OF PHOTOPHERESIS IN KIDNEY TRANSPLANTATION

Abstract

Aim – to perform a comparative study of the long-term results of the combined use of extracorporeal photochemotherapy (photopheresis) and drug immunosuppression and standard immunosuppressive therapy in patients after kidney transplantation.Materials and methods. An open cohort randomized study was conducted, including 60 patients with chronic kidney disease stage 5D. All patients underwent single-group cadaveric kidney transplantation. Patients were randomly divided into two groups. All transplants were paired, the fi rst kidney transplant was received by the patient of the main group, the second – by comparison group. 30 patients of the main group received standard protocol of immunosuppression and 10–15 sessions of photopheresis during the fi rst six months after transplantation. All patients of the comparison group received standard immunosuppressive therapy only. End points: primary – graft loss, surrogate – the number of acute rejection episodes and infectious complications, the dynamics of creatinine blood concentration, the glomerular fi ltration rate and daily proteinuria, the dynamics of tacrolimus C0 blood concentration. To study the mechanism of photopheresis action in the late postoperative period, we evaluated the immunological parameters: subpopulation of naive T-cells (CD3+CD4+CD45RO–CD28+), the level of CD28 molecule expression (MFI) on these cells and also – subpopulation of T-regulatory cells (CD3+CD4+CD25 (Hi)CD127–).Results. The use of photopheresis leads to the graft function improvement in the late postoperative period: the creatinine concentration (p = 0.017) in the blood and daily proteinuria (p = 0.011) were lower in patients of the main group, the glomerular fi ltration rate was higher (p = 0.027). The incidence rate ratio (IRR) of rejection in the main group was signifi cantly lower than in the comparison group: 0.2509 (95% CI 0.05386, 0.9167), p = 0.0358. The risk of graft loss was also lower in the main group: IRR 0.2782 (95% CI 0.07562, 0.8657), p = 0.026, as well as the risk of infectious complications: IRR 0.3888 (95% CI 0.2754; 0, 5445), p < 0.0001. Survival rate of transplants was higher in the main group (Log Rank p = 0.009; Breslow p = 0.005). The use of photopheresis made it possible to reduce the concentration of tacrolimus in the late postoperative period (p = 0.0017) without increasing the risk of graft rejection. The photopheresis tolerogenic effect in the late postoperative period may be due to an increase in the population of T-regulatory cells with the CD3+CD4+CD25(Hi)+CD127– phenotype compared to the patients which received only standard immunosuppressive therapy (p = 0.024).Conclusion. The preventive use of photopheresis contributes to improvement of the kidney transplantation long-term outcomes. Further studies are needed to study the mechanisms of photopheresis action and markers of partial immunological tolerance to the allograft.

Keywords

• kidney transplantation
• photopheresis
• extracorporeal photochemotherapy
• immunosuppression
• immunological tolerance
• regulatory cells