: Of those eligible (n = 2,837), LOMS comprised 132 (4.7%), with PPMS predominating (54.5% vs 10.6% in AOMS, p < 0.0005). Motor onset symptoms were more prevalent in LOMS and sensory and optic neuropathy more prevalent in AOMS (p < 0.0005). AOMS averaged 27.7 years (95% CI: 26.3 to 29.1) to EDSS 6 from onset vs 16.9 years (95% CI: 9.0 to 24.8) in LOMS, p < 0.0005. However, AOMS was associated with a younger age at EDSS 6 (58.4 years [95% CI: 57.1 to 59.6] vs 71.2 years [95% CI: 65.2 to 77.3] in LOMS, p < 0.0005). There were no differences in progression between AO or LO for those with PPMS (p = 0.373) or R-MS (p = 0.438), although considerable variation was observed. CONCLUSIONS: Late-onset multiple sclerosis (LOMS) is not necessarily associated with a worse outcome: first, progression in the primary progressive or relapsing patients differed little between late-onset vs adult-onset; secondly, those with LOMS were older when reaching Expanded Disability Status Scale 6. The disease course has a far greater implication for disease prognosis than the presence of LOMS.

Adolescent↗
PubMed2006

Disability progression in multiple sclerosis is slower than previously reported.

OBJECTIVE: To investigate disease progression and risk factors in a large geographically based population with multiple sclerosis (MS), using two different inception points--clinical onset and date of birth. METHODS: The authors reviewed a database of subjects with definite MS and symptom onset prior to July 1988. The main outcome was sustained progression to Expanded Disability Status Scale (EDSS) 6 (requires a cane), using the date of birth and date of MS onset as inception points in separate analyses. Risk factors examined were sex, relapsing vs primary progressive course, onset age, and onset symptoms. RESULTS: The study included 2,837 patients, followed prospectively for 22,723 patient years. The median time to EDSS 6 was 27.9 years, 15 years after onset; only 21% reached EDSS 6, and by age 50, 28% required a cane. Men progressed 38% more quickly than women from onset (p < 0.0005), yet both required canes at similar ages: 58.8 years for men and 60.1 for women (p = 0.082). A younger onset age predicted a slower progression, but those older at onset were consistently older when reaching EDSS 6. A primary progressive course predicted a more rapid progression from both onset (p < 0.0005) and birth (hazard ratio = 2.7 [95% CI: 2.2 to 3.3]). No onset symptom consistently predicted progression. CONCLUSION: Disability progression in multiple sclerosis (MS) accrued more slowly than found in earlier longitudinal studies. The authors also challenged two fundamental concepts in MS, demonstrating that neither male sex nor older onset age was associated with worse disease outcome.

Adult↗
PubMed2005

The natural history of primary progressive MS in British Columbia, Canada.

BACKGROUND: Primary progressive multiple sclerosis (PPMS) has a distinct clinical phenotype and has historically been understudied with few longitudinal natural history studies spanning a reasonable time period. The authors examined patient characteristics, disease progression, and associated risk factors in the PP population of British Columbia, Canada. METHOD: The authors report on the PP population from an upcoming publication of the natural history study of definite MS in British Columbia, Canada. The main outcome was sustained progression to Expanded Disability Status Scale (EDSS) 6, secondary outcome time to EDSS 8. Risk factors for progression included sex, onset age, onset symptoms, and for time to EDSS 8, time to EDSS 6. RESULTS: Of the 2,837 patients with definite MS in the original study, 352 (12.4%) had PPMS. Mean disease duration was 17.2 years (0.3 to 49.6 years), mean onset age was 40.1 years (SD 11.5), and 53% (187) were female. One-quarter of the population had reached EDSS 6 after 7.3 years from onset, yet another 25% still did not require a cane after 25 years. Sex, onset age, and onset symptoms did not predict progression (p > 0.05). A shorter time to EDSS 6 predicted a shorter time to EDSS 8 (p < 0.0005). DISCUSSION: Progression of disability was slower than found in previous primary progressive multiple sclerosis natural history studies. However, considerable variation existed, with few predictors, other than "sooner to cane, sooner to wheelchair."

Adult↗
PubMed2004

Hepatic injury, liver monitoring and the beta-interferons for multiple sclerosis.

This review explores the salient issues surrounding liver injury and liver monitoring associated with beta-interferon (IFNB) treatment for multiple sclerosis (MS). Post-marketing studies have found a higher proportion of IFNB-treated MS patients with elevated aminotransferases than reported in the pivotal clinical trials. Although the risk of severe liver injury appears small, the true incidence is unknown. Post-marketing studies have shown that the greatest period of risk for the development of liver test abnormalities appears to be in the first year of IFNB treatment. The risk also increases with the more frequently administered, higher-dosage IFNBs. Males are more likely than females to develop elevated aminotransferases (> upper normal limit), although females appear at a greater risk of severe liver injury. Of the commonly used biochemical liver tests, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AP) and bilirubin appear the most useful for routine monitoring of IFNB treatment. Whilst many other factors can affect liver test results, including obesity, alcohol, concomitant medications, co-morbidities and theoretically even MS itself, regular liver testing both prior and during IFNB therapy might help minimise Type A or dose/frequency dependent aminotransferase elevations. However, testing will probably not prevent the Type B idiosyncratic reactions which can result in severe hepatic injury; hence patients need to be aware, and to report hepatic side effects promptly.

Aspartate Aminotransferases↗