Ask Dr. Scott: Smoking, Bacteria & Arthritis: Unraveling the Complex Relationships



If your New Year’s resolutions include quitting smoking, you may be lowering your risk for rheumatoid arthritis, or RA, and that of those around you. A Brigham & Women’s Hospital study published in Arthritis & Rheumatology recently found a 75% increased risk of rheumatoid disease in children living with smoking parents, according to lead author Kazuki Yoshida, cited in Rheumatology News.

While anecdotal impressions don’t go far, my own observations suggest that smoking is a major risk factor for inflammatory arthritis, consistent with observations in the scientific literature. When I was in medical training, smoking was down, but still prevalent. The occasional doctor breathed during the mapping. We have seen rheumatoid deformities of the hand frequently.

Decades later, the incidence of smoking in the United States has declined and smoking around children is stigmatized. Coinciding with these changes, cases of severe RA seem less common. Rheumatoid disease was unknown in Europe until Christopher Columbus returned from the Americas, leading to the introduction of tobacco into the Old World.

There are precedents for environmental toxins, or infections, leading to inflammatory autoimmune diseases.

For example, the incidence of rheumatic fever, caused by streptococcal throat infections, began to decline before the advent of penicillin as a treatment around World War II. In rheumatic fever, antibodies formulated to fight infection also attack heart tissue, joints and kidneys. Although bacterial throat infections directly cause rheumatic fever, the total square footage available to an individual is also clinically relevant. People crammed into poorly ventilated housing are at increased risk. Rheumatic fever is now mainly encountered in developing countries.

This concept of normal tissue suffering from immune responses also applies to viral infections. For example, when it comes to Covid-19, researchers are concerned about pro-inflammatory cytokines that can worsen acute disease states, damaging tissue.

In the case of RA, it is known that anti-citrullinated cyclic peptide, or anti-CCP, antibodies often emerge. A link between certain bacteria, including proteus, has been observed vis-à-vis anti-CCP antibodies. It is questioned whether a mechanism involving “molecular mimicry” may be involved in the pathogenesis of RA, in the wake of autoantibody production. Immune responses to bacteria and the joint lining, for example, could lead to inflammatory cascades that damage the joints. Rheumatoid factor, a test for RA, can turn positive in chronic infections, including hepatitis or tuberculosis.

A report from the European League Against Rheumatism meeting links air pollution to rheumatoid arthritis flares. The first author Giovanni Adami, of the University of Verona, described increased levels of the inflammatory marker C-reactive protein “at very low exposure levels” as quoted in Rheumatology News. Could autoimmune diseases gradually decline if the world slowly moves towards lower levels of endemic air pollution?

American researchers view e-cigarettes and tobacco-free nicotine delivery systems with caution. For example, Sam N. Cwaline and his co-authors published an op-ed in the New England Journal of Medicine titled “Tobacco-Free Nicotine – New Name, Same Scheme?” The article details how synthetic nicotine products can escape the regulatory burden of the Family Smoking and Tobacco Control Act of 2009, which granted the Food and Drug Administration regulatory authority over tobacco products. The authors criticize the marketing tactics directed at adolescents and young adults for nicotine supplements and electronic cigarettes. The authors raise legitimate concerns related to our youth.

The Centers for Disease Control and Prevention reports that 68% of smokers want to quit, more than half try to quit each year, but only 7.5% do. Smoking cessation programs, such as the one offered by UC Davis, provide counseling, medication, and appear to promote greater success.

Does nicotine delivery systems have a role to play among those who still fail to quit smoking? We need more research on harm reduction.

Scott T. Anderson, MD ([email protected]), is a Clinical Professor in the Davis School of Medicine, University of California. This section is informative and does not constitute medical advice.



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