If a better and faster detection system could be developed for ankylosing spondylitis (AS) – a form of arthritis that primarily impacts the spine – it would mean quicker diagnosis and more personalized treatment.
This is the logic behind the current research by Dr. Robert Inman, a senior scientist at the Krembil Research Institute, rheumatologist and co-director of the Spondylitis Program at Toronto Western Hospital, and his colleague Dr. Florence Tsui. They say the first step towards more personalized medicine for AS patients is refining the screening instruments used by the first line of care, like general practitioners and chiropractors.
It’s a tough but necessary undertaking as patients can go months, even years, without a proper diagnosis.
“There is a real imperative to identifying the patients in the community more accurately than we have in the past,” says Dr. Inman. “The patients are often undertreated or inappropriately treated for their back pain because they haven’t been correctly diagnosed.”
Medical treatment that is tailor-made to the individual is now becoming a reality. It’s helping medical professionals analyze and treat their patients with more precise medicines, which will hopefully lead to better long-term outcomes.
Typical AS patients have disease onset when they are between 20 and 35 years of age, but there is also a subgroup of younger patients with onset before 15 years of age, called juvenile AS.
“If we understand the reasons why the AS disease develops and progresses, we will be in a better position to not only design the appropriate tests for diagnosis, but also find the effective targets for treatments,” explains Dr. Inman.
The difficulty emerges as a result of the initial stage of AS. The disease usually presents as lower back pain, so it can prove difficult to detect this type of arthritis from a relatively common symptom.
“Many of our patients don’t start with a [doctor]. They may see a chiropractor, a registered massage therapist, or a sports clinic specialist because they have back pain and may think it’s something else,” explains Dr. Inman. “What we are trying to do is apply more effective screening mechanisms in the community that would allow for appropriate referrals to a rheumatologist.”
Dr. Inman and Dr. Nigil Haroon, also a Krembil scientist, rheumatologist and co-director of the Spondylitis Program at University Health Network (UHN), are currently working with a group of physiotherapists experienced in AS, “so they can apply some well-validated screening mechanisms at the bedside about who should or should not be referred to a rheumatologist,” Dr. Haroon explains.
The hope is to optimize these assessment tools by working with community practitioners and then release them on a larger scale to first-point-of-care professionals.
“There’s good evidence now that if we can identify these patients earlier and treat them earlier, it supports better long-term outcomes,” adds Dr. Inman.
The next phase of AS detection falls under the umbrella of personalized medicine and requires specific genetic tests.
Right now, 80-90 per cent of the population with AS test positive for a protein in the body called HLA-B27. However, a positive HLA-B27 result does not mean a patient automatically has AS, as a percentage of the population will be positive for the marker, but never develop symptoms.
“There are several dozen other genes involved with the susceptibility to AS, so we’ve been acting with a Canadian consortium called SPARCC (Spondyloarthritis Research Consortium of Canada) on how we could actually apply genetic tests at the frontline, right at the point of care, to more accurately stratify patients with back pain who might have AS,” explains Dr. Inman.
With more precise genetic analysis, says Dr. Tsui, AS patients could see a more suitable cocktail of medicines based on their pre-determined response to certain treatments.
“We want to have a clear idea on how the disease develops. This will then lead to preventive and novel treatment approaches for the patients,” she adds.
Treatments for AS begin with non-steroidal anti-inflammatory drugs and those patients that show limited improvement with this treatment will likely be given inhibitors of TNF (a molecule that contributes to inflammation) and about 75 per cent respond well with these treatments.
Developed in the last 15 years, these drugs have been a game changer for many suffering with AS, giving them a better quality of life.
However, the other 25 per cent of AS patients will not tolerate or respond well to these biologics and “thus we have to keep searching for better alternative treatments for these patients,” adds Dr. Tsui.
With all of the ongoing research, the hope is that early detection and more precise medicine will soon be only a simple blood test away.
“Our vision is actually to profile the patient accurately from the genetic and immunological perspective. If those patients can be accurately profiled we can tailor-make the treatment more specifically for each patient,” says Dr. Inman.
“And that’s what drives our studies.”
This content was produced by The Globe and Mail's Globe Edge Content Studio, in consultation with an advertiser. The Globe's editorial department was not involved in its creation.