High Flu Risk in RA Patients

Rheumatoid arthritis patients may have higher influenza risk when taking anti TNF drugs

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) Every year, thousands of Americans come down with the flu. If you have a condition like rheumatoid arthritis, you may be more likely to get the flu.

Despite high levels of vaccination, about half of rheumatoid arthritis patients reported flu-like symptoms in a recent study.

The risk of flu symptoms was greater in patients taking anti-TNF drugs and in those with a higher body mass index (BMI), a measure of body fat using height and weight.

"Get vaccinated to prevent the flu."

Rheumatoid arthritis is a type of inflammatory arthritis, meaning it can affect how well the body fights off infection. Also, many drugs used to treat rheumatoid arthritis can weaken the immune system. With a weakened immune system, people may face a higher risk of more severe flu and flu complications.

In their study, Linda Dirven, MSc, of Leiden University Medical Center, and colleagues wanted to find out the rates and predictors of flu and flu-like symptoms in people with rheumatoid arthritis.

They found that 74 percent (about 579) of patients reported getting vaccinated.

While 50 percent (about 391) of patients reported flu-like symptoms, only 5.9 percent (about 46) actually had the flu.

Patients taking anti-TNF drugs were 2.4 times more likely to have symptoms of the flu and patients with a higher BMI were 1.06 times more likely to have flu symptoms.

"In 2009-2010, the prevalence of reported influenza in patients with rheumatoid arthritis was 5.9 percent," the authors write.

Other factors that may have affected the risk of flu in rheumatoid arthritis patients were age, being female, having received a flu vaccination, and having a previous lung condition.

"Patients using anti-TNFs and with higher BMI seemed to be more at risk for influenza symptoms. Milder upper respiratory tract infections were reported more often by females, younger patients, and those vaccinated against influenza or with previous lung conditions," the authors write.

These findings suggest that doctors should watch their rheumatoid arthritis patients closely for flu symptoms, especially in those times of year when flu is more common.

For this study, the researchers sent questionnaires to rheumatoid arthritis patients. Patients were asked to track flu-like symptoms and report vaccination. A total of 783 patients were qualified for follow-up. A rheumatology expert measured disease level and use of rheumatoid arthritis drugs. Flu was defined as a fever over 100.4 degrees Fahrenheit, headache, muscle soreness and coughing or shortness of breath.

The results were published July 20 in the Scandinavian Journal of Rheumatology.

Reviewed by: 
Review Date: 
July 23, 2012
Last Updated:
February 7, 2013