Long-term outcome of early steroid withdrawal in pediatric renal transplantation

BACKGROUND

Steroid use in renal transplant is related to multiple adverse effects. Long-term effects of early withdrawal steroids in pediatric renal transplant were assessed.

METHODS

Renal transplant children with low immunological risk treated on basiliximab, tacrolimus, and mycophenolate with steroid withdrawal or steroid control were evaluated between 2003 and 2019. Clinical variables, treatment adherence, acute rejection, graft loss, and death were analyzed through hazard ratios, and Kaplan-Meier and multivariate analyses.

RESULTS

The study included 152 patients, 71.1% steroid withdrawal, mean follow-up 8.5 years, 64.5% structural abnormalities, and 81.6% deceased donor. At 12 years of transplant, event-free survival analysis for graft loss or death showed no significant difference between steroid withdrawal and control steroid treatment (85.9% vs. 80.4%, p = .36) nor in acute rejection at 10 years (18.5% vs. 20.5%, p = .78) or in donor-specific antibody appearance (19.6% vs. 21.4%, p = .98). Delta height Z-score was increased in the steroid withdrawal group (p < .01). The main predictor of graft loss or death was non-adherence to treatment (p = .001; OR: 17.5 [3.3-90.9]).

CONCLUSIONS

Steroid withdrawal therapy was effective and safe for low-risk pediatric renal transplant in long-term evaluation. Non-adherence was the main predictor of graft loss or death.

Free 25-hydroxyvitamin-D concentrations are lower in children with renal transplant compared with chronic kidney disease

BACKGROUND

Total serum 25-hydroxyvitamin D [25(OH)D] is considered the best marker of vitamin D status and used routinely in clinical practice. However, 25(OH)D is predominantly bound to vitamin D-binding protein (VDBP), and it has been reported that the free-25(OH)D and 25(OH)D loosely bound to albumin fraction correlates better with clinical outcomes.

METHODS

We assessed total-25(OH)D, measured free-25(OH)D, and calculated free-25(OH)D and their relationship with VDBP and biomarkers of mineral metabolism in 61 children (22 CKD 2-3, 18 dialysis, and 21 post-transplant).

RESULTS

Total-25(OH)D concentrations were comparable across the three groups (p = 0.09), but free- and bioavailable-25(OH)D (free- and albumin-25(OH)D) were significantly lower in the transplant group (both: p = 0.01). Compared to CKD and dialysis patients, the transplant group had significantly higher VDBP concentrations (p = 0.03). In all three groups, total-25(OH)D concentrations were positively associated with measured free-, calculated free-, and bioavailable-25(OH)D. Multivariable regression analysis showed that total-25(OH)D was the only predictor of measured free-25(OH)D concentrations in the dialysis group (β = 0.9; R² = 90%). In the transplant group, measured free-25(OH)D concentrations were predicted by both total-25(OH)D and VDBP concentrations (β = 0.6, - 0.6, respectively; R² = 80%). Correlations between parathyroid hormone with total-25(OH)D and measured and calculated free-25(OH)D were only observed in the transplant group (all: p < 0.001).

CONCLUSIONS

In transplanted patients, VDBP concentrations were significantly higher compared to CKD and dialysis patients, and consequently, free-25(OH)D concentrations were lower, despite a comparable total-25(OH)D concentration. We suggest that free-25(OH)D measures may be required in children with CKD, dialysis, and transplant, with further research required to understand its association with markers of mineral metabolism.

Steroid withdrawal improves blood pressure control and nocturnal dipping in pediatric renal transplant recipients: analysis of a prospective, randomized, controlled trial

BACKGROUND

Variable effects of steroid minimization strategies on blood pressure in pediatric renal transplant recipients have been reported, but data on the effect of steroid withdrawal on ambulatory blood pressure and circadian blood pressure rhythm have not been published so far.

METHODS

In a prospective, randomized, multicenter study on steroid withdrawal in pediatric renal transplant recipients (n = 42) on cyclosporine, mycophenolate mofetil, and methylprednisolone, we performed a substudy in 28 patients, aged 11.2 ± 3.8 years, for whom ambulatory blood pressure monitoring (ABPM) data were available.

RESULTS

In the steroid-withdrawal group, the percentage of patients with arterial hypertension, defined as systolic and/or diastolic blood pressure values recorded by ABPM > 1.64 SDS and/or antihypertensive medication, at month 15 was significantly lower (35.7%, p = 0.002) than in controls (92.9%). The need of antihypertensive medication dropped significantly by 61.2% (p < 0.000 vs. control), while in controls, it even rose by 69.3%. One year after steroid withdrawal, no patient exhibited hypertensive blood pressure values above the 95th percentile, compared to 35.7% at baseline (p = 0.014) and to 14.3% of control (p = 0.142). The beneficial impact of steroid withdrawal was especially pronounced for nocturnal blood pressure, leading to a recovered circadian rhythm in 71.4% of patients vs. 14.3% at baseline (p = 0.002), while the percentage of controls with an abnormal circadian rhythm (35.7%) did not change.

CONCLUSIONS

Steroid withdrawal in pediatric renal transplant recipients with well-preserved allograft function is associated with less arterial hypertension recorded by ABPM and recovery of circadian blood pressure rhythm by restoration of nocturnal blood pressure dipping.

Immunosuppressants in Organ Transplantation

The goal of immunosuppressive therapy post-transplantation in pediatric renal transplant recipients is to prevent acute and chronic rejection while minimizing drug side effects. Most therapies alter immune response mechanisms but are not immunologically specific, and a careful balance is required to find the dose that prevents rejection of the graft while minimizing the risks of overimmunosuppression leading to infection and cancer. While this chapter because of space constraints focuses on immunosuppressive therapy in pediatric renal transplant recipients, many aspects can be applied on pediatric recipients of other solid organ transplants such as the liver and heart. The major maintenance immunosuppressive agents currently used in various combination regimens are tacrolimus, cyclosporine, mycophenolate mofetil, azathioprine, everolimus, sirolimus, and glucocorticoids (steroids). Although data from adult renal transplantation trials are used to help guide management decisions in pediatric patients, immunosuppressive therapy in pediatric renal transplant recipients often must be modified because of the unique dosage requirements and clinical effects of these agents in children, including their impact on growth and development. The optimal immunosuppressive therapy post-transplant is not established. The goal remains to find the best combination of immunosuppressive agents that optimizes allograft survival by preventing acute rejection while limiting drug toxicities.

JC polyomavirus replication and associated disease in pediatric renal transplantation: an international CERTAIN Registry study

BACKGROUND

JC polyomavirus (JCPyV)-associated nephropathy (JCPyVAN) is a severe, but rare complication in adult renal transplant (RTx) recipients. Related data in pediatric patients are scarce.

METHODS

Based on the CERTAIN Registry, we therefore performed a multi-center, retrospective study on the JCPyV antibody status, prevalence of JCPyV replication, and its associated disease in 139 pediatric RTx recipients (mean age, 8.5 ± 5.3 years). JCPyV DNA in plasma and/or urine was measured by quantitative PCR at a median time of 3.2 (IQR, 0.3-8.1) years post-transplant.

RESULTS

53.2% of patients were JCPyV-seronegative prior to transplantation; younger age was associated with JCPyV seronegativity. 34/139 (24.5%) patients post-transplant showed active JCPyV replication in either urine (22.0%), plasma (13.4%), or both (7.6%). JCPyV viremia occurred significantly (p < 0.001) more often in patients with viruria (34.6%) than in those without (7.6%), but 7/118 (5.9%) had isolated viremia. High-level viruria (> 10⁷ copies/mL) was found in 29.6% of viruric patients. A higher net state of immunosuppression constituted an independent risk factor for JCPyV replication both in urine and plasma (OR 1.2, p < 0.02). Male patients tended to have a higher risk of JCPyV viremia than females (OR 4.3, p = 0.057). There was one male patient (0.7%) with JCPyVAN 7 years post-transplant, which resolved after reduction of immunosuppressive therapy. No patient exhibited progressive multifocal leukoencephalopathy.

CONCLUSIONS

This first multi-center study on JCPyV in pediatric renal transplant recipients shows that JCPyV replication is common (24.5%), with strong immunosuppression being a significant risk factor, but associated nephropathy is rare.

Prevalence, morbidity, and therapy of hepatitis E virus infection in pediatric renal allograft recipients

BACKGROUND

Hepatitis E virus (HEV) infection in immunocompromised patients such as solid organ transplant recipients may bear a high risk of becoming a chronic infection with progression to liver cirrhosis. So far, data on HEV infection in pediatric renal transplant recipients are limited.

METHODS

This single-center cohort study investigated period prevalence, morbidity, and treatment of HEV infection in 90 pediatric renal allograft recipients aged 9.9 ± 5.6 years at transplantation (58.9% males). HEV serology was determined by enzyme-linked immunosorbent assay and immunoblot, HEV replication by quantitative nucleic acid testing.

RESULTS

Twelve of 90 (13.3%) patients were HEV seropositive, and 4/90 (4.4%) recipients showed active HEV replication (10³-10⁸ copies/mL, corresponding to 0.5 × 10³ and 0.5 × 10⁸ WHO IU/mL) in serum and stool. In all patients with HEV replication, genotype 3 was identified by partial sequencing of HEV ORF1 and ORF2 and phylogenetic analysis. All patients with HEV replication developed chronic infection associated with moderately elevated liver enzymes. HEV replication was unresponsive to reduction of immunosuppression, whereas ribavirin monotherapy (mean dosage 9.7 ± 3.6 mg/kg per day over 85 ± 11 days) was associated with sustained viral clearance and normalization of liver enzymes in all patients. Ribavirin therapy was associated with reversible, hyporegenerative anemia.

CONCLUSIONS

Given an HEV seroprevalence of 13.3% in pediatric renal transplant recipients and an HEV viremia of 4.4%, HEV infection should be considered in patients with otherwise unexplained elevation of liver enzymes. HEV infection does not necessarily respond to reduction of immunosuppressive therapy, but can be effectively and safely treated with ribavirin.

Anesthetic Management of Pediatric Liver and Kidney Transplantation

Pediatric patients with liver dysfunction and renal failure may exhibit many comorbidities. There are often associated congenital syndromes to be taken into account. Liver and renal transplantation offer a solution and substantial improvement in quality of life. Anesthetic management of pediatric liver and renal transplantation has not been well described. There are key differences between adults and children undergoing these procedures, and acknowledgment of some key principles provide a solid foundation to optimize perioperative outcomes. This article provides an overview of the perioperative management and considerations in pediatric patients undergoing liver and renal transplantation.