SNOWMASS, COLO. — Extraarticular disease occurs in almost half of all rheumatoid arthritis patients, and greatly increases the risk of premature mortality, Dr. Eric L. Matteson reported at a symposium sponsored by the American College of Rheumatology.
In a review of 609 incident cases of rheumatoid arthritis occurring in Rochester between 1955 and 1995 and followed through 2000, Dr. Matteson of the Mayo Clinic, Rochester, Minn., and his colleagues found that 46% of patients with rheumatoid arthritis developed some extraarticular disease.
The most common extraarticular manifestations in patients included subcutaneous nodules (34%), Sjögren's syndrome (11%), pulmonary fibrosis (7%), pericarditis (5%), and pleuritis (5%). The least common—occurring in 1% or fewer of patients—included neuropathy, xerostomia, and amyloidosis.
Their review also found that the likelihood of premature mortality was greatly increased by extraarticular disease; for example, a female rheumatoid arthritis patient aged 50 years with vasculitis, pericarditis, pleuritis, or pulmonary fibrosis had a life expectancy that was 13–15 years shorter than that of a healthy peer. Male patients with the same manifestations were found to have a life expectancy 15 years shorter than that of healthy peers.
When Dr. Matteson and his colleagues plotted the survival curve of the patients against that of the general Rochester population, there was a significant difference in survival. But when they took out the patients with extraarticular disease and compared only patients with rheumatoid arthritis without extraarticular disease, there was no difference. “The impact is profound,” he said.
Analysis of data showed that the relevant factors most associated with extraarticular disease in patients were antinuclear antibody positivity, male gender, and smoking.
Extraarticular disease was reported by 60% of the rheumatoid arthritis patients who reported having ever smoked. The association has been noted before in other investigations, and some of that evidence suggests that smoking actually drives the disease process, he said.
Rates of extraarticular disease may be different now in the era of biologic treatment, Dr. Matteson allowed. However, during the time of this review, there was no improvement in the incidence rate of extraarticular disease.