Comparison of the effectiveness and safety of antithmocyte globulin and basiliximab induction therapies in low immunological risk kidney transplant patients

Introduction: In order to reduce the risk of graft rejection after kidney transplantation, induction and maintenance therapy is applied by evaluating the immunological risk. Antithymocyte globulin (ATG) and basiliximab, an anti-IL2 receptor antagonist, are used in induction therapy in immunologically low-risk patients. In this study, we aimed to compare the effectiveness and safety of basiliximab and ATG use as an induction therapy in kidney transplant patients with low immunological risk and to contribute to the literature. Materials and Methods: A retrospective study was designed by reviewing the files and hospital database of a total of 200 patients (100 patients who underwent basiliximab protocol for induction therapy and 100 patients who underwent ATG) who underwent living donor kidney transplantation between January 1, 2020 and December 31, 2022 at Akdeniz University Faculty of Medicine Hospital, who were over 18 years of age and had low immunological risk. A maximum period of 41 months was evaluated in the retrospective evaluation of the patients. Gender, age, HLA tissue group data, last available creatinine value, presence of biopsy-proven rejection attack, graft and patient survival, survival time, renal biopsy result, CMV and BKV PCR test results after transplantation, presence of DM or HT after transplantation were compared. All recipients received tacrolimus, MMF and steroids as maintenance therapy. CMV PCR values of 1000 copies/ml and above and BKV PCR values of 10,000 copies/ml and above were considered positive. Cadaveric donor kidney transplant, PRA (+), combined organ transplant and second or more kidney transplant patients were excluded. Results: We evaluated 100 patients with low immunologic risk who received basiliximab as induction therapy and 100 patients who received ATG. Both groups receiving basiliximab and ATG were similar in terms of age, gender and last serum creatinine levels. The mean HLA compatibility and DR compatibility were higher in patients receiving basiliximab than in those receiving ATG and were found to be significant (3.46 ± 1.13 versus 1.57 ± 1, respectively, p<0.05; 1 .14 ± 0.42 vs. 0.55 ± 0.63, p<0.05). Renal biopsy-proven rejection rates between the two groups receiving basiliximab and ATG (19% versus 13%, respectively, p=0.335), death-censored graft survival rates (96% versus 96%, respectively, p=1.0), and Patient survival rates were similar (96% vs. 95%, respectively, p=0.733). Both groups were similar in terms of the development of CMV and BKV infection in the post-transplant period. Both groups were similar in terms of the presence of post-transplant DM (NODAT) and post-transplant HT. The effect of age and gender on graft survival was not determined. Last serum creatinine levels in patients with graft loss were 7.5 ± 2.4 mg/dL and 1.2 ± 0.3 mg/dL in those with intact grafts (p<0.05). A statistically significant difference was found between the mean HLA compatibility and DR compatibility in patients with and without graft loss (2.63 ± 1 vs. 2.51 ± 1.58, respectively, p<0.05; 1.13 ± 0.36 vs 0.83 ± 0.61, p<0.05). Rejection proven by renal biopsy is present in 100% of patients with graft loss and in 12.5% of patients with intact grafts, and this difference is statistically significant (p<0.05). When the biopsy results of patients with graft loss were compared with patients with intact grafts, a statistically significant difference was detected (p = 0.007). CMV and BKV infection after transplantation had a significant impact on graft survival (p=0.002 and p=0.004, respectively). The effect of post-transplant DM (NODAT) and post-transplant HT on graft loss has not been determined. The 12-month, 24-month and 36-month death-censored graft survival rates in patients receiving basiliximab were 99%, 94.2% and 94.2%, respectively, while those in those receiving ATG were 99%, 93.5% and 93.5%, respectively. It was found to be 93.5%. The average graft survival time was found to be 39.6 months in those receiving basiliximab and 39.3 months in those receiving ATG, and they were similar (log-rank: 0.791). Conclusion: In our study, it was observed that there was no significant difference between basiliximab and ATG induction therapies in terms of biopsy-proven rejection, graft survival and patient survival. Death-censored graft survival times were found to be similar. No significant difference was detected between the two treatments in terms of CMV and BKV infection after transplantation. It has been observed that CMV and BKV infection after transplantation increases the risk of graft loss. HLA and DR compatibility was observed to be higher in patients receiving basiliximab. Key Words: Kidney transplant induction therapy, basiliximab, antithymocyte globulin, rejection, graft survival