Which is the most sensitive and specific antibody for Celiac sprue?
**Core Concept**
Celiac sprue, also known as celiac disease, is an autoimmune disorder triggered by the ingestion of gluten, leading to small intestine mucosal damage. The condition is characterized by an inappropriate immune response to gluten, which is a protein found in wheat, barley, and rye.
**Why the Correct Answer is Right**
The most sensitive and specific antibody for celiac sprue is tissue transglutaminase antibody (tTGA), also known as anti-tissue transglutaminase antibody. This antibody is directed against tissue transglutaminase, an enzyme found in the small intestine. The presence of tTGA indicates an autoimmune response against gluten, which is a hallmark of celiac disease. The sensitivity and specificity of tTGA make it a valuable diagnostic tool for detecting celiac disease.
**Why Each Wrong Option is Incorrect**
* **Option A:** Endomysial antibody (EMA) is another antibody used to diagnose celiac disease, but it is not as sensitive and specific as tTGA. EMA is more specific for celiac disease, but its sensitivity is lower compared to tTGA.
* **Option B:** Gliadin antibody is an antibody directed against gliadin, a protein found in wheat. While gliadin antibody can be present in individuals with celiac disease, it is not as sensitive and specific as tTGA.
* **Option D:** Anti-gliadin antibody (AGA) is another antibody used to diagnose celiac disease, but it is not as sensitive and specific as tTGA. AGA is more commonly used in children and may have lower specificity in adults.
**Clinical Pearl / High-Yield Fact**
Remember that tTGA is the most sensitive and specific antibody for celiac sprue, and its presence indicates an autoimmune response against gluten. However, a negative tTGA result does not rule out celiac disease, as some individuals may not produce this antibody.
**Correct Answer:** A. Tissue transglutaminase antibody (tTGA)