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LONDON, ON – New findings from Ontario have shown that children born in Sarnia have a higher risk of developing asthma compared to neighbouring cities. A research team from Lawson Health Research Institute and Western University, using provincial data from ICES, found that higher air pollution exposure in the first year of life very likely contributed to this higher risk. Their results are published today in CMAJ Open.  

Summary of study results:  

• Children born in Sarnia in the 1990s and early 2000s were disproportionally at a higher risk of developing asthma in the first few years of life, compared to neighbouring cities.  
• Air pollution exposure in the first year was found to be associated with the development of asthma in children.  
• Overall rates of new childhood asthma diagnosis in Southwestern Ontario have been decreasing over time in parallel to decreases in air pollution levels.  

“It’s known that cities in Southwestern Ontario have varied levels of air pollution because of differences in industry and traffic. For example, Sarnia is home to the ‘Chemical Valley’ where numerous chemical plants and oil refineries are clustered,” says Dr. Dhenuka Radhakrishnan, an Adjunct ICES Scientist, formerly working out of ICES Western in London, and Pediatric Respirologist at CHEO. “We wanted to see if children born in three cities – London, Windsor and Sarnia – had a different risk of developing asthma due to the differing air pollution levels in the three regions, even though the people living in these cities are otherwise comparable in many ways.”  

The researchers followed 114,427 children born in these cities between 1993 and 2009 for 10 years, and found that those in Sarnia were at the highest risk of developing asthma. The researchers found that by the age of 10, nearly 24 per cent of children in Sarnia were diagnosed with asthma, compared to 21 per cent in Windsor and 17 per cent in London. The differences were also present after accounting for many risk factors associated with asthma, such as sex, socioeconomic status and urban versus rural setting. The findings were most apparent in the first two years of life, but persistent beyond the age of six.   

“Reassuringly, we found the asthma risk for children has reduced in more recent years as pollution levels have also decreased,” adds Dr. Radhakrishnan.  

Asthma is the most common chronic disease in Canadian children and has significant impact on quality of life. Asthma is the leading cause of emergency department visits and hospital admissions in this age group.  

“It’s important to find strategies to prevent asthma development and this study suggests that reducing air pollution exposure, including environmental causes, might reduce the number of children who suffer from asthma,” explains Dr. Salimah Shariff, Associate Scientist at Lawson, Adjunct Professor at Western and Scientist at ICES Western.  

There is also growing evidence that exposure during pregnancy can influence development of asthma in children. “We need to carefully examine how reducing air pollution exposures within a geographic area translates to reductions in asthma development. Understanding the amount of air pollution that a mother and infant are exposed to, and how this impacts their personal risk, could enable regions to target safer levels for their residents,” adds Dr. Shariff. 

Wednesday, May 5 is World Asthma Day (WAD). Recognizing symptoms of asthma early is the best a parent can do to improve the health of their child, so they can be diagnosed quickly and start appropriate treatments. If a parent notices their child has wheezing, persistent cough or difficulty with exercise, they are encouraged to bring this to the attention of a health care provider.  

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Child using an age-appropriate valved spacer device with an asthma inhaler. They should be used together for children to ensure the medication is properly delivered to the lungs.

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Child using an age-appropriate valved spacer device with an asthma inhaler. They should be used together for children to ensure the medication is properly delivered to the lungs.

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Dr. Dhenuka Radhakrishnan, an Adjunct ICES Scientist, formerly working out of ICES Western in London, and Pediatric Respirologist at CHEO

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Dr. Salimah Shariff, Associate Scientist at Lawson, Adjunct Professor at Western and Scientist at ICES Western

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Proportion of children with an asthma diagnosis by studied region

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LONDON, ON – Researchers at Lawson Health Research Institute are offering new hope to patients with treatment-resistant depression through participation in a national clinical trial. The study is the first randomized controlled trial to examine the efficacy of a new treatment called magnetic seizure therapy (MST) for patients with treatment-resistant depression as a result of bipolar disorder. 

Treatment-resistant depression is a severe form of depression that does not respond to traditional therapies like medication. It is particularly common in patients with depression from bipolar disorder who are left with limited treatment options. 

For years electroconvulsive therapy (ECT) has been the gold standard for patients with treatment-resistant depression. ECT uses an electric field to induce a seizure that provides a therapeutic benefit. But while ECT is effective, many patients opt out of treatment due to stigma surrounding the therapy and the potential for cognitive side effects like disorientation and amnesia. 

MST has emerged as a promising alternative. MST works in a similar way to ECT but uses a focused magnetic field as opposed to electricity. As a result, MST induces a more focused seizure to reduce the risk of cognitive side effects.

“Magnetic seizure therapy has already been shown as a promising treatment for major depressive disorder or unipolar depression,” explains Dr. Amer Burhan, local site lead, researcher at Lawson and neuropsychiatrist at St. Joseph’s Health Care London. “For the first time, we’re studying how effective the treatment is for depression as a result of bipolar disorder and whether it can reduce the risk of cognitive side effects associated with electroconvulsive therapy.”

The clinical trial is being led by the Centre for Addiction and Mental Health (CAMH) and will also be offered through Lawson and University of British Columbia (UBC) Hospital. Lawson researchers will invite eligible patients with treatment-resistant depression from bipolar disorder to participate in the trial at Parkwood Institute, a part of St. Joseph’s Health Care London.

Eligible patients will be randomized to receive either ECT or MST. Patients will be offered support throughout the study with the goal of improving patient outcomes in both groups. Patient outcomes will be compared to study the efficacy of MST and whether it is associated with reduced cognitive side effects.

MST will be delivered under anesthesia in 12 to 20 sessions. Sessions will last 10 to 15 minutes each with 60 to 90 minutes of recovery time.

“Magnetic seizure therapy holds promise of one day replacing electroconvulsive therapy as the gold standard for treatment-resistant depression,” says Dr. Burhan. If proven as a viable first-line treatment, MST would be very easy to implement in existing ECT clinics. MST would therefore be readily available to patients in need.

“We are on the leading edge of the field of brain stimulation for treatment-resistant depression in collaboration with CAMH and UBC,” says Dr. Burhan. “Our goal is to continue informing the care process through clinically-relevant research that serves patients, medical professionals and the public.”

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LONDON, ON – A study led by researchers at Lawson Health Research Institute (Lawson) provides clinical validation of EpiSign, a molecular genomics test that diagnoses rare, heritable neurodevelopmental conditions.

Invented at Lawson by Dr. Bekim Sadikovic, the diagnostic test uses machine learning to analyze the EpiSign Knowledge Database. This database compiles information on rare genetic diseases using laboratory analyses of the epigenome from patients with suspected genetic abnormalities. The epigenome is a process that can change the expression of a gene without changing the gene sequence.

“Using 211 blood samples, we measured test performance and diagnostic yield in 207 subjects from two different cohorts,” explains Dr. Sadikovic, lead researcher at Lawson and Scientific and Clinical Director of the Verspeeten Clinical Genome Centre at London Health Sciences Centre (LHSC). The targeted cohort were subjects with previous genetic findings that were ambiguous or inconclusive. The screening cohort were those with clinical findings consistent with hereditary neurodevelopment syndromes but with no previous genetic findings.

“Of the 207 subjects tested, 57 were positive for a diagnostic episignature including 48 in the targeted cohort, and 8 in the screening cohort. Only four remained inconclusive after EpiSign analysis,” says Dr. Sadikovic. “This gives us strong evidence for the clinical use of EpiSign, as well as the ability to provide conclusive findings in the majority of subjects tested.”

While currently there are limited treatment options associated with many of these conditions,

providing a diagnosis can help physicians better predict the course of the disease, and allows for better planning and support for the patient. EpiSign is the only test in the world that has been clinically validated for testing these kinds of genetic disorders.

“Patients with rare diseases often wait years and undergo numerous exams and tests before receiving a correct diagnosis, if one is found at all,” says Matthew Tedder, PhD, staff scientist at the Greenwood Genetic Center, one of the EpiSign clinical testing laboratories. “EpiSign provides an additional high-yield diagnostic tool for clinicians to include in their evaluation of patients with undiagnosed diseases, providing better medical management for patients and hope for their families.”

The study, “Clinical epigenomics: genome-wide DNA methylation analysis for the diagnosis of Mendelian disorders", is published in February’s Genetics in Medicine and was completed in collaboration with the Greenwood Genetic Center and the University of Amsterdam.

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