Renal Graft Function and Low-Dose Cyclosporine Affect Mycophenolic Acid Pharmacokinetics in Kidney Transplantation

Transition from antigenemia to quantitative nucleic acid amplification testing in cytomegalovirus-seropositive kidney transplant recipients receiving preemptive therapy for cytomegalovirus infection

Due to the high costs, the strategy to reduce the impact of cytomegalovirus (CMV) after kidney transplant (KT) involves preemptive treatment in low and middle-income countries. Thus, this retrospective cohort study compared the performance of antigenemia transitioned to quantitative nucleic acid amplification testing, RT-PCR, in CMV-seropositive KT recipients receiving preemptive treatment as a strategy to prevent CMV infection. Between 2016 and 2018, 363 patients were enrolled and received preemptive treatment based on antigenemia (n = 177) or RT-PCR (n = 186). The primary outcome was CMV disease. Secondarily, the CMV-related events were composed of CMV-infection and disease, which occurred first. There were no differences in 1-year cumulative incidence of CMV-disease (23.7% vs. 19.1%, p = 0.41), CMV-related events (50.8% vs. 44.1%, p = 0.20), neither in time to diagnosis (47.0 vs. 47.0 days) among patients conducted by antigenemia vs. RT-PCR, respectively. The length of CMV first treatment was longer with RT-PCR (20.0 vs. 27.5 days, p < 0.001), while the rate of retreatment was not different (14.7% vs. 11.8%, p = 0.48). In the Cox regression, acute rejection within 30 days was associated with an increased the risk (HR = 2.34; 95% CI = 1.12-4.89; p = 0.024), while each increase of 1 mL/min/1.73 m² of 30-day eGFR was associated with a 2% reduction risk of CMV-disease (HR = 0.98; 95% CI = 0.97-0.99; p = 0.001). In conclusion, acute rejection and glomerular filtration rate are risk factors for CMV disease, showing comparable performance in the impact of CMV-related events between antigenemia and RT-PCR for preemptive treatment.

Early Immunosuppressive Exposure of Enteric-Coated-Mycophenolate Sodium Plus Tacrolimus Associated with Acute Rejection in Expanded Criteria Donor Kidney Transplantation

Background:

Immunosuppressive agents are still inefficient in preventing biopsy-proven acute rejection (BPAR) after expanded criteria donor (ECD) kidney transplantation. The aim of this study was to investigate the relationships between early immunosuppressive exposure and the development of BPAR.

Methods:

We performed a retrospective study of 58 recipients of ECD kidney transplantation treated with enteric-coated-mycophenolate sodium, tacrolimus (Tac), and prednisone. The levels of mycophenolic acid-area under the curve (MPA-AUC)_0-12h and Tac C₀ were measured at the 1^st week and the 1^st month posttransplant, respectively. The correlation was assessed by multivariate logistic regression.

Results:

The occurrence rates of BPAR and antibody-mediated rejection were 24.1% and 10.3%, respectively. A low level of MPA-AUC_0-12h at the 1^st week posttransplant was found in BPAR recipients (38.42 ± 8.37 vs. 50.64 ± 13.22, P < 0.01). In addition, the incidence of BPAR was significantly high (P < 0.05) when the MPA-AUC_0-12h level was <30 mg·h^-1·L^-1 at the 1^st week (15.0% vs. 44.4%) or the Tac C₀ was <4 ng/ml at the 1^st month posttransplant (33.3% vs. 21.6%). Multivariable logistic regression analysis showed that the MPA-AUC_0-12h at the 1^st week (OR: 0.842, 95% CI: 0.784-0.903) and the Tac C₀ at the 1^st month (OR: 0.904, 95% CI: 0.822–0.986) had significant inverse correlation with BPAR (P < 0.05).

Conclusions:

Low-level exposure of MPA and Tac C₀ in the early weeks posttransplant reflects an increased acute rejection risk, which suggested that MPA-AUC_0-12h <30 mg·h^-1·L^-1 and Tac C₀ <4 ng/ml should be avoided in the first few weeks after transplantation.

Anemia in children following renal transplantation-results from the ESPN/ERA-EDTA Registry

BACKGROUND

Our aim was to determine the prevalence of sub-target hemoglobin (Hb) levels in children with a renal allograft and to identify potential determinants associated with these Hb levels.

METHODS

Data from 3669 children with a functioning renal allograft, aged <18 years between 1 January 2000 and 31 December 2012, from 20 European countries were retrieved from the ESPN/ERA-EDTA Registry, providing 16,170 Hb measurements.

RESULTS

According to the NKF/KDOQI classification and the UK-NICE guidelines, 49.8 and 7.8% of the patients, respectively, were anemic. Hb levels were strongly associated with graft function, with Hb levels of 12.6 g/dl in children with chronic kidney disease (CKD) stage 1, declining to 10.7 g/dl in children with CKD stage 5 (P < 0.001). Higher Hb levels were associated with the use of tacrolimus compared to ciclosporin (0.14 g/dl; 95% confidence interval 0.02-0.27; P = 0.002). Low Hb levels were associated with an increased risk of graft failure (P = 0.01) or combined graft failure and death (P < 0.01), but not with death alone (not significant).

CONCLUSIONS

Anemia is present in a significant proportion of European pediatric kidney transplant recipients and is associated with renal allograft dysfunction and type of immunosuppressants used. In our patient cohort, higher Hb levels were associated with better graft and patient survival and less hypertension.

Calcineurin inhibitor-sparing regimens based on mycophenolic acid after kidney transplantation

The use of calcineurin inhibitors (CNIs) has dramatically reduced the number of acute rejections and improved kidney allograft survival. However, CNIs can also cause kidney damage and several adverse events. This has prompted transplant physicians to use CNI-sparing regimens. CNI withdrawal, minimization, or avoidance protocols have been conducted using mycophenolic acid (MPA), and/or mammalian-target-of-rapamycin inhibitors, and/or belatacept. Herein, we review the outcomes of minimizing, withdrawing, or avoiding CNIs when giving mycophenolic acid to de novo and maintenance kidney transplant patients. Protocols on CNI withdrawal, when based on MPA without mammalian-target-of-rapamycin inhibitors (mTORi) or belatacept, in de novo and maintenance kidney transplant patients, are associated with an increased risk of acute rejection. Consequently, these strategies have been abandoned and are not recommended. Protocols on CNI minimization show a beneficial impact of kidney function and acceptable acute rejection rates mainly in patients who have been recipients of a graft for >3-5 years. However, no significant improvement to graft survival has been observed.