Immune System: Immunity and Immunization

Immune System and Disorders

• Diagnostic procedures involve identifying pathogenic micro-organisms
• Leukopenia is a less-than-normal amount of WBCs in circulation (30-40%)
• Leukocytosis refers to an increase of leukocytes (WBCs) in the circulation
• Neutrophils are the first cells to arrive at the site of inflammation
• White blood cells are produced in the bone marrow
• Natural immunity is the first line of defense
• The initial response to pathogens involves the production of cytokines

Immunization and Immunity

• Immunization involves administering a vaccine to cause the production of antibodies
• Vaccines are made from either killed or live, attenuated viruses
• Active immunity is immunity that is acquired through production of antibodies
• This immunity develops over weeks to months and is long-lasting
• Active-natural immunity occurs when the body develops antibodies in response to exposure to a live pathogen
• Active-artificial immunity develops after a vaccine is given
• Passive immunity develops when antibodies are transferred from another human or animal to a client
• Passive immunity is temporary
• Passive-natural immunity occurs when antibodies are passed from mother to fetus/newborn through the placenta and breast milk
• Passive-artificial immunity occurs when antibodies in the form of immune globulins are administered for immediate protection

HIV Pathophysiology and Transmission

• HIV belongs to the lentivirus and retrovirus subfamily
• HIV carries its genetic material in the form of RNA rather than DNA
• HIV targets cells with CD4+ receptors, which are on the surface of T-lymphocytes
• HIV transmission occurs through inflammation and breaks in the skin or mucosa
• HIV is transmitted through unprotected sex with an infected partner
• HIV is transmitted through blood, seminal fluid, vaginal secretions, amniotic fluid, and breast milk
• HIV is transmitted from mother to child through breast-feeding
• Perinatal infections often occur after exposure during delivery
• HIV is not transmitted through casual contact
• Risk from blood transfusions has been virtually eliminated
• Prevention is achieved by eliminating high-risk behaviors
• Consistent and correct condom use is an effective prevention method
• Medical male circumcision reduces the risk of HIV infection in men by approximately 60%
• PrEP involves taking tenofovir disoproxil fumarate 300 mg and emtricitabine 200 mg (Truvada) daily to avoid HIV acquisition
• A person's HIV status should be checked every 3 months when taking PrEP

Preventing HIV Transmission in Healthcare and Stages

• Standard precautions should be used in all healthcare settings, regardless of the patient's diagnosis
• Hand hygiene should be implemented after touching blood, body fluids, secretions, excretions or contaminated items
• Use gloves, gowns, and face protection during care
• Encourage wounds to bleed after a needle stick by holding it under running water
• Post-exposure prophylaxis involves taking antiretroviral medicines as soon as possible, but no more than 72 hours after exposure
• If an occupational exposure to HIV happens, alert a supervisor immediately
• HIV testing occurs at baseline plus 6 weeks, 12 weeks, and 6 months after exposure
• Blood counts and renal and function tests performed at baseline and 2 weeks after exposure

HIV Life Cycle

• Attachment/binding: GP120 and GP41 glycoproteins of HIV bind with the hosts CD4+ receptor and chemokine co-receptors
• Uncoating/fusion: HIV releases its two strands of viral RNA and three viral enzymes
• DNA synthesis: HIV changes its genetic material from RNA to DNA through reverse transcriptase
• Integration: New viral DNA enters the nucleus and is mixed with the T cell DNA resulting in permanent, lifelong infection
• Transcription: The activated CD4+ T cell forms messenger RNA (mRNA)
• Translation: Messenger RNA creates chains of new proteins and enzymes
• Cleavage: HIV protease enzyme cuts the polyprotein chain into the individual proteins
• Budding: Proteins and viral RNA migrate to the membrane, exit, and start the process all over

Diagnosing & Treating HIV

• HIV infection has five stages based on clinical history, physical examination, and laboratory evidence
• Primary HIV infection involves high levels of viral replication and widespread dissemination of HIV
• CD4+ T cell counts drop from a normal level of 500-1,500 cells/mm3 of blood
• HIV can last for 8 to 10 years before complications develop
• HIV disease progression is classified from less to more severe
• The diagnosis of stage 3 has implications for disability benefits, housing, and food stamps
• Screening tests diagnose HIV and determine the stage and severity of the infection
• Antibodies, antigens, and nucleic acids are directly detected in new tests
• A postive HIV antibody test requires an antibody differentation test to look for virus RNA
• Patients in stage 3/AIDS are severely immune depressed and can develop opportunistic infections
• Common opportunistic infections for AIDS patients includes pneumonia, bacterial and fungal infections
• ART suppresses HIV Replication

Rheumatoid Arthritis and Lupus

• Rheumatoid arthritis (RA) is a chronic, progressive inflammatory disease that attacks tissues and organs
• RA causes joint inflammation bilaterally and symmetrically
• RA is an autoimmune disorders precipitated by WBCs attacking synovial tissue
• A diagnosis of RA requires a score of 6 or greater.
• Patients with RA have red and/or abnormally shaped pupils
• Early signs of RA include fatigue and joint discomfort in older adults
• Treatment for RA begins with NSAIDs and may cause GI distress
• DMARDs suppress the immune system's reaction to RA to relieve pain and inflammation
• These meds inclue hydroxychloroquine, minocycline, sulfasalazine, penicillamine
• Lupus triggers include cigarette smoke, ultraviolet rays exposure from sunlight and fluorescent light bulbs
• With lupus monitor for pain, mobility, and fatigue as well as vital signs.
• Assess for hypertension, edema and diminished breath sounds.
• Implemented small, frequent meals.
• Corticosteriods are used for immunosuppresion
• Clients should avoid UV and prolonged sun exposure. Use sunscreen when outside and exposed to sunlight.

Gout and Fibromyalgia

• Uric acid buildup causes joint pain and inflammation

• Gout, or gouty arthritis, is a systemic disorder caused by hyperuricemia

• Big toes are most susceptible to Gout

• For Gout monitor erythocyte sedmination and uric acid levels

• Acute gouty arthritis results in a red limb

• Diet adjustments are recommended for Gout

• Colchicine helps decrease pain and inflammation for Gout

• Fibromyalgia is a chronic pain syndrome that manifests as pain, stiffness, and tenderness at trigger points in the body

• Patients may be numb and suffer headache

• Assess for depression

• Provide emotional support and monitor pain

• SNRIs and antipconvulsants help relieve symtpoms

Covid-19

• Signs of Covid-19 includes fever or chills, cough that is nonproductive and Shortness of breath or lack of smell.
• Also Muscle aches, Nausea or vomiting with Diarrhea
• Contact & droplet precautions and airborne
• PPE involves hats, N95 respirators, goggles, face shields, shoe covers, and protective coveralls
• Layperson Education from CDC in discharge

Medications

• Treatment for RA includes cytotoxic medications, and corticosteroids
• Octreotide is an anti-diarrheal therapy sometimes used for chronic HIV diarrhea
• Intravenous Immune globulin (IVIG) replaces inadequate amounts of IgG in patients at risk for recurrent infection.
• Medication for Pneumocystis Pneumonia includes; trimethoprim–sulfamethoxazole (TMP–SMX).
• TB can be treated using a combination of isoniazid, rifampin (Rifadin), pyrazinamide, and ethambutol.
• Common medication for treating is Febuxostat & Allopurinol increases fluids and decreases kidney stones/uric acid
• NSAIDs like Naproxen are used for pain relief resulting from Gout
• Truvada (tenofovir disoproxil fumarate and emtricitabine) is a pill taken daily to lower risk of acquiring HIV
• Pegloticase is used for difficult Gout cases.