Rheumatoid arthritis flare-ups linked to gum disease

High levels of certain bacteria in the mouth are associated with signatures of immune activity that can affect joints in a small study

To Claire Wilson

Oral bacteria enter the bloodstream and can trigger the immune activity hallmarks implicated in rheumatoid arthritis, supporting the idea that periodontal disease may contribute to painful joint conditions.

The study is one of the first to show that the same antibodies that target rheumatoid arthritis joints also attack the bacteria that live in the gums, and people with the condition maintain good dental hygiene. Reinforce advice that you need to. new york.

Rheumatoid arthritis is an autoimmune condition, meaning that the immune system attacks tissues in the body. Previous studies have found that people with this condition are more likely to develop periodontal disease, in which the gums become inflamed and sometimes bleed, but the reasons for this are unknown.

In the latest study, Orange and her colleagues monitored five people with rheumatoid arthritis, two of whom also had periodontal disease, and asked them to provide weekly blood samples for up to four years. These samples were tested for bacterial genetic material and several markers of immune system activity.

Unlike the three individuals without periodontal disease, those with periodontal disease frequently had genetic signatures from oral bacteria such as: Streptococcus Seeds are usually seen every few weeks.

This is probably due to bleeding gums, says Orange. “When the blood comes out, the bacteria come in.”

When oral bacteria peaked, there was also characteristic activity from a type of immune cell called monocytes, which is known to be involved in the immune response to arthritic joints.

Researchers have also occasionally found traces of bacteria that normally live on the skin in blood samples, but these were not associated with immune activity.This suggests that skin bacteria contaminated the samples while they were being taken from the participants, says Orange. [the immune system] We are not ignoring bacteria in the blood. Bacteria are usually eliminated very quickly. ”

In the second part of the study, one-time blood samples from 73 individuals were analyzed. About half of them had rheumatoid arthritis. One of his blood tests for rheumatoid arthritis looks for antibodies that target a group of proteins with a chemical modification called citrullination. Although this change can occur in any protein, certain citrullinated proteins are found at high levels in the joints of rheumatoid arthritis patients.

In this study, antibodies against citrullinated proteins in rheumatoid arthritis patients also acted against citrullinated proteins made by oral bacteria entering the blood. It has been suggested that it triggers the production of antibodies against the protein, which causes a flare-up of immune attack on the joints.

Although the study was small, Paul Emery of the University of Leeds in the UK said that weekly sampling of the participants’ blood increased the validity of the results. “this is, [markers of] Inflammation and blood bacteria in rheumatoid arthritis. ”

The immune activity triggered by periodontal disease, which may involve a variety of mechanisms and bacteria, is associated with an increasing number of diverse medical conditions, from heart attacks to Alzheimer’s disease. called oral bacteria Porphyromonas gingivalis involved in the state.