Immunosuppression is associated with a high incidence of malignancies among renal transplant patients. In this study, we investigated the relationship between CD4 lymphopenia and the development of posttransplant malignancy (PTM) after induction therapies in renal transplant recipients (RTR).
Patients and methods: This retrospective study included 966 RTR who were transplanted between 1993 and 2005 and had a mean follow-up of 83 +/- 46 months. Induction with antithymocyte globulin (ATG) was employed in 747 patients, while remaining 219 recipients received anti-CD25 antibodies. CD4 T-cell counts determined yearly were correlated with the occurrence of PTM.
Results: Eighty-five (8.8%) patients developed a PTM: cutaneous neoplasia (n = 33), lymphoma (n = 14), noncutaneous solid cancer (n = 36). Only age was observed to be significantly different among patients with versus without PTM (48 +/- 10 vs 41 +/- 12 years; P < .001). An early CD4 lymphopenia (<300/mm(3)) was frequent after ATG as compared with anti-CD25 induction (69.8% vs 12.1% at 3 months; P < .0001). The proportion of T CD4 lymphopenic patients progressively decreased over time remaining stable at 5- and 10-year follow-ups (12% and 10.8%, respectively). However, CD4 lymphopenia was not associated with a greater incidence of PTM.
Conclusion: ATG induced CD4 lymphopenia, which persisted in a small proportion of patients in the long term, but did not seem to be correlated with the occurrence of PTM.