A 32-year-old woman undergoes renal transplantation for end-stage renal disease. She requires induction immunosuppression to prevent acute rejection. Which of the following is the drug of choice for induction therapy in this patient?

Explanation

## Induction Immunosuppression in Renal Transplantation **Key Point:** Basiliximab, a chimeric monoclonal antibody against IL-2 receptor (CD25), is the preferred induction agent in renal transplantation because it provides potent T-cell depletion without the systemic toxicity of polyclonal antibodies. ### Mechanism of Basiliximab Basiliximab blocks the IL-2 receptor on activated T lymphocytes, preventing IL-2-mediated T-cell proliferation and activation. This selective targeting of activated T cells makes it ideal for induction therapy. ### Comparison of Induction Agents | Agent | Type | Mechanism | Advantage | Disadvantage | |-------|------|-----------|-----------|---------------| | **Basiliximab** | Chimeric mAb | IL-2R blockade | Selective, well-tolerated, no systemic toxicity | Expensive | | Daclizumab | Humanized mAb | IL-2R blockade | Similar to basiliximab | Withdrawn in many countries | | ATG/ALG | Polyclonal Ab | Pan-T-cell depletion | Potent | Serum sickness, CMV risk | | OKT3 | Murine mAb | CD3 blockade | Potent | Cytokine release syndrome | **High-Yield:** Basiliximab is given as two doses: one preoperatively and one on postoperative day 4. It is combined with calcineurin inhibitors (tacrolimus/cyclosporine), mycophenolate, and corticosteroids in triple or quadruple therapy regimens. **Clinical Pearl:** Basiliximab has largely replaced polyclonal antibodies (ATG/ALG) and murine monoclonal antibodies (OKT3) in modern transplant practice due to its superior safety profile and lack of human anti-mouse antibody (HAMA) formation. ### Why Basiliximab Over Other Options - **Mycophenolate mofetil:** Maintenance agent, not induction; used after initial immunosuppression - **Azathioprine:** Older maintenance agent; less effective than mycophenolate; not used for induction - **Tacrolimus:** Calcineurin inhibitor for maintenance therapy; requires therapeutic drug monitoring; not an induction agent [cite:KD Tripathi 8e Ch 75]