Genes, lifestyle, immunity Flashcards
Answers to note-taking guide D115
Cause of immune deficiency
failure of self-defense mechanisms (phagocytes, complement, inflammatory response) to function at normal capacity, primary is genetic - disrupted lymphocyte development, secondary is acquired (most common). Clinical hallmark is recurrent, severe infections
autoinflammatory diseases are characterized by
abnormally high levels of inflammation, secondary to mutations in control of inflammasome activation, defects in cellular receptors of cytokines that decrease inflammation. Related to diminished control of infections of epithelial surfaces
causes of acquired immunodeficiencies
complications of other physiologic or pathophysiologic conditions. Infections (AIDS), malnutrition, certain meds, prolonged illnesses, pregnancy, prematurity, infancy - immunological immaturity, aging, trauma, vitamin deficiency, malignancies, chronic diseases, physical trauma, surgery stress, anesthesia, corticosteroids, splenectomy,
how deficiencies in immunity are treated
primary immune deficiencies are treated by replacing the missing component (IvIG, IgA, FFP in monthly infusions, transplants-stem cells, fetal thymic tissue, fetal liver, bone marrow, glycerol packed erythrocytes, gene therapy)
four phases of infectious disease
1) incubation - initial exposure to onset of symptoms
2) prodromal - initial symptoms-discomfort and fatigue
3) invasion period - pathogen is multiplying rapidly, invading further and other areas, immune and inflammatory responses are initiated
4) convalescence - immune system removes infectious agent, or disease may be fatal, or enter latency with resolution of symptoms until later reactivation
direct transmission of infectious disease
physical contact, ingestion, inhalation, placental transfer
indirect transmission of infectious disease
contact with contaminated material, ranging from towels, to food, or thru a vector (mosquitos, ticks, fleas, snails, etc)
example/characteristics of bacterial infection
Ex - staph, cholera, streptococcal pna, TB, chlamydiae, rickettsiae, mycoplasma, E coli, pseudomonoas aeruginosa, plague, c diff. Characterized by fever, chills, fatigue, headache, swollen lymph nodes (symptoms persist longer than viral, fever is higher than viral, fever gets worse into illness rather than improving)
example/characteristics of fungal infection
Mold and yeast. Infection with fungus is called mycosis. Tinea pedis (athletes foot), tinea cruris (jock itch), tinea corporis (ringworm), candida albicans (most common cause) - cutaneous and subq, scaling, fissures, itching rash, lesions, raised borders, thrush, vaginal infections, ulcers or abscesses on skin or other organ systems.
Systemic are black mold, coccidioidomycosis, histoplasmosis, blastomycosis, cryptococcosis, systemic candidiasis-rash, headaches, nausea, pains, flulike symptoms, eye/other organ involvement, pneumonia, pneumonia like, sepsis, endocarditis, meningitis
example and characteristics of parasitic infections
Worms, protozoa. Toxoplasma gondii, trichomonas vaginalis, trichinosis (most common in US), giardia, cryptosporidium parvum, amoeboids, flagellate, ciliate, sporozoa. Characterized by GI symptoms, diarrhea, n/v, pain, cramping, bloating/gas, constipation. Skin-rash, blisters, hives, itching, irritation. Anemia, joint pain, seizures (severe cases), anal itching and discharge
example and characteristics of viral infections
adenoviruses, herpesviruses, papillomaviruses, reoviruses, HEP A, polio, HEP C, West Nile, rubella, flu, measles, mumps, noro, rabies, hanta, HIV, HEP B
Characterized by fever, fatigue, body-aches, headaches, sore throat, cough, runny nose, congestion, n/v, diarrhea, skin rashes, lesions, blisters, warts, stiff neck, photosensitivity, confusion
HIV
Increases antigenic diversity by incorporating frequent functional translational errors in mRNA. Can infect and kill immune CD4+ cells, which also causes broad immunosuppression. Sexual, maternal, needles or blood transmission, sharing of blood-born pathogen thru infected bodily fluids. Risks are sharing needles, unprotected sex, drugs. Fever, fatigue, headache, rash, lymphadenopathy, pharyngitis, myalgia, arthralgia, will resolve initially but HIV will continue killing CD4 cells. Tx - HAART (highly active antiretroviral therapy) combination of drugs that attack different viral replication pathways. Vaccine in development. Can detect antigen 4-10 days after exposure, 23-90 days for antibodies. May need repeat testing.
Effective countermeasures for infectious disease transmission
rigorous environmental infection control, controlling insects, modern sanitation, clean water, uncontaminated food, vaccines, antimicrobials
how vaccinations activate immune system and lead to immunity
Shorter than infection-induced immunity. Introduces weakened/killed pathogen, triggering the body to create antibodies and memory cells to fight future cells. Memory cells create faster and stronger immune response if pathogen is encountered later
why vaccine is safer than infection
Infections can cause serious illness, complications, hospitalization, even death. Vaccines confer immunity and create memory cells (usually) without the infection and the risks.
difference between incidence rate and prevalence rate
Incidence measures rate of new cases over time period. Ex-new cases of COVID in LA last week.
Prevalence measures proportion of individuals in a population who have disease at a specific time. Ex- Percentage of people in LA who currently have DM.
How relative risk is used in relation to disease process
Is a measure of association between exposure and a health outcome (disease.) RR of 1 is no difference between two groups (exposed and unexposed.) RR < 1 is decreased risk in exposed group compared to unexposed group. RR of 2 means exposed group is twice as likely to experience outcome as the unexposed group.
Increased rate of disease among individuals exposed to a risk factor / incidence rate of disease among individuals not exposed to risk factor
Examples of diseases that correspond with liability model
Refers to individual’s genetic liability for disease. To be affected, must exceed threshold. Psychiatric, substance use, heart disease, DM, asthma, eczema, migraine, depression
Empirical risks and how they affect disease
Based on observation or experience, can be verified or disproven by experiment or observation. EX - Estimating chance of child inheriting genetic condition based on family hx of condition. Empiric risks are influenced by smoking, excess alcohol, poor nutrition, sedentary, poor diet, pollution, lack of clean water, etc, all of which can contribute to disease development.
multifactorial and single-gene disease differences
Multifactorial diseases arise from interaction of multiple genes and environmental factors.
Single-gene diseases like cystic fibrosis or sickle cell are caused by mutation in one single gene.
Can change substantially from one population to another because gene frequencies and environmental factors can differ among populations.
Gene-environment interaction
different effect of environmental exposure on disease risk in persons with different genotypes. Ex - how person’s genetic makeup influences their response to diet
Multifactorial diseases that are common
high BP, CVD, DM2, CA - breast, prostate, skin, Alzheimers, obesity, asthma, arthritis, osteoporosis, schizophrenia, bipolar, cleft palate, spina bifida
UV light and its effects
Causes basal cell and squamous cell carcinoma. In DNA strands, causes thymine base pairs that are side by side to pair together, becoming thymine dimers. These dimers lead to cell death or cancer.
Exercise and colon cancer
Exercise-induced myokines cause apoptosis of colon cancer cells
Incorporating genetic factors into differential/definitive diagnosis
Consider family hx, complete thorough physical exams, utilize genetic testing when appropriate, seek expert consultation when indicated
How to assess for health literacy barriers, and which ones are common
Use a food label and assess reading, comprehension, numeracy skills. Ask patient to explain in their own words. Observe patient’s ability to follow instructions. Use teach-back. Look for red flags-missed appointments, non-adherence to medication, incomplete intake forms, saying they forgot their glasses. Common barriers include limited education, language barriers, socioeconomic factors, cultural differences, difficulties understanding health information.
How to address health literacy barriers
Use plain language, visual aids, culturally appropriate materials, actively listen, encourage question. Use teach-back. Speak slow and allow patient to process. Provide written materials. Tailor communication to culture. Use interpreters.
