Infectious disease risks in pediatric renal transplantation

The simultaneous presence of active BK, Epstein Barr, and human cytomegalovirus infection and their correlation by host factors in patients suspected of kidney transplant rejection

AIMS

This study aims to evaluate the presence of EBV, HCMV, and BKV genomic sequences in the plasma samples (active infection/viremia) of kidney transplant recipients suspected of rejection and to investigate host and risk factors related to the activation of these viruses in these patients.

METHODS

In this cross-sectional single-center study, plasma samples were collected from 98 suspected kidney transplant rejection patients at Labafinejad Hospital, Tehran, Iran, between December 2022 and June 2023. Quantitative real-time PCR assays for HCMV, EBV, and BK were performed using GeneProof Real-time PCR kits. ROC curve analysis was used to determine the viral load cutoff point for each virus.

FINDINGS

HCMV active viremia was detected in 18 (18.36%) recipients, EBV active viremia in 7 (7.14%), and BKV active viremia in 5 (5.10%). ROC results indicated viral load cutoff points of 778, 661, and 457 points for HCMV, EBV, and BKV, respectively. The duration of time after transplantation significantly differed between active viremia and no viremia groups (120.5 vs. 46 months, P = 0.014). In the BKV active viremia group, the increase in creatinine compared to baseline creatinine was significantly higher than in the no viremia group (2.7 vs. 0.8, P = 0.017). The odds ratio of HCMV active viremia in patients taking tacrolimus was 2.84 times higher, and the odds of HCMV active viremia in patients taking antithymocyte globulin was 3.01 times higher than in patients not taking these drugs.

CONCLUSION

Rapid and timely diagnosis of viral active infections in kidney transplant patients is crucial for effective disease management and implementation of appropriate treatment strategies. Identifying potential risk factors, including host and treatment-related factors that influence transplantation, can facilitate the development of suitable preventive strategies.

Children Are Not Small Adults: Similarities and Differences in Renal Transplantation Between Adults and Pediatrics

Kidney transplantation is the treatment of choice for all patients with end-stage kidney disease, including pediatric patients. Graft survival in pediatrics was lagging behind adults, but now is comparable with the adult cohort. Although many of the protocols have been adopted from adults, there are issues unique to pediatrics that one should be aware of to take care of this population. These issues include recipient size consideration, increased incidence of viral infections, problems related to growth, common occurrence of underlying urological issues, and psychosocial issues. This article addresses the similarities and differences in renal transplantation, from preparing a patient for transplant, the transplant process, to post-transplant complications.

Approach to acute kidney injury following paediatric kidney transplant

PURPOSE OF REVIEW

In a child with evidence of acute kidney injury (AKI) following renal transplantation, it is important to quickly and accurately diagnose the cause to enable timely initiation of therapeutic interventions. The following article will discuss the differential diagnosis of acute graft dysfunction in paediatric kidney transplant recipients. This review will systematically guide the clinician through the common and less common causes and provide updates on current treatments.

RECENT FINDINGS

In patients with signs of graft dysfunction, rejection is an important cause to consider. Diagnosis of rejection relies on biopsy findings, an invasive and costly technique. Over the past 5 years, there has been a focus on noninvasive methods of diagnosing rejection, including serum and urinary biomarkers.

SUMMARY

This review discusses the differential diagnosis of acute graft dysfunction following transplant, with a focus on acute rejection, urinary tract infections and common viral causes, prerenal and postrenal causes, nephrotoxic medications, specifically calcineurin inhibitor toxicity, thrombotic microangiopathy and recurrence of the underlying disease. Each condition is discussed in detail, with a focus on clinical clues to the cause, incidence in the paediatric population, workup and treatment.

Evaluation of pediatric renal transplant recipients admitted to the intensive care unit: A retrospective cohort study

Background/Aim: The best course of treatment for children with end-stage kidney disease (ESKD) is renal transplantation (RT), but some pediatric RT recipients are admitted to an intensive care unit (ICU) post-transplant. In the early and late post-operative phases, clinical data about pediatric RT recipients who are admitted to ICU are available. In this study, we aimed to evaluate demographic features, main reasons, and outcomes of pediatric RT patients admitted to the ICU during the early and late post-operative phases. Methods: This study was a cohort study. We analyzed the medical records of pediatric RT recipients (<18 years of age) who were admitted to the ICU between May 30, 2011, and October 16, 2021, at our center, retrospectively. Patients ≥18 years of age and those without available data were excluded. We obtained the following data from ICU follow-up records and hospital medical records. The median (minimum-maximum) for continuous variables, frequencies, and percentages for categorical variables were used. The Chi-square test was used to compare categorical variables. We created graphs using percentages and frequencies to summarize the results. Results: Nineteen (16.5%) of the 115 pediatric patients who underwent RT were admitted to the ICU during the study period. Thirteen patients (68.4%) were male, and the mean age was 10.2 (4.9) years. Hypertension (21.2%) was the most common comorbidity. Eighteen (94.7%) received transplants from living donors. Cystic-hereditary-congenital disorders (42.1%, n=8) and congenital anomalies of the kidney and urinary tract (26.3%, n=5) were among the etiologies of ESKD. Ten patients (52.6%) were admitted to the ICU >6 months after transplantation. Epileptic seizure (n=6, 31.6%), respiratory failure (n=4, 21.1%), and cardiac diseases (n=2, 10.5%) were among the main reasons for ICU admission. During ICU follow-up, invasive mechanical ventilation was needed for five patients (26.3%), and renal replacement treatment was needed for four patients (21.1%). The mean length of ICU was 12.4 (28.5), and the mean hospital stay was 25.8 (29.4) days. The ICU and hospital survival rates were 78.9% and 97%, respectively, while 3.5% was the hospital mortality rate. Hemorrhagic cerebrovascular disease, acute hepatic failure, and cardiogenic shock secondary to pericardiocentesis were the causes of death in the ICU. Conclusion: Patients mostly had ICU admissions because of epileptic seizures and acute respiratory failure. A multidisciplinary approach involving pediatric nephrologists, transplant surgeons, and an intensive care team successfully manages pediatric RT recipients admitted to the intensive care unit.

EBV, CMV, and BK viral infections in pediatric kidney transplantation: Frequency, risk factors, treatment, and outcomes

BACKGROUND

Improved short- and long-term outcomes of kidney transplantation have been achieved over the past decades due to improved immunosuppression. This may have increased the risk for infections and, particularly, for the viral infections: cytomegalovirus (CMV), Epstein-Barr virus (EBV), and polyoma BK virus (BKV).

METHODS

A retrospective review of viremic CMV, EBV, and BKV infections in pediatric renal transplant recipients treated and followed by a national referral center over a 10-year period.

RESULTS

Sixty-seven patients (68% males) received 68 kidney grafts (62% from living donors) during the study period; the mean follow-up period was 5.2 ± 2.4 years. Twenty-seven viremic episodes were documented (CMV: 13, EBV: 6, BKV: 8) in 24 patients (35.2%). The median time (interquartile range) to viremia post-transplant was 11 (4-38) months. The viral infection rate was significantly higher in the years 2014-2015 than in previous years (61% vs. 29%, p = .017). Compared to patients who did not develop viremia, patients with viremias were younger at the time of transplantation, were more likely to receive thymoglobulin induction pre-transplant and to develop an acute rejection. Multiple logistic regression modeling identified transplant year and recipient's age as significant risk factors for viremia. Graft outcome and eGFR at the last follow-up was similar between patients who did and did not develop viremia.

CONCLUSIONS

Viral infections continue to be a major cause of morbidity in pediatric kidney transplant recipients. However, with close monitoring and prompt intervention, patient and renal outcomes remain favorable.

Antibody-mediated rejection after kidney transplantation in children; therapy challenges and future potential treatments

Antibody‐mediated rejection (AMR) remains one of the most critical problems in renal transplantation, with a significant impact on patient and graft survival. In the United States, no treatment has received FDA approval jet. Studies about treatments of AMR remain controversial, limited by the absence of a gold standard and the difficulty in creating large, multi‐center studies. These limitations emerge even more in pediatric transplantation because of the limited number of pediatric studies and the occasional use of some therapies with unknown and poorly documented side effects. The lack of recommendations and the unsharp definition of different forms of AMR contribute to the challenging management of the therapy by pediatric nephrologists. In an attempt to help clinicians involved in the care of renal transplanted children affected by an AMR, we rely on the latest recommendations of the Transplantation Society (TTS) for the classification and treatment of AMR to describe treatments available today and potential new treatments with a particular focus on the pediatric population.

Pediatric kidney transplant recipients with and without underlying structural kidney disease have a comparable risk of hospitalization associated with urinary tract infections

INTRODUCTION

Urinary tract infections (UTIs) are a common and potentially serious kidney transplant complication. Pediatric kidney transplants are potentially at increased risk for UTIs when structural kidney disease is the underlying end-stage kidney disease (ESKD) etiology. The objective of this manuscript is to determine if children with structural kidney disorders are more prone to UTIs post kidney transplant.

MATERIALS AND METHODS

Hospitalizations for pediatric kidney transplant recipients were retrospectively reviewed over a 4-year period for UTIs in the diagnostic codes. The patient's age, sex, graft age, underlying diagnosis for cause of ESKD, symptoms at presentation, urinalysis results, and urine culture results were recorded. UTI rates, febrile UTI rates, and UTI rates in the 1st year post-transplant were compared between children with ESKD due to structural vs. non-structural kidney disease.

RESULTS

Overall, 62 of 145 pediatric patients with kidney transplants accounted for 182 hospitalizations for kidney transplant complications over the 4-year study period. UTIs were components of 34% of the hospitalizations. Overall, UTI rates, febrile UTI rates, and UTI rates for the 1st year post kidney transplant were comparable for children with vs. without structural ESKD etiologies.

CONCLUSION

Urinary tract infections are frequent components of hospitalizations for pediatric kidney transplant recipients. Children with and without structural kidney disease as an ESKD etiology have similar UTI rates indicating that UTI susceptibility is primarily due to the transplant process and/or medication regimens. UTIs represent a potentially modifiable risk factor for pediatric kidney transplant complications.

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.

Outcome of a thorough screening of lower urinary tract function in all pediatric kidney recipients

LUTD is one of the possible factors influencing pediatric kidney graft outcomes. This study evaluates the results of a thorough assessment of voiding behavior in pediatric transplants. Data of patients with kidney disease of nephrological origin are compared to those with urological origin. A single-center analysis of pediatric kidney transplants performed from 2005 to the present was executed. Donor and recipient characteristics as well as voiding and drinking habits were documented using FVCs and uroflowmetry with PVR measurements. LUTD was defined by a mean MVV >150% or <65% of the EBC for age, abnormal uroflowmetry, PVR repeatedly >15% of EBC or >20 mL, abnormal voiding patterns or behavior, and presence of LUT symptoms. LUTD was diagnosed in 71% of the 56 screened children and more present in urological origin of kidney disease (100%) compared to nephrological origin (61%, P = .005). Individual presence of LUT symptoms, abnormal voiding behavior, FVC parameters, UTIs, and uroflowmetry/PVR parameters were not different between the two groups. Polyuria after transplantation was seen in 63% of patients, mainly in the first post-transplant years and recipients aged <10 years. Time after transplantation was a significant independent predictive factor for the presence of LUTD. LUTD is common in all pediatric kidney recipients and underestimated in those with a nephrological origin of disease. Active screening, monitoring and a care attention plan prior to transplantation and during follow-up, is advocated to optimize outcomes for all patients.

Prognostic Factors on Graft Function in Pediatric Kidney Recipients

BACKGROUND

Graft survival in pediatric kidney transplant recipients has increased in the last decades. Determining prognostic factors for graft function over time allows the identification of patients at risk for graft loss and could lead to improvement of current guidelines.

METHODS

Data were collected among pediatric kidney transplant recipients in a single center during the first 5 years after transplantation. Mixed model analysis was used to indicate possible prognostic factors for the loss of graft function.

RESULTS

A total of 100 pediatric kidney transplant recipients were analyzed. Negative prognostics of graft function are higher donor age and higher recipient age, presence of obstructive uropathology, re-transplant, and occurrence of BK viremia. The negative influence on graft function of both donor age and presence of obstructive uropathology increased over time. In this study, the factors that did not influence graft function over time were the number of HLA mismatches, pre-transplant dialysis, intra-abdominal graft placement, ischemia time, occurrence of acute rejection, presence of lower urinary tract dysfunction, occurrence of urinary tract infections, and infections with cytomegalovirus and Epstein-Barr virus.

CONCLUSIONS

This study showed that a higher donor age and higher recipient age, presence of obstructive uropathology, a re-transplant, and the occurrence of BK viremia were negative prognostic factors of graft function over time, in the first 5 years after transplant. Graft function was comparable between steroid-sparing regimens (preferable in low-risk patients) and regimens including steroids (for special reasons).

Cancer morbidity and mortality after pediatric solid organ transplantation-a nationwide register study

BACKGROUND

The prevalence of malignancies after pediatric solid organ transplantation was evaluated in a nationwide study.

METHODS

All patients who had undergone kidney, liver, or heart transplantation during childhood between the years 1982 and 2015 in Finland were identified. The inclusion criteria were age under 16 years at transplantation and age over 18 years at the last follow-up day. A total of 233 (137 kidney, 53 liver, and 43 heart) transplant recipients were enrolled. Controls (n = 1157) matched by the year of birth, gender, and hometown were identified using the Population Register Center registry. The cancer diagnoses were searched using the Finnish Cancer Registry.

RESULTS

Altogether 26 individuals diagnosed with cancer were found, including 18 transplant recipients. Cancer was diagnosed at a median of 12.0 (IQR 7.8-17.8) years after the transplantation. The transplant recipients' risk for cancer was significantly higher when compared with the controls (HR 14.7; 95% CI 6.4-33.9). There was no difference for different graft types. Sixty-one percent of cancers among the transplant recipients were diagnosed at age older than 18 years.

CONCLUSION

The risk for cancer is significantly higher among young adults having undergone solid organ transplantation during childhood in comparison with population controls. Careful follow-up and attention to prevent cancers throughout adulthood are warranted.