Antibody-mediated rejection in pediatric kidney transplant recipients: A report from the Pediatric Nephrology Research Consortium

BACKGROUND

Antibody-mediated rejection (AMR) is a major cause of kidney allograft loss. There is a paucity of large-scale pediatric-specific data regarding AMR treatment outcomes.

METHODS

Data were obtained from 14 centers within the Pediatric Nephrology Research Consortium. Kidney transplant recipients aged 1-18 years at transplant with biopsy-proven AMR between 2009 and 2019 and at least 12 months of follow-up were included. The primary outcome was graft failure or an eGFR <20 mL/min/1.73 m2 at 12 months following AMR treatment. AMR treatment choice, histopathology, and DSA class were also examined.

RESULTS

We reviewed 123 AMR episodes. Median age at diagnosis was 15 years at a median 22 months post-transplant. The primary outcome developed in 27.6%. eGFR <30 m/min/1.73 m2 at AMR diagnosis was associated with a 5.6-fold higher risk of reaching the composite outcome. There were no significant differences in outcome by treatment modality. Histopathology scores and DSA class at time of AMR diagnosis were not significantly associated with the primary outcome.

CONCLUSIONS

In this large cohort of pediatric kidney transplant recipients with AMR, nearly one-third of patients experienced graft failure or significant graft dysfunction within 12 months of diagnosis. Poor graft function at time of diagnosis was associated with higher odds of graft failure.

Pregnancy History and Kidney Disease Progression Among Women Enrolled in Cure Glomerulonephropathy

Introduction

Preeclampsia increases the risk for future chronic kidney disease (CKD). Among those diagnosed with CKD, it is unclear whether a prior history of preeclampsia, or other complications in pregnancy, negatively impact kidney disease progression. In this longitudinal analysis, we assessed kidney disease progression among women with glomerular disease with and without a history of a complicated pregnancy.

Methods

Adult women enrolled in the Cure Glomerulonephropathy study (CureGN) were classified based on a history of a complicated pregnancy (defined by presence of worsening kidney function, proteinuria, or blood pressure; or a diagnosis of preeclampsia, eclampsia, or hemolysis, elevated liver enzymes, and low platelets [HELLP] syndrome), pregnancy without these complications, or no pregnancy history at CureGN enrollment. Linear mixed models were used to assess estimated glomerular filtration rate (eGFR) trajectories and urine protein-to-creatinine ratios (UPCRs) from enrollment.

Results

Over a median follow-up period of 36 months, the adjusted decline in eGFR was greater in women with a history of a complicated pregnancy compared to those with uncomplicated or no pregnancies (-1.96 [-2.67, -1.26] vs. -0.80 [-1.19, -0.42] and -0.64 [-1.17, -0.11] ml/min per 1.73 m² per year, P = 0.007). Proteinuria did not differ significantly over time. Among those with a complicated pregnancy history, eGFR slope did not differ by timing of first complicated pregnancy relative to glomerular disease diagnosis.

Conclusions

A history of complicated pregnancy was associated with greater eGFR decline in the years following glomerulonephropathy (GN) diagnosis. A detailed obstetric history may inform counseling regarding disease progression in women with glomerular disease. Continued research is necessary to better understand pathophysiologic mechanisms by which complicated pregnancies contribute to glomerular disease progression.

Age of Onset and Disease Course in Biopsy-Proven Minimal Change Disease: An Analysis From the Cure Glomerulonephropathy Network

RATIONALE & OBJECTIVE

Adolescent- and adult-onset minimal change disease (MCD) may have a clinical course distinct from childhood-onset disease. We characterized the course of children and adults with MCD in the Cure Glomerulonephropathy Network (CureGN) and assessed predictors of rituximab response.

STUDY DESIGN

Prospective, multicenter, observational study.

STUDY PARTICIPANTS

CureGN participants with proven MCD on biopsy.

EXPOSURE

Age at disease onset, initiation of renin-angiotensin-aldosterone system (RAAS) blockade, and immunosuppression including rituximab during the study period.

OUTCOME

Relapse and remission, change in estimated glomerular filtration rate (eGFR), and kidney failure.

ANALYTICAL APPROACH

Remission and relapse probabilities were estimated using Kaplan-Meier curves and gap time recurrent event models. Linear regression models were used for the outcome of change in eGFR. Cox proportional hazards models were used to estimate the association between rituximab administration and remission.

RESULTS

The study included 304 childhood- (≤12 years old), 49 adolescent- (13-17 years old), and 201 adult- (≥18 years) onset participants with 2.7-3.2 years of follow-up after enrollment. Children had a longer time to biopsy (238 vs 23 and 36 days in adolescent- and adult-onset participants, respectively; P<0.001) and were more likely to have received therapy before biopsy. Children were more likely to be treated with immunosuppression but not RAAS blockade. The rate of relapse was higher in childhood- versus adult-onset participants (HR, 1.69 [95% CI, 1.29-2.21]). The probability of remission was also higher in childhood-onset disease (HR, 1.33 [95%CI, 1.02-1.72]). In all groups eGFR loss was minimal. Children were more likely to remit after rituximab than those with adolescent- or adult-onset disease (adjusted HR, 2.1; P=0.003). Across all groups, glucocorticoid sensitivity was associated with a greater likelihood of achieving complete remission after rituximab (adjusted HR, 2.62; P=0.002).

LIMITATIONS

CureGN was limited to biopsy-proven disease. Comparisons of childhood to nonchildhood cases of MCD may be subject to selection bias, given that childhood cases who undergo a biopsy may be limited to patients who are least responsive to initial therapy.

CONCLUSIONS

Among patients with MCD who underwent kidney biopsy, there were differences in the course (relapse and remission) of childhood-onset compared with adolescent- and adult-onset disease, as well as rituximab response.

Costs associated with acute kidney injury in critically Ill neonates with patent Ductus arteriosus: pediatric health information system (PHIS) analysis

OBJECTIVE

Compare costs of hospitalization between critically-ill neonates with patent ductus arteriosus (PDA) who did and did not develop acute kidney injury (AKI).

STUDY DESIGN

Using the Children's Hospital Association's Pediatric Health Information System (PHIS) database, we ascertained the marginal estimated total cost of hospitalization between those who did and did not develop AKI.

RESULTS

Query of 49 PHIS centers yielded 14,217 neonates with PDA, 1697 with AKI and 12,520 without AKI. Predictors of cost included AKI, birth weight, ethnicity, race, length of stay (LOS), and Feudtner Complex Chronic Conditions Classification System. LOS was the strongest predictor (AKI: median 71 days [IQR 28-130]; No AKI: 28 days [10-76]; p < 0.01). Neonates with AKI had $48,416 greater costs (95% CI: $43,804-53,227) after adjusting for these predictors (AKI: $190,063, 95% CI $183,735-196,610; No AKI: $141,647, 95% CI $139,931-143,383 l; p < 0.01).

CONCLUSION

AKI is independently associated with increased hospital costs in critically-ill neonates with PDA.

Urinary Tract Dilation in the Fetus and Neonate

Urinary tract dilation (UTD), previously known as hydronephrosis, is the most common congenital condition identified on prenatal ultrasonography. UTD can be physiologic and resolve spontaneously or can be caused by various congenital anomalies of the urinary tract, which can lead to renal failure if not treated properly. In 2014, a multidisciplinary consensus group established UTD definitions, a classification system, and a standardized scheme for perinatal evaluation. Various imaging modalities are available to help diagnose the cause of UTD in fetuses and neonates and to help identify those patients who may benefit from fetal or early postnatal intervention. In this article, we will review the diagnosis and quantification of antenatal and postnatal UTD based on the UTD classification system, outline the imaging studies available to both evaluateUTD and determine its cause, briefly review the most common causes of UTD in the fetus and neonate, outline management strategies for UTD including the role for fetal intervention and prophylactic antibiotics, and report on the outcome and prognosis in patients with UTD.

Teriparatide Therapy in a 4-Month-Old With Severe Hypoparathyroidism

Teriparatide is a human parathyroid hormone analog approved for the treatment of osteoporosis in adult patients. Its use for hypocalcemia and hypoparathyroidism in the pediatric population is described through case reports and small case series; however, larger studies that demonstrate long-term efficacy and safety are limited. At our institution, a 4-month-old premature (gestational age: 32 weeks) infant with multiple congenital anomalies, functional athymia, and severe hypoparathyroidism and receiving calcitriol, vitamin D, and calcium carbonate supplementation was initiated on subcutaneous injection of teriparatide. During the course of treatment, her calcium carbonate, vitamin D, and calcitriol supplementation requirements substantially decreased. Teriparatide effectively increased serum ionized calcium concentrations and decreased serum phosphorus concentrations in the present case-study over a 6-month period. Teriparatide was well tolerated, and no evidence of hypercalcemia was observed throughout treatment.

Clinical presentation and management of nephrotic syndrome in the first year of life: A report from the Pediatric Nephrology Research Consortium

BACKGROUND AND OBJECTIVES

Nephrotic syndrome (NS) in the first year of life is called congenital (CNS) if diagnosed between 0-3 months, or infantile (INS) if diagnosed between 3-12 months of age. The aim of this study was to determine if there were clinically meaningful differences between CNS and INS patients, regarding clinical presentation, management and outcomes.

DESIGN SETTING PARTICIPANTS AND MEASUREMENTS

Eleven Pediatric Nephrology Research Consortium sites participated in the study, using IRB-approved retrospective chart reviews of CNS and INS patients born between 1998 and 2019. Data were collected on patient characteristics, pertinent laboratory tests, provided therapy, timing of unilateral/bilateral nephrectomy and initiation of renal replacement therapy (RRT).

RESULTS

The study included 69 patients, 49 with CNS and 20 with INS, with a median age at diagnosis of 1 and 6 months, respectively. Management for the two groups was similar regarding nutrition, thyroxin supplementation, immunoglobulin administration, and thrombosis prophylaxis. Within the first 2 months after diagnosis, daily albumin infusions were used more often in CNS vs. INS patients (79 vs. 30%; p = 0.006), while weekly infusions were more common in INS patients (INS vs. CNS: 50 vs. 3%; p = 0.001). During the 6 months preceding RRT, albumin infusions were more frequently prescribed in CNS vs. INS (51 vs. 15%; p = 0.007). Nephrectomy was performed more often in CNS (78%) than in INS (50%; p = 0.02). End-stage kidney disease tended to be more common in children with CNS (80%) vs. INS (60%; p = 0.09).

CONCLUSION

Compared to INS, patients with CNS had a more severe disease course, requiring more frequent albumin infusions, and earlier nephrectomy and RRT. Despite center-specific variations in patient care, 20-40% of these patients did not require nephrectomy or RRT.

Human Papillomavirus Vaccination in Male and Female Adolescents Before and After Kidney Transplantation: A Pediatric Nephrology Research Consortium Study

Background: Kidney transplant (KT) recipients have higher incidence of malignancies, including Human Papillomavirus (HPV)-associated cancers. Thus, HPV vaccines may have an important role in preventing HPV-related disease in this population; however, immunogenicity and safety data are lacking. Objective: To examine the immunological response and tolerability to HPV vaccination in pediatric KT recipients compared to future KT candidates. Methods: The quadrivalent HPV vaccine was administered to girls and boys age 9-18 recruited from seven centers part of the Pediatric Nephrology Research Consortium. Subjects were recruited for three groups: (1) CKD: chronic kidney disease stages 3, 4, and 5 not on dialysis; (2) Dialysis; (3) KT recipients. The outcome consisted of antibody concentrations against HPV 6, 11, 16, and 18. Geometric mean titers (GMTs) and seroconversion rates were compared. Vaccine tolerability was assessed. Results: Sixty-five participants were recruited: 18 in the CKD, 18 in the dialysis, and 29 into the KT groups. KT patients had significantly lower GMTs after vaccination for all serotypes. The percentages of subjects who reached seroconversion were overall lower for the KT group, reaching statistical significance for HPV 6, 11, and 18. Comparing immunosuppressed subjects (anyone taking immunosuppression medications, whether KT recipient or not) with the non-immunosuppressed participants, the former had significantly lower GMTs for all the HPV serotypes and lower seroconversion rates for HPV 6, 11, and 18. KT females had higher GMTs and seroconversion rates for certain serotypes. There were no adverse events in either group. Conclusions: HPV vaccine was well-tolerated in this population. Pediatric KT recipients had in general lower GMTs and seroconversion rates compared to their peers with CKD or on dialysis. Immunosuppression played a role in the lack of seroconversion. Our results emphasize the importance of advocating for HPV vaccination prior to KT and acknowledge its safety post transplantation. Future studies are needed to investigate the effect of a supplemental dose of HPV vaccine in KT recipients who do not seroconvert and to evaluate the long-term persistence of antibodies post-KT.

Early continuous renal replacement therapy during infant extracorporeal life support is associated with decreased lung opacification

Lung opacification on chest radiography (CXR) is common during extracorporeal life support (ECLS), often resulting from pulmonary edema or inflammation. Concurrent use of continuous renal replacement therapy (CRRT) during ECLS is associated with improved fluid balance and cytokine filtration; through modification of these pathologic states, CRRT may modulate lung opacification observed on CXRs. We hypothesize that early CRRT use during infant ECLS decreases lung opacification on CXR. We conducted a retrospective cohort study comparing CXRs from infants receiving ECLS and early CRRT (n = 7) to matched infants who received ECLS alone (n = 7). The CXR obtained prior to ECLS, all CXRs obtained within the first 72 h of ECLS, and daily CXRs for the remainder of the ECLS course were analyzed. The outcome measure was the degree of opacification, determined by independent assessment of two, blinded pediatric radiologists using a modified Edwards et al.'s lung opacification scoring system (from Score 0: no opacification to Score 5: complete opacification). 220 CXRs were assessed (cases: 93, controls: 127). Inter-rater reliability was established (Cohen's weighted к = 0.74; p < 0.0001, good agreement). At baseline, the mean opacification score difference between cases and controls was 1 point (cases: 1.8, controls 2.8; p = 0.049). Using mixed modeling analysis for repeated measures accounting for differences at baseline, the average overall opacification score was 1.2 points lower in cases than controls (cases: 2.1, controls: 3.3; p < 0.0001). The overall distribution of scores was lower in cases than controls. Early CRRT utilization during infant ECLS was associated with decreased lung opacification on CXR.

Confidence in Women's Health: A Cross Border Survey of Adult Nephrologists

A range of women’s health issues are intimately related to chronic kidney disease, yet nephrologists’ confidence in counseling or managing these issues has not been evaluated. The women’s health working group of Cure Glomerulonephropathy (CureGN), an international prospective cohort study of glomerular disease, sought to assess adult nephrologists’ training in, exposure to, and confidence in managing women’s health. A 25-item electronic questionnaire was disseminated in the United States (US) and Canada via CureGN and Canadian Society of Nephrology email networks and the American Society of Nephrology Kidney News. Response frequencies were summarized using descriptive statistics. Responses were compared across provider age, gender, country of practice, and years in practice using Pearson’s chi-squared test or Fisher’s exact test. Among 154 respondents, 53% were women, 58% practiced in the US, 77% practiced in an academic setting, and the median age was 41–45 years. Over 65% of respondents lacked confidence in women’s health issues, including menstrual disorders, preconception counseling, pregnancy management, and menopause. Most provided contraception or preconception counseling to less than one woman per month, on average. Only 12% had access to interdisciplinary pregnancy clinics. Finally, 89% felt that interdisciplinary guidelines and/or continuing education seminars would improve knowledge. Participants lacked confidence in both counseling and managing women’s health. Innovative approaches are warranted to improve the care of women with kidney disease and might include the expansion of interdisciplinary clinics, the development of case-based teaching materials, and interdisciplinary treatment guidelines focused on this patient group.

Dextran-Sulfate Plasma Adsorption Lipoprotein Apheresis in Drug Resistant Primary Focal Segmental Glomerulosclerosis Patients: Results From a Prospective, Multicenter, Single-Arm Intervention Study

Background: Focal segmental glomerulosclerosis (FSGS) causes end stage renal disease (ESRD) in significant proportion of patients worldwide. Primary FSGS carries poor prognosis and management of FSGS patients, refractory to standard treatments or resistant to steroids, remains a major challenge. Lipoprotein apheresis is a therapeutic approach for drug resistant primary FSGS and post-renal transplant primary FSGS recurrence. Objectives: To examine the safety and probable benefit at 1, 3, 6, 12, and 24-months following completion of apheresis treatment using Liposorber® LA-15 system in patients with nephrotic syndrome (NS), due to refractory primary FSGS or primary FSGS associated NS, in post renal transplant children. Material and Methods: Prospective, multicenter, single-arm intervention study using Liposorber® LA-15 system. Patients ≤21 years old with drug resistant or drug intolerant NS secondary to primary FSGS with glomerular filtration rate (GFR) ≥60 ml/min/1.73 m² or post renal transplant patients ≤21 years old with primary FSGS associated NS were included in the study. Each patient had 12 dextran-sulfate plasma adsorption lipoprotein apheresis sessions over a period of 9 weeks. All patients were followed up at 1, 3, 6, 12, and 24-months following completion of treatment. Results: Of 17 patients enrolled, six were excluded from the outcome analysis (protocol deviations). Of the remaining 11 patients, all but one have completed apheresis treatments. Three patients were lost to follow-up immediately after completion of apheresis and excluded from outcome analysis. At one-month follow-up, 1 of 7 patients (14.3%) attained partial remission of NS while 2 of 4 subjects (50%) and 2 of 3 subjects (66.7%) had partial/complete remission at 3- and 6-months follow-up, respectively. One of two patients followed up for 12 months had complete remission and one patient had partial remission of NS after 24 months. Improved or stable eGFR was noted in all patients over the follow-up period. Conclusion: The results of our multicenter study showed improvement in the response rates to steroid or immunosuppressive therapy and induced complete or partial remission of proteinuria in some of the patients with drug resistant primary FSGS. The main limitation of our study is the small number of subjects and high dropout rate.

Early Continuous Renal Replacement Therapy Improves Nutrition Delivery in Neonates During Extracorporeal Life Support

OBJECTIVE

Optimizing nutrition in neonatal patients as soon as possible after extracorporeal life support (ECLS) initiation is imperative as malnutrition can worsen both short- and long-term outcomes. Fluid restriction, used to manage the fluid overload that commonly complicates neonatal ECLS, severely impairs nutrition delivery. Continuous renal replacement therapy (CRRT) can be used to help manage fluid overload. We hypothesize that early CRRT utilization ameliorates the need for fluid restriction and allows providers to prescribe higher parenteral nutrition (PN) volumes leading to better nutrition delivery.

DESIGN

The design of the study was a retrospective chart review, and the setting was a single, level III neonatal intensive care unit.

SUBJECTS

Neonatal patients (n = 42) treated with ECLS between January 1, 2008, and December 31, 2013.

INTERVENTIONS

Comparisons were made between 2 groups: neonates who received ECLS without early CRRT initiation (group 1; n = 23) and with early CRRT initiation (group 2; n = 19).

MAIN OUTCOME MEASURES

The main outcome measures were goal total fluid intake, prescribed PN volume, protein, glucose infusion rate, intralipid, and kilocalories.

RESULTS

Infants who received early CRRT were prescribed higher mean total fluid intake goals (group 1: 99 mL/kg/day vs. group 2: 119 mL/kg/day, P < .001) and higher mean volumes of PN (group 1: 61 mL/kg/day vs. group 2: 81 mL/kg/day, P < .001) over the first 72 hours of ECLS compared with infants who did not receive early CRRT. Early CRRT receivers also were prescribed greater mean amounts of protein during the first 72 hours of ECLS (group 1: 2.7 g/kg/day vs. group 2: 3 g/kg/day, P = 0.03). There were no significant changes noted in prescribed glucose infusion rates, intralipid, or total kilocalories.

CONCLUSIONS

Institution of early CRRT in neonates on ECLS allows for administration of greater volumes of PN with improved protein delivery. This study characterizes one benefit of early CRRT initiation in neonates on ECLS and suggests these patients could experience improved nutritional outcomes.

Immunogenicity of Augmented Compared With Standard Dose Hepatitis B Vaccine in Pediatric Patients on Dialysis: a Midwest Pediatric Nephrology Consortium Study

BACKGROUND AND OBJECTIVES

Patients on maintenance dialysis have a higher risk of unresponsiveness to hepatitis B vaccination and loss of hepatitis B immunity. Adult guidelines recommend augmented dosing (40 mcg/dose), resulting in improved response in adults. We sought to determine whether children on dialysis mount a similar antibody response when given standard or augmented dosing of hepatitis B vaccine.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This is a retrospective review of patients on dialysis aged <19 years from May 1, 2008 to May 1, 2013 at 12 pediatric dialysis units. Hepatitis B surface antibody (HBsAb) titers ≥10 mIU/ml were defined as protective.

RESULTS

A total of 187 out of 417 patients received one or more hepatitis B vaccine boosters. The median age was 13 years; the cohort was 57% boys and 59% white. Booster dose or HBsAb titers were missing in 17 patients. Conversion to protective HBsAb titers was achieved in 135 out of 170 patients (79%) after their first single-dose booster or multidose booster series. In patients receiving a single-dose booster, the response rate was 53% (nine out of 17) after a 10 mcg dose, 86% (65 out of 76) after a 20 mcg dose, and 65% (17 out of 26) after a 40 mcg hepatitis B vaccine dose. In patients receiving a multidose booster series, the response rate was 95% (19 out of 20) after a 10 mcg/dose series, 83% (20 out of 24) after a 20 mcg/dose series, and 71% (five out of seven) after a 40 mcg/dose series. Patients receiving a multidose booster series had a response rate of 86% (44 out of 51), compared with 76% (91 out of 119) in patients receiving a single-dose booster (P=0.21). Twenty-seven patients received more than one single-dose booster or multidose series, and 26 out of 27 (96%) eventually gained immunity after receiving one to three additional single-dose boosters or multidose booster series.

CONCLUSIONS

There was no clear gradient of increasing seroconversion rate with increasing vaccine dose in this cohort of pediatric patients on dialysis.