Progression of pulse pressure in kidney recipients durably exposed to CsA is a risk factor for epithelial phenotypic changes: an ancillary study of the CONCEPT trial.

In this ancillary study of the CONCEPT trial, we studied the role of CsA withdrawal at 3 months (3M) post-transplant on the intensity of epithelial phenotypic changes (EPC, an early marker for kidney fibrogenesis) on the 12 M surveillance biopsy. Although conversion from CsA to sirolimus (SRL) at 3M was reported to have improved mean graft function at 12 M, it did not reduce the score of EPC (1.73 ± 1.15 in the SRL group vs. 1.87 ± 1 in the CsA group, P = 0.61). Acute rejection, which had occurred twice more frequently in SRL-converted patients included here, was associated with 12 M EPC. Interestingly, we observed that the patients durably exposed to CsA and who developed 12 M EPC had a significant progression of blood pulse pressure (pp) from 1 to 6M post-transplantation (Δpp = +12.3 mmHg, P = 0.0035). Pulse pressure at 4, 6, and 9 M and pp progression from 1 to 6M were significantly associated with the development of EPC at 12 M in renal grafts. Logistic regression analysis revealed that a high 6M pp (≥ 60 mmHg) was an independent risk factor for 12 M EPC with an odds ratio of 2.25 per additional 10 mmHg pp (95%CI: 1.14-4.4, P = 0.02) after adjustment with recipient's and donor's age, acute rejection incidence and immunosuppressive regimen. A post hoc analysis of the data collected in the whole population CONCEPT study revealed that pp was significantly higher at 6 months in patients maintained on CsA and that at this time point pp correlated negatively with GFR at 1 year.

Sirolimus-based regimen is associated with decreased expression of glomerular vascular endothelial growth factor.

BACKGROUND: Sirolimus (SRL) is a potent immunosuppressant used in organ transplantation. It is known to decrease vascular endothelial growth factor (VEGF) synthesis, making it an interesting treatment option for transplant patients who develop Kaposi sarcoma or other malignant diseases. Because VEGF plays a key role in glomerular function and vascular remodelling, we determined the effect of SRL on renal VEGF expression. METHODS: Using immunohistochemistry and quantitative image analysis, we examined renal VEGF expression in routine kidney biopsies performed at 1 year post-transplant in the CONCEPT study, a prospective randomized study comparing a cyclosporine (CsA)-based regimen to a SRL-based regimen in association with mycophenolate mofetil (MMF). RESULTS: A total of 74 patients were included in this substudy; 35 were randomized to the CsA group and 39 to the SRL group. Using continuous variables, the mean percentage of glomerular VEGF expression at Week 52 was significantly lower in the SRL group (14.7 ± 13%) compared to CsA group (21.2 ± 14%: P = 0.02). The percentage of glomerular VEGF expression at Week 52 was not influenced by recipient or donor age, gender, renal function, CsA dose, CsA blood level, SRL dose or SRL blood level. It was significantly lower in patients with a proteinuria over versus below 0.5 g/day (11.58 ± 7.9 versus 19.45 ± 15.53; P = 0.036). CONCLUSIONS: There is emerging evidence that the VEGF system can play either a beneficial or a detrimental role depending on the specific pathologic situations. Therefore, modulating the renal VEGF axis by using an SRL-based regimen may influence the evolution of kidney injury associated with renal transplantation.

Factors predictive of medication nonadherence after renal transplantation: a French observational study.

BACKGROUND: There have been few prospective studies on the natural history of nonadherence (NA) in kidney transplant recipients (KTRs) over time. The objective of this study was to prospectively evaluate the rate of and risk factors for NA in a French cohort of KTRs. METHOD: A total of 312 KTRs from eight French transplantation centers were included in this prospective, noninterventional cohort study. A computer-learning software package (the Organ Transplant Information System) was made available to all patients. RESULTS: Using the four-item Morisky scale, we showed that 17.3%, 24.1%, 30.7%, and 34.6% of patients were nonadherent at posttransplant month 3 (M3), M6, M12, and M24, respectively. Young age was predictive of NA at M6, M12, and M24. Surprisingly, simple treatment regimens including a small number of doses per day and a small number of tablets per day were associated with NA at M3 and M12, respectively. Other factors predictive of NA included failure to use the Organ Transplant Information System software package at M6 and patient reports of adverse events at M12 and M24. Importantly, we observed that physicians underestimated the prevalence of adverse events when compared to patient self-reporting. CONCLUSION: Our observed rate of medication NA in France is consistent with rates reported in previous studies. We found variability in NA risk factors over time as well as an unexpected risk factor (simple treatment regimens). These findings will be useful in developing effective adherence-promoting interventions.