Factors affecting catch-up growth after liver transplantation

Long-term Catch-up Growth and Risk Factors for Short Adult Height After Pediatric Liver Transplantation: A Retrospective Study

BACKGROUND

Children requiring liver transplantation generally have severe growth retardation. Recipients experience posttransplantation catch-up growth, although some show short adult heights. We aimed to determine decades-long catch-up growth trends and risk factors for short adult height following liver transplantation.

METHODS

We analyzed long-term height Z scores and risk factors for short adult height in a single-center retrospective cohort of 117 pediatric liver transplantation recipients who survived >5 y, with 75 of them reaching adult height.

RESULTS

Median age at transplantation was 1.3 y, and the most common primary diagnosis was biliary atresia (76.9%). Mean height Z scores pretransplantation and 1, 3, and 8 y after transplantation were -2.26, -1.59, -0.91, and -0.59, respectively. The data then plateaued until 20 y posttransplantation when mean adult height Z score became -0.88, with a median follow-up of 18.6 y. Nineteen recipients did not show any catch-up growth, and one quarter of recipients had short adult height (<5th percentile of the healthy population). Multivariate analysis identified old age (odds ratio, 1.22 by 1 y; P = 0.002), low height Z scores at transplantation (odds ratio, 0.46 by 1 point; P < 0.001), and posttransplantation hospital stay ≥60 d (odds ratio, 4.95; P = 0.015) as risk factors for short adult height. In contrast, prolonged steroid use after transplantation was not considered a significant risk factor.

CONCLUSIONS

Although tremendous posttransplantation catch-up growth was observed, final adult height remained inadequate. For healthy physical growth, liver transplantation should be performed as early as possible, before growth retardation becomes severe.

Treatment optimization of maintenance immunosuppressive agents in pediatric renal transplant recipients

Introduction: Graft survival in pediatric kidney transplant patients has increased significantly within the last three decades, correlating with the discovery and utilization of new immunosuppressants as well as improvements in patient care. Despite these developments in graft survival for patients, there is still improvement needed, particularly in long-term care in pediatric patients receiving grafts from deceased donor patients. Maintenance immunosuppressive therapies have narrow therapeutic indices and are associated with high inter-individual and intra-individual variability.Areas covered: In this review, we examine the impact of pharmacokinetic variability on renal transplantation and its association with age, genetic polymorphisms, drug-drug interactions, drug-disease interactions, renal insufficiency, route of administration, and branded versus generic drug formulation. Pharmacodynamics are outlined in terms of the mechanism of action for each immunosuppressant, potential adverse effects, and the utility of pharmacodynamic biomarkers.Expert opinion: Acquiring abetter quantitative understanding of immunosuppressant pharmacokinetics and pharmacodynamic components should help clinicians implement treatment regimens to maintain the balance between therapeutic efficacy and drug-related toxicity.

Long-term Follow-up After Pediatric Liver Transplantation: Predictors of Growth

OBJECTIVES

The aim of the study was to describe long-term growth postpediatric liver transplantation and to conduct bivariate and multivariate analysis of factors that may predict post-transplantation growth in children who received a liver transplant from January 1999 to December 2008 at the Hospital for Sick Children.

METHODS

A retrospective cohort study was conducted with follow-up of up-to 10 years post-transplantation. Mean height and weight z scores and annual differences in mean z scores were plotted against time after transplantation. A 1-way analysis of variance was conducted. Multivariate and univariate Cox proportional hazards analyses were conducted to determine factors associated with reaching the 50th and 25th percentiles for height.

RESULTS

A total of 127 children met eligibility criteria. The mean height z score at time of transplantation was -2.21 which by the second year post-transplantation increased significantly to -0.66 (mean increase of 1.55 standard deviation units). There were no further significant increases in mean height z score from 2 years post-transplantation until the end of follow-up at year 10. In multivariate analysis, height at transplant was the most important predictor of linear growth post-transplantation.

CONCLUSIONS

Children who underwent liver transplantation had significant catch-up growth in the first 2 years post-transplantation followed by a plateau phase. Increased height z-score at transplantation is the most important predictor of long-term growth.

Corticosteroid-free Kidney Transplantation Improves Growth: 2-Year Follow-up of the TWIST Randomized Controlled Trial

BACKGROUND

Corticosteroid withdrawal (CW) after pediatric kidney transplantation potentially improves growth while avoiding metabolic and other adverse events. We have recently reported the results of a 196 subject randomized controlled trial comparing early CW (tacrolimus, mycophenolate mofetil (MMF), daclizumab, and corticosteroids until day 4) with tacrolimus, MMF, and corticosteroid continuation (CC). At 6 months, CW subjects showed better growth with no adverse impact on acute rejection or graft survival (Am J Transplant 2010; 10: 828-836). This 2-year investigator-driven follow-up study aimed to determine whether improved growth persisted in the longer term.

METHODS

Data regarding growth, graft outcomes and adverse events were collected at 1 year (113 patients) and 2 years (106 patients) after transplantation. The primary endpoint, longitudinal growth calculated as delta height standard deviation score, was analyzed using a mixed model repeated measures model.

RESULTS

Corticosteroid withdrawal subjects grew better at 1 year (difference in adjusted mean change, 0.25; 95% confidence interval, 0.10, 0.40; P = 0.001). At 2 years, growth remained numerically better in CW subjects (0.20 (-0.01, 0.41); P = 0.06), and significantly better in prepubertal subjects (0.50 (0.16, 0.84); P = 0.004). Bacterial and viral infection was significantly more common in CW subjects at 1 year only. Corticosteroid withdrawal and CC subjects received similar exposure to both tacrolimus and MMF at 1 and 2 years. No significant difference in patient or graft survival, rejection, estimated glomerular filtration rate, or other adverse events was detected.

CONCLUSION

Early CW effectively and safely improves growth up to 2 years after transplantation, particularly in prepubertal children.

A randomized trial to assess the impact of early steroid withdrawal on growth in pediatric renal transplantation: the TWIST study

Minimizing steroid exposure in pediatric renal transplant recipients can improve linear growth and reduce metabolic disorders. This randomized multicenter study investigated the impact of early steroid withdrawal on mean change in height standard deviation score (SDS) and the safety and efficacy of two immunosuppressive regimens during the first 6 months after transplantation. Children received tacrolimus, MMF, two doses of daclizumab and steroids until day 4 (TAC/MMF/DAC, n=98) or tacrolimus, MMF and standard-dose steroids (TAC/MMF/STR, n=98). Mean change in height SDS was 0.16 +/- 0.32 with TAC/MMF/DAC and 0.03 +/- 0.32 with TAC/MMF/STR. The mean treatment group difference was 0.13 (p < 0.005 [95% CI 0.04-0.22]), 0.21 in prepubertal (p = 0.009 [95% CI 0.05-0.36]) and 0.05 in pubertal children (p = ns). Frequency of biopsy-proven acute rejection was 10.2%, TAC/MMF/DAC, and 7.1%, TAC/MMF/STR. Patient and graft survival and renal function were similar. Significantly greater reductions in total cholesterol and triglycerides but significantly higher incidences of infection and anemia were found with TAC/MMF/DAC (p < 0.05 all comparisons). Early steroid withdrawal significantly aided growth at 6 months more so in prepubertal than pubertal children. This was accompanied by significantly better lipid and glucose metabolism profiles without increases in graft rejection or loss.

Corticosteroids usage in pediatric liver transplantation: To be or not to be!

The theoretical risks of early SW, <3 months post-LT, and complete elimination (steroid-free LT) lie in mainly three areas, namely the risks of AGR, CGR, and the development of d-AIH that has been described in SW post-LT in children. These should be balanced against the benefits of early SW mainly manifested as effects on growth post-LT. In this paper, we focused on the clinical trials that included CS therapy risks and benefits in pediatric LT. Focusing mainly on CGR and d-AIH as risks, and the beneficial effects on growth post-LT with either low-dose CS, SW, or steroid-free regimens. Main conclusions from comparing a large number of studies are: early SW or elimination from immunosuppression protocols was neither harmful to the patient nor to the graft survival rate in the short term, the overall impression is that steroids negatively affect growth in LT recipients when used in high doses and prolonged course, and that development of d-AIH is not associated with CS therapy with evidence that chronic low dose steroids post-LT have no preventative role against d-AIH.

Growth and final height after liver transplantation during childhood

OBJECTIVE

To evaluate the effect of end-stage pediatric liver disease and liver transplantation on growth and final height.

PATIENTS AND METHODS

We evaluated growth at 2 years (n = 101) and 5 years (n = 63) after pediatric liver transplantation (LTx). Twenty-three children reached final height. Height was expressed as a standard deviation score of the target height (zTH score) of each patient.

RESULTS

At the first 2 years after LTx, the zTH score was significantly increased from -1.7 to -1.3 SD (P < 0.05). Growth at 2 or 5 years after LTx, expressed as DeltazTH score, was positively correlated with pretransplant growth retardation (P < 0.05). In comparison with patients with noncholestatic primary liver disease, patients with cholestatic primary liver disease were more severely growth retarded before LTx (zTH score -2.0 vs -1.2 SD, P < 0.05) and had better growth in the first 2 years after LTx (DeltazTH score +0.6 vs -0.1 SD, P < 0.05). Twelve of the 23 patients had a final height below -1.3 SD of their target height.

CONCLUSIONS

Growth retardation is common in children before LTx, particularly in children with an underlying cholestatic disease. After LTx, catch-up growth was partial and was prominent only in cholestatic children who had been severely growth retarded before LTx. After LTx during childhood, approximately 50% of patients reach a final height lower than -1.3 SD of their genetic potential.