Deposition of anti ds DNA Ab in kidney, skin, choroid plexus and joints is seen
**Core Concept**
The deposition of anti-dsDNA antibodies in various tissues is a hallmark of systemic lupus erythematosus (SLE), an autoimmune disease characterized by the production of autoantibodies against self-antigens. This phenomenon is a result of the immune system's dysregulation, leading to the production of antibodies against double-stranded DNA (dsDNA).
**Why the Correct Answer is Right**
The deposition of anti-dsDNA antibodies in the kidneys (lupus nephritis), skin (lupus rash), choroid plexus (neurolupus), and joints (arthritis) occurs due to the immune complex formation. Immune complexes are formed when the antibodies bind to the antigens, and these complexes can deposit in various tissues, triggering an inflammatory response. This process is mediated by the complement system, which is activated by the binding of C1 to the Fc region of the antibody. The activation of the complement system leads to the production of various inflammatory mediators, including C3a and C5a, which attract neutrophils and macrophages to the site of deposition, causing tissue damage.
**Why Each Wrong Option is Incorrect**
* **Option A:** This is not a known manifestation of SLE.
* **Option B:** While vasculitis can occur in SLE, it is not the primary manifestation of anti-dsDNA antibody deposition.
* **Option C:** This option is incorrect as it does not accurately describe the primary manifestations of SLE.
**Clinical Pearl / High-Yield Fact**
The presence of anti-dsDNA antibodies is a highly specific marker for SLE, but it is not sensitive enough to be used as a sole diagnostic criterion. However, a high titer of anti-dsDNA antibodies is often associated with active disease and lupus nephritis.
**Correct Answer:** D. SLE