Deposition of anti ds DNAAb in kidney, skin, choroid plexus and joints is seen in –
**Core Concept**
The question is testing the understanding of systemic lupus erythematosus (SLE), an autoimmune disease characterized by the deposition of immune complexes, including anti-double-stranded DNA (anti-dsDNA) antibodies, in various tissues. This deposition leads to inflammation and tissue damage.
**Why the Correct Answer is Right**
The deposition of anti-dsDNA antibodies in various tissues, such as the kidneys (lupus nephritis), skin (lupus rash), choroid plexus (neuropsychiatric SLE), and joints (arthritis), is a hallmark of SLE. These antibodies bind to the nuclei of cells, leading to the activation of complement and the recruitment of inflammatory cells, resulting in tissue damage. This process is mediated by the classical pathway of complement activation, involving the binding of C1q to the antibody-antigen complex.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the correct disease associated with the deposition of anti-dsDNA antibodies. While other autoimmune diseases may involve the deposition of immune complexes, the specific pattern of tissue involvement described in the question is characteristic of SLE.
**Option B:** This option is incorrect because it refers to a different disease process. Rheumatoid arthritis is characterized by the deposition of immune complexes, but the specific antibodies and tissues involved are different from those described in the question.
**Option C:** This option is incorrect because it is too vague and does not specify the correct disease. While vasculitis can involve the deposition of immune complexes, the specific pattern of tissue involvement described in the question is characteristic of SLE.
**Option D:** This option is incorrect because it is a type of vasculitis, but it does not specifically involve the deposition of anti-dsDNA antibodies in the tissues described in the question.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the presence of anti-dsDNA antibodies is a specific marker for SLE and can be used to support the diagnosis. However, a positive test result should be interpreted in the context of other clinical and laboratory findings.
**Correct Answer:** Systhemic Lupus Erythematosus