The immune system protects the body from pathogens through primary organs like the thymus and bone marrow, and secondary organs like the spleen and lymph nodes. It uses innate defenses like physical barriers and acquired defenses through active and passive immunity. When injured, the body responds through inflammation mediated by histamine, leukotrienes, prostaglandins, and platelet activating factor. HIV infects and depletes CD4+ T-cells, leading to opportunistic infections as cellular and humoral immunity declines. While there is no cure for HIV/AIDS, combination antiretroviral therapy can suppress the virus and prolong life.

1. IMMUNE SYSTEM TONSILS, ADENOIDS- either side of behind the nose on
the posterior on the soft palate and wall of the
M. Dablo- Dec. 16, 2011 nasopharynx and oropharynx
- Filter bacteria from tissue fluid
Immune system- to protect every tissue and organ in - Exposure infected and locally inflamed
the body against any pathogen - Mgt: erythromycin (ruins stomach lining),
cephalelxin
- Defense against infection
- Protection against some tumor SPLEEN- hematopoietic and immune functions
Primary Organs- thymus, bone marrow (WBC - Emerging reservoir of blood and blood filter
production) - Macrophages remove bacteria and old, dead, or
damaged blood cells from circulation
- Bone marrow: RBC, WBC, Platelets
o WBC: Lymphocytes LYMPH NODES- lymphatic system- Vessels that drain
 Monocytes- ingests foreign tissue fluid === lymph
materials, wastes
- Converge and drain into large structures (lymph
 Eosinophils- found usually at nodes)
the skin, allergic reactions, - Contain B & T lymphocytes- eliminate bacteria
parasites
and other foreign materials
 Basophils- primarily for allergic
reaction
 Neutrophils- bacterial infection
HOST DEFENSES
Secondary organs- spleen, lymph nodes, tonsils
1. Innate- physical/chemical barriers
- SPLEEN: backs up bone marrow in the - Complement complex
production of WBC - Cells such as phagocytes, natural killer
lymphocytes
Lymphoid tissues- also found on the surface of the 2. Acquired
mucous membranes of the intestines, on alveolar
membranes of the lungs, and in the lining of the ___ of
A. Active immunity
the liver B. Passive immunity
THYMUS GLAND- below the thyroid gland and extends 1. Natural passive- when antibodies are passed
into the thorax behind the top of the sternum from the mother to thet fetus via the placenta
or to the infant through the colostrum and
- Produces lymphocytes during fetal breast milk
development 2. Artificial – involves injecting a person with
o Embryonic origin of other lymphoid antibodies that were produced in another
structures- spleen and lymph person or animal
- After birth: programs T lymphocytes to become
regulation or effector cells
- During adolescence: becomes smaller but retain 2 types of immunity:
activity
1. Humoral- B lymphocytes
- Antibody mediated response
- Production of immunoglobulin

2. - Activation of complement cascade Specific and Non-specific immunity
2. Cell-mediated immunity- T-lymphocytes 1. Recognize
(mature in mast cells) 2. Respond
3. Distinguish autoimmune disorders
T-cells
Inflammation- mechanism that allows cells to be
Helper T-cells- also called T4+ or CD4+ cells reapaired when subjected to stress or damage
- Recognize antigen (protein that stimulates - Response to injury: vascular and celllular
immune reaction) - Vascular phase
- Stimulate B-cells to produce antibodies  o Vasonconstricton vasodilation  inc
chemical substances that destroy foreign agents capilllary pressure  plasma and blood
cells to tissues
Suppressor T-cells- referreed to as T8 or CD8 cells
Inflammatory mediators regulation
- Limit or turn off the immune response in the
absence of continued antigenic stimulation 1. Histamine- temporary constriction of large
- Ratio of helper T-cells: suppressor T cells- 2:1 vessels, increasing vascular permeability
2. Leukotrienes- contraction of smooth muscle,
Natural Killer cells- also known as CD16+ cells greater permeability of vessels, inc motility of
- Can exert killing effects without being first neutrohils and eosinphils
sensitized 3. Prostglandins- inc smooth muscl contraction,
- Conduct “seek and destroy” missions in the vascuular permeability, may modulate
body to eliminate non-self cells inflammation by suppressing the release of
- Specifically determined with HIV histamine
4. Platelet activating factor- inc vascular
B-cells permeability, helps to facilitate the movement
of white cells out of the vessels to damaged
- Mature in the bone marrow
tissue, activates platelets
- Humoral
- Blood
Pathophysiology
Cytokines Causative agent: retrovirus
TUMOR NECROSIS FACTOR (TNF)- first discovery: - Infects & depletes CD4+ T-helper lymphocytes
shrinking tumors AND infects monocytes & macrophages 
integrates into the lymphocytic genome--.
- Small doses cellular repair
Prodn of new HIV virions cell death for T4
- Large doses destroy health tissues
cellular and humoral immunity declines 
Physiologic aspects of cellular defense mechanism opportunistic infxns
3 main lines of defense HIV cannot be transmitted through: sweat, salive, tears,
urine, mosquito bites, sharing food/drinks, kissing,
1. Anatomic barriers hugging
2. Inflammatory and non-specific immune
responses - High risk groups: homosexual or bisexual, IV
3. Specific immune responses drug users, BT (before 1985), heterosexual

3. contact with infected partner, babies from HIV - Tests conducted are confidential
+ mother
Complications:
Natural history
- Resistant HIV, repeated opportunistic
- Normal CD4 count: 800-1000/mm infections, wasting, med-related conditions,
- 2-4wwks post exposure- 50-90% with flu-like sx renal failure
[Primary HIV infxn (acute)]
AIDS Research:
- 4-6wks- seroconversion  HIV +
- No cure yet due to the mutating nature of the
CxMx- peresistent cough, PCP, MTB, CMV
virus
- GI: diarrhea, wt. Loss, anorexia, enteric - Much work being done on vaccines
pathogens (salmonella, shigella) - Combination therapies- drug to boost the
- CNS: AIDS dementia/HIV encephalopathy, immune system
neuorpathies - HAART- highly active anti retroviral therapy-
- Ocular- retinopathy, blindness suppress the virus and prolong life but very
- Oral- lesions- C. Albicans, vesicles, hairy expensive
leukoplakia, oral warts –HPV, peridontitis, - Vaginal microbicides
apthous ulcers
- Malignancies: Kaposi’s sarcoma can signal the Med mgt:
final stage of HIV infxn - HAART- suppresses viral action
Dx: - Antiretroviral drugs: NRTI, NNRTI, PI, Entry
inhibitors
- History
- Blood test (>12wks) Goals of tx:
o ELISA - Improve quality of life
o Western blot- more specific - Prolong life
o Rapid HIV test - Dec viral load
o Orasure - Inc CD4 count
o Celypte HIV-1 urine EIA
o Lymphocyte panel Preventive:
o CBC
- Infections
o Presence of indicator dse
o PCP- started with CD4 <200  Dactrim
o Neuropsychological testing
o M. Avium complex- CD4 <50 
o Viral load
Azithromycin, clarithromycin
HIV antibody test - Vaccinations
o TB- PPD
- Looks for antibodies in the blood, not the HIV o PCP- pneumovax
virus o Influenza- flu vaccine
- Must be accompanied by pre- and post- test
counseling Standards of care
- Window period- the period during which
- Universal precaution
antibodies cannot be detected despite the
- Protect confidentiality
possible presence of HIV, can be up to six
- Medication compliance
months but a person with HIV is infectious from
- Nonjudgmental attitude
early stage

4. - Reverse isolation
- Nutrition
- Enteric precaution
- Suicide precaution
- Safer sex
- Encourage to disclose diagnosis
- Refer complementary medicines to AP