Prolonged lymphopenia following anti-thymocyte globulin induction is associated with decreased long-term graft survival in liver transplant recipients.

BACKGROUND AND AIM

Induction with anti-thymocyte globulin (ATG) during solid organ transplantation is associated with an improved clinical course and leads to prolonged lymphopenia. This study aims to investigate whether prolonged lymphopenia, caused by ATG induction, has an impact on patient and graft survival following liver and kidney transplantation.

PATIENTS AND METHODS

This was a single-center, retrospective study. A total of 292 liver and 417 kidney transplants were performed with ATG induction (6 mg/kgr, divided into four doses), and the transplant recipients were followed for at least three months. The average lymphocyte count for the first 30 days after the operation was calculated, and the cut-off value for defining lymphopenia was arbitrarily set to ≤ 500 cells/mm(3).

RESULTS

There were 210 liver transplant recipients (71.9%) who achieved prolonged lymphopenia, whereas the remaining 82 recipients (28.1%) did not. The mean survival time of these patient groups was 10.27 and 12.71 years, respectively (p = 0.1217), and the mean graft survival time was 8.98 and 12.25 years, respectively (p = 0.0147). Of the kidney transplant patients, 330 (79.1%) recipients achieved prolonged lymphopenia, whereas the remaining 87 (20.9%) did not. The mean survival time of these patient groups was 13.94 and 14.59 years, respectively, (p = 0.4490), and the mean graft survival time was 11.84 and 11.54 years, respectively (p = 0.7410).

CONCLUSION

The efficacy and safety of ATG induction partially depend on decreased total lymphocyte counts. Following ATG induction in liver transplant recipients, a reasonable average lymphocyte count during the first postoperative month would be above 500 cells/mm(3).