Anti-TNF Therapies for Rheumatoid Arthritis Could Reduce Alzheimer’s Risk

Newswise — Anti-TNF therapies commonly used to treat rheumatoid arthritis have been found to potentially reduce the risk of developing Alzheimer’s dementia among people with rheumatoid arthritis, according to research presented this week at the American College of Rheumatology Annual Scientific Meeting in Atlanta.

Rheumatoid arthritis is a chronic disease that causes pain, stiffness, swelling, and destruction of the joints. People with RA often experience limitation in the motion and function of multiple joints. Though joints are the principal body parts affected by RA, inflammation can develop in other organs as well. An estimated 1.3 million Americans have RA, and the disease typically affects women twice as often as men.

A complication of chronic inflammation in RA is amyloidosis, caused by excess deposits of amyloid proteins in different organs, which can cause harmful effects to the normal function of many organs. While people with Alzheimer’s disease are found to have local deposits of a type of amyloid protein—beta-amyloid peptide—in the brain, the actual cause of Alzheimer’s remains unclear.

Researchers recently set out to evaluate if there is a relationship between different treatments for RA and the incidence of Alzheimer’s dementia. They reviewed medical and pharmacy claims data of over eight million subjects in the U.S. from a commercial database (Verisk Health). A total of 42,193 people with RA were identified. Each RA subject with newly diagnosed Alzheimer’s dementia was compared to 10 people with RA who did not have Alzheimer’s dementia (called “controls”). As researchers made these comparisons, they ensured they were comparing people of the same age, gender, and with the same use of methotrexate, a medication commonly used for RA. Researchers examined the exposure of these individuals to several drugs used to treat RA including sulfasalazine, prednisone, three anti-TNFs (infliximab, etanercept, and adalimumab) and rituximab.

A total of 165 RA subjects with Alzheimer’s dementia were compared to 1,383 RA controls without Alzheimer’s dementia. Researchers found that those who received anti-TNF treatment had a 55 percent reduction in risk of developing Alzheimer’s dementia. This effect was not seen with other drugs used for treatment of RA, including sulfasalazine, prednisone and rituximab. The researchers concluded that anti-TNF agents used to treat people with RA may be useful in reducing the development of Alzheimer’s dementia, although the mechanisms need further investigation.

“In this study, the incidence of Alzheimer's disease was found to be lower in patients with rheumatoid arthritis who had been treated with anti-TNF agents,” says Dr. Richard Chou, MD, PhD; assistant professor at Dartmouth Medical School and lead investigator in the study. “Although the cause of Alzheimer's disease is not known, the results suggest that TNF may play a role in its development."

TNF-antagonists (also called biologics or anti-TNF therapy) are a class of drugs that have been used since 1998. Overall, they have been given to more than 600,000 people worldwide. These drugs are given to lessen inflammation by interfering with a biologic substance called TNF that cause or worsen inflammation.

Patients should talk to their rheumatologists to determine their best course of treatment.

The American College of Rheumatology is an international professional medical society that represents more than 8,000 rheumatologists and rheumatology health professionals around the world. Its mission is to advance rheumatology. The ACR/ARHP Annual Scientific Meeting is the premier meeting in rheumatology. For more information about the meeting, visit www.rheumatology.org/education or join the conversation on Twitter by using the official hashtag: #ACR2010.

###Editor’s Notes: Richard C. Chou, MD, PhD will present this research during the ACR Annual Scientific Meeting at the Georgia World Congress Center at 2:30 PM on Monday, November 8 in Room A411. Dr. Chou will be available for media questions and briefing at 1:30 PM on Tuesday, November 9 in the on-site press conference room, B 212.

Presentation Number: 640

Tumor Necrosis Factor Inhibition Reduces the Incidence of Alzheimer's Disease in Rheumatoid Arthritis Patients

Richard C Chou, MD, PhD (Section of Rheumatology, Dartmouth-Hitchcock Medical Center and Dartmouth Medical School, Lebanon, NH)Michael A Kane, MD (Division of Rheumatology, Allergy and Immunology, Massachusetts General Hospital and Massachusetts Institute of Technology, Boston, MA)Sanjay Ghimire, MD (Verisk Health, Waltham, MA)Shiva Gautam, PhD (Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA)

Body: Objective: To investigate the relationship between different rheumatoid arthritis treatments and Alzheimer's dementia

Background: A complication of chronic inflammation in rheumatoid arthritis (RA) is the deposition of amyloid proteins, resulting in secondary amyloidosis. Alzheimer's dementia (AD) is associated with the local deposition of beta-amyloid peptide in the brain, although the pathogenetic mechanisms of AD are unclear. The relationship between RA and AD has not been established.

Design/Methods: We reviewed medical and pharmacy claims data from January 2000 to November 2007 for a commercially insured cohort of 8.5 million adults throughout the US. We derived a subcohort of 42,193 patients with a pre-existing diagnosis of RA. In this subcohort, we conducted a nested case-control study of the incidence of AD. We excluded individuals with psoriatic arthritis, inflammatory bowel disease, previous stroke or previous AD. For each individual with newly diagnosed AD (cases) we matched up to 10 controls who did not have a prior diagnosis of AD and were free of AD during the exposure assessment period. Matching criteria included age, gender, duration of exposure assessment period and methotrexate treatment. We examined exposure to sulfasalazine, prednisone, three anti-tumor necrosis factor (TNF) agents (infliximab, etanercept, adalimumab) and rituximab.

Results: In this nested case-control study, a total of 165 patients with AD (cases) were matched to 1,383 controls without AD. Treatment with anti-TNF agents in RA was associated with lower risk for incident AD [adjusted odds ratio (OR) 0.440; 95% confidence interval (CI) 0.223-0.868; p=0. 0178). The risk of AD was not affected by exposure to sulfasalazine, prednisone or rituximab. The results were similar [adjusted OR 0.448; 95% CI 0.225-0.892; p = 0.0222) after adjustment for covariates, including hypertension, hyperlipidemia, diabetes mellitus, peripheral vascular disease, and coronary artery disease.

Conclusion: In this population of adults with RA, we observed that the risk of AD was reduced by TNF inhibitor therapy, but not by other disease modifying agents used for treatment of RA. Tumor necrosis factor may be an important component in the pathogenesis of AD.

Disclosure: Richard Chou, nothing to disclose; Michael Kane, Verisk Health: Consulting fees; Shiva Gautama, nothing to disclose, Sanjay Ghirmire, Verisk Health: Employment (full or part-time).