Understanding HIV and AIDS: Immune System Impact

Understanding HIV and AIDS: Impact on the Immune System

In 1981, a rare form of pneumonia, caused by a protozoan, was observed. Medical investigators noticed a relationship between this pneumonia and a rare form of skin cancer. Both the pneumonia and the skin cancer seemed to be associated with a widespread failure of the body's immune system.

The Discovery of HIV

By 1983, the pathogen responsible for this immune system disease had been identified. It is a retrovirus. The disease is now known as Human Immunodeficiency Virus (HIV). HIV specifically targets and kills helper T cells in the body, which are crucial for immune function. The progression of HIV infection ultimately leads to Acquired Immune Deficiency Syndrome (AIDS).

How HIV is Transmitted

HIV is spread from an infected person through direct contact with their blood or body fluids. This can occur through:

• Direct contact with infected blood or body fluids.
• Contact with objects contaminated by infected blood or body fluids.
• Intimate sexual contact.
• Use of contaminated intravenous needles.
• Blood transfusions, if the blood is contaminated.
• Mother-to-child transmission during pregnancy or childbirth.
• Transmission through breast milk from an infected mother to her infant.

Early Symptoms of AIDS

The initial symptoms associated with AIDS can include:

• Swollen lymph nodes
• Loss of appetite
• Weight loss
• Fever
• Rashes
• Night sweats
• Fatigue

Immune System Glossary

Acquired Immunity

The body's defense against a specific pathogen by gradually building up resistance to that pathogen.

B Cell

A lymphocyte that, when activated by a T cell, becomes a plasma cell and produces antibodies.

Innate Immunity

The ability of your immune system to defend the body against any and all pathogens; white blood cells play a significant role in providing innate immunity.

Interferon

A host-cell-specific protein that protects cells of one species from viruses.

Lymph

Tissue fluids composed of water and dissolved substances from the blood that have collected and entered the lymph vessels.

Lymph Node

A small mass of tissue made of an interlaced network of connective tissue fibers that contains lymphocytes. It filters pathogens from the lymph.

Lymphocyte (LIHM-fuh-site)

A type of white blood cell that defends the body against foreign substances.

Macrophage

A white blood cell that provides the first defense against pathogens that have entered body tissues; these giant cells surround and engulf pathogens, and lysosomal enzymes inside the macrophage digest the engulfed particle.

Phagocyte (FAG-uh-site)

A white blood cell that destroys pathogens by surrounding and engulfing them.

Pus

A collection of living and dead white blood cells, living and dead pathogens, and body fluids.

T Cell

A lymphocyte produced in bone marrow and processed in the thymus gland.

Tissue Fluid

Composed of water and dissolved substances that diffuse from the blood into the spaces between the cells that make up the surrounding tissues.

Vaccine

A substance consisting of weakened, dead, or incomplete portions of pathogens or antigens that, when injected into the body, causes an immune response.