Human Immune System, a personal army relentlessly defending its fortress, the human body, is one of the least understood internal systems and many interesting revelations lie ahead as we explore further into its realm. It some times behaves in interesting although counter-productive ways in response to presence and absence of infections and infestations.
The normal expected behavior of the immune system is to fight and eradicate any external agent including disease causing organisms entering our body. To the immune system everything is a chemical molecule (agent) be it from the human body or from a harmful bacteria/virus/parasite. But the story of immunity goes beyond this simple scenario and the immune system some times shows its rough edges. Many non-communicable diseases are increasingly linked to the aberrant activities of the immune system commonly referred to as Auto-Immune Diseases where one’s own immunity wages a war against other systems of the human body. These can range from simple allergic rash to life threatening conditions. The triggers for such felonious actions by the immune system have been identified to be both external and internal to human body including but not limited to genetic defects. Off late Modern Medicine has made much progress into understanding and taming immunity with respect to many auto-immune diseases. Rheumatology is a branch of advance medicine dealing with the aberrant behavior of the immune system.
This anomalous behavior of the otherwise protective immune system has prompted many researchers to look deep and some have come up with interesting yet radical theories to explain it. They found that many intestinal commensual organisms and parasites have immuno modulatory mechanisms that help ensure their survival by taming the immune system. Our immune system in the process of co-evolution over millions of years has learnt to function acceptably in the presence of these immuno-modulatory forces as man and his ancestors never lived in a near clean environment previously.
Increasingly especially in the developed western world the incidence and prevalence of these infections and parasitic diseases have decreased considerably owing to better standard of living and accessible health care. Now the immune system which is naturally accustomed to functioning in presence of these pathogens is encountering less of these agents and their immuno-modulatory forces. Our immune system which deals with internal and external agents continuously is increasingly seeing less of external agents and more of internal agents. Such fast tilt of ratios in a relatively narrow period of time in evolutionary perspective is making the immune system make erroneous judgement calls regarding the identity of the enemy and is wrongly targeting the co-processes of the human body.
Many theorize that such clean environment may be the cause of over-reactive and over-sensitive behavior of the immune system. Many studies are now being undertaken to study the effects of commensals on the human immune system and aim to throw more light on how we can exploit this relationship to tame the erroneous immune system in certain auto-immune diseases.
Much remains to be explored and learnt about this enigmatic yet benevolent system and the future of modern health care practices rests mostly on how deeply and holistically we understand the immune system.