Which Fully humanized antibody is used in treatment of rheumatoid ahritis?
**Core Concept**
Adalimumab is a fully humanized monoclonal antibody that targets tumor necrosis factor-alpha (TNF-alpha), a pro-inflammatory cytokine involved in the pathogenesis of rheumatoid arthritis (RA). By inhibiting TNF-alpha, Adalimumab reduces inflammation and joint damage in patients with RA.
**Why the Correct Answer is Right**
Adalimumab is a fully humanized antibody, meaning it has a high degree of similarity to human antibodies and is less likely to induce an immune response. It specifically binds to TNF-alpha, preventing it from interacting with its receptor on cell surfaces, which in turn reduces the inflammatory cascade. This mechanism of action is distinct from non-biological disease-modifying antirheumatic drugs (DMARDs) like Leflunomide, which work through different mechanisms. Adalimumab is administered via subcutaneous injection, allowing for convenient dosing and minimizing the risk of adverse effects associated with oral DMARDs.
**Why Each Wrong Option is Incorrect**
**Option A:** Anakira, also known as Anakinra, is an interleukin-1 receptor antagonist (IL-1RA) used in the treatment of RA. While it is a biologic DMARD, it targets a different cytokine pathway and is not fully humanized.
**Option C:** Infliximab is a chimeric monoclonal antibody that targets TNF-alpha, but it has a murine component, which can increase the risk of immunogenicity and adverse effects compared to fully humanized antibodies like Adalimumab.
**Option D:** Leflunomide is a non-biological DMARD that inhibits dihydroorotate dehydrogenase (DHODH), an enzyme involved in pyrimidine synthesis. It is not a monoclonal antibody and does not target TNF-alpha.
**Clinical Pearl / High-Yield Fact**
Fully humanized antibodies like Adalimumab have a lower risk of immunogenicity and adverse effects compared to chimeric or murine antibodies. This is an important consideration when selecting biologic DMARDs for patients with RA, particularly those with a history of adverse reactions to previous therapies.
**✓ Correct Answer: B. Adalimumab**