Complications by age in primary pediatric renal transplant recipients

Hypogammaglobulinemia in pediatric kidney transplant recipients

Infections remain the most common cause of hospitalization after kidney transplantation, contributing to significant post-transplant morbidity and mortality. There is a growing body of literature that suggests that immunoglobulins may have a significant protective role against post-transplant infections, although the literature remains sparse, inconsistent, and not well publicized among pediatric nephrologists. Of great concern are data indicating a high prevalence of immunoglobulin abnormalities following transplantation and a possible link between these abnormalities and poorer outcomes. Our educational review focuses on the epidemiology and risk factors for the development of immunoglobulin abnormalities after kidney transplantation, the outcomes in patients with low immunoglobulin levels, and studies evaluating possible interventions to correct these immunoglobulin abnormalities.

Live vaccines after pediatric solid organ transplant: Proceedings of a consensus meeting, 2018

Growing evidence suggests receipt of live-attenuated viral vaccines after solid organ transplant (SOT) has occurred and is safe and needed due to lapses in herd immunity. A 2-day consortium of experts in infectious diseases, transplantation, vaccinology, and immunology was held with the objective to review evidence and create expert recommendations for clinicians when considering live viral vaccines post-SOT. For consideration of VV and MMR post-transplant, evidence exists only for kidney and liver transplant recipients. For MMR vaccine post-SOT, consider vaccination during outbreak or travel to endemic risk areas. Patients who have received antiproliferative agents (eg. mycophenolate mofetil), T cell-depleting agents, or rituximab; or have persistently elevated EBV viral loads, or are in a state of functional tolerance, should be vaccinated with caution and have a more in-depth evaluation to define benefit of vaccination and net state of immune suppression prior to considering vaccination. MMR and/or VV (not combined MMRV) is considered to be safe in patients who are clinically well, are greater than 1 year after liver or kidney transplant and 2 months after acute rejection episode, can be closely monitored, and meet specific criteria of "low-level" immune suppression as defined in the document.

Long-term outcomes of pediatric kidney transplant recipients with a pretransplant malignancy

A childhood malignancy can rarely progress to ESRD requiring a KT. To date, few reports describe long-term outcomes of pediatric KT recipients with a pretransplant malignancy. Between 1963 and 2015, 884 pediatric (age: 0-17 years old) recipients received 1055 KTs at our institution. KT outcomes were analyzed in children with a pretransplant malignancy. We identified 14 patients who had a pretransplant malignancy prior to KT; the majority were <10 years old at the time of KT. Ten (71%) patients received their grafts from living donors, the majority of which were related to the recipient. Wilms' tumor was the dominant type of pretransplant malignancy, seen in 50% of patients. The other pretransplant malignancy types were EBV-positive lymphoproliferative disorders, non-EBV-positive lymphoma, leukemia, neuroblastoma, soft-tissue sarcoma, and ovarian cancer. Ten of the 14 patients received chemotherapy as part of their pretransplant malignancy treatment. Graft survival at 1, 3, and 5 years was 93%, 83%, and 72%, respectively. Patient survival at 1, 5, and 10 years was 100%, 91%, and 83%, respectively. Six (40%) patients suffered AR following KT; half of them had their first episode of AR within 1 month of KT. Our single-center experience demonstrates that pediatric KT recipients with a previously treated pretransplant malignancy did not exhibit worse outcomes than other pediatric KT patients.

Incidence and magnitude of post-transplant cardiovascular disease after pediatric kidney transplantation: Risk factor analysis of 1058 pediatric kidney transplants at the university of Minnesota

BACKGROUND

KT recipients have increased the risk of CVD. The incidence of post-transplant CVEs among pediatric recipients has not been well-characterized.

PATIENTS AND METHODS

Between 1963 and 2015, 884 pediatric (age: 0-17 years old) recipients received 1058 KTs at our institution. The cumulative incidence of CVEs was analyzed. Statistical models were used to estimate risk factors for developing post-transplant CVEs.

RESULTS

Overall median patient survival was 33 years (IQR: 18.7-47). A total of 362 CVEs occurred in 161 (18.3%) patients at a median age of 20.5 years. Arrhythmias (18%) were most common. Cumulative risk of post-transplant CVEs was 9% at 10 years, 17% at 20 years, 25% at 30 years, and 36% at 40 years. Development of post-transplant CVEs was associated with increased mortality (HR 2.25 [95% CI 1.61-3.14]); of those who developed a CVE and died, 22/51 (43.1%) died of CVD. Multivariable risk factors for post-transplant CVEs included a history of pretransplant CVD (aHR 1.92 [1.18-3.13] and graft failure (4.57 [3.13-6.67]).

DISCUSSION

A pretransplant history of CVD and a failed graft are significant risk factors for the development of post-transplant CVE. CVD increases the risk of post-transplant death or graft loss.

Renal transplantation in children under 3 years of age: Experience from a single-center study

RTx remains challenging in children under 3 years of age. This single-center study reviewed the medical records of children <3 years transplanted since 1987 (N = 32, Group 1). They were matched for donor type and RTx period with children aged 3-13 years (N = 32, Group 2) and 13-18 years (N = 32, Group 3). There were no between-group significant differences regarding distributions of gender, primary renal disease, proportion of dialysis before RTx, and growth (SDS). Compared to Groups 2 and 3, Group 1 had more peritoneal dialyses (P < .001), more EBV mismatches (P = .04), and longer warm ischemia times (P < .001). The risk of graft loss was not significantly different among age groups (hazard ratio, 2.4 in Group 2 and 2.0 in Group 3 vs Group 1; P = .2). Death occurred in four patients (3 in Group 1 and 1 in Group 2) and graft loss occurred in 28 patients, mainly due to chronic allograft nephropathy. In recipients <3 years of age, the outcomes of RTx are close to those obtained in older pediatric age groups. Thus, young patients may be transplanted in experienced multidisciplinary teams without additional risks provided that particular attention is paid to donor selection and prevention/early diagnosis of comorbidities and complications.

Infection rates in tacrolimus versus cyclosporine-treated pediatric kidney transplant recipients on a rapid discontinuation of prednisone protocol: 1-year analysis

AR is lower in pKTx recipients on Tac vs CsA. Data comparing infection outcomes for children treated with these agents are limited. We retrospectively studied infection outcomes in 96 pKTx recipients on a RDP. PS, DCGS, AR, and infection-free survival were assessed using Kaplan-Meier/log-rank tests and proportional hazards models. There were no differences in 1-year PS, DCGS, or AR between Tac and CsA recipients. After adjusting for AR, the hazard of CMV viremia was 4.0 times higher (95%CI: 1.04, 15.5; P = .044) and that of BK viremia was 3.8 times higher (95%CI: 1.5, 10.2; P = .007) in Tac recipients. The incidence of EBV viremia was similar between the groups (P = .56). PostTx lymphoproliferative disease was only observed in Tac recipients (3%). There was no difference in the incidence of pneumonia, urinary tract, or Clostridium difficile infections between Tac and CsA recipients. Among KTx recipients on RDP, the hazards of CMV and BK viremia within 1 year post-KTx were significantly higher in Tac recipients compared to CsA. Regular assessment for infections and lower Tac trough levels may be warranted in Tac recipients.

Three-yr safety and efficacy of everolimus and low-dose cyclosporine in de novo pediatric kidney transplant patients

The three yr results of a multicenter trial in de novo pediatric KT treated with a proliferative signal inhibitor and low dose CNI are presented. Thirty-seven children (9.1 ± 5 yr old) received basiliximab, cyclosporine A (CyA C2:1400 ng/mL), (MMF C0:1.5-3 μg/mL), and prednisone. Three wk later everolimus was started (C0:5-10 ng/mL), CyA was reduced (C2:600 ng/mL after 90 days 300 ng/mL), and MMF discontinued. During the three-yr period patient and graft survivals were 96%. One patient died for causes unrelated to the immunosuppression. Cumulative acute rejection rate including protocol and indication biopsies was 21.9%. None of the patients had signs of chronic humoral rejection. Incidence of dnDSA was 5%, 11%, and 22% at one, two, and three yr post-transplant, respectively. Mean glomerular filtration rate measured at one yr and three yr post-transplant was 105.5 ± 31 and 110.7 ± 27 mL/min/1.73 m(2), respectively. A growth velocity of 7.7 ± 6.7 cm/yr was achieved with positive catch-up growth. No malignancy or post-transplant lymphoproliferative diseases were diagnosed. In conclusion, the treatment based on basiliximab induction, everolimus, low-dose cyclosporine, and low-dose prednisone leads to good long-term efficacy in de novo pediatric KT recipients.

Antihypertensive pharmacotherapy and long-term outcomes in pediatric kidney transplantation

Hypertension (HTN) is common in pediatric recipients following kidney transplantation (KT). We retrospectively assessed the impact of HTN on long-term (>10-yr) outcomes in pediatric KT recipients (aged < 18 yr) at our center. Two hundred and ninety-three pediatric KT recipients (83% living donor [LD]) with graft survival (GS) for ≥5 yr were studied. HTN was defined by antihypertensive medication use at five yr post-KT. One hundred and sixty (55%) recipients did not have HTN, and 133 (45%) had HTN at five yr post-KT. There were no differences in actuarial patient survival between cohorts. Actuarial GS at 15 and 20 yr was 68% and 53% for recipients without HTN, and 53% and 33% for recipients with HTN (p = 0.006). Among LD recipients using one antihypertensive, GS at 15 yr was 100% for those using an angiotensin-converting enzyme inhibitor (ACEI) and 44% for those not using an ACEI (p = 0.04). Among these recipients, HTN treated with no ACEI was a significant risk factor for graft failure at >5 yr (hazard ratio [HR] = 2.5, p = 0.02), but HTN treated with an ACEI was not (HR = 0.6, p = 0.7). HTN at five yr post-KT is associated with poorer long-term GS in pediatric recipients, but ACEI therapy may enable better outcomes and should be studied further.

Serious bacterial infections in febrile outpatient pediatric kidney transplant recipients

BACKGROUND

the purpose of this study was to describe the incidence of serious bacterial infections in febrile outpatient pediatric kidney transplant recipients and to assess the utility of using white blood cell indices to identify patients at low risk for bacteremia.

METHODS

a retrospective study was conducted on all kidney transplant recipients followed at a single children's hospital. All outpatient visits from January 1, 1995 to June 6, 2007 in which fever was evaluated were reviewed. Patients with history of a primary immunodeficiency, receiving concurrent chemotherapy, or a stem cell or small bowel transplant were excluded. Demographic, historical, physical examination, laboratory, and radiographic data were then recorded.

RESULTS

in all, 101 patients had 251 individual episodes of fever evaluation. In 209 visits, a blood culture was drawn with results available. There were 21 (10.0%) true positive blood cultures and 3 (1.4%) false positives. Two-thirds of the true positive blood cultures occurred in patients with indwelling hardware. There was a positive urine culture in 52/192 (27.1%) visits. Pneumonia was diagnosed in 14/74 (18.9%) visits. In nonill-appearing children without indwelling central lines or focal bacterial infections, the incidence of bacteremia was zero. No practical decision rule based on white blood cell indices could be derived.

CONCLUSIONS

the majority of bacteremic cases in febrile outpatient pediatric kidney transplant patients occurred in patients with indwelling hardware. We did not detect any occult cases of bacteremia in this study cohort. A larger prospective multicenter study is required to confirm the low incidence of bacteremia in this patient subset.

Efficacy and safety of measles, mumps, rubella and varicella live viral vaccines in transplant recipients receiving immunosuppressive drugs

BACKGROUND

This review was designed to summarize published data on the efficacy and safety of live viral vaccines for measles, mumps, rubella, or varicella in post-transplant patients currently on immunosuppression.

DATA SOURCES

Medline, EMBASE and Evidence Based Medicine Reviews were searched from 1966 to November 2007 for case reports or studies describing the efficacy and/or safety of live attenuated measles, mumps, rubella, or varicella vaccine in children on immunosuppression following solid organ, bone marrow or stem cell transplantation.

RESULTS

The review identified 6 case series and 2 case reports describing 114 solid organ transplant recipients and one case series describing 27 bone marrow transplant recipients who had received a combined total of 206 doses of live varicella, measles, mumps, or rubella vaccine while on immunosuppression. Post-immunization titers were in the immune range in 109 of the 171 situations where they were measured following a single dose of vaccine (64%) and in 15 of 22 situations following 2 doses (68%). There were no major safety concerns in this small sample.

CONCLUSION

There are insufficient published data to derive evidence-based guidelines for use of live viral vaccines in transplant recipients on immunosuppression but preliminary data on efficacy and safety suggest that the use of these live viral vaccines in transplant recipients still on immunosuppression could be a reasonable strategy.

Increased urologic complications in children after kidney transplants for obstructive and reflux uropathy

In the cyclosporine era, reports on pediatric kidney transplant (KTx) patients with obstructive and reflux uropathy are limited by small numbers, short follow-up, and/or lack of control groups. Our single-center study evaluated long-term outcomes (patient and graft survival, urinary tract infections [UTIs], urologic complications) in a large cohort of KTx recipients (<20 years old). We matched our 117 study patients with obstructive and reflux uropathy with 117 controls whose KTx was needed for other reasons; all 234 underwent their KTx between April 25, 1984, and October 23, 2002. The mean age was 8.0 +/- 6.2 years; mean follow-up, 133 +/- 67 months. The urologic complication rate was higher in study patients (43%) than in controls (11%) (p < 0.0001), as was the UTI rate (45% vs. 2%; p < 0.0001). The metabolic acidosis and UTI rates were higher in study patients who did (vs. did not) undergo bladder augmentation (p < 0.0001). We found no significant difference between study patients and controls in patient or graft survival, acute or chronic rejection, or mean estimated glomerular filtration rates. Unique to our study is the finding of higher metabolic acidosis and UTI rates in study patients who underwent bladder augmentation.

Younger age and antibody induction increase the risk for infection in pediatric renal transplantation: a NAPRTCS report

Infections now exceed rejection as a cause of hospitalization in the first 2 years post-renal transplantation. We analyzed data from the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) to determine risks for hospitalization for infection (HI), either bacterial (HBI) or viral (HVI). 3106 children transplanted between 1996 and 2002 with 2-year follow-up were analyzed. Univariate and multivariate logistic regression analyses identified factors for cause-specific hospitalization.

RESULTS

23.4% experienced HBI, 23.9% HVI; 8.9% were hospitalized for both. Children 0-1 years age at transplant had higher rates of HI (64.2%), HBI (40.3%) and HVI (43.3%) compared to >12 years (31%, 17.5% and 18.9%, p < 0.0001). In comparison to no induction, patients receiving monoclonal or polyclonal antibody were more likely to have HI (>42% vs. 34.0%), HBI (>24% vs. 21%) or HVI (>29% vs. 21%, all p < 0.003) but had equivalent graft survival (p = NS). Higher rates of HI, HBI and HVI were also seen with prophylactic antimicrobial use and with >5 transfusions pretransplant. Since antibody induction in recent era was not associated with better graft or patient survival but was associated with more HI and HVI, the need for routine antibody induction in children needs to be reassessed.

Risk factors for hospitalization for bacterial or viral infection in renal transplant recipients--an analysis of USRDS data

We previously showed that children are more likely to develop viral infections post-kidney transplant while adults are more likely to develop bacterial infections. In this study we determined the overall risk factors for hospitalization with either a bacterial (HBI) or a viral infection (HVI). We analyzed data from 28 924 United States Renal Data System (USRDS) Medicare primary renal transplant recipients from January 1996 to July 2000, for adjusted hazard ratio (AHR) for HBI or HVI in the first 3 years posttransplant. For HVI, significantly higher AHR was seen with (a) recipient age <18 years (AHR 1.57, 95% CI = 1.02, 2.42), (b) donor CMV positive (AHR 1.72, 95% CI = 1.34, 2.19). For HBI, significantly higher AHR was seen with (i) delayed graft function (AHR 1.28, 95% CI = 1.076, 1.518), (ii) primary renal diagnosis chronic pyelonephritis (AHR 1.71, 95% CI = 1.18, 2.49); (iii) associated pretransplant diabetes (AHR 1.80, 95% CI = 1.53, 2.12); (iv) female gender AHR 1.63, 95% CI = 1.41, 1.88). Lower AHR for HVI was seen in CMV-positive recipients and for HBI with more recent year of transplant. Other covariates did not impact significantly in either HVI or HBI.

Infection-Related Hospitalization Rates in Pediatric versus Adult Patients with End-Stage Renal Disease in the United States

Infection is a common cause of morbidity and mortality in patients with ESRD. Infection-related hospitalization (IH) incidence among US Medicare incident pediatric and adult dialysis and transplant patients within 3 yr of presentation was compared from 1996 to 2001: Hemodialysis (HD) patients (pediatric n = 1469; adult n = 305,323); peritoneal dialysis (PD) patients (pediatric n=982; adult n=27,119), and kidney transplant (KTx) patients (pediatric n=1108; adult n=31,663). IH were identified from principal diagnosis codes; IH cumulative incidence and rates were calculated from claims data. Cumulative incidence of IH at 36 mo for incident pediatric patients with ESRD during 1996 to 2001 was 39.9% in HD, 51.2% in PD, and 47.4% in KTx patients (HD or PD versus KTx, P<0.0001). Cumulative incidence for adults was 52.6% in HD, 51.8% in PD, and 39.8% in KTx patients (HD or PD versus KTx, P<0.0001). IH rates per 1000 patient-months were highest for pediatric KTx patients (adjusted rate ratio 1.53 versus HD and 1.90 versus PD, P<0.001 for each) and adult HD patients (adjusted rate ratio 1.20 versus KTx and 1.11 versus PD, P < 0.001 for each). Within the first 36 mo of incidence, IH rates are highest for incident pediatric KTx patients compared with HD and PD patients, in contrast to findings for adult patients with ESRD. Pediatric KTx patients require infection surveillance after transplantation.

Effects of Urinary Tract Infection on Outcomes after Renal Transplantation in Children

Urinary tract infection (UTI) is the most common infection after kidney transplantation. A previous analysis showed that late (>6 mo after transplantation) UTI is associated with earlier graft loss in adults. It was hypothesized that children who are younger than 18 yr would be at higher risk to develop UTI and develop graft loss after both early and late UTI. The US Renal Data System database was analyzed from 1996 to 2000 for Medicare claims (composite of inpatient and outpatient) for UTI up to 36 mo after transplantation. SPSS software and Cox regression models were used to determine association of UTI and age after adjustment for covariates. Early UTI was defined as occurring <6 mo after transplantation, and late UTI was defined as occurring > or =6 mo after transplantation. The risk for graft loss after early UTI was elevated in all children (adjusted hazard ratio [AHR] 5.47; 95% confidence interval [CI] 1.93 to 15.4; P < 0.001) but not after late UTI (AHR 2.09; 95% CI 0.56 to 7.80; P = 0.27). Risk for posttransplantation death was not increased significantly after either early UTI (AHR 1.23; 95% CI 0.37 to 4.08) or late UTI (relative risk 2.22; 95% CI 0.90 to 5.44). Boys aged 2 to 5 (versus age 13 to <18 years) were at significantly higher risk for UTI. In girls, only those in the youngest age category (0 to 1) had higher risk for UTI. Children are at greater risk for graft loss after early but not necessarily late UTI. UTI was not an independent predictor of death in this population.

Pharmacokinetic of cyclosporine microemulsion in pediatric kidney recipients receiving A quadruple immunosuppressive regimen: the value of C2 blood levels

BACKGROUND

The management of cyclosporine therapy in pediatric kidney-transplant recipients is largely based on single center's experience rather than on a univocal pharmacokinetic approach based on therapeutic drug monitoring. A prospective multicenter trial was designed to address the question whether C2 blood level monitoring of cyclosporine microemulsion therapy is feasible in the pediatric setting.

METHODS

Sixty-four pediatric kidney-transplant recipients receiving a triple immunosuppressive regimen based on cyclosporine microemulsion had their cyclosporine dose adjusted to the same protocol-defined C2 targets from the time of the transplant until 2 years posttransplant. The interim analyses after 1 year of enrollment is presented in this study.

RESULTS

One-year patient and graft survival were 100% and 94.8%, respectively. One-year rejection rate was 15%. C2 management of cyclosporine did not affect graft function: 1-year serum creatinine and glomerular filtration rate were 1.3+/-1 mg/mL and 71.2+/-20 mL/min/1.73 m2, respectively. C2 was the best single-point predictor of the area under the concentration curve throughout the entire follow-up, with a mean coefficient of correlation of 0.97+/-0.01.

CONCLUSIONS

C2 management of cyclosporine microemulsion therapy is effective and safe in pediatric kidney-transplant recipients given a combined immunosuppressive treatment.

Thymoglobulin Versus ATGAM Induction Therapy in Pediatric Kidney Transplant Recipients: A Single-Center Report

BACKGROUND

Induction immunosuppressive therapy with the anti-T-cell antibody Thymoglobulin decreases the incidence of acute rejection in adult kidney transplant (KTx) recipients, but limited data are available for pediatric KTx recipients.

METHODS

We conducted a historical cohort study to compare rates of survival, rejection, and infection in pediatric (age <19 years) KTx recipients who received induction therapy with polyclonal antibody, ATGAM (n=127) or Thymoglobulin (n=71), from December 1, 1992, to January 31, 2003. Maintenance immunosuppression included cyclosporine, azathioprine or mycophenolate mofetil, and prednisone. Mean follow-up was 90+/-25 months for ATGAM recipients and 32+/-15 months for Thymoglobulin recipients.

RESULTS

Overall, the incidence of acute rejection was lower in Thymoglobulin recipients versus ATGAM recipients (33% vs. 50%, P=0.02). Epstein-Barr virus (EBV) infection was higher in Thymoglobulin recipients versus ATGAM recipients (8% vs. 3%, P=0.002). But the two groups did not significantly differ in patient and graft survival rates, incidence of chronic rejection, EBV lymphoma, or other infection.

CONCLUSIONS

Thus, Thymoglobulin induction was associated with a decreased incidence of acute rejection and an increased incidence of EBV infection in pediatric KTx recipients. EBV monitoring should be performed in EBV-naive recipients receiving Thymoglobulin.

Current status of ABO-incompatible kidney transplantation in children

This article reviews the current status of ABO-incompatible kidney transplantation in the pediatric population. ABO blood type incompatibility between a donor and recipient was generally considered a contraindication to kidney transplantation because of the associated high risk for hyperacute rejection. However, due to a severe shortage of suitable cadaveric allografts, much effort has been made over the last decade to investigate whether successful and effective kidney transplantation is possible across the ABO blood group barrier. At present, ABO-incompatible kidney transplantation has been shown to be a valid alternative even for children with end stage renal disease. In this review, we will discuss protocols available for successfully performing ABO-incompatible kidney transplantation in children: (1) pre-transplant extracorporeal immunomodulation with removal of pre-existing anti-A and/or anti-B antibodies; (2) immunosuppressive therapy and anti-rejection therapy; (3) splenectomy and the associated infectious complication in asplenic children. Also, we will speculate regarding the mechanisms underlying accommodation following transplantation.

Mortalité en transplantation rénale pédiatrique : 15 ans d'expérience

The aim of the study was to analyse retrospectively the patient survival and mortality risk factors in renal transplant children at Edouard-Herriot hospital, Lyon.

PATIENTS AND METHODS

One hundred and ninety four patients 0 to less than 18 years of age received a renal transplant between April 1987 and January 2002. We collected data concerning the age at transplantation, the mean duration of dialysis prior to transplantation, the type of donor (living related: LRD, or cadaver: CAD) as well as long term follow-up of all the patients. Eleven patients died during the study period and we collected mortality and morbidity factors.

RESULTS

Mean age at transplantation was 9.5 years (range: 0.6-17.9 years); 16 children were transplanted before 2 years of age. Eighty six percent received a first graft, 10% a second graft, and 3% a third graft. One third of the patients had preemptive transplantation. The graft was carried out respectively from a LRD in 18% and from CAD in 82% of the cases. Eleven patients (5.7%) died during this period; four of them were transplanted twice. Death occurred within 2.4 years after transplantation (range: 2 days-6.3 years). Five of these deceased children developed an acute rejection episode treated with methylprednisolone pulses and OKT3 monoclonal antibodies. Four had a cytomegalovirus (CMV) infection and three required repeated surgery. The causes of death were bacterial infections (4/11), CMV infection (2/11), neurological involvement (2/11), Burkitt lymphoma (1/11) and unexplained sudden death (2/11).

CONCLUSION

The main causes of deaths in renal transplant children are bacterial infections. The improvement in patient survival probably will come from both better preventive approach to nosocomial infections and a less aggressive immunosuppression.

Post-transplant infections now exceed acute rejection as cause for hospitalization: a report of the NAPRTCS

Newer immunosuppressive agents have dramatically reduced the rates of acute graft rejection (AR) over the last decade but may have exacerbated the problem of post-transplant infections (PTI). We analyzed data from the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) to determine the risks of hospitalization from PTI vs. AR in the years 1987-2000. For patients transplanted in 1987, the AR-associated hospitalization rate exceeded the equivalent hospitalization rate for PTI at both early (1-6 months) and later time points (6-24 months). In contrast, for patients transplanted in the year 2000, the PTI-associated hospitalization rate was twice that for AR-associated hospitalization during each time period. During the first two years post-transplant, rates of AR hospitalization trended significantly downwards (p < 0.001) while rates of PTI-associated hospitalization stayed constant. In the 6-24-month time period post-transplant, the risk of bacterial and viral infection-related hospitalization rose significantly from 1987 to 2000 (p < 0.001 for trend by transplant year). We conclude that the causes of hospitalization at all times up to 24 months post-transplant, including the critical early 6 months, have shifted away from AR to PTI.

Urinary tract infections beyond the early post-transplant period in pediatric renal graft recipients

BACKGROUND

Urinary tract infection is a frequent bacterial complication after renal transplantation in adults and children, however there are only very limited data on children beyond the early post-transplant period. In this study we investigated urinary tract infections in pediatric outpatients who had received transplants more than six months previously. Incidence, risk factors and impact on short-term graft function were analyzed.

METHODS

47 children who had received a total of 58 allografts were analyzed between 1997 and 2000. At the time of analysis they had had their transplants for an average of 3.5 years (range 0.5-9.4). Urinary tract infection was defined as the presence of both significant bacteriuria (> 10(5) CFU/ml) and symptoms.

RESULTS

Of the 47 patients, 15 (32%) had from 1 to 7 urinary tract infections each. In total 35 infections were recorded. Median age at urinary tract infection was 5.5 years (range 1.8-24.2). Gender, donor source, immunosuppression and underlying disease (urologic vs non-urologic) did not influence the incidence of urinary tract infection. Creatinine but not C-reactive protein rose significantly during the infection.

CONCLUSIONS

Our data suggest that urinary tract infection remains a frequent but mostly benign complication in the pediatric transplant population, even beyond the early post-transplant period. More extended studies are needed to assess the long-term effects on graft function.

Improved late graft survival and half-lives in pediatric kidney transplantation: a single center experience

We evaluated variables associated with improved late graft survival in 290 children transplanted between 11/1/1984 and 12/31/1997, and who had > 1 year graft survival. We studied the following variables: age, gender, race, primary disease (diseases prone to recurrence, i.e. hemolytic uremic syndrome, focal segmental glomerulosclerosis or oxalosis vs. others), primary vs. retransplant; donor source, acute tubular necrosis, acute rejection episodes in the first year, transplant era and discharge serum creatinine. Graft half-life was defined as the time taken for 1/2 of the grafts functioning at 1 year to fail. There were 205 living donor and 85 cadaveric transplant. The cumulative graft survival at 5 and 10 years was 88% and 75% for living donor, and 72% and 46% for cadaveric, respectively. Multivariate analyses showed a higher late graft survival to be associated with: no acute rejection episodes (risk ratio 0.16, p = 0.0001), age 2-5 years (risk ratio 0.24, p = 0.0007), living donor (risk ratio 0.46, p = 0.017), primary nonrecurrent disease (risk ratio 0.29, p = 0.001), Caucasian race (risk ratio 0.40, p = 0.006). A high half-life was seen with living donor transplant (21.3 years) and the age group 2-5 years (27.5 years). Further, living donor patients with no acute rejection episodes had the best half-life of 37.6 years, while children with hemolytic uremic syndrome, focal segmental glomerulosclerosis or oxalosis had the lowest overall half-life of 5.6 years. This study finds that living donor, no acute rejection episodes, age 2-5 years, Caucasian race and having a disease not prone to recurrence are strong predictors of late graft survival. Hence, preferential use of living donor and prevention of acute rejection episodes in the first year are key variables that can improve long-term renal graft survival in children.

A multicenter, open-label, pharmacokinetic/pharmacodynamic safety, and tolerability study of basiliximab (Simulect) in pediatric de novo renal transplant recipients

BACKGROUND

Basiliximab (Simulect) has been shown to be safe and effective in adult renal transplant recipients, when used in combination with cyclosporine (Neoral) and corticosteroids. We report on the safety and preliminary efficacy of basiliximab in pediatric de novo renal transplant recipients.

METHODS

This was an open-label, 12-month study of basiliximab in 41 patients (2 cohorts: <9 and 9 to <16 years). In phase 1, two intravenous (IV) bolus injections of basiliximab (12 mg/m ) were administered (before and 4 days postsurgery). In phase 2, two injections (<40 kg, 10 mg and > or =40 kg, 20 mg) were administered at the same time points. Most patients (26/41 [63%]) received cadaveric kidneys. Almost half of the patients had three human leukocyte antigen mismatches with the organ donors. Concurrent immunosuppression included Neoral and corticosteroids. Azathioprine was allowed after 28 days.

RESULTS

All patients completed the 1-year study. The acute tolerability of basiliximab via IV bolus injection was good, without evidence of cytokine-release syndrome or acute local reactions. All patients experienced adverse events, but most (71%) were mild or asymptomatic. No deaths or malignancies occurred. The incidence and types of serious adverse events (59%) and serious infections (44%) were as expected in this patient population, and few were drug-related (7% and 5%, respectively). Thirty-eight patients (93%) had infections, mostly urinary tract infections, as expected for renal transplant patients. Six patients (15%) had drug-related adverse events. Biopsy-confirmed acute rejection episodes occurred in 6/41 (15%) of patients during the first 6 months posttransplantation and in 9/41 (22%) patients during the first 12 months. Five patients (12%) experienced graft loss, none of which were preceded by acute rejection episodes.

CONCLUSIONS

Basiliximab is safe and well tolerated when administered by IV bolus injection in de novo pediatric renal transplant recipients. These preliminary data suggest that basiliximab, given in combination with cyclosporine and corticosteroids, is an effective immunosuppressive regimen for the prevention of acute rejection in pediatric renal transplantation.

Efficacy and safety of immunization for pre- and post- liver transplant children

BACKGROUND

Infection is a serious complication after liver transplantation. Immunization is one means of controlling infections. The objective of this study was to investigate the efficacy and safety of simultaneous administration of several vaccines before transplantation and the efficacy and safety of administration under immunosuppressive conditions after transplantation.

METHODS

Fifty-eight patients who underwent living-related liver transplantation between April 1994 and March 2000 were included in this study. Simultaneous administration of a maximum of six vaccines was performed in a short period of time before transplantation. We also readministered vaccines to 15 patients with waning antibody titers after transplantation from June 1999. We investigated whether patients could seroconvert for measles, rubella, mumps, and varicella after immunization and how long antibody titers could be retained by measuring them several times throughout the period before and after transplantation. We also examined side effects caused by immunization.

RESULTS

The rates of seroconversion against measles, rubella, mumps, and varicella after the pretransplantation vaccination were 82%, 100%, 90%, and 95%, respectively. The rates of reseroconversion against measles, rubella, mumps, and varicella after the posttransplantation revaccination were 85%, 100%, 100%, and 71%, respectively. Although antibody titers against these viruses generally waned with time, no patient exhibited any serious illness or side effects.

CONCLUSION

Although 12 of 58 patients (21%) had an infection, pretransplantation immunization was effective to prevent serious illness, especially for the 6 months after transplantation. Posttransplantation live-vaccine administration under immunosuppressive conditions is effective and safe.

Varicella-zoster infection in pediatric solid-organ transplant recipients: a hospital-based study in the prevaricella vaccine era

We reviewed 58 cases of varicella-zoster infection that occurred between 1988 and 1998 in 47 pediatric solid-organ transplant recipients. The median age of patients at the time of admission with varicella-zoster infection was 8.0 yr (range 1-17 yr). The median interval between transplantation (Tx) and varicella-zoster virus (VZV) infection was 1.6 yr (range 0.06-9.3 yr). Varicella infection occurred at a rate of one case for every seven transplant recipients. Among the 58 cases of VZV infection, 53% were varicella while 47% were herpes-zoster. Varicella infection occurred despite treatment with varicella-zoster immune globulin (VZIG) in 17 of 31 cases of varicella infection. However, the disease was generally mild with severe disease occurring in only two patients. One patient (1.7%) died as a result of bacterial sepsis. There was no significant relationship between VZV infection and specific immune suppressants. Episodes of rejection were more likely to be temporally associated with the occurence of herpes zoster than with varicella infection (p = 0.02). The data generated provide useful background information in our population in the prevaricella vaccine era.

Kidney transplantation in children younger than 1 year using cyclosporine immunosuppression

OBJECTIVE

The optimal age for transplantation in children with end-stage renal disease remains controversial. Supported by national data, many centers recommend dialysis until the child reaches a certain minimum age. The authors' policy, however, has been to encourage living donor (LD) transplants for young children, with no minimum age restriction.

METHODS

Between January 1, 1984, and December 31, 1996, the authors performed 248 kidney transplants in children younger than age 13 years, using cyclosporine as the primary immunosuppressive agent. Recipients were analyzed in three age groups: group 1, younger than age 1 year (n = 26); group 2, age 1 through 4 (n = 92); and group 3, age 5 through 13 (n = 130). Almost all recipients in group 1 underwent a primary LD transplant. Therefore, to compare results more meaningfully among the three age groups, only primary LD transplants were analyzed (group 1, n = 25; group 2, n = 59; group 3, n = 58).

RESULTS

In primary LD transplants, no significant difference was noted among the age groups in 1-and 5-year patient or graft survival rates. To date, all 25 recipients from group 1 are alive and well; 19 still have a functional original graft. Causes of graft loss in the remaining six recipients were chronic rejection (n = 3), vascular thrombosis (n = 2), and recurrent disease (n = 1). The incidence of acute rejection in group 1 recipients was lower than in the two older groups. However, the incidence of delayed graft function was slightly higher in the youngest group than in the two older groups. For recipients in group 1, growth (as measured by weight) improved significantly posttransplant: the mean standard deviation score rose from -2.8 pretransplant to -0.2 by age 5 and to +1.8 by age 10. The improvement in height was not as dramatic: the mean standard deviation score rose from -3.2 pretransplant to -1.6 by age 5 and to -1.4 by age 10.

CONCLUSIONS

Kidney transplantation in young children, including those younger than 1 year old, can achieve results comparable to those in older children. As long as an adult LD is available, the timing of the transplant should be based on renal function rather than age.