Reacción a "Reactions: tobacco alters the immune response even in the long term"

The paper, published in Nature by the Millieu Interieur consortium and French researchers from the Pasteur Institute in Paris and Karolinska in Sweden, has carried out a systematic study of the levels of substances (called cytokines) released by the immune system in response to infection or damage (such as exposure to smoking tobacco).  

Researcher Polly Matzinger proposed in the late 1990s that the immune system is an internal control system of the body and that it is activated in situations not only of infection, but also of harm and danger. This is why analysing what elements can modulate the immune system is very important, as it is not only pathogens that can do this, and tobacco may be one of them. 

These researchers have analysed the effect of various parameters such as age, sex and smoking, among others. Their intention was to study how the immune system is affected in response to certain stimuli, which they analysed in vitro, studying the production of cytokines that are related to the cell type that produces them. They found that age, sex, genetic variations, DNA methylation levels and cell subtypes, cytomegalovirus infection and body mass index, along with smoking, were the most important variables in terms of the changes they observed in cytokine production.  

In this work they have shown that being a smoker changes the immune system. But the important thing is that it does so persistently and that even after quitting smoking its effects last.If a person stops smoking, he or she recovers the innate immunity, but not the adaptive immunity (mediated by lymphocytes). This would indicate that there would be a persistent 'memory of smoking' in the immune system, which has an important implication, as smokers may develop other diseases such as cancer, autoimmunity or allergies, or respond abnormally to infections.  

The study is very interesting, although the results would have to be validated with another cohort, but it opens up a line of study to also analyse other aspects that could act on the immune system, such as environmental pollutants, chemical agents, fertilisers, pesticides, etc.  

A limiting aspect of the work is that all the studies have been carried out with peripheral blood cells and there are no data on how tobacco exposure affects the respiratory level (such as the mucosa and bronchoalveolar fluid).