Lab results alone don’t give full picture of antiphospholipid syndrome

by Valerie Goodwin, University of Michigan

Associations between patient-reported outcomes for physical function, cognitive function, and pain intensity (n = 130 for A and C; n = 139 for B). Pearson r and associated P values are indicated. aPL, antiphospholipid antibodies; APS, antiphospholipid syndrome. Credit: ACR Open Rheumatology (2022). DOI: 10.1002/acr2.11512

Antiphospholipid syndrome is an autoimmune disease that preferentially affects women. Patients with APS are typically given different medications to reduce their risk of blood clotting and help normalize lab values such as platelet count. Despite this, patients sometimes internally feel that they are not doing as well as the numbers are showing.

APS is characterized by persistently positive antiphospholipids antibodies in the setting of adverse obstetric events or dangerous blood clots. Patients may be diagnosed with “primary APS” when APS is the main autoimmune disease or “secondary APS” when the is APS diagnosis is paired with Lupus.

A study conducted by University of Michigan Medicine titled “Predictors and Interrelationship of Patient-Reported Outcomes in Antiphospholipid Syndrome: A Cross-Sectional Study,” published in the American College of Rheumatology’s ACR Open Rheumatology, researchers found that many patients perceived their physical and cognitive function to be less than optimal.

Patients with APS have many self-reported symptoms that impact on different dimensions on their quality of life. However, they do not routinely receive opportunities to explain these impacts in a way that can be connected to APS. It is even rarer for these patient reports to be systematically studied on a large scale. More often APS is studied from the perspective of the physician. Here, the authors used validated patient-reported outcomes measures to ask how patients viewed their health in a systematic and consistent way.

One hundred and thirty-nine APS patients at University of Michigan Health were each given three questionnaires upon arrival to an appointment with their APS physician. The questionnaires asked APS patients to rate their physical function, cognitive function, and pain intensity.

The study found that roughly half of patients had a physical function score of less than 45, suggesting at least mild self-perceived impairment in how one is able to carry out their day-to-day physical activity. Another important domain, cognitive function, is often not assessed from a patient self-report perspective. 

A pioneering effort in this study was to systematically assess the relationship between cognitive function and the quality of life. While the cognitive function questionnaires have not previously been deployed as widely as those for physical function (limiting a deep understanding of score interpretations), a quarter of patients with primary APS were assigned a cognitive score of less than 40, suggesting at least moderate self-perceived impairment in this area.

Interestingly, impairments in self-reported physical function and cognitive function, as well as higher pain intensity, were not only associated with clinical markers suggestive of more severe disease, but also with potentially modifiable lifestyle factors such as obesity and smoking status.

Unexpectedly, patients taking drugs typically prescribed for mental health, such as selective serotonin reuptake inhibitors, also reported worse physical and cognitive function and higher pain intensity. Struggles with mental health are common in patients with unpredictable autoimmune diseases like APS, although the impacts of mental health and associated medications have only rarely been studied in this condition.

“The next step is to study this all longitudinally to see how these numbers hold up over time,” said Julia Weiner, an undergraduate student and researcher working with Jason Knight M.D., Ph.D., an associate professor of rheumatology and internal medicine and supervisor of the lab. “Distributing a questionnaire that focuses specifically on depression and SSRI use alongside assessing impairments in cognitive function is also likely to help us gain a better understanding of how these symptoms and associated medications impact APS patients.”

As another next step, Weiner hopes to administer the Montreal Objective Cognitive Assessment, a standard way to objectively score cognitive function, to a larger volume of patients who also complete questionnaires. This can help the team understand how well self-perceived cognitive function predicts actual cognitive performance.

Overall, the Michigan Medicine team is very enthusiastic about finding more ways to incorporate patients into all aspects of their research, from providing their perceptions of their disease (as in this study), to study design, to study interpretation. “Patients and researchers will have to partner together if we are ever going to achieve the ultimate goal of a cure for APS,” said Weiner.