34 year old male presents with recent development of AIDS. Had a diagnosis of HIV over a year ago. questioning treatment and why he cannot have antibiotics.
Patient's adaptive immune system is being slowly shut down by HIV and the inability of T cells to fight off infection and activate other Leukocytes.
HIV vs AIDS-
Leukocytes
DIRECT CAUSE
Lytic v Lysogenic cycles
Innate vs Adaptive Immune System
INDIRECT CAUSE
Bacterial infection v Viral Infection
Organs/Cells of the Immune System
Innate- basic, non specific, quick. It depends on barriers. External barriers to keep stuff out, internal barriers to help with a more physical response. Pathogen type does not matter.
Cells
Lymphocytes- Cells of adaptive immune system. mature into one of 2 types. protect against antigens.
T Cells- manage immune response. attack/destroy infected cells
B Cells- produce plasma cells which secrete antibodies (antibodies mark antigens for destruction)
Dendric Cells- Capture antigens and deliver them to lymph nodes. help activate
T-Calls
Macrophages- phagocytize foreign substances and help activate T-Cells
Reticular cells- supporting cells. produce reticular fibers called stroma in lymphoid organs
Organs- Includes spleen, thymus, tonsils, lymph nodes, and other lymphoid tissues
Primary Lymphoid Organs- Areas where T & B cells mature. Red Bone Marrow and Thymus
Secondary lymphoid organs- areas where mature lymphocytes first encounter their antigen and become activated. Nodes, spleen, MALT (mucosa associated lymphoid tissue) and diffuse lymphoid tissue
Lymph nodes- principle secondary lymphoid organ of the body.
Adaptive- specialized, specific, takes longer to respond. Specific to antigen. Cells and antibody based.
Basophil- releases histamine and other mediators of inflammation. Contains heparin
Monocyte- phagocytosis- develops into macrophage in tissue
Eosinophil- kills parasitic worms. has a role in allergies and asthma
Lymphocyte- mounts immune response by direct cell attack or via antibodies
Neutrophil- phagocytize bacteria
B Cells- humoral- presents antigens to specific T Cells (helper T Cells) to help in their own activation. Targets extracellular pathogens
T Cells- cellular- cell to cell interactions. targets inter-cellular pathogens. Can destroy viral infected cells, cancer, foreign cells. releases chemicals that regulate immune response.
Bacterial- simple cell, can survive on its own. extracellular. Bacterial infections can be treated directly with antibiotics as well as treating symptoms. Can eventually be eliminated from the body
Viral infection- not cells. Needs a host to survive- inhabits the cells to replicate its own DNA. Viral infections cannot be removed from the body. viruses have a high mutation rate that makes it next to impossible for medication to keep up. You treat the symptoms with a viral infection
Lytic- "reproductive"
- virus attatches to host and injects DNA
- New viral components constructed
- Host cell lyses "dies" and new viruses are released.
Lysogenic- doesn't kill host cell. creates copies of viral DNA
- virus attatches to host and injects DNA
- viral DNA integrates its DNA into host chromosomes
- Host cells and viral DNA replicate and divide
- When triggered the virus becomes active
HIV- human immunodeficiency virus. transmitted in bodily fluids. HIV targets CD4 protein on Helper T Cells. sets up shop in host cells and uses reverse transcriptase to produce viral RNA. The virus cranks out copies of the viral RNA to infect and multiply in other cells. HIV destroys Helper T Cells depressing both branches of adaptive immuity. Reverse transcriptase is not accurate, creates many mutations.
AIDS- acquired immune deficiency syndrome- condition resulting from HIV- "Stage 3 HIV" develops when HIV has cause severe damage to one's immune system. HIV has effectively destroyed the adaptive immune system by taking out Helper T Cells. Pt has to rely on innate immune system to fight off pathogens. Simple, normally not severe illnesses are now severe because the body cannot fight them off at a cellular level.
/humoral immunity- antibody mediated immunity- provided by antibodies in bodily fluids "humors"
Infection of HIV thru infected bodily fluid coming into contact with patients's own fluids or mucus membranes. Contact thru sexual activity, transfusion of infected bloods or coming into contact with an infected person's fluids. HIV targets and shuts down Helper TCells, effectively shutting down the adaptive immune system. The adaptive immune system can no longer fight pathogens that are infecting the body.
Constant bombardment on patient's adaptive immune system from HIV. Rapid HIV production inside cells causing more cell infection. Adaptive immune system is basically shut down. Patient now has to rely on Innate immune system to fight off as much infection as possible. not a very good system on its own.
Patient condition has progressed from HIV to AIDS because the helper T cells are being attacked. helper T cells help activate B cells and other Tcells to fight pathogens. Without helper T cells there is no adaptive immune system.
Patient is now relying on innate immune system. He must be much more careful as to not cause any breech in his skin or other physical batrriers of the innate system. He must also take care around people who are ill and contagious. If the patient was to catch an illness from the community, it could prove too hard for his body to fight off and he could succumb to a simple illness.
Indirectly the virus has caused the patient to become susceptible to illnesses that a person who has a normal, functioning immune system may be able to fight off.
The virus is called AIDS- acquired immune deficiency syndrome- because it is a condition of HIV. HIV has been left untreated and has damaged the patients immune system to the point that the adaptive immune system is no longer able to function to any usable degree. While it is possible that his adaptive immune system has working parts, the TCells that have been destroyed were a large player in the health of the individual.
If untreated the patient will eventually succumb to any variety of common illnesses. His body will not be able to fight off any infection. Respiratory infections are particularly dangerous.
The immune system has 2 parts, innate and adaptive. The innate is the basic physical parts of the immune system. The adaptive is the system that is affected by HIV and AIDS. As long as the patient has no history of conditions pertaining to his skin or other physical barriers, the innate part of his immune system is working. The innate is not enough to keep a person healthy and living for long. He will be immunocompromised for the rest of his life.