Question

Describe the pathogenesis of drug-induced lupus.

Hint:

Drug-induced lupus is typically reversible once the causative drug is discontinued, unlike systemic lupus erythematosus, which requires ongoing management.

Answer 1

Step 1: Overview of Drug-Induced Lupus (DIL).
Drug-induced lupus (DIL) is a form of lupus-like disease that is induced by certain medications. It is an autoimmune disorder that resembles systemic lupus erythematosus (SLE), but it differs in its clinical course and pathology. Unlike SLE, DIL is generally reversible upon discontinuation of the offending drug.
Step 2: Pathogenesis of DIL.
The pathogenesis of DIL involves the formation of immune complexes consisting of drugs, autoantibodies, and antigens. When the body is exposed to certain drugs, immune tolerance is disrupted, leading to the activation of T cells and the production of autoantibodies. The most common autoantibodies involved in DIL are anti-histone antibodies, which are associated with the drugs that trigger the condition.
Step 3: Immune System Activation.
The immune system's activation occurs in response to the drug and its metabolites, which can mimic self-antigens, leading to an autoimmune response. These immune complexes can deposit in tissues such as the skin, kidneys, and joints, causing inflammation and damage similar to that seen in SLE, but without the extensive organ damage.