Periodontal disease may negatively affect organ transplant survival

Given the association between transplant rejection and levels of interleukin-6, researchers explore the possible association between chronic periodontitis and transplant rejection.

CHICAGO--Researchers from the University of Connecticut Health Center have reported an interrelationship between periodontal and systemic inflammation in solid organ transplant recipients. This study appears in this month's issue of the Journal of Periodontology.

For a long time researchers have known that inflammation plays a pivotal role in organ transplant rejection and that levels of serum interleukin-6 can identify individuals who are at greater risk for transplant rejection. IL-6 is a protein that is secreted to stimulate the immune response to trauma, foreign antigens, or infections, such as periodontal infection.

Once secreted, IL-6 can enter the bloodstream and circulate in an active form long enough to mediate distal effects in other tissues and organs.

"Our goal was to assess the periodontal status of solid organ transplant patients to quantify the IL-6 levels in bloodstream and gingival tissues and explore their possible association with chronic periodontitis," explains Principal Investigator Anna Dongari-Bagtzoglou, DDS, MS, PhD, Associate Professor and Chair of the Division of Periodontology at University of Connecticut Health Center.

"We found that in transplant patients with chronic periodontitis, bloodstream IL-6 levels were elevated compared to those with no periodontitis, and were positively association with locally synthesized levels of IL-6 within periodontal tissue. This suggests that periodontal infections have the potential to affect systemic levels of IL-6 in this population."

In support of this, it was also found that clinical periodontal parameters such as probing depth and clinical attachment loss were independent predictors of the body's IL-6 levels.

"With research and science advancing every day, the life expectancy after organ transplantation is on a steady rise," said Preston D. Miller, DDS and AAP president. "Further studies monitoring periodontal disease, IL-6 and transplant tissues are needed to provide conclusive evidence that periodontal inflammation may have negative effects on long-term transplant survival."

Study background
Forty-seven kidney and cardiac transplant patients were recruited for this study. Patients had to be clinically stable, at least one-year post transplant, absent of additional systemic conditions that might elevate the systemic inflammatory status and no history of periodontal treatment within the last year. A group of 18 systemically healthy individuals that matched the age and sex were also recruited.

All individuals received a complete clinical periodontal examination, medical records of the transplant subjects were reviewed and a blood and gingival sample were taken to quantify levels of IL-6. This study was supported by the National Institute of Dental and Craniofacial Research.

A referral to a periodontist and a free brochure titled "Periodontal Diseases: What You Need to Know" is available by visiting the AAP Web site at, or calling toll-free at 800/FLOSS-EM — (800) 356-7736.

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