The Real Truth About the Human Defense System

The Human Defense System is one of the most challenged systems of all the organ systems. It essentially requires a collaborative surveillance of many types of organs from skin to the organs which make up the overall reticulo-endothelial system (which includes cells formed by bone marrow, spleen, thymus, lymph node, tonsil, Intestine,etc).

In fact, most diseases that are derived from the human defense system are classified as “Reactive Diseases” because they are triggered by “an inflammatory response.”  The “inflammatory response” allows the body to determine self from NON-self through this surveillance of different types of cells.  The response is primarily initiated by invading pathogens, such as bacteria, fungi, parasites, viruses, or foreign matter (such as allergens), or at times, simply self-cells which may be misinterpreted as foreign (autoimmunity) due to an abnormal protein (as with Systemic Lupus Erythematosus, or Psoriasis, etc) or tumor cell, etc.  Depending on the nature of the invading foreign matter, the defense system incorporates the activities of different organ systems to generate an overall “REACTIVE RESPONSE.”  Such response may require  simple bacteria that generate a chemical toxin that attracts certain white blood cells which will phagocytize the bacteria and destroy it. Or, an immune response may require labeling the foreign cell, i.e. fungi, parasite, viral infected cell, or tumor cell, to be destroyed by the immune-mediated defense system.  The immune mediated defense system is the most complex  because it requires a humoral activity and/or a cell-mediated activity, and thus the topic for this discussion.

Often times, the humoral and cell-mediated immune responses overlap or at least work together to destroy foreign matter.  In simple language, the humoral response requires a communication between B-lymphocytes and T-lymphocytes for the production of antibodies which will essentially label foreign substances to be recognized by the defense system to be destroyed.  Foreign matter and/or cells labeled by antibodies may also be further labeled to be attacked by specialized cytotoxic T-cell lymphocytes and/or compliment factors that will eventually cause lysis or destruction of the foreign cell all together, or picked up by the reticulo-endothelial system to be removed from the human body, as with certain viral infected cells, or tumor cells, or organ-transplant cells.



With a normally functioning IMMUNE OR DEFENSE SYSTEM, this process takes place often times and soon resolved in an ACUTE REACTION.  Still at other times, medications, such as antiviral, antibacterial, and antifungal, OR STEROIDS, etc may be used to resolve the inflammatory reaction sooner.  Or still, yet, supportive care, which may include among others,  intravenous-IV injection of recombinant-monoclonal antibodies (antiserum), may be necessary while the Immune Defense System is in the process of completely destroying a foreign matter, or invading pathogen, or tumor cell, etc, as with a CHRONIC REACTION.  The final outcome is recovery, or maintenance, or death.

MDC Atlanta remains committed to keeping our patients informed for better quality and safe medical care.