🧠 Immunity & HIV/AIDS Study Guide

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📌 1. Immune Function & Key Terms

• Immunocompetence: Normal immune system function
• Immune deficiency: Decreased production/function of immune cells or antibodies
• Autoimmune disorder: Immune system attacks the body’s own tissues
• Immunosuppression: Reduced or inhibited immune response

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⚠️ 2. Immune Deficiency Conditions

Types of Immune Deficiency

Primary (Congenital)

• Genetic/inherited
• Present at birth

Acquired (Secondary)

• Develops after birth

Common Causes:

• HIV infection
• Immunosuppressive medications
• Bone marrow disorders

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💊 3. Therapeutic Immunosuppression

• Drug-induced suppression of immune system
• Requires balance between treatment and infection risk

Common Uses:

• Organ transplantation
• Autoimmune diseases (e.g., rheumatoid arthritis)
• Cancer treatment (e.g., lymphomas)

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🧪 4. Diagnostic Testing

Basic Evaluation:

• Health history
• Physical assessment

Lab Tests:

• CBC with differential
• Immunoglobulin levels
• T-cell and B-cell assays
• Bone marrow biopsy (if indicated)

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💉 5. Treatment of Immune Deficiency

• Immune globulin (IG) therapy
• Bone marrow transplant
• Colony-stimulating factors (increase neutrophils)
• Antimicrobial therapy

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🦠 6. HIV Overview

• Virus that attacks the immune system
• Targets CD4 T cells
• Leads to immune suppression

Types:

• HIV-1 (most common in U.S.)
• HIV-2 (slower progression, less common)

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🔄 7. HIV Progression

1. Acute infection
2. Clinical latency
3. AIDS

AIDS Diagnosis:

• CD4 count < 200 cells/µL
• OR presence of opportunistic infection

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🔬 8. Pathophysiology

• HIV infects and destroys CD4 T lymphocytes
• Weakens immune system
• Increases susceptibility to infections

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🚨 9. Transmission of HIV

Spread Through:

• Blood
• Semen
• Vaginal fluids
• Breast milk

High-Risk Activities:

• Unprotected sexual contact
• Needle sharing
• Maternal-fetal transmission

Not Spread By:

• Casual contact

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🛑 10. Prevention

• Safe sex (condoms/barriers)
• PrEP (pre-exposure prophylaxis)
• PEP (post-exposure prophylaxis within 72 hrs)
• Screened blood products

Key Point: Abstinence is the only 100% effective prevention

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🧍‍♂️ 11. Signs & Symptoms

Early (Acute HIV):

• Flu-like illness
• Fever
• Fatigue
• Swollen lymph nodes

Advanced (AIDS):

• Opportunistic infections
• Weight loss (wasting)
• Chronic diarrhea
• Night sweats

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🧫 12. Diagnosis

• HIV antigen/antibody test
• Confirmatory differentiation assay
• Nucleic acid testing (NAT)

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📊 13. Monitoring HIV

• CD4 Count

  • Normal: 500–1500 cells/mm³
  • AIDS: < 200 cells/mm³

• Viral Load

  • Measures amount of virus

• Drug resistance testing

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💊 14. Treatment of HIV

Antiretroviral Therapy (ART)

• Combination drug therapy
• Required for all HIV patients
• Lifelong adherence

Goals:

• Reduce viral load
• Increase CD4 count
• Prevent progression to AIDS
• Reduce transmission

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⚠️ 15. Opportunistic Infections

Occur due to weakened immune system

Viral:

• Herpes simplex
• Varicella-zoster
• Cytomegalovirus

Bacterial:

• Tuberculosis
• Mycobacterium avium

Fungal:

• Candidiasis (thrush)
• Pneumocystis jirovecii

Parasitic:

• Toxoplasmosis
• Cryptosporidiosis

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🧠 16. Key Memory Tips

• HIV attacks CD4 cells → weak immune system
• CD4 < 200 = AIDS
• ART = lifelong treatment
• Opportunistic infections = major complication

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