Analyzing the clinical outcomes of switching from cyclosporine to tacrolimus in pediatric hematopoietic stem cell transplantation

Comparison of tacrolimus vs. cyclosporine in pediatric hematopoietic stem cell transplantation for thalassemia

OBJECTIVES

Graft-versus-host disease (GvHD) is one of the leading causes of morbidity and mortality in patients undergoing allogeneic HSCT, and effective prevention of GvHD is critical for the success of the HSCT procedure. Calcineurin inhibitors (CNI) have been used for decades as the backbone of GvHD prophylaxis. In this study, the efficacy and safety of Cyclosporine A (CsA) and tacrolimus (TCR) were compared in pediatric HSCT for thalassemia.

MATERIALS AND METHODS

This is a retrospective analysis of 129 pediatric patients who underwent HSCT with the diagnosis of thalassemia at Medicalpark Göztepe and Antalya Hospitals between January 2017 and December 2020.

RESULTS

Despite the GvHD prophylaxis, grade II-IV acute GvHD developed in 29 patients. Of these patients, 12 had only gut, 10 had only skin, 6 had combined gut and skin, and one had only liver GvHD. Fifteen of these 29 patients were in the CsA group, and 14 of them were in the TCR group. There was no significant difference between the groups in terms of acute GvHD occurrence, GvHD stage, or involvement sites. In terms of CNI-related toxicity, neurotoxicity in 15 (CsA n = 9, TCR n = 6) and nephrotoxicity in 18 (CsA n = 4, TCR n = 14) patients were observed. While there was no difference between the two groups in terms of neurotoxicity, more nephrotoxicity developed in patients using TCR (p = .013). There was no significant difference between the groups in terms of engraftment syndrome, veno-occlusive disease, CMV reactivation, PRES, or graft rejection.

CONCLUSION

Regarding GvHD, there was no difference in efficacy between TCR and CsA usage. Patients taking TCR experienced noticeably higher nephrotoxicity in terms of adverse effects. This difference should be considered according to the patient's clinical situation while choosing a CNI.

Involvement of oxidative species in cyclosporine-mediated cholestasis

Cyclosporine is an established medication for the prevention of transplant rejection. However, adverse consequences such as nephrotoxicity, hepatotoxicity, and cholestasis have been associated with prolonged usage. In cyclosporine-induced obstructive and chronic cholestasis, for example, the overproduction of oxidative stress is significantly increased. Additionally, cyclosporine exerts adverse effects on liver function and redox balance responses in treated rats, as evidenced by its increasing levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and bilirubin while also decreasing the levels of glutathione and NADPH. Cyclosporine binds to cyclophilin to produce its therapeutic effects, and the resulting complex inhibits calcineurin, causing calcium to accumulate in the mitochondria. Accumulating calcium with concomitant mitochondrial abnormalities induces oxidative stress, perturbation in ATP balance, and failure of calcium pumps. Also, cyclosporine-induced phagocyte oxidative stress generation via the interaction of phagocytes with Toll-like receptor-4 has been studied. The adverse effect of cyclosporine may be amplified by the release of mitochondrial DNA, mediated by oxidative stress-induced mitochondrial damage. Given the uncertainty surrounding the mechanism of cyclosporine-induced oxidative stress in cholestasis, we aim to illuminate the involvement of oxidative stress in cyclosporine-mediated cholestasis and also explore possible strategic interventions that may be applied in the future.