🦋 SLE Flare Mechanism Simulator

Flare Trigger Exposure

A trigger event switches a quiet lupus baseline into active flare.

• UV light: Common trigger (sunlight exposure)
• Infection: Common trigger (viral or bacterial)
• Stress: Common trigger (physical or emotional)
• Days: Onset window (trigger to symptoms)

UV light exposure

Sunlight damages skin cells and exposes hidden self-antigens.

Infection

Viral or bacterial infection activates innate immune alarms.

Stress and hormones

Physiologic stress and estrogen shifts lower the flare threshold.

Autoantibody Production Surge

Activated B-cells mass-produce antibodies against the body's own nuclear material.

• dsDNA: Key target (anti-dsDNA antibody)
• Nuclear Ag: Key target (ANA positive)
• Plasma cells: Cell driver (antibody factories)
• ↑ Rising: Titer trend (during flare)

Loss of self-tolerance

B-cells that should be silenced instead activate and expand.

Antibody classes

Anti-dsDNA and anti-Smith antibodies rise sharply in flare.

Titer as a marker

Rising titers often precede clinical flare symptoms.

Immune Complex Deposition

Antibody-antigen complexes form in circulation and settle into tissue.

• Ag-Ab: Complex type (circulating complex)
• Basement mem.: Deposit site (vessel walls)
• Impaired: Clearance (in active SLE)
• Low C3/C4: Complement (consumed)

Complex formation

Excess antibody binds antigen faster than it can be cleared.

Tissue trapping

Complexes lodge in small vessels and basement membranes.

Complement drop

C3 and C4 levels fall as complement is consumed locally.

Multi-Organ Inflammation

Deposited complexes trigger inflammation across skin, kidney, and joints together.

• Malar rash: Skin (photosensitive)
• Nephritis: Kidney (proteinuria risk)
• Arthritis: Joints (symmetric, non-erosive)
• High: Overlap risk (when multi-organ)

Cutaneous flare

Butterfly rash appears over cheeks and nose bridge.

Renal flare

Immune complexes in glomeruli drive lupus nephritis.

Articular flare

Joint linings inflame causing pain without erosion.

Flare Management & Remission

Treatment dampens the autoimmune cycle and steers toward low disease activity.

• Hydroxychlor.: First line (baseline therapy)
• Steroids: Flare therapy (rapid control)
• Immunosupp.: Steroid-sparing (long-term control)
• Low activity: Goal (or remission)

Suppress the trigger response

Sun protection and infection control reduce future flares.

Quiet the antibody surge

Immunosuppressants reduce autoantibody-producing cells.

Treat-to-target

Monitor organs and taper toward sustained low activity.