HLTH module 3: immunodeficiency Flashcards
what is immunodeficiency?
a loss of function of the immune system, leading to increased risk of infection and cancer
primary deficiencies
involve a basic development failure somewhere in the immune system (ex. bone marrow)
examples of primary deficiencies
hypogammaglobulinemia and DiGeorge syndrome
hypogammaglobulinemia
low antibody levels because of a B-cell defect
DiGeorge Syndrome
hypoplasia of the thymus
hypoplasia
incomplete development of a tissue
secondary immunodeficiency
aka acquired immunodeficiency; loss of the immune system response resulting from specific causes; can occur with infection (particularly viral infections), removal of the spleen, malnutrition, liver disease, the use of immunosuppressive drugs, and radiation or chemo
why is cancer associated with immonodeficency?
because there is malnutrition, blood loss, and the effects of treatment that depress bone marrow production of WBCs
how do glucocorticoids increase immunodeficiency?
they decrease leukocyte production, cause atrophy of lymph nodes, and suppression of the immune response
why does stress cause immunodeficiency?
because high levels of glucocorticoids are produced in the body
how does AIDS or HIV cause immunodeficiency
by affecting T-helper cells, causing an increased risk to secondary infections and cancer
what drugs are important for immunodeficient individuals?
prophylactic antimicrobial drugs (these are preventative antibiotics)
what are increased risks for immunodeficient individuals?
higher risk of cancer and opportunistic infections from normally harmless microorganisms
treatment for immunodeficient individuals
replacement therapy for antibodies using gamma globulins, as well as sometimes bone marrow or thymus transplants
HIV stages
prolonged period followed by a period of active infection
what is AIDS?
the active stage of infection in individuals with the HIV virus
what are markers that someone may be HIV positive?
P carinii pneumonia or Kaposi sarcoma cancer with no other pathologies present
how is HIV transferred?
usually male-to-male sexual contact, but also heterosexual contact, drug injection, and a combination of drug use and male-to-male sexual contact
what type of virus is HIV?
a retrovirus and this means that is has an RNA genome
what is the subfamily of the HIV virus?
lentivirus
where is HIV-1 commonly found?
US and Europe
where is HIV-2 commonly found?
central Africa
what specific T-helper lymphocyte does HIV affect?
the CD4 positive ones
HIV and the lymphatic system relationship
the virus often uses the lymph nodes, tonsils, and spleen as a reservoir for continued infection
HIV virus anatomy
the core contains two strands of RNA and the enzyme reverse transcriptase; the coat is covered with a lipid envelope studded with spikes of glycoproteins that the virus uses to attach to human cells
what type of HIV transmission develops quickest?
injections
how is HIV tested for?
looking for antibodies and viral RNA or DNA through polymerase chain reaction technology; can also look for opportunistic infections of cancers
why can antibodies not destroy HIV virus?
because the virus is hidden safely inside host cells in the lymphoid tissue, there are slight mutations in the viral envelope, and the destruction of T-helper cells and macrophages depresses the immune system
what measures should healthcare workers take when working with a HIV patient?
should always assume that there is a risk of infection, should seek counselling, and postexposure prophylaxis
who are individuals with high risk of HIV?
those who are intravenous drug users and those with multiple shared sexual partners
what drug helps to protect the fetus from an HIV mother?
azidothymidine
three-stage process for HIV testing
- look for HIV1/2 antigen or antibody 2/ differentiate between HIV1/2 antibodies 3. use a nucleic acid test to confirm HIV-1 positivity and eliminate a false negative
what do CD4 lymphocytes change to during opportunistic infection?
CD8
what antibody increases during HIV infection?
igG
HIV symptoms during the first phase
flu like symptoms including low fever, fatigue, and sore throat
HIV symptoms during the second phase
enlarged lymph nodes or general lymphadenopathy; many exhibit no symptoms during this phase
final acute stage symptoms of HIV
GI effects, neurological effects, secondary infections, infection around the teeth, weight loss, necrosis, and malignancies
HIV encephalopathy
aka general brain dysfunction; is the AIDS dementia by brain cell infection, often aggravated by malignant tumors
HIV encephalopathy signs
confusion, cognitive impairment, memory loss, loss of coordination and balance, and depression
what is the primary cause of death in AIDS patients?
secondary infections
what does kaposi sarcoma affect?
the skin, mucous membranes and internal organs; skin appears purple or brown and is not itchy
signs of AIDS in children
children are usually smaller, exhibit failure to thrive, have developmental delays, and neurologic impairs (seizures and poor motor skills)
six classes of HIV drugs
non nucleoside reverse transcriptase inhibitors, nucleoside reverse transcriptase inhibitors, protease inhibitors, fusion inhibitors, CCR5 antagonists, and integrase strand transfer inhibitors
antiretroviral therapy
the use of multiple drugs to treat HIV; often used in combinations of 3-5 to prolong the latent phase
when should HIV treatment begin?
when severe symptoms are present, when CD-4 positive T cell count is less than 500, during pregnancy, during HIV-related kidney disease, and ongoing treatment for hep B
sepsis
a toxic condition resulting from the spread of bacteria or their toxic products from a focus of infection; combination of SIRS and infection
SIRS
systemic inflammatory response syndrome
signs of SIRS
high or low temperature, high heart rate, and high or low WBC
causes of sepsis
endogenous tissue damage (ex. pancreatitis), immune freak out, exogenous tissue damage (ex. burns), miscellaneous (thyroid storm, exam jitters)
how does sepsis happen
a bacterium comes in contact with an immune cell, causing cytokines migrate to injury site via vasodilation, as well as coagulation
