Several risk factors play a role in the development of rheumatoid arthritis (RA), including genetic factors, eating habits, but in particular smoking. However, the exact cause is still unknown. By detecting the disease at an early stage, it could be combated more effectively.
This is stated by professor of rheumatology Dirkjan Schaardenburg in his inaugural lecture on November 26. The way in which smoke has an impact on rheumatoid arthritis is not exactly known.
Van Schaardenburg: “It is known that it is responsible for one-third of the cases and that it causes damage on three levels: it provides a higher incidence, more serious symptoms and it also worsens the response to medications.” There are indications that RA occurs only about four hundred years in Europe, about as long as tobacco is used here.
It is striking that, when we look back at the past century, the incidence and severity of RA appears to run parallel with the rise and later fall in cigarette consumption. The genetic contribution is estimated at about 16 percent. The strongest genetic risk factor for RA is called HLA-SE and occurs in about 35 percent of Europeans. Research has shown that when this gene is present, the effect of smoking increases.
According to van Schaardenburg only half of RA cases are explained by the factors genes and tobacco and it is likely that nutrition is responsible for a larger part of the other half. He mentions several surveys which revealed that a diet low in saturated fats, animal protein and sugar, so a mostly plant-based diet, may have an impressive influence on the development and course of several modern chronic diseases, including RA. So according to the professor, a lot of gains could still be made in this area.
“Most people still have dramatically bad eating habits. The choice of nutrition is not often given as a real supportive option to tackle RA. Physicians ought to take the lead in this by means of dietary advice, but also by setting a good example.”
Currently research is being conducted into the early recognition and treatment of RA patients. Early treatment of RA leads to a better prognosis and it would therefore be beneficial to identify patients even before they get arthritis. This is possible by screening for rheumatoid factor (RF) or anti-citrullinated protein antibodies (ACPA), which occur in more than half respectively three quarters of rheumatoid arthritis patients.
The test is still not suitable for large-scale screening. “Population screening leads to high costs and a lot of incorrect predictions, so the test is currently only used in people at high risk,” says Van Schaardenburg.
By analyzing patient data registration of general practitioners, researchers of Reade and the AMC are trying to see which combinations of complaints eventually lead to the RA diagnosis and thus making it useful to screen these patients.
An effort is also being made to prevent the disease by influencing the immune system. This is called the induction of tolerance and has not yet succeeded. Still Van Schaardenburg is positive about the prospect for the future: “With a mixture of lifestyle modification, induced tolerance and smart medication schedules I expect that in the coming years, we will be able to take major steps towards finally ending rheumatoid arthritis”