Determinants of hyperparathyroidism in children after kidney transplantation.

INTRODUCTION: Hyperparathyroidism (HPT) can contribute to metabolic bone disease following kidney transplantation. We evaluated post-transplant trends in intact parathyroid hormone (iPTH) and determined predictors of HPT in pediatric kidney transplant (KTx) recipients. METHODS: In this single-center study, retrospective data were collected on 88 children from 2013 to 2019. Data collected included dialysis vintage, biochemical parameters, post-transplant trends in iPTH, 25(OH)Vitamin D levels and estimated glomerular filtration rate (eGFR ml/min/1.73 m2 ). Pre-transplant treatment for HPT was quantified with a Treatment Burden score (TB, score range: 0-100). After log-transforming skewed variables (iPTH and eGFR), multivariable linear regression was performed to determine predictors of log {iPTH} at 6 and 36 months (mo) post-transplant. RESULTS: Median age was 12.8 (range: 1.9-20.5) years, and dialysis vintage was 11.2 (range: 0.0-112.9) months. The majority were of Hispanic and African Ancestry (77.3%). Median post-transplant iPTH was 69.5 (range: 1.8-306.8) pg/ml at 6 mo with a gradual downward trend to 59.0 (range: 28.0-445.0) pg/ml at 36 mo. Significant multivariable predictors of higher log {iPTH} post-transplant included longer dialysis vintage, higher TB, and lower log{eGFR} at 6 mo, and higher TB, lower log{eGFR}, and deceased donor transplant at 36 mo. CONCLUSIONS: Recognition of risk factors for HPT and monitoring iPTH post-transplant may facilitate timely interventions to mitigate cardiovascular and bone disease in pediatric KTx recipients. KEY MESSAGE: Describe serial trends in intact PTH after kidney transplantation. Pre- and post-transplant factors that contribute to persistence or re-occurrence of hyperparathyroidism after kidney transplantation in children include longer dialysis vintage, high pre-transplant treatment burden and decreased post-transplant GFR. Recognition of these factors, and monitoring intact PTH after kidney transplantation, could facilitate timely interventions to mitigate cardiovascular and bone disease in children.

Venous vascular reconstruction of a robotically procured right kidney with two renal veins transplanted into a pediatric recipient.

BACKGROUND: Right versus left kidney donor nephrectomy remains a controversial topic in renal transplantation given the increased incidence of right kidney vascular anomalies and associated venous thrombosis. We present the case of a 3-year-old pediatric recipient with urethral atresia and end-stage kidney disease who received a robotically procured living donor right pelvic kidney with two short same-size renal veins and a short ureter. METHODS: We utilized a completely deceased iliac vein system (common iliac vein with both external and internal veins) to extend the two renal veins. Due to the distance between both renal veins, the external iliac vein was anastomosed to the upper hilum renal vein, and the internal iliac vein was anastomosed to the lower hilum renal vein. The donor's short ureter was anastomosed to the recipient's ureter end-to-side. RESULTS: The patient had immediate graft function and there were no post-operative complications. Renal ultrasound was unremarkable at 48 hours post-transplant. Serum creatinine was 0.5 mg/dL at 3 months post-transplant. CONCLUSION: We demonstrate the successful transplantation of a robotically procured right pelvic donor kidney with two short renal veins using a deceased donor iliac vein system for venous reconstruction without increasing technical complications. This technique of venous reconstruction can be used in right kidneys with similar anatomical variations without affecting graft function.

Postoperative Delirium Screening Characteristics in Pediatric Intestinal, Liver, and Renal Transplant Recipients: Single-Center Retrospective Cohort Study.

OBJECTIVES: To describe and compare the results of delirium screening in the immediate post-transplant PICU admission for pediatric intestinal, liver, and renal transplant recipients. We also examined associations with known and suspected risk factors for pediatric delirium (PD). DESIGN: Retrospective analysis of a single-center cohort, 2016-2022. SETTING: Twenty-four-bed PICU in a high-volume transplant center. PATIENTS: All intestinal, liver, and renal transplant recipients under 23 years old admitted between July 2016 and August 2022. MEASUREMENTS AND MAIN RESULTS: We identified 211 pediatric transplant recipients: intestinal (n = 36), liver (n = 78), and renal (n = 97). Results of the Cornell Assessment for PD during the immediate post-transplant PICU admission were reviewed and patients were categorized into screen positive, screen negative, and unscreened. Corresponding data on known and suspected risk factors for PD were also collected. Data on delirium subtypes were not collected. Screens were available for 156 of 211 patients (74%) who were included in the final analysis. The prevalence of a positive screen by transplant category was: intestine 80% (24/30), liver 75% (47/63), and renal 14% (9/63). A positive screen was associated with younger age, greater duration of mechanical ventilation, and greater PICU length of stay (LOS) in bivariate analysis. In multivariable analysis, age and PICU LOS remained strongly correlated with a positive screen (p < 0.05). Deep sedation and agitation as categorized by the State Behavioral Scale was associated with a positive screen, as was significant iatrogenic withdrawal symptoms (p < 0.05). Most patients screened positive by post-transplant days 2 and 3 (58/80 [72%] and 64/80 [80%], respectively). CONCLUSIONS: In our 2016 to 2022 experience, we found a high prevalence of positive PD screens in pediatric intestinal and liver transplant recipients in the immediate post-transplant PICU admission. A positive screen was associated with younger age and greater PICU LOS.

Benefit of B7-1 staining and abatacept for treatment-resistant post-transplant focal segmental glomerulosclerosis in a predominantly pediatric cohort: time for a reappraisal.

BACKGROUND: Primary FSGS manifests with nephrotic syndrome and may recur following KT. Failure to respond to conventional therapy after recurrence results in poor outcomes. Evaluation of podocyte B7-1 expression and treatment with abatacept (a B7-1 antagonist) has shown promise but remains controversial. METHODS: From 2012 to 2020, twelve patients developed post-KT FSGS with nephrotic range proteinuria, failed conventional therapy, and were treated with abatacept. Nine/twelve (< 21 years old) experienced recurrent FSGS; three adults developed de novo FSGS, occurring from immediately, up to 8 years after KT. KT biopsies were stained for B7-1. RESULTS: Nine KTRs (75%) responded to abatacept. Seven of nine KTRs were B7-1 positive and responded with improvement/resolution of proteinuria. Two patients with rFSGS without biopsies resolved proteinuria after abatacept. Pre-treatment UPCR was 27.0 ± 20.4 (median 13, range 8-56); follow-up UPCR was 0.8 ± 1.3 (median 0.2, range 0.07-3.9, p < 0.004). Two patients who were B7-1 negative on multiple KT biopsies did not respond to abatacept and lost graft function. One patient developed proteinuria while receiving belatacept, stained B7-1 positive, but did not respond to abatacept. CONCLUSIONS: Podocyte B7-1 staining in biopsies of KTRs with post-transplant FSGS identifies a subset of patients who may benefit from abatacept. A higher resolution version of the Graphical abstract is available as Supplementary information.

Practice patterns and influence of allograft nephrectomy in pediatric kidney re-transplantation: A pediatric nephrology research consortium study.

INTRODUCTION: There are no guidelines regarding management of failed pediatric renal transplants. MATERIALS & METHODS: We performed a first of its kind multicenter study assessing prevalence of transplant nephrectomy, patient characteristics, and outcomes in pediatric renal transplant recipients with graft failure from January 1, 2006, to December 31, 2016. RESULTS: Fourteen centers contributed data on 186 pediatric recipients with failed transplants. The 76 recipients that underwent transplant nephrectomy were not significantly different from the 110 without nephrectomy in donor or recipient demographics. Fifty-three percent of graft nephrectomies were within a year of transplant. Graft tenderness prompted transplant nephrectomy in 91% (P < .001). Patients that underwent nephrectomy were more likely to have a prior diagnosis of rejection within 3 months (43% vs 29%; P = .04). Nephrectomy of allografts did not affect time to re-listing, donor source at re-transplant but significantly decreased time to (P = .009) and incidence (P = .0002) of complete cessation of immunosuppression post-graft failure. Following transplant nephrectomy, recipients were significantly more likely to have rejection after re-transplant (18% vs 7%; P = .03) and multiple rejections in first year after re-transplant (7% vs 1%; P = .03). CONCLUSIONS: Practices pertaining to failed renal allografts are inconsistent-40% of failed pediatric renal allografts underwent nephrectomy. Graft tenderness frequently prompted transplant nephrectomy. There is no apparent benefit to graft nephrectomy related to sensitization; but timing / frequency of immunosuppression withdrawal is significantly different with slightly increased risk for rejection following re-transplant.

Donor considerations in pediatric kidney transplantation.

This article reviews kidney transplant donor options for children with end-stage kidney disease (ESKD). Global access to kidney transplantation is variable. Well-established national policies, organizations for organ procurement and allocation, and donor management policies may account for higher deceased donor (DD transplants) in some countries. Living donor kidney transplantation (LD) predominates in countries where organ donation has limited national priority. In addition, social, cultural, religious and medical factors play a major role in both LD and DD kidney transplant donation. Most children with ESKD receive adult-sized kidneys. The transplanted kidney has a finite survival and the expectation is that children who require renal replacement therapy from early childhood will probably have 2 or 3 kidney transplants in their lifetime. LD transplant provides better long-term graft survival and is a better option for children. When a living related donor is incompatible with the intended recipient, paired kidney exchange with a compatible unrelated donor may be considered. When the choice is a DD kidney, the decision-making process in accepting a donor offer requires careful consideration of donor history, kidney donor profile index, HLA matching, cold ischemia time, and recipient's time on the waiting list. Accepting or declining a DD offer in a timely manner can be challenging when there are undesirable facts in the donor's history which need to be balanced against prolonging dialysis in a child. An ongoing global challenge is the significant gap between organ supply and demand, which has increased the need to improve organ preservation techniques and awareness for organ donation.

Systemic causes of non-dermatologic chronic pruritus in the pediatric population and their management: An unexplored area.

Chronic pruritus associated with systemic diseases in the pediatric population has been infrequently addressed in the literature. This review focuses on chronic pruritus presenting without cutaneous manifestations. Common systemic etiologies include diseases with hepatic, renal, and hematologic origins. This encompasses several congenital liver disorders, end-stage renal disease (ESRD), and lymphoproliferative disorders such as Hodgkin's lymphoma. In this paper, an expert panel describes the clinical characteristics, pathophysiology, and therapeutic treatment ladders for chronic pruritus associated with the aforementioned systemic etiologies. Novel therapies are also reviewed. Our aim is to shed light on this unexplored area of pediatric dermatology and instigate further research.

Long-term outcomes and response to treatment in diacylglycerol kinase epsilon nephropathy.

Recessive mutations in diacylglycerol kinase epsilon (DGKE) display genetic pleiotropy, with pathological features reported as either thrombotic microangiopathy or membranoproliferative glomerulonephritis (MPGN), and clinical features of atypical hemolytic uremic syndrome (aHUS), nephrotic syndrome or both. Pathophysiological mechanisms and optimal management strategies have not yet been defined. In prospective and retrospective studies of aHUS referred to the United Kingdom National aHUS service and prospective studies of MPGN referred to the National Registry of Rare Kidney Diseases for MPGN we defined the incidence of DGKE aHUS as 0.009/million/year and so-called DGKE MPGN as 0.006/million/year, giving a combined incidence of 0.015/million/year. Here, we describe a cohort of sixteen individuals with DGKE nephropathy. One presented with isolated nephrotic syndrome. Analysis of pathological features reveals that DGKE mutations give an MPGN-like appearance to different extents, with but more often without changes in arterioles or arteries. In 15 patients presenting with aHUS, ten had concurrent substantial proteinuria. Identified triggering events were rare but coexistent developmental disorders were seen in six. Nine with aHUS experienced at least one relapse, although in only one did a relapse of aHUS occur after age five years. Persistent proteinuria was seen in the majority of cases. Only two individuals have reached end stage renal disease, 20 years after the initial presentation, and in one, renal transplantation was successfully undertaken without relapse. Six individuals received eculizumab. Relapses on treatment occurred in one individual. In four individuals eculizumab was withdrawn, with one spontaneously resolving aHUS relapse occurring. Thus we suggest that DGKE-mediated aHUS is eculizumab non-responsive and that in individuals who currently receive eculizumab therapy it can be safely withdrawn. This has important patient safety and economic implications.

Pediatric Kidney Transplantation Outcomes in Children with Primary Urological Abnormalities Versus Nonurological Abnormalities: Long-Term Results.

PURPOSE: We assessed renal function, graft survival rates and the risk of graft loss in children based on etiology with a focus on differences between urological causes from congenital anomalies of the kidney and urinary tract vs other causes of end stage kidney disease. MATERIALS AND METHODS: A retrospective chart review was performed including patients younger than 18 years who underwent kidney transplantation at our institution from December 1984 to November 2010 with the last followup recorded in March 2018. Patient clinical characteristics, demographics and end stage kidney disease etiology were recorded. Patients were divided into the 2 groups of urological (congenital anomalies of the kidney and urinary tract) vs nonurological based on end stage kidney disease etiology, and survival analysis was performed. RESULTS: Of 112 kidney transplant cases 90 (80.4%) were associated with nonurological causes and 22 (19.6%) with urological causes. Median (IQR) patient age at transplantation was 12 (7-15) years. Median graft survival time was not statistically different according to end stage kidney disease etiology (nonurological 12 years 95% CI 10.01-13.99 vs urological 16 years 95% CI 7.59-24.41, p=0.532). There was a significant risk of graft loss in patients with urinary tract infections after transplantation (HR 3.15, 95% CI 1.59-6.25, p=0.001). CONCLUSIONS: Children requiring transplantation due to urological causes have no disadvantage in graft survival compared to children with end stage kidney disease with other causes. Patients with urinary tract infection after transplantation had a higher rate of graft loss.

Extraperitoneal pediatric kidney transplantation of adult renal allograft using an en-bloc native liver and kidney mobilization technique.

BACKGROUND: We describe the safety and efficacy of performing pediatric kidney transplantation with a modified extraperitoneal approach that includes mobilization of the native liver and kidney. METHODS: We retrospectively identified pediatric renal transplants performed using this technique between 2015 and 2019. Data on patient demographics, surgical technique, and intraoperative details were collected. Outcomes were measured by morbidity and re-operation at 90 days, as well as serum creatinine, allograft survival, and overall survival at 1 year. RESULTS: Twenty-one patients with a median age of 5 (IQR 3-9) years, weighing 17.5 (IQR 14.5-24) kg were included. Median donor age was 24 (IQR 19-31) years. No intraoperative complications occurred. One child required a right native nephrectomy to allow sufficient space. Postoperatively, all patients had immediate graft function without urine leak or allograft thrombosis. 90-day morbidity and re-operation rates were zero. Both 1-year allograft and overall survival were 100% (on follow-up of all 21 patients through 1 year post-transplant), with a median serum creatinine of 0.58 (IQR 0.47-0.70) mg/dl at 1 year post-transplant. CONCLUSIONS: Pediatric kidney transplantation of adult renal allografts using an extraperitoneal approach with native liver and kidney mobilization has promising allograft and patient survival outcomes that eliminates peritoneal violation and may diminish the need for native nephrectomy.

Cinacalcet as rescue therapy for refractory hyperparathyroidism in young children with advanced chronic kidney disease.

BACKGROUND: Studies in the use of the calcimimetic, cinacalcet, in pediatric chronic kidney disease (CKD) are few and limited to older children with secondary hyperparathyroidism (sHPT), a major morbid complication contributing to poor growth, bone deformities, and cardiovascular disease. Our objectives were to determine a safe and effective dosing regimen of cinacalcet in the treatment of infants and young children with sHPT that was refractory to standard care and to examine their growth during treatment. METHODS: Ten young pediatric patients with advanced CKD were studied retrospectively during 11 courses of treatment with cinacalcet. All had severe sHPT with intact parathyroid hormone (iPTH) levels ≥ 500 pg/ml and were refractory to standard therapy with phosphate binders and active vitamin D analogs at high doses for > 30 days. The cinacalcet dose was advanced by 50% every 2-4 weeks to achieve a decline in the iPTH to a goal of 150-300 pg/ml. Linear growth was assessed at 6-month intervals by change in z-scores (△SDS) for length before and during cinacalcet therapy. RESULTS: Median age at initiation of cinacalcet was 18 months (IQR 6, 36) with an average starting dose of 0.7 ± 0.2 mg/kg/day. Median effective dose required to reach iPTH goal of 150-300 pg/ml was 2.8 mg/kg/day (IQR 2.0, 3.1), and time to goal was 112 days (IQR 56, 259) with a median overall decline in iPTH of 82% from baseline by 6 months (p < 0.0001). No subject experienced a clinical adverse event, although 4 had biochemical asymptomatic hypocalcemia. Linear growth improved significantly during cinacalcet therapy (△SDS - 0.62 ± 1.2 versus + 0.91 ± 1.4; p < 0.005). By multiple regression analysis, the primary determinants of growth were concurrent treatment with growth hormone and age < 2 years (R2 = 89.6%; p < 0.001). A shorter treatment time required to achieve iPTH goals also was associated with improved growth (r = - 0.75; p < 0.01). CONCLUSIONS: Cinacalcet may be used effectively and safely in infants and small children with refractory sHPT in advanced CKD using a cautious dosing regimen. Cinacalcet successfully brings iPTH to target level and supports growth when other treatments have been ineffective.

Transplantation in autosomal recessive polycystic kidney disease: liver and/or kidney?

Autosomal recessive polycystic kidney disease (ARPKD) is characterized by enlarged kidneys with dilated collecting ducts and congenital hepatic fibrosis. There is a variable rate of progression of kidney and liver disease. Portal hypertension and Caroli's disease occur from liver involvement that contributes to morbidity and mortality. Approximately 40 % of patients have a severe disease phenotype leading to rapid onset of end-stage kidney disease (ESKD) and signs of portal hypertension and the rest may have predominant involvement of either the kidney or liver. It is important for the physician to establish the extent of organ involvement before deciding on the ultimate plan of management, especially when transplantation is required. Isolated renal transplantation can be considered when liver involvement is minimal. If hepatobiliary disease is prominent, and kidney function is preserved, management options are based on individual characteristics. In the presence of significant liver disease and ESKD, consideration should be given to combined liver kidney transplantation, which can be beneficial in eliminating the consequences of both kidney and liver disease. However, this is a complex surgical procedure that needs to be performed at experienced transplant centers. Improvement in surgical techniques has considerably improved short-term graft survival with the added advantage of the liver offering immunologic protection to the kidney allograft.

Neonatal kidney size and function in preterm infants: what is a true estimate of glomerular filtration rate?

OBJECTIVES: To distinguish between cystatin C (CysC) and creatinine (Cr) as markers of estimated glomerular filtration rate (eGFR) in preterm infants and to correlate eGFR with total kidney volume (TKV) as a surrogate of nephron mass. STUDY DESIGN: Sixty preterm (<37 weeks' gestational age [GA]) and 40 term infants were enrolled at birth. Serum Cr and CysC levels were assessed during the first week of life. Renal ultrasounds were performed to assess kidney dimensions with calculation of the TKV as a surrogate of nephron mass. Six equations derived from reference inulin, iohexol, and iothalamate clearance studies were used to calculate eGFR. Multiple regression analysis was applied to assess the relative impact of neonatal measures on eGFR, including TKV, GA, and mean arterial pressure (MAP). RESULTS: Renal lengths correlated with GA and were within the reference values for intrauterine measurements. Estimation equations for glomerular filtration rate (GFR) based on Cr, CysC, and combined CysC + Cr demonstrated that Cr-based equations consistently underestimated GFR, whereas CysC and combined equations were more consistent with referenced inulin clearance studies. Term infants demonstrated significantly better eGFR than preterm infants. TKV, GA, and MAP correlated positively with eGFR, although only MAP and GA remained significant when adjusted for other covariates. CONCLUSIONS: Primary determinants of eGFR in preterm infants are GA and MAP. The CysC level is a superior biomarker to serum Cr in the assessment of GFR in premature infants.

Abnormalities in renal tubular phosphate handling in children with sickle cell disease.

BACKGROUND: The mechanisms responsible for the hyperphosphatemia in patients with sickle cell disease (SCD) and preserved glomerular filtration rate (GFR) are not fully understood. The role of fibroblast growth factor 23 (FGF23), a phosphaturic hormone has not been investigated in SCD. Hence, we evaluated parameters of renal tubular phosphorus handling and their relation to prevailing FGF23 levels in a cohort of young SCD patients. METHODS: Renal tubular phosphate handling and circulating levels of various analytes including FGF23 and parathyroid hormone (PTH) were measured in 24 children with SCD and normal estimated GFR in a cross sectional study. Correlation and regression analysis were employed to derive relationships between serum phosphorus and several variables. RESULTS: Most children showed elevated age- adjusted serum phosphorus (5.1 ± 0.7 mg/dl) levels. Tubular re-absorption of phosphorus(TRP) (96.3 ± 2.1%) and tubular maximum re-absorption of phosphorus per unit volume of GFR (TMP/GFR) (4.9 ± 0.6 mg/dl) were both elevated. Plasma intact FGF23 concentrations were elevated (81 ± 38 pg/ml) while the average PTH values were normal in most patients (50 ± 27 pg/ml). Univariate analysis showed significant correlations of serum phosphorus with TMP/GFR, alkaline phosphatase, age, lactate dehydrogenase (LDH), and log intact FGF23. TMP/GFR correlated with log intact FGF23 (r = 0.5, P< or = 0.01) but not with PTH. Multiple regression analysis yielded an independent relationship of serum phosphorus with TMP/GFR. CONCLUSION: The elevated serum phosphorus concentrations with simultaneously increased TMP/GFR and elevated FGF23 levels collectively suggest that patients with SCD display proximal tubular resistance to the action of FGF23 before any decline in GFR.

Transplantation: platform to study recurrence of disease.

Beyond the direct benefit that a transplanted organ provides to an individual recipient, the study of the transplant process has the potential to create a better understanding of the pathogenesis, etiology, progression and possible therapy for recurrence of disease after transplantation while at the same time providing insight into the original disease. Specific examples of this include: 1) recurrence of focal segmental glomerulosclerosis (FSGS) after kidney transplantation, 2) recurrent autoimmunity after pancreas transplantation, and 3) recurrence of disease after orthotopic liver transplantation (OLT) for cirrhosis related to progressive steatosis secondary to jejuno-ileal bypass (JIB) surgery. Our team has been studying these phenomena and their immunologic underpinnings, and we suggest that expanding the concept to other pathologic processes and/or transplanted organs that harbor the risk for recurrent disease may provide novel insight into the pathogenesis of a host of other disease processes that lead to organ failure.

Therapeutic plasma exchange in the treatment of exertional heat stroke and multiorgan failure.

BACKGROUND: Exertional heat stroke (EHS) results in a constellation of systemic inflammatory responses resulting in multiorgan failure and an extremely high mortality. CASE DIAGNOSIS AND TREATMENTS: We present the case of an 11-year-old obese male who suffered EHS with rhabdomyolysis and concurrent renal, pulmonary, and hepatic failure. Conventional therapies including continuous veno-venous hemodiafiltration (CVVHDF) were ineffective in preventing ongoing deterioration in clinical status. Liver biopsy was reported as "extensive hepatocyte ballooning" and liver-kidney transplantation was tentatively planned. CONCLUSIONS: The addition of therapeutic plasma exchange using the Prismaflex® system (Gambro, Lakewood, CO, USA) resulted in a reversal of the inflammatory process and recovery from multiorgan failure. Liver biopsy was not a reliable indicator of irreversible hepatic injury.

The podocyte: glomerular sentinel at the crossroads of innate and adaptive immunity.

Focal segmental glomerulosclerosis (FSGS) is a common glomerular disorder that manifests clinically with the nephrotic syndrome and has a propensity to recur following kidney transplantation. The pathophysiology and therapies available to treat FSGS currently remain elusive. Since the podocyte appears to be the target of apparent circulating factor(s) that lead to recurrence of proteinuria following kidney transplantation, this article is focused on the podocyte. In the context of kidney transplantation, the performance of pre- and post-reperfusion biopsies, and the establishment of in vitro podocyte liquid biopsies/assays allow for the development of clinically relevant studies of podocyte biology. This has given insight into new pathways, involving novel targets in innate and adaptive immunity, such as SMPDL3b, cGAS-STING, and B7-1. Elegant experimental studies suggest that the successful clinical use of rituximab and abatacept, two immunomodulating agents, in our case series, may be due to direct effects on the podocyte, in addition to, or perhaps distinct from their immunosuppressive functions. Thus, tissue biomarker-directed therapy may provide a rational approach to validate the mechanism of disease and allow for the development of new therapeutics for FSGS. This report highlights recent progress in the field and emphasizes the importance of kidney transplantation and recurrent FSGS (rFSGS) as a platform for the study of primary FSGS.

Retroperitoneal kidney transplantation with liver and native kidney mobilization: a safe technique for pediatric recipients.

BACKGROUND: Pediatric kidney transplant (KT) using larger, deceased or living donor adult kidneys can be challenging in the pediatric population due to limited space in the retroperitoneum. Liver and native kidney (L/NK) mobilization techniques can be used in smaller and younger transplant recipients to aid in retroperitoneal placement of the renal allograft. Here, we compare the clinical outcomes of pediatric retroperitoneal KT with and without L/NK mobilization. METHODS: We retrospectively analyzed pediatric renal transplant recipients treated between January 2015 and May 2021. Donor and recipient demographics, intraoperative data, and recipient outcomes were included. Recipients were divided into two groups according to the surgical technique utilized: with L/NK mobilization (Group 1) and without L/NK mobilization (Group 2). Baseline variables were described using frequency distributions for categorical variables and means and standard errors for continuous variables. Tests of association with the likelihood of using L/NK mobilization were performed using standard χ2 tests, t tests, and the log-rank test. RESULTS: Forty-six pediatric recipients were evaluated and categorized into Group 1 (n = 26) and Group 2 (n = 20). Recipients in Group 1 were younger (6.7 ± 0.8 years vs. 15. 3 ± 0.7, P < 0.001), shorter (109.5 ± 3.7 vs. 154.2 ± 3.8 cm, P < 0.001) and weighed less (21.4 ± 2.0 vs. 48.6 ± 3.4 kg, P < 0.001) than those in Group 2. Other baseline characteristics did not differ between Groups 1 and 2. One urologic complication was encountered in Group 2; no vascular or surgical complications were observed in either group. Additionally, no stents or drains were used in any of the patients. There were no cases of delayed graft function or graft primary nonfunction. The median follow-up of the study was 24.6 months post-transplant. Two patients developed death-censored graft failure (both in Group 2, P = 0.22), and there was one death with a functioning graft (in Group 2, P = 0.21). CONCLUSIONS: Retroperitoneal liver/kidney mobilization is a feasible and safe technique that facilitates implantation of adult kidney allografts into pediatric transplant recipients with no increased risk of developing post-operative complications, graft loss, or mortality.

A child with BK virus infection: inadequacy of current therapeutic strategies.

In this report, we describe the development of BKVN in the native kidneys of a child with a cardiac transplant. Elevated BK viral DNA load by PCR necessitated a prolonged course of treatment with escalating doses of cidofovir. Despite a reduction in plasma BK viral load, the infection evolved into an invasive CNS disease, resulting in rhomboencephalitis. This case highlights the need for awareness of the possibility of developing multiorgan complications from BKV infection. The current treatment options for BKV tissue invasive disease are inadequate and need to be improved.

Hypertensive crisis in children.

Hypertensive crisis is rare in children and is usually secondary to an underlying disease. There is strong evidence that the renin-angiotensin system plays an important role in the genesis of hypertensive crisis. An important principle in the management of children with hypertensive crisis is to determine if severe hypertension is chronic, acute, or acute-on-chronic. When it is associated with signs of end-organ damage such as encephalopathy, congestive cardiac failure or renal failure, there is an emergent need to lower blood pressures to 25-30% of the original value and then accomplish a gradual reduction in blood pressure. Precipitous drops in blood pressure can result in impairment of perfusion of vital organs. Medications commonly used to treat hypertensive crisis in children are nicardipine, labetalol and sodium nitroprusside. In this review, we discuss the pathophysiology, differential diagnosis and recent developments in management of hypertensive crisis in children.