Keratinocyte Carcinoma Risk: Antithymocyte Globulin vs. Other Induction Therapy in Solid Organ Transplant Patients: A Meta-Analysis.

BACKGROUND: Induction immunosuppression reduces early rejection after solid organ transplantation but may increase long-term malignancy risk, including keratinocyte carcinoma. Antithymocyte globulin is commonly used as a lymphocyte-depleting induction agent, yet its relative risk compared with other strategies remains unclear. OBJECTIVE: To evaluate the association between antithymocyte globulin induction therapy and keratinocyte carcinoma risk in adult solid organ transplant recipients compared with no induction, nondepleting agents, and other lymphocyte-depleting therapies. METHODS: PubMed, EMBASE, and MEDLINE were searched from January 1997 to February 2024. Observational studies and randomized trials reporting keratinocyte carcinoma outcomes in adult recipients exposed to antithymocyte globulin were included. Risk of bias was assessed using validated tools. Random-effects meta-analyses using risk ratios with 95% confidence intervals were performed. RESULTS: Twelve studies including 56,159 recipients with a weighted mean follow-up of 7.27 years were analyzed. Antithymocyte globulin induction was not associated with increased keratinocyte carcinoma risk compared with no induction. Lower risk was observed compared with alemtuzumab and OKT3. No significant difference in risk was observed compared with nondepleting anti-CD25 agents. CONCLUSION: Antithymocyte globulin induction does not increase keratinocyte carcinoma risk compared with no induction and is associated with lower risk than more potent lymphocyte-depleting agents after solid organ transplantation.