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Disease Tolerance as a Defense Strategy - 2012 article

natasa778

Senior Member
Messages
1,774
Just came across this paper, looks very intriguing and discusses a few interesting concepts that I haven't seen mentioned on forums but could be relevant to ME ...

Free access

ABSTRACT:
The immune system protects from infections primarily by detecting and eliminating the invading pathogens; however, the host organism can also protect itself from infectious diseases by reducing the negative impact of infections on host fitness. This ability to tolerate a pathogen’s presence is a distinct host defense strategy, which has been largely overlooked in animal and human studies. Introduction of the notion of “disease tolerance” into the conceptual toolkit of immunology will expand our understanding of infectious diseases and host pathogen interactions. Analysis of disease tolerance mechanisms should provide new approaches for the treatment of infections and other diseases.


... Alterations in host metabolism and electrolyte balance, changes in blood pressure, impaired absorptive functions of intestinal and respiratory epithelia, local tissue hypoxia and excessive extracellular matrix remodeling, are all examples of disturbances in host physiology that can be caused by pathogens or the immune responses they elicit (17, 32). In each case, there are dedicated mechanisms that restore homeostasis and normal tissue function (regardless of what caused their dysregulation), and engagement of these mechanisms helps to reduce the fitness costs associated with infections. When these mechanisms are sufficient to prevent significant disruptions of physiological functions, infections remain asymptomatic ...
 

natasa778

Senior Member
Messages
1,774
have you read the whole article? I still haven\t finished but think that would be missing the point .. .
 

lansbergen

Senior Member
Messages
2,512
Pathogen tolerance is an old and much better term.

When there are no sighns and symptoms there is no disease.
 

anciendaze

Senior Member
Messages
1,841
Please note, everyone, that there is a very fine line between inside and outside the body. If your mucous membranes were spread out flat they would cover many square meters, yet the difference between inside and outside is only a few cells thick. The old idea of the immune system distinguishing between "self" and "non-self" is inadequate for dealing with this. The context in which a pathogen occurs is extremely important. If you have e. coli in your gut, right next to capillaries, that is normal, and necessary for some digestive processes. If e. coli shows up inside the bloodstream it should be attacked immediately. You can tolerate helicobacter pylori inside your stomach, unless there is tissue damage resulting in an ulcer. About half the human race has h. pylori in its stomach without ulcers.

Immune systems respond to multiple clues to indicate a pathogen is present and causing damage. When organisms do not cause damage to host cells they will most often be tolerated. You need to remember that bacterial cells outnumber human cells in your body, and most viruses, fungi, etc. in your gut, bladder, lungs or sinuses are in a constant battle to keep other species from taking over. Those that target human host cells are likely to come to a bad end. The majority of pathogens inside you are not doing this, they are going after other organisms you would consider human pathogens. If your body ever decides to go after all "other" organisms in there, you will feel deathly ill, if you survive.