Pathology of Calcineurin and Mammalian Target of Rapamycin Inhibitors in Kidney Transplantation

The recent evolution in immunosuppression therapy has led to significant improvement in short-term kidney allograft outcomes; however, this progress did not translate into similar improvement in long-term graft survival. The latter, at least in part, is likely to be attributed to immunosuppressant side effects. In this review, we focus on the histologic manifestations of calcineurin inhibitor and mammalian target of rapamycin inhibitor toxicity. We discuss the pathologic features attributed to such toxicity and allude to the lack of highly specific pathognomonic lesions. Finally, we highlight the importance of clinicopathologic correlation to achieve a meaningful pathologic interpretation

Belatacept in kidney transplant patients with systemic lupus erythematosus

Objectives: Lupus nephritis (LN) requires renal replacement therapy in 10%-30% of patients. About 30% of these patients receive a kidney transplant. Belatacept is a second-generation, selective, T-cell co-stimulator blocker (inhibits cytotoxic, T-lymphocyte antigen 4, CTLA-4) used as an alternative to calcineurin inhibitors (CNI) for maintenance regimens after kidney transplantation. The pathogenic relevance of CTLA-4 inhibition and the favourable cardiovascular profile of belatacept make it an attractive therapeutic option in systemic lupus erythematosus (SLE). Intravenous administration of belatacept ensures therapeutic adherence. Methods: This retrospective, single-centre study evaluates the outcomes of LN kidney transplant recipients treated with belatacept for reasons not related to SLE at the Columbia University Lupus and Renal Transplant Cohort. Results: Belatacept was started in six patients on CNI regimens at 15.5±17.1 months following transplantation for LN. In five patients, creatinine levels stabilised 6 months after belatacept, one returned to haemodialysis due to CNI toxicity and pyelonephritis and one relisted for a kidney transplant following acute cellular rejection and cortical necrosis. Five patients are followed for extrarenal lupus; no extrarenal manifestations were documented in the other two patients. Data on SLE disease activity pre-belatacept and post-belatacept were available and scored in three patients using the SLE Disease Activity Index Glucocorticosteroid Index (SLEDAI-2KG), which accounts for clinical and laboratory manifestations, as well as steroid dose. Mean SLEDAI-2KG decreased from 13 to 7.6. Conclusion: Belatacept in LN kidney transplant recipients may decrease extrarenal manifestations, attenuate CNI toxicity and stabilise allograft function, providing a better alternative to CNI regimens. Furthermore, these data suggest that belatacept, although initiated for reasons not related to SLE, might have a beneficial effect in SLE