Increasing incidence and prevalence of multiple sclerosis in the Greater Hobart cohort of Tasmania, Australia.

BACKGROUND: The Greater Hobart region (42.5°S) of Tasmania has consistently had the highest recorded prevalence and incidence rates of multiple sclerosis (MS) in Australia. We reassessed MS epidemiology in 2009-2019 and assessed longitudinal changes over 68 years. METHODS: Cases recruited from clinic-based datasets and multiple other data sources. 2019 prevalence and 2009-2019 annual incidence and mortality rates estimated, and differences assessed using Poisson regression. RESULTS: 436 MS cases resident on prevalence day were identified, and 130 had symptom onset within 2009-2019. Prevalence 197.1/100 000 (95% CI 179.4 to 216.5; 147.2/100 000 age standardised, 95% CI 126.5 to 171.3), a 36% increase since 2001 and 3.1-fold increase since 1961. 2009-2019 incidence rate=5.9/100 000 person-years, 95% CI 5.0 to 7.0 (6.1/1000 000 age standardised, 95% CI 4.7 to 7.9), a 2.8-fold increase since 1951-1961 and 65% since 2001-2009. 2009-2019 mortality rate=1.5/100 000 person-years, 95% CI 1.1 to 2.2 (0.9/100 000 age standardised, 95% CI 0.4 to 1.7), comparable to 2001-2009 (1.0/100 000) but reduced by 61% from 1951 to 1959 (2.1/100 000). 2001-2009 standardised mortality ratio=1.0 in 2009-2019, decreased from 2.0 in 1971-1979. Female:male prevalence sex ratio was 2.8, comparable to the 2009 value (2.6); incidence sex ratio (2.9) increased from 2001 to 9 (2.1). Comparisons with Newcastle, Australia (latitude=32.5°S) demonstrate a near complete abrogation of the latitudinal gradients for prevalence (ratio=1.0) and incidence (ratio=1.1), largely attributable to changing Hobart demography. CONCLUSIONS: Prevalence and incidence of MS continue to increase significantly in Hobart, alongside marked reductions in mortality and increased case longevity. The marked increase in incidence is of particular note and may reflect longstanding changes in MS risk behaviours including changing sun exposure, obesity rates, and smoking behaviours, particularly in females. Falling mortality contributes to increase longevity and prevalence, likely reflecting improved overall MS healthcare and implementation of disease-modifying therapy.

Predicting Infection Risk in Multiple Sclerosis Patients Treated with Ocrelizumab: A Retrospective Cohort Study.

BACKGROUND: Ocrelizumab safety outcomes have been well evaluated in clinical trials and open-label extension (OLE) studies. However, risk factors for infection in patients with multiple sclerosis (MS) receiving ocrelizumab have not been extensively studied in the real-world setting. OBJECTIVE: The aim of this study was to examine factors determining risk of self-reported infections and antimicrobial use in patients receiving ocrelizumab for MS. METHODS: A retrospective, observational cohort study was conducted in patients receiving ocrelizumab at the Royal Melbourne Hospital. Infection type and number were reported by patients, and the associations of potential clinical and laboratory risk factors with self-reported infection and antimicrobial use were estimated using univariate and multivariable logistic regression models. RESULTS: A total of 185 patients were included in the study; a total of 176 infections were reported in 89 patients (46.1%), and antimicrobial use was identified in 47 patients (25.3%). In univariate analyses, a higher serum IgA was associated with reduced odds of infection (OR 0.44, 95% CI 0.25-0.76). In multivariable analyses, older age (OR 0.94, 95% CI 0.88-0.99), higher serum IgA (OR 0.37, 95% CI 0.17-0.80) and higher serum IgG (OR 0.81, 95% CI 0.67-0.99) were associated with reduced odds of infection. Older age (OR 0.85, 95% CI 0.75-0.96) and higher serum IgA (OR 0.23, 95% CI 0.07-0.79) were associated with reduced odds of antimicrobial use, whilst longer MS disease duration (OR 1.22, 95% CI 1.06-1.41) and higher Expanded Disability Status Scale (EDSS) score (OR 1.99, 95% CI 1.02-3.86) were associated with increased odds of antimicrobial use. CONCLUSIONS: Higher serum IgA and IgG and older age were associated with reduced odds of infection. Our findings highlight that infection risk is not uniform in patients with MS receiving ocrelizumab and substantiate the need to monitor immunoglobulin levels pre-treatment and whilst on therapy.

Evaluating the perspective of patients with MS and related conditions on their DMT in relation to the COVID-19 pandemic in one MS centre in Australia.

OBJECTIVE: Patients with Multiple Sclerosis (MS) and on disease modifying therapies (DMTs) that can be immunosuppressive or immunomodulatory form a special group where risk of continuation of DMT needs to be taken into account with risk of contracting Covid-19. This concept can pose a degree of anxiety for patients as well as neurologists. We aimed to evaluate patient perspectives regarding the use of Natalizumab and anti-CD20 therapies (Rituximab and Ocrelizumab) in the context of the COVID-19 pandemic. METHODS: cross-sectional study conducted via voluntary survey filled in by patients with MS and related disorders receiving their infusional treatment in one MS centre in Australia, exploring their concerns regarding their therapy, their therapy and COVID-19, precautions undertaken in response to the pandemic, and factors impacting their decision-making. RESULTS: 170 patients completed the survey. Of patients on Natalizumab, the majority had either no or mild concern regarding their DMT and COVID-19, and of patients on B-cell depleting therapies, again, the majority had no or mild concern, though a slightly higher proportion had a moderate level of concern. Asked to delineate their concerns, an increased risk of contracting COVID-19 was more commonly conveyed than MS-specific factors or poor outcomes pertaining to COVID-19 if contracted, by patients in both groups. Conversely, being invited to specifically consider the possibility of contracting COVID-19 or experience a relapse of MS, almost half of the cohort rated both of equal of concern. More than half of the cohort were self-isolating more stringently than general government advice and government-related resources followed by information provided by patient's neurologist where the commonest means of information to guide decision making. CONCLUSIONS: Whilst a large proportion of patients had some concern regarding the impact of their DMT on COVID-19, whether on their risk of contracting COVID-19 or a theoretical risk for more severe disease, the overall level of concern in most cases was at most mild. Patients on B-cell depleting therapies were more inclined to express a higher level of concern. A similar concern was ascribed to a risk of a relapse or worsening MS symptoms compared to the risk of contracting COVID-19. Such attitudes may underscore a willingness of patients to continue their DMT where benefits outweigh risks during future phases of the COVID-19 pandemic.