Scientists have managed to predict when rheumatoid arthritis patients are most likely to suffer infections. Not only is rheumatoid arthritis crippling and agonizing, it also makes the patient more vulnerable to infections that coincide with the disorder, increasing their risk of death. However, physicians have had a difficult time assessing the potential danger of infection an individual might face.

According to a Mayo Clinic study, a person’s chances of having severe infections can be predicted by developing a risk score, which uses information regarding the impact the disease has on a patient, plus factors including age, corticosteroid use and if any other illnesses are present.

The findings, which were published in the American College of Rheumatology journal Arthritis & Rheumatism, came from medical records in the National Institutes of Health-funded Rochester Epidemiology Project of 584 individuals struggling with rheumatoid arthritis. The subjects were diagnosed between 1955 and 1994 and were observed until January 2000.

Almost half (252) of those studied needed hospitalization and/or intravenous antibiotic because of more than one severe infection. Collectively, the subjects had a total of 646 infections.

An infection risk score, based on those participants and other patients they observed, was created by the Mayo experts. In order to get an accurate calculation, scientists focused on certain factors, including:

  • previous severe infections
  • age
  • corticosteroid use
  • a low white blood cell count
  • elevated results in a blood test used to detect signs of inflammation, called an erythrocyte sedimentation rate
  • signs of rheumatoid arthritis outside the joints
  • the existence of other serious conditions such as heart disease, diabetes, lung disease, heart failure, alcoholism, and vascular disease.

The accuracy of the risk score was confirmed in a second group of people with rheumatoid arthritis from the same population.

Eric Matteson, M.D., chair of the Division of Rheumatology at Mayo Clinic and leading author, explained:

“Using a risk score in this way can alert physicians that their patient is at high risk for infection and needs more frequent follow-ups, measures for infection prevention and possible changes in treatments. Rheumatoid arthritis patients are at higher risk of infection, and that risk is clearly not just because of the arthritis drugs.”

Further studies are required which focus on infection risk levels, so that patients may be prescribed the right drugs treat infections. The team added that infection risk impacts on what type of medications doctors may recommend, especially with regards to DMARDs (disease-modifying antirheuatic drugs). DMARDs are commonly used to treat rheumatoid arthritis.

In June 2012 German scientists tried to predict rheumatoid arthritis risk in an animal experiment with rabbits. They managed to successfully predict infection risk.

Written by Sarah Glynn