When someone has an autoimmune disease, their immune system mistakenly attacks their own healthy cells and tissues. But unlike when a healthy immune system attacks something that can cause harm—like a virus—theirs never calls off the attack.
While acquired immunodeficiency syndrome (AIDS) is another type of immune system malfunction, in this case, a person’s immune system is weakened or ineffective.
Verywell / Michela Buttignol
What Is AIDS?
Human immunodeficiency virus (HIV) is a virus that causes a person’s body to attack the cells they need to fight off infection, making them more vulnerable to other infections and diseases. While there is currently no cure for HIV, there are a variety of treatments that can significantly extend and improve the quality of life for people living with the virus.
After an initial acute infection period—which can last from several days to several weeks—a person enters the second stage of HIV: chronic infection. With proper treatment, a person with HIV may remain in the second stage for the rest of their life. However, if left untreated, HIV could progress to its final stage: AIDS.
Symptoms of AIDS may include:
- Rapid weight loss
- Recurring fever or profuse night sweats
- Extreme and unexplained tiredness
- Prolonged swelling of the lymph glands in the armpits, groin, or neck
- Diarrhea that lasts for more than a week
- Sores of the mouth, anus, or genitals
- Pneumonia
- Red, brown, pink, or purplish blotches on or under the skin or inside the mouth, nose, or eyelids
- Memory loss, depression, and other neurologic disorders
These symptoms can, however, also be the result of other illnesses. The only way to find out for certain (for those who don’t already know they have HIV) is to take an HIV test.
Diagnosing AIDS
HIV test results, combined with a person’s set of symptoms, will help a doctor determine whether to diagnosis someone with AIDS.
How the Immune System Works
The immune system—which is made up of various organs, cells, and proteins—is designed to protect a person’s body from harmful substances, germs, and cell changes that could make them sick.
A normal, healthy immune system is able to ward off most of what comes in contact with the body, with the exceptions of when there are particularly aggressive germs or it is somehow weakened. When a person gets sick with a cold, the flu, or another type of bacterial or viral infection, the fever and other symptoms they experience are caused by their body’s immune response.
A person’s immune system has three primary tasks:
- Fighting disease-causing germs (also known as pathogens) like bacteria, viruses, parasites, or fungi to be removed from the body
- Recognizing and neutralizing harmful substances from the environment
- Fighting disease-causing changes in the body, such as cancer cells
There are also three different types of immunity: innate, acquired, and passive.
Innate Immunity
This is the immunity a person is born with, which protects them against antigens—proteins found on the surface of cells, viruses, fungi, or bacteria.
The purpose of innate immunity is to maintain effective barriers against harmful materials that may enter a human body and provide its first line of defense. Some of the functions and barriers of innate immunity include:
- Cough reflex
- Enzymes in tears and skin oils
- Mucus, which traps bacteria and small particles
- Skin
- Stomach acid
- Immune system cells such as phagocytes and natural killer cells
If an antigen gets past these barriers, it is attacked and destroyed by other parts of the immune system.
Acquired Immunity
Acquired immunity develops following exposure to various antigens that have made it past the body’s initial barriers.
When this happens and a person’s immune system detects an antigen, it creates a specific protein that it uses to neutralize and/or fight off that particular antigen if it attempts to attack the body again. That protein is called an antibody.
Passive Immunity
Passive immunity is the result of antibodies that are produced outside of a person’s own body. Most notably, this occurs when a fetus receives antibodies that are transferred through the placenta. After it’s born, an infant typically has these antibodies for between 6 and 12 months.
AIDS and autoimmune diseases both affect the immune system, though in two different ways:
- AIDS, which is an acquired immune deficiency disorder, is caused by HIV and weakens a person’s immune system.
- Autoimmune diseases, on the other hand, are when a person’s own immune system turns against them, attacking healthy cells.
AIDS vs. Autoimmune Diseases
When a person has an autoimmune disease, their body’s immune system—which is there to protect them—can’t distinguish between something that is potentially harmful and their own healthy cells and tissues, so it attacks everything.
AIDS, however, is an immunodeficiency disorder. Unlike an autoimmune disease—in which a body’s immune system attacks its own healthy tissue—the immune system of a person with an immunodeficiency disorder is very weak, or absent altogether. This is also known as immunosuppression.
AIDS and Autoimmune Disease Research
HIV—the virus that causes AIDS—can also cause an immune dysregulation, which can lead to the development of autoimmune and systemic diseases.
In one 2017 study, a cohort of people living with HIV had certain autoimmune diseases at a more frequent rate than the general public. These include:
- Immune thrombocytopenic purpura
- Sarcoidosis
- Inflammatory myositis
- Guillain–Barré syndrome
A separate 2017 study found that people with HIV/AIDS had an increased risk of developing some autoimmune diseases, specifically:
- Sjögren syndrome
- Psoriasis
- SLE
- Autoimmune hemolytic anemia
- Uveitis
A Word From Verywell
When your immune system is functioning properly, you typically don’t even realize that it’s there. But for people with certain disorders involving the immune system, it might feel like it controls their entire life.
While AIDS and autoimmune diseases both affect the immune system, they do so in two different ways. AIDS, which is an acquired immune deficiency disorder, is caused by HIV and weakens a person’s immune system. Autoimmune diseases, on the other hand, are when a person’s own immune system turns against them, attacking healthy cells.