Effects of tobacco smoking on innate immunity: A study based on neutrophil phagocytic index

The present study was undertaken to find out the effects of tobacco smoking on innate immune mechanism of the body. A total of 60 adult consenting men in the age group of 30 to 50 years were recruited of which 30 were chronic smokers and the rest were non smoking controls. 5ml of venous blood was drawn from each of the subjects and the following parameters were assessed: phagocytic index of neutrophils (which is an index of neutrophil function and is defined as number of neutrophils positive for ingested microbes per 100 neutrophils), total leucocyte count (TLC), differential count of neutrophils. The values from smokers were compared with those from non-smokers. There was a statistically significant decrease in the phagocytic index among smokers when compared to non-smokers (9.44±6.62 vs 28.16±7.31; p<0.0011). An increase in TLC and neutrophil percentage was found in smokers which were not statistically significant (p=0.37 and p=0.12 respectively). Hence it can be concluded that tobacco smoking adversely affects the capacity of neutrophils to ingest microbes and so has suppressive effect on the innate immune mechanism.