Diseases of the Immune System
HIV stands for human immunodeficiency virus. HIV is a type of virus that infects and kills helper T cells. Without functioning T cells, the immune system cannot respond properly to antigens. As a result, when HIV develops into AIDS (acquired immune deficiency syndrome), patients cannot mount an immune response to infections that are not normally considered lethal for healthy individuals, known as opportunistic infections.
Cause: HIV is a virus that is spread from contact with an infected person’s body fluids, like blood, breast milk, semen, or vaginal fluid. Having unprotected sex and sharing needles for drug use are common ways to contract HIV.
Symptoms: HIV occurs in four stages. When the virus is initially contracted, it quietly integrates itself during the incubation period and the newly infected person may not have any symptoms for 2 to 4 weeks. In the acute infection stage, which lasts about 28 days, people can experience fever, swollen lymph nodes, sore throat, sore muscles, and mouth sores. The latency or dormant stage can last 2 weeks to 20 years where few to no symptoms are noticed. In the final AIDS stage, patients can display the symptoms of whatever opportunistic infection they contract.
Treatment: Typically HIV is treated with antiretroviral drugs that prevent the virus from infecting new cells or making copies of itself. However, HIV is a fast-evolving virus; if it is treated with only one type of medicine, it quickly changes its genetic composition to be resistant to that drug. Currently HIV is treated with several drugs, called a “cocktail,” that prevent the virus from developing resistance to the medicine.
Autoimmune diseases include many types of disorders in which the immune system does not recognize the body’s own cells. The immune system thus makes a mistake and labels for attack its own cells, just like it would if it were an antigen. Some examples of autoimmune disorders are rheumatoid arthritis where the immune system attacks the joints and some forms of type 1 diabetes where the immune system attacks the pancreatic islet cells that make insulin.
Cause: Some autoimmune diseases are inherited genetically. Others are a result of a mutation or change in a person’s cells that spur an attack by their own immune system. Still other autoimmune disorders may be caused by environmental factors.
Symptoms: Symptoms can vary widely depending on which part of the body or organ is affected.
Treatment: Immunosuppressants are the most common type of drugs used to reduce the response of the immune system. Other treatments like pain medication or anti-inflammatories may ease the secondary side-effects of autoimmune disease.