Systemic Lupus Erythematosus (SLE) Basics

Study Notes

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that affects multiple organs and systems.
It is characterized by the production of autoantibodies against nuclear and cytoplasmic antigens.
SLE affects approximately 1 in 2,000 people worldwide, with a higher prevalence in women (9:1 female-to-male ratio) and certain ethnic groups (African Americans, Hispanics, and Asians).

The immune system mistakenly attacks healthy tissues, leading to inflammation and damage to organs such as the skin, joints, kidneys, and nervous system.
Autoantibodies against double-stranded DNA, histones, and other nuclear antigens contribute to the disease process.
Cytokines, such as TNF-α and IL-1β, play a role in promoting inflammation and tissue damage.

Mucocutaneous: butterfly rash (malar rash), discoid lupus, oral ulcers, and photosensitivity
Musculoskeletal: arthritis, arthralgia, and myalgia
Renal: glomerulonephritis, proteinuria, and nephrotic syndrome
Neurological: seizures, psychosis, and peripheral neuropathy
Cardiovascular: pericarditis, myocarditis, and premature atherosclerosis
Hematological: anemia, leukopenia, lymphopenia, and thrombocytopenia

Diagnostic criteria: at least 4 of the following 11 criteria:
1. Malar rash
2. Discoid rash
3. Photosensitivity
4. Oral ulcers
5. Arthritis
6. Serositis (pleuritis or pericarditis)
7. Renal disorder (proteinuria or cellular casts)
8. Neurological disorder (seizures, psychosis, or mononeuropathy)
9. Hematological disorder (anemia, leukopenia, lymphopenia, or thrombocytopenia)
10. Immunological disorder (anti-dsDNA, anti-Sm, or antiphospholipid antibodies)
11. Antinuclear antibody (ANA) positivity
Laboratory tests: complete blood count, erythrocyte sedimentation rate, ANA, anti-dsDNA, and complement levels

Medications: NSAIDs, corticosteroids, immunosuppressants (e.g., hydroxychloroquine, azathioprine), and biologics (e.g., belimumab)
Lifestyle modifications: sun protection, stress management, and regular exercise
Monitoring: regular check-ups, laboratory tests, and disease activity scores (e.g., SLEDAI)

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that affects multiple organs and systems.
SLE is characterized by the production of autoantibodies against nuclear and cytoplasmic antigens.
The disease affects approximately 1 in 2,000 people worldwide.
SLE has a higher prevalence in women (9:1 female-to-male ratio) and certain ethnic groups (African Americans, Hispanics, and Asians).

The immune system mistakenly attacks healthy tissues, leading to inflammation and damage to organs.
Autoantibodies against double-stranded DNA, histones, and other nuclear antigens contribute to the disease process.
Cytokines, such as TNF-α and IL-1β, play a role in promoting inflammation and tissue damage.

Mucocutaneous manifestations include butterfly rash, discoid lupus, oral ulcers, and photosensitivity.
Musculoskeletal manifestations include arthritis, arthralgia, and myalgia.
Renal manifestations include glomerulonephritis, proteinuria, and nephrotic syndrome.
Neurological manifestations include seizures, psychosis, and peripheral neuropathy.
Cardiovascular manifestations include pericarditis, myocarditis, and premature atherosclerosis.
Hematological manifestations include anemia, leukopenia, lymphopenia, and thrombocytopenia.

Diagnosis is based on at least 4 of the 11 criteria, including malar rash, discoid rash, photosensitivity, and more.
Laboratory tests include complete blood count, erythrocyte sedimentation rate, ANA, anti-dsDNA, and complement levels.

Medications used to treat SLE include NSAIDs, corticosteroids, immunosuppressants, and biologics.
Lifestyle modifications include sun protection, stress management, and regular exercise.
Regular monitoring is necessary, including check-ups, laboratory tests, and disease activity scores (e.g., SLEDAI).