ANCA negative vasculitis amongst the following is:
**Core Concept:** ANCA (Anti-neutrophil cytoplasmic antibodies) are a type of autoantibody that bind to neutrophil granule proteins. ANCA-negative vasculitis refers to a group of vasculitides characterized by inflammation of blood vessels, where no ANCA antibodies are detected in the patient's serum.
**Why the Correct Answer is Right:** Systemic vasculitis refers to inflammation of small- and medium-sized blood vessels, leading to tissue ischemia and damage. ANCA-negative vasculitis encompasses three main types:
1. Granulomatosis with Polyangiitis (Wegener's granulomatosis) - characterized by necrotizing granulomas involving respiratory system, renal involvement, and necrotizing glomerulonephritis.
2. Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss syndrome) - characterized by eosinophilia, asthma, and neuropathy.
3. Microscopic Polyangiitis - a more indolent variant with renal involvement and alveolar hemorrhage.
**Why Each Wrong Option is Incorrect:**
A. ANCA-positive vasculitis is a different entity characterized by immune complex deposition and includes polyarteritis nodosa, Churg-Strauss syndrome, and Goodpasture syndrome.
B. Vasculitis due to other causes like infections, medications, or malignancies may show vasculitis but do not fall under ANCA-negative vasculitis.
C. Vasculitis due to other autoimmune diseases such as rheumatoid arthritis typically affects larger vessels and is different from ANCA-negative vasculitis.
D. Vasculitis due to infections like leptospirosis, syphilis, or leprosy usually involves larger vessels and is distinct from ANCA-negative vasculitis.
**Clinical Pearl:** ANCA-negative vasculitis is typically associated with a poorer prognosis than ANCA-positive vasculitis, as it is often more severe and less responsive to treatment. However, effective immunosuppressive therapy has improved survival rates in recent years.
**Correct Answer:** C. Vasculitis due to other autoimmune diseases such as rheumatoid arthritis typically affects larger vessels and is different from ANCA-negative vasculitis.