What Factors Influence Linear Growth After Transplantation?

Patient Presentation
A 12-year-old male came to clinic for his health supervision visit. He had a history of living related donor renal transplant at age 10 after a few years of peritoneal dialysis. He was doing well in school and activities. His parents were very happy with his overall health. They expressed concerns about him starting into puberty because of the potential risks for non-adherence with his immunosuppressive medications and also with his growth. The family history showed a predicted mid-parental height between 25-50%.

The pertinent physical exam showed a male with normal vital signs including blood pressure. His height was 10%-25% and weight was 50% and tracking. His abdomen showed several scars and his kidney was palpable without pain/tenderness. He was Tanner 1 for pubertal growth. The diagnosis of a healthy male with a renal transplant was made. The pediatrician discussed that his current height was not significantly different than his predicted height but agreed that seeing endocrinology to discuss potential growth hormone use would be appropriate after the parents said that the nephrologist had suggested an appointment. The pediatrician also talked with the family about supporting their child’s independence over the next few years including medication management. “This is a common concern for families dealing with chronic illnesses. The nephrology team, along with me are here to help you. There are also psychologists who can work with him, and also with you on ways to successfully parent him during adolescence. Just let us know if you think you need help and we’re going to ask about it too,” the pediatrician offered.

Discussion
Growth is a defining characteristic of children. Children are expected to have normal height, weight and head circumference growth velocities for their specific age. A review of mid-parental height determination and other growth parameters can be found here.

For children with chronic illness and organ dysfunction or failure, their bodies cannot be expected to continue to have normal growth and therefore these children often have failure of normal growth for any and all of the growth parameters. For children facing organ failure or high risk or relapsed cancers, organ transplantation can be life-saving, but is not without its own problems including neurocognitive abnormalities, psychosocial dysfunction, endocrine abnormalities, bone abnormalities, primary or secondary malignancy, increased risk of infections and growth abnormalities.

While evaluation of weight and head circumferences are important, many studies have focused on outcomes of final height in children who have undergone transplantation.

Learning Point
Linear growth following organ transplantation appears to be influenced by the following:

  • Genetic potential – mid-parental height should be assessed as obviously this determines target height for the individual.
  • Reasons for the transplant – underlying disorders may change the expected target height, for example certain genetic diseases have short stature and therefore the final height would be less than predicted by mid-parental height. The primary diagnosis is often an important predictor.
  • Organ transplanted – specific organ, and solid organ versus hematopoietic transplant
  • Status before transplant – patients who are more ill (i.e. have spent more time in hospital, have poorer transplanted organ function, have other organ disease) tend to have less catch-up growth however age appears to also influence this. If the child has better height at transplant they tend to have better height after transplant.
  • Age at transplant – younger children often have poorer growth before transplant but have greater catch-up growth than older children and teens
  • Pubertal growth spurt – this appears to play an important role in attainment of final height for patients with transplant as it does for children without them. Some patients have growth hormone deficiency because of their treatment and exogenous growth hormone is sometimes used to assist general linear growth and pubertal growth.
  • Graft function after transplant – patients whose grafts function well (i.e. good overall function and few rejection episodes) tend to have better final heights. Secondary renal or bone dysfunction tends to cause poor final heights.
  • Corticosteroid use – corticosteroid use basically causes poor linear growth. Smaller amounts of corticosteroid tends to improve linear growth.

Overall, final height potentially is improved with smaller amounts of corticosteroids, excellent nutritional support, control of other complications such as rejection or secondary organ dysfunction, and the potential use of growth hormone. All of these can be hard to balance when treating the patient and family. Side effects of immunosuppressive medications can be found here.

Questions for Further Discussion
1. What are risk factors for poor linear growth for patients with chronic diseases and cancer?
2. What type of followup care do patients who have had transplantation need?
3. What type of followup care do adult patients who are survivors of pediatric cancer need?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Organ Transplantation, Kidney Transplantation and Puberty.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Perkins JL, Kunin-Batson AS, Youngren NM, et.al. Long-term follow-up of children who underwent hematopoeitic cell transplant (HCT) for AML or ALL at less than 3 years of age. Pediatr Blood Cancer. 2007 Dec;49(7):958-63.

Laster ML, Fine RN. Growth following solid organ transplantation in childhood. Pediatr Transplant. 2014 Mar;18(2):134-41.

Kerkar N, Danialifar T. Changing definitions of successful outcomes in pediatric liver transplantation. Curr Opin Organ Transplant. 2014 Oct;19(5):480-5.

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa Children’s Hospital