Growth following solid organ transplantation in childhood.

One of the ultimate goals of successful transplantation in pediatric solid organ transplant recipients is the attainment of optimal final adult height. This manuscript will discuss the attainment of height following solid organ transplantation in pediatric recipients of kidney, liver, heart, lung, and small bowel transplantation. Age is a primary factor with younger recipients exhibiting the greatest immediate catch up growth. Graft function is a significant contributory factor with a reduction in glomerular filtration rate correlating with poor growth in kidney recipients and the need for re-transplantation with impaired growth in liver recipients. The known adverse impact of steroids on growth has led to modification of steroid dosage and even to steroid withdrawal and steroid avoidance. In kidney and liver recipients, this has been associated with the development on occasion of acute rejection episodes. In infant heart transplantation, avoidance of maintenance corticosteroid immunosuppression is associated with normal growth velocity in the majority of patients. With marked improvement in patient and graft survival rates in pediatric organ graft recipients, it is timely that the quality of life issues, such as normal adult height, receive paramount attention. In general, normal growth post-transplantation should be an achievable goal that results in normal adult height for many solid organ transplantation recipients.

Adherence to the immunosuppressive regimen in pediatric kidney transplant recipients: a systematic review.

As most prior reviews on NA focus on adult transplant patients, there is a need for a comprehensive overview on adherence to the immunosuppressive regimen in pediatric kidney transplant patients. This systematic review searched for English-language papers (1990-2008) addressing the prevalence of NA to the immunosuppressive regimen, its consequences, determinants, and interventions in pediatric kidney transplant patients (< age 21 yr). We found 36 papers, showing a prevalence of NA (weighted mean) of 31.8% with adolescents being more at risk compared to younger patients. About 44% of all graft losses and 23% of late acute rejection episodes are associated with NA. Most studies investigated socio-economic, condition-related or treatment-related determinants. Only one educational intervention has been tested but yielded inconclusive results. NA to the immunosuppressive regimen is prevalent with serious clinical consequences in pediatric kidney transplant patients, but the economic consequences have not yet been explored. More studies on determinants of NA are needed. The literature currently lacks fully powered RCTs testing adherence-enhancing interventions. The results of this systematic review identify the gaps in the present evidence-based information regarding NA and can be used as a tool to pursue future adherence research in pediatric populations.

Nonadherence consensus conference summary report.

This report is a summary of a 'Consensus Conference' on nonadherence (NA) to immunosuppressants. Its aims were: (1) to discuss the state-of-the-art on the definition, prevalence and measurement of NA, its risk factors and impact on clinical and economical outcomes and interventions and (2) to provide recommendations for future studies. A two-day meeting was held in Florida in January 2008, inviting 66 medical and allied health adherence transplant and nontransplant experts. A scientific committee prepared the meeting. Consensus was reached using plenary and interactive presentations and discussions in small break-out groups. Plenary presenters prepared a summary beforehand. Break-out group leaders initiated discussion between the group members prior to the meeting using conference calls and e-mail and provided a summary afterward. Conclusions were that NA: (a) is more prevalent than we assume; (b) is hard to measure accurately; (c) tends to confer worse outcomes; (d) happens for a number of reasons, and system-related factors including the patient's culture, the healthcare provider and the setting and (e) it is not currently known how to improve adherence. This consensus report provided some roadmaps for future studies on this complicated, multifaceted problem.

Pediatric transplantation in the United States, 1995-2004.

This article reviews trends in pediatric solid organ transplantation over the last decade, as reflected in OPTN/SRTR data. In 2004, children younger than 18 years made up nearly 3% of the 86,378 candidates for organ transplantation and nearly 7% of the 27,031 organ transplant recipients. Children accounted for nearly 14% of the 7152 deceased organ donors. The transplant community recognizes important differences between pediatric and adult organ transplant recipients, including different etiologies of organ failure, surgical procedures that are more complex or technically challenging, effects of development on the pharmacokinetic properties of common immunosuppressants, unique immunological aspects of transplant in the developing immune system and increased susceptibility to posttransplant complications, particularly infectious diseases. For these reasons, and because of the impact of end-stage organ failure on growth and development, the transplant community has generally provided pediatric candidates with special consideration in the allocation of deceased donor organs. Outcomes following kidney, liver and heart transplantation in children often rank among the best. This article emphasizes that the prospects for solid organ transplantation in children, especially those aged 1-10 years are excellent. It also identifies themes warranting further consideration, including organ availability, adolescent survival and challenges facing pediatric transplant clinical research.

Outcome after transplantation of young patients with systemic lupus erythematosus: a report of the North American pediatric renal transplant cooperative study.

BACKGROUND: The risk of progressing to end-stage renal disease in children with lupus glomerulonephritis is 18% to 50%. Published reports of transplantation secondary to end-stage renal failure in adult patients with systemic lupus erythematosus (SLE) demonstrate equivalent patient and graft survival. The purpose of this analysis is to compare patient and graft outcomes of pediatric SLE renal transplant recipients with an age-, race-, and gender-matched control group. METHODS: A retrospective analysis of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) database identified 100 renal transplants performed in 94 young SLE patients. A control group of 470 children having received 501 renal transplants was identified. RESULTS: The SLE cohort was primarily female (82%), non-Caucasian (61%), adolescents and differed from the control group in being less likely to be preemptively transplanted, in receiving longer pretransplant dialysis, and in being likely to have received more than five pretransplant transfusions. After transplantation, there were no differences seen in patient survival at 3 years (89% vs. 95%, SLE vs. control) or in overall graft failure rates (31% vs. 29%, SLE vs. control). There was a trend toward poorer graft survival in non-white SLE patients receiving living donor grafts compared with white SLE patients. An increased graft failure rate was seen among those SLE cadaveric transplant recipients receiving peritoneal dialysis before transplant compared with controls and compared with SLE patients receiving hemodialysis. No differences were seen in rates of acute tubular necrosis or overall acute rejection incidence, although there was a significant increase in the percentage of living donor SLE patients who experienced greater than four rejection episodes. There were nonsignificant trends toward increased graft loss due to patient death with a functioning graft as well as increased mortality secondary to infection in the SLE patients. CONCLUSIONS: The results of renal transplantation in young SLE patients are comparable to those seen in an age-, race- and gender-matched control group. The similar patient and graft survival is seen despite the SLE patients having an underlying disease with multiorgan involvement and despite receiving immunosuppression for potentially prolonged periods before transplantation. No outcome differences were seen except for an unexplained increase in the incidence of recurrent rejections (> or =4) in the living donor SLE patients as well as increased graft failure rate in those patients receiving cadaveric renal transplants after a period of peritoneal dialysis. The nonsignificant trends toward increased graft failures in non-white SLE patients receiving living donor grafts, increased graft loss secondary to death with a functioning graft, as well as the increased mortality due to infection deserve recognition and further study.

Avascular necrosis of the femoral head in children with chronic renal disease.

PURPOSE: To determine the incidence of avascular necrosis (AVN) of the femoral head in children with chronic renal failure. MATERIALS AND METHODS: Pelvic radiographs in 205 children (age range, 6 months to 16 years; mean age, 6 years +/- 3.5 [SD]) with chronic renal failure were reviewed. Serial radiographs were obtained every 6 months for 1-7 years (mean, 3 years +/- 2) to assess the presence of AVN of the femoral head; six children had metabolic renal disease, 21 had acquired renal disease, and 178 had structural renal lesions. RESULTS: Radiographic findings of AVN were seen in 14 of 205 patients (approximately one in every 15). The frequency of AVN was similar in boys and girls; AVN was observed in 11 (6.9%) of 159 boys and in three (6.5%) of 46 girls and was not related to the duration of renal disease, type of renal disease, or growth hormone therapy. Affected children were frequently asymptomatic, and, when present, the clinical complaints were mild. In two instances, AVN developed while the patients were receiving corticosteroids before entering this study. CONCLUSION: The results of this study indicate that AVN of the femoral head is a frequent complication in children with chronic renal failure, occurring in approximately 7% of this population. Unlike Legg-Calvé-Perthes disease, AVN in children with chronic renal failure is frequently asymptomatic and has no sex predilection.

The contribution of renal transplantation to final adult height: a report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS).

Final adult height following renal transplantation was assessed in 237 recipients enrolled in NAPRTCS before the ages of 11 (girls) and 12 (boys) years and followed for at least 6 months with a functioning graft at or after 18 years of age. The overall change in standardized height (SDS) from baseline to final adult height (FH) was 0.0; however, delta SDS was significantly better for the youngest recipients (6-8 years) than for the older age group. Retarded FH was associated with higher average prednisone dosage and better FH was associated with good graft function. Low baseline SDS was also predictive of retarded FH. Final adult height continues to be suboptimal in the cyclosporine A era.

The impact of recombinant human growth hormone treatment on final adult height.

There are limited data addressing the issue of final adult height following treatment with recombinant human growth hormone (rhGH). Utilizing the chronological age of 18 years as the arbitrary age of final adult height for children with chronic renal insufficiency, all patients enrolled in the North American Pediatric Renal Transplant Cooperative Study prior to January 1999, and who had at least one follow-up visit at age 18 years or older, were evaluated. When comparing the final adult height in those patients receiving prior rhGH with a group not receiving rhGH, the delta height standard deviation score was greater in the rhGH treatment group.

Pretransplant dialysis status and outcome of renal transplantation in North American children: a NAPRTCS Study. North American Pediatric Renal Transplant Cooperative Study.

BACKGROUND: There are no large studies of the effect of pretransplant dialysis status on the outcome of renal transplantation (Tx) in children. This study evaluated the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) registry data for the outcome of Tx in pediatric patients who either (1) received their transplants preemptively or (2) were maintained on dialysis before receiving their transplants. METHODS: We compared graft survival and patient survival rates, incidence of acute tubular necrosis (ATN), acute rejection episodes, and causes of graft failure in peritoneal dialysis (PD) patients with those maintained on hemodialysis (HD) and those undergoing preemptive Tx (PTx). RESULTS: Primary Tx was performed in 2495 children (59% male; 61% Caucasian; 1090 PD, 780 HD, 625 PTx) between 1/1/1992 and 12/31/1996. The overall graft survival rates of the PD and HD groups were similar, but were less than that of the PTx group (3-year: 82% PD and HD, 89% PTx, overall P = 0.0003). Improved graft survival in the PTx group was present only in recipients of grafts from living donors. There was no difference in the overall patient survival rate at 3 years, or in time to first acute-rejection episodes in the three groups. The incidence of ATN in the first 7 days post-Tx was higher in PD and HD patients than in PTx patients (11% PD and 12% HD vs. 2% PTx, P<0.001; HD vs. PD, P = NS). The major single cause of graft failure in each group was: PD, vascular thrombosis (200%); HD, chronic rejection (27%); PTx, acute and chronic rejection (21% each). CONCLUSION: NAPRTCS data show that graft survival is improved in patients receiving PTx, compared with those receiving PD and HD. Graft loss resulting from vascular thrombosis is more common in children who receive PD than in those receiving HD.

The impact of recombinant human growth hormone treatment during chronic renal insufficiency on renal transplant recipients.

OBJECTIVE: To evaluate post-transplant outcomes for patients treated with human growth hormone (rhGH) during the course of chronic renal insufficiency (CRI). STUDY DESIGN: Patients (the "cohort" group) were identified who had been enrolled in 2 controlled studies to determine the efficacy and safety of rhGH in growth-retarded children with CRI and were subsequently enrolled in the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) and received a renal transplant. Patient survival, graft survival, time to first acute rejection episode, causes of graft failure, adverse events, and serial growth data from transplant to 60 months were evaluated. Data from the cohort group of 102 patients were compared with data from 4913 primary transplants from "other NAPRTCS" recipients (the "control" group). RESULTS: No significant difference was seen in patient survival or graft survival, incidence of acute rejection episode, or time to first rejection episode between the cohort and control groups. No specific adverse events were attributable to previous rhGH treatment. Only 2 patients had post-transplant lymphoproliferative disease in the cohort group, with no other malignancies reported. The mean height z scores in the cohort group at baseline and 60 months after transplant were -1.92 and -1.90, and the Deltaz score at 60 months was +0.20 compared with the control group (-1.88 and -2.10). CONCLUSIONS: Treatment of growth-retarded patients with CRI does not adversely affect graft function after renal transplantation. "Catch-down" growth does not occur after renal transplantation.

Predictive factors for delayed graft function (DGF) and its impact on renal graft survival in children: a report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS).

We define delayed graft function (DGF) as the need for dialysis during the first post-transplant week. We analyzed 5272 transplants, of which 2486 were of living donor (LD) and 2786 were of cadaver donor (CD) origin. Twelve per cent (620/5272) of all patients developed DGF. Donor specific rates were 5.6% for LD and 19.1% for CD patients. Factors predictive of DGF in CD patients were: African-American race (25%), prolonged cold ischemia (24%), absence of T-cell induction antibody therapy and absence of HLA-DR matching. The relative risk (RR) for graft failure due to DGF was 6.02 (p < 0.001) in LD patients and 2.58 (p < 0.001) for CD recipients. Two-year graft survival (GS) in LD patients without DGF was 89.6%, compared to 41.6% for those with DGF (p < 0.001); in CD patients it was 80.2% and 49.5%, respectively (p < 0.001). Censoring for primary non-function, GS for LD patients with a functioning graft at 30 d post-transplant and no DGF was 91.5%, compared to 70.1% for those with DGF (p < 0.001); GS for CD patients was 83.8% and 68.7%, respectively (p < 0.001). However, when patients whose grafts had failed during the first year were censored no differences in GS were noted between patients with and without DGF for either LD or CD recipients. To determine whether DGF acts as an independent risk factor for graft failure, patients were segregated into four groups: rejection with DGF; rejection without DGF; DGF without rejection; and no DGF, no rejection. When these groups were compared DGF emerged as an independent risk factor for graft failure. This large study reviewing pediatric renal transplantation over 10 yr clearly delineates the role of DGF as a major risk factor for graft failure.

Steady improvement in short-term graft survival of pediatric renal transplants: the NAPRTCS experience.

This report of pediatric renal transplantation covers the years 1987-1998. Since its inception in 1987, the NAPRTCS has collected data on 6,038 transplants performed in 5,516 patients provided by 73 renal centers across the country. FSGS, together with developmental lesions of dysplasia and obstructive uropathy, account for 40% of all transplants. There has been a steady increase in the use of LD donors among children with 54% of all transplants in 1996 and 1997 being live-related. About 72% of LD transplants are performed in Caucasian children, with African-American children unfortunately receiving a disproportionate percentage of CD kidneys. There has been a steady decline in the use of CD kidneys recovered from young individuals and a gradual decline in the number of transplants performed in young recipients (< 6 years old). Graft survival for LD recipients was 91%, 84% and 79% at one, 3 and 5 years, respectively, and the comparative figures for CD recipients were 81%, 72% and 64%, respectively. Acute and chronic rejections account for most of the graft losses, with chronic rejection accounting for more than 30%. There has been a steady improvement in one-year graft survival of CD recipients with the 1997-1998 cohort exhibiting an improvement of 16% over the 1987-1988 cohort. This improvement has been brought about by eliminating the use of infant donor kidneys, reducing the number of random transfusions and increasing the maintenance dose of cyclosporine. Posttransplant growth continues to be poor, with catch-up growth being exhibited only in children under age 6.

The impact of donor source, recipient age, pre-operative immunotherapy and induction therapy on early and late acute rejections in children: a report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS).

Acute rejection is a frequent event in pediatric transplantation. In addition to graft loss, acute rejection episodes stimulate the development of chronic rejection and inhibit growth in children post-transplantation. In this study, we analyzed our data from 1987 through 1996 to identify acute rejection episodes in children. In 2,520 living donor (LD) transplants there were 2,540 rejection episodes (rejection ratio: 1.1), and in 2,579 cadaver donor (CD) transplants 3,653 episodes were observed (rejection ratio: 1.32). For LD recipients the first rejection occurred sooner when there was at least one HLA-DR mismatch (RR=1.6, p<0.001) and prophylactic T-cell antibody was not used (RR=1.4, p<0.001). For CD transplants absence of prophylactic T-cell antibody (RR=1.2, p<0.001) and donor age below five years were risk factors (RR=1.5, p<0.001). Late initial acute rejections were seen in 327 of 1,471 patients (22.2%) who were rejection free at one year. At risk for the development of late rejections were children over the age of six years at transplantation (RR=1.7, p<0.001) and children of non-white origin (RR=1.5, p <0.002). For LD transplant recipients in the age range of 0-5 years, irreversible rejection was observed in 8.7% compared to 4.1% for older children (RR=1.46, p<0.001). Similar results for CD transplants were 12.6% versus 6.6% (RR=1.5, p<0.00). The high frequency of rejection episodes in children and the greater irreversibility in younger children suggest pediatric patients may have a more robust immune response. Current ongoing studies in the molecular mechanisms of the pathogenesis of rejection in surveillance biopsies of children may help determine if this hypothesis is valid.

Living-unrelated renal transplantation in children: a report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS)

The shortage of cadaver kidneys available for organ donation compared to growing demand has led to an increase in the use of living-unrelated donors (LURD) for renal transplantation (Tx). Results from trials in adults show that 1-year graft survival rates in LURD are similar to living-related donor (LRD) rates and superior to those of cadaver renal donor (CAD) transplants. We report our experience with 38 LURD transplants for children enrolled in NAPRTCS that were performed between 1987 and 1997. Ages of recipients at Tx were 0-5 years (n=8), 6-12 (n=10), and >12 years (n=20). Twenty nine were primary Tx, seven were second Tx, and two were third Tx. HLA antigen data showed that the number of 2-antigen mismatches for each locus was 44.7% for HLA-A, 71.1% for HLA-B, and 55.3% for HLA-DR. There were 7 donor/recipient pairs with a 6-antigen mismatch, 12 pairs with a 5-antigen mismatch, while there were 6 pairs with a 3-antigen match of which 3 pairs had at least one match at each of the A, B, and DR loci. A total of 38 acute rejection episodes occurred in 25 LURD recipients. Among primary grafts the incidence of first acute rejection at 30 d post-Tx was 46% in LURD vs. 29% in LRD and 37% in CAD recipients; at 1 year post-Tx it was 76% in LURD vs. 48% in LRD and 62% in CAD recipients. Acute tubular necrosis (ATN) was reported in four or 10.5% of LURD transplants compared with 5.4% in LRD and 19.0% in CAD recipients. There were 12 LURD graft failures, due to vascular thrombosis (3), acute rejection (2), recurrence of original disease (1), infection (3), and patient death (3). Estimated primary graft survival probabilities (+/- SE) at 12 months post-Tx are 0.825 +/- 0.071 for LURD, compared to 0.911 +/- 0.006 for LRD, and 0.815 +/- 0.009 for CAD. We conclude that data from this study show that LURD Tx in children have a low rate of ATN that is similar to that of LRD Tx. However, LURD Tx have a high incidence of acute rejection, and the graft survival at 12 and 24 months post-Tx is inferior to LRD Tx. There is a high frequency of graft loss due to causes other than rejection, and these may be related to adverse recipient selection criteria.

Growth post renal-transplantation in children: lessons from the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS).

Growth retardation following successful transplantation has been noted since the availability of ESRD care for children more than a quarter of a century ago. During the past decade, data collection and analysis of the NAPRTCS data base have detailed the factors which have an impact on growth in renal allograft recipients transplanted in the cyclosporine era. These analyses have led to the following conclusions. 1. Standardized height (z score) worsens in the majority of pediatric recipients following renal transplantation. 2. Catch-up growth (improvement in standardized height) occurs primarily in recipients <6 years of age at transplantation. Therefore, age at transplantation is a significant factor determining the magnitude of post-transplant growth. 3. Reduced allograft function has a profound negative impact on growth following transplantation. 4. Height deficit at the time of transplantation correlates with increment in height following transplantation. The most profoundly growth-retarded recipients exhibit the greatest increase in standardized height. 5. Race has been identified by NAPRTCS as a factor affecting post-transplant growth. Caucasian recipients exhibit a greater improvement in standardized height compared to African-American and Hispanic recipients. 6. Since serial evaluation of NAPRTCS data indicates that catch-up growth is unlikely to occur in 75% of renal allograft recipients, strategies such as the use of growth hormone would be advantageous in the future.

Growth-hormone treatment of renal transplant recipients: the National Cooperative Growth Study experience--a report of the National Cooperative Growth Study and the North American Pediatric Renal Transplant Cooperative Study.

OBJECTIVE: To evaluate growth response and renal allograft measures after recombinant human growth-hormone (GH) treatment in pediatric renal transplant recipients. STUDY DESIGN: Data on GH-treated children in the National Cooperative Growth Study (NCGS) database were linked to the database of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS). Data were analyzed for growth rate, graft survival, graft function, acute rejection, and adverse events. Data on 2390 transplant recipients in the NAPRTCS who had at least 24 months of graft function were used in the comparisons. RESULTS: Fifty-nine patients were treated with GH after renal transplantation. One-year growth data were available for 42 of these; 2-year, for 31; and 3-year, for 13. Growth velocity increased from 2.47 +/- 1.83 cm/yr to 7.17 +/- 2.97 cm/yr after 1 year. Year-2 and -3 growth rates were 5.93 +/- 2.29 cm/yr and 6.31 +/- 2.32 cm/yr. Height standard deviation score immediately after transplantation was -3.26 +/- 1.44 and at the initiation of GH was -3.59 +/- 1.15; it increased to -3.18 +/- 1.06 at year 1 and to -3.16 +/- 0.92 at year 2 and was -3.31 +/- 1.00 at year 3. Five-year graft survival was 80% in the GH cohort and 85% in the NAPRTCS cohort. Acute rejection ratio was 1.44 and 1.43 episodes per patient in the GH and NAPRTCS cohorts, respectively. Calculated creatinine clearance at 6 years was 68 and 63 ml/min per 1.73 m2, respectively. CONCLUSIONS: Growth hormone increase growth velocity for up to 3 years without an apparent decrease in graft survival or renal function, and no relation between GH therapy and acute rejection is seen. A randomized, prospective study to evaluate further the safety and efficacy of this promising therapy is required.