A patient presents with hemoptysis and hematuria few weeks after a respiratory tract infection. ANCA antibodies are present. Likely diagnosis is:
**Core Concept**
The patient's symptoms of hemoptysis and hematuria, along with the presence of ANCA (Anti-Neutrophil Cytoplasmic Antibodies), suggest a systemic vasculitis involving multiple organ systems. This condition is characterized by inflammation of blood vessels, leading to damage and dysfunction.
**Why the Correct Answer is Right**
The presence of ANCA antibodies is a hallmark of ANCA-associated vasculitides (AAV), specifically Granulomatosis with Polyangiitis (GPA) and Microscopic Polyangiitis (MPA). GPA is characterized by inflammation of small to medium-sized vessels, including those in the respiratory tract and kidneys, leading to symptoms such as hemoptysis and hematuria. The inflammation is caused by an immune-mediated response, with ANCA antibodies playing a key role in the disease process.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not account for the presence of ANCA antibodies, which are a key diagnostic feature of AAV.
**Option B:** This option is incorrect because it does not specify the involvement of multiple organ systems, which is a characteristic feature of AAV.
**Option C:** This option is incorrect because it does not mention the presence of ANCA antibodies, which are a diagnostic hallmark of AAV.
**Clinical Pearl / High-Yield Fact**
ANCA-associated vasculitides (AAV) are a group of systemic vasculitides characterized by the presence of ANCA antibodies and inflammation of small to medium-sized vessels. The presence of ANCA antibodies is a key diagnostic feature of GPA and MPA, and their absence makes these diagnoses less likely.
**Correct Answer:** C. **Granulomatosis with Polyangiitis (GPA)**