Antirheumatoid drug has specific act on the T-cell is
**Core Concept**
The question is testing the student's understanding of the specific mechanisms of action of antirheumatoid drugs, particularly their effects on the immune system. The correct answer will involve a drug that targets T-cells, a key component of the immune system involved in rheumatoid arthritis.
**Why the Correct Answer is Right**
The correct answer is Leflunomide, which specifically inhibits the mitochondrial enzyme dihydroorotate dehydrogenase (DHODH), leading to a decrease in pyrimidine synthesis. This action affects the proliferation of T-cells, which are crucial in the pathogenesis of rheumatoid arthritis. Leflunomide's mechanism of action is unique among antirheumatoid drugs, making it a key target for this question.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not specify a drug with a unique action on T-cells. While some antirheumatoid drugs may have immunosuppressive effects, they do not target T-cells specifically.
* **Option B:** This option is incorrect because it does not accurately describe the mechanism of action of the correct answer. While some antirheumatoid drugs may affect pyrimidine synthesis, they do not do so through the inhibition of DHODH.
* **Option C:** This option is incorrect because it does not specify a drug that targets T-cells. While some antirheumatoid drugs may have anti-inflammatory effects, they do not target T-cells specifically.
**Clinical Pearl / High-Yield Fact**
Leflunomide is a disease-modifying antirheumatoid drug (DMARD) that is specifically indicated for the treatment of rheumatoid arthritis. Its unique mechanism of action makes it a valuable addition to the treatment armamentarium for this disease.
**Correct Answer:** C. Leflunomide