Drug induced lupus antibodies are found in –
**Core Concept**
Drug-induced lupus erythematosus (DILE) is a rare autoimmune disorder triggered by certain medications, characterized by the production of autoantibodies against nuclear antigens, resembling systemic lupus erythematosus (SLE). The pathogenesis involves the formation of immune complexes and activation of T-cells, leading to inflammation and tissue damage.
**Why the Correct Answer is Right**
The correct answer is related to the specific autoantibody associated with DILE. Antihistone antibodies are the most common type of autoantibody found in patients with DILE, which is distinct from the antinuclear antibodies (ANA) found in SLE. Antihistone antibodies are directed against the histone proteins that DNA wraps around in the nucleus, and their presence helps differentiate DILE from SLE.
**Why Each Wrong Option is Incorrect**
* **Option A:** Anti-SSA/Ro and anti-SSB/La antibodies are more commonly associated with Sjögren's syndrome and SLE, not DILE.
* **Option B:** Anti-Smith (anti-Sm) antibodies are highly specific for SLE and are not typically found in DILE.
* **Option C:** Anti-dsDNA antibodies are also characteristic of SLE, particularly in patients with active disease, and are not commonly found in DILE.
**Clinical Pearl / High-Yield Fact**
When suspecting DILE, clinicians should consider the temporal relationship between the onset of symptoms and the initiation of the offending medication, as well as the presence of antihistone antibodies. Discontinuation of the culprit drug often leads to resolution of symptoms.
**Correct Answer: C. Antihistone antibodies. Antihistone antibodies.**