Overview
This lecture discusses how the immune system can malfunction, leading to autoimmune diseases, cancer, and HIV infection, along with treatments and impacts on health.
Autoimmune Diseases
- Autoimmune diseases occur when the immune system attacks the body's own cells, causing inflammation and tissue damage.
- Lupus is a chronic autoimmune disease affecting organs like skin, kidneys, and joints, often marked by a butterfly-shaped facial rash.
- Rheumatoid arthritis is an autoimmune disorder targeting joints, causing pain and swelling, unlike osteoarthritis.
- Triggers for autoimmune diseases include genetics, environmental factors (e.g., sunlight), and dormant virus reactivation.
- Autoimmune diseases are not curable but can be managed with anti-inflammatory drugs, immunosuppressants, and lifestyle changes.
- Corticosteroids are used to reduce inflammation and suppress immune activity in conditions like lupus.
Cancer and the Immune System
- Cancer involves uncontrolled growth and spread of abnormal cells, which can form tumors and invade tissues.
- Cancer treatments include surgery, radiation, chemotherapy, hormonal therapy, and targeted inhibitors.
- Chemotherapy drugs, such as doxorubicin, prevent cancer cell replication by interfering with DNA.
- Major drug classes for cancer include alkylating agents, antimetabolites, biological response modifiers, anti-tumor antibiotics, and plant alkaloids.
HIV and Immune Suppression
- HIV (human immunodeficiency virus) directly attacks the immune system, leading to vulnerability to infections and some cancers.
- HIV-1 is the most common type worldwide, while HIV-2 is less common.
- HIV is transmitted via sexual contact, mother-to-child, or exposure to infected bodily fluids.
- AIDS (acquired immunodeficiency syndrome) results when HIV severely weakens the immune system, especially if CD4 cell count falls below 200/mm³.
- HIV infection progression includes initial transmission, a long asymptomatic period, symptom onset, AIDS development, and advanced immune suppression.
- Medications for HIV include nucleoside and non-nucleoside reverse transcriptase inhibitors, which prevent viral replication (e.g., zidovudine).
Key Terms & Definitions
- Autoimmune disease — condition where the immune system attacks the body's own tissues.
- Lupus — a chronic autoimmune disease affecting multiple organs, often with a facial rash.
- Rheumatoid arthritis — autoimmune disease causing joint inflammation and pain.
- Cancer — disease of uncontrolled cell growth that can invade body tissues.
- Chemotherapy — drugs that kill rapidly dividing cancer cells.
- HIV — virus that infects and weakens the immune system.
- AIDS — advanced stage of HIV infection with severe immune deficiency.
- CD4 cell — a type of immune cell targeted and destroyed by HIV.
- Reverse transcriptase inhibitor — drug that blocks viral replication in HIV.
Action Items / Next Steps
- Review symptoms, causes, and treatment options for autoimmune diseases, cancer, and HIV.
- Learn key drug classes and their functions in cancer and HIV treatment.