TNF blockers may have a previously unrecognized effect on the immune system that could be a significant aspect of rheumatoid arthritis treatment. When the first TNF blocker was introduced nearly a decade ago, the inhibition of tumor necrosis factor (TNF) was viewed as a revolutionary way of controlling rheumatoid arthritis symptoms and reducing joint damage. According to a study published in the January 15th issue of the Journal of Immunology, TNF blockers -- Enbrel (etanercept), Remicade (infliximab), and Humira (adalimumab) -- may also eliminate abnormal B-cell activity.

Researchers studied 45 patients with rheumatoid arthritis and 22 healthy adults. The rheumatoid arthritis patients were treated with Enbrel alone, methotrexate alone, or both. A small sample from the patient's tonsils allowed researchers to observe the effect on the lymph system rather than the usual analysis of cells in the bloodstream -- and it proved to be more telling.

• The Facts of Enbrel
• The Facts of Humira
• The Facts of Remicade
• The Facts of Rituxan
• The Facts of Methotrexate

Researchers found that TNF blockers disrupted what are called "germinal centers" in the lymph system. Germinal centers serve as a training ground for immune cells. In healthy people: germinal centers pop up when people get sick; T-cells and B-cells swap information about foreign invaders like bacteria or viruses; B-cells are churned out and tag the foreign invader for destruction; germinal centers fade away once the foreign invader is destroyed. But in people with rheumatoid arthritis, germinal centers hang around too long and cause the body to mistakenly attack its own tissues.

In the study, TNF blockers reduced memory B-cells in lymph tissue by 40 percent. Arthritis patients receiving the TNF blocker had one-fourth the number of germinal centers as other arthritis patients and they were smaller and less organized. Researchers felt this could also explain why some patients who fail TNF blockers do well on Rituxan (rituximab), a rheumatoid arthritis treatment that targets B-cells directly. The effect of TNF blockers on B-cells is more subtle than rituximab's effect. Also, B-cell activity may be more prominent in some rheumatoid arthritis patients.

More Related Resources:

• Test Your Knowledge: TNF Blocker Drugs
• TNF Blockers: How Are They Similar and Different?
• Should Patients Fear Side Effects of TNF Blockers?
• Do Biologic Drugs Prevent Joint Damage and Deformity?
• When is it Appropriate to Switch Your TNF Blocker Drug?

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