Immunodeficiencies and HIV

Overview of Immune Deficiencies

  • Immunodeficiency syndromes are conditions where the immune system is not functioning properly, resulting in frequent, severe, or long-lasting infections.

Types of Immunodeficiency Syndromes

1. Primary Immunodeficiency Disorders (PID)

  • Definition: PID is a group of disorders caused by inherited genetic mutations affecting the immune system.

  • Characteristics:

    • Individuals are born with the condition.

    • Typically manifests early in life.

    • Directly impacts the development or function of immune cells.

    • Leads to frequent, severe infections and other immune-related issues.

  • Examples of PID:

    • Severe Combined Immunodeficiency (SCID)

    • Common Variable Immunodeficiency (CVID)

  • Prevalence:

    • Over 6 million people worldwide have PID according to the CDC.

    • 70% to 90% of these cases go undiagnosed.

  • Hypothesis:

    • People with PID may be more likely to experience severe symptoms from viruses, including COVID-19.

2. Secondary Immunodeficiency Disorders (SID)

  • Definition: SID is acquired later in life due to external factors that weaken the immune system.

  • Causes:

    • Infections (e.g., HIV or AIDS)

    • Malnutrition

    • Certain medications (e.g., chemotherapy, immunosuppressive drugs)

    • Diseases (e.g., cancer, diabetes)

  • Characteristics:

    • The immune system starts off functioning normally but becomes compromised due to external influences.

Human Immunodeficiency Virus (HIV)

  • Definition: HIV is a virus that attacks the body's immune system by targeting white blood cells, specifically CD4 white blood cells.

  • Transmission:

    • Spread through body fluids such as breast milk, semen, blood, and vaginal secretions.

  • Testing for HIV:

    • Detected through blood and/or saliva testing.

    • It may take up to 12 weeks to develop antibodies and test positive.

3 Stages of HIV

  1. Asymptomatic HIV: Seropositive (HIV-positive) without symptoms.

  2. Early Symptomatic HIV: Symptoms may include fever, fatigue, and weight loss.

  3. HIV Advanced Disease/AIDS:

    • The immune system is severely damaged.

    • Symptoms may include neurologic manifestations, sores, persistent diarrhea, and skin blemishes.

    • A person is diagnosed with AIDS when CD4 cell counts fall below 200 cells/mm³; healthy counts range from 500 to 1,600 cells/mm³, or when they develop opportunistic infections regardless of CD4 count.

Treatment and Prevention

a. Prevention of HIV

  • Methods include:

    • Using latex condoms.

    • Testing prior to new sexual partners.

    • Eliminating shared needles.

    • Pre-Exposure Prophylaxis (PREP) for at-risk groups:

    • Definition: Medication taken to prevent contracting HIV; acts as a prophylactic antiretroviral.

b. Treatment After Contracting HIV

  • Antiretroviral Therapy (ART):

    • Used to reduce the viral load in the body after contracting HIV.