Corticosteroid exposure not associated with long-term bone mineral density in pediatric liver transplantation

Five-year evaluation of bone health in liver transplant patients: developing a risk score for predicting bone fragility progression beyond the first year

Introduction

Liver transplant (LT) recipients have a substantial risk of bone loss and fracture. An individual's risk is highest before and within the first year after transplantation and returns to baseline in some patients but not all. We aim to identify risk factors for bone loss and fracture beyond the first year LT and to create a risk-scoring tool to aid clinicians in identifying those at high risk for bone loss and fracture.

Methods

We conducted a retrospective review of 264 liver transplant recipients between 2011 and 2014, who were followed in our transplant clinic for an additional five years. Clinical records were evaluated at the one-year post-LT visit and subsequently on an annual basis for up to five years.

Results

Over a median follow-up of 3.6 years post-liver transplantation, 40 out of 264 patients experienced disease progression, defined as worsening bone mineral density (BMD), initiation of osteoporosis treatment, or a new fracture. Factors associated with BMD progression included female sex, Caucasian race, new fractures, number of acute rejection events requiring treatment, and lower dual energy X-ray absorptiometry (DXA) scores after the first year post-LT. A risk model was developed using multivariable analysis, with a risk score based on BMD categories. The concordance index was 0.771, indicating good discrimination between those who progressed and those who did not. Risk categories were defined as low (0-4 points), medium (5 points), and high (6-9 points) based on model coefficients. The probability of progression-free survival at two years post-LT was 96.7% for low-risk, 83.1% for medium-risk, and 59.1% for high-risk groups.

Conclusion

We developed a simple, clinically applicable risk score that predicts bone disease progression beyond the first year after LT. This tool may help guide appropriate bone health follow-up, although prospective validation is necessary.

Predictors for pathological bone fractures in children undergoing liver transplantation: A retrospective cohort study

BACKGROUND

Hepatic osteodystrophy refers to bone disorders associated with chronic liver disease, including children undergoing liver transplantation (LT). The aim of this study was to quantify the prevalence of pathological fractures (PF) in children before and after LT and to identify associated factors for their occurrence.

METHODS

Children aged 0-18 years who underwent LT from 1/2005 to 12/2020 were included in this retrospective study. Data on patient demographics, types and anatomical locations of fracture and biological workups were extracted. Variables were assessed at 3 time points: T - 1 at the moment of listing for LT; T0 at the moment of LT and T + 1 at 1-year post-LT.

RESULTS

A total of 105 children (49 [47%] females) were included in this study. Median age at LT was 19 months (range 0-203). Twenty-two patients (21%) experienced 65 PF, 11 children before LT, 10 after LT, and 1 before and after LT. The following variables were observed as associated with PF: At T - 1, low weight and height z-scores, and delayed bone age; at T0, low weight and height z-scores, high total and conjugated bilirubin; at T + 1, persistent low height z-score. Patients in the PF-group were significantly more under calcium supplementation and/or nutritional support at T - 1, T0 and T + 1.

CONCLUSION

More than one in five children needing LT sustain a PF before or after LT. Patients with low weight and height z-scores and delayed bone age are at increased risk for PF. Nutritional support remains important, even if to date it cannot fully counteract the risks of PF.

Incidence of malnutrition and changes in phosphocalcic metabolism in perioperative liver transplantation patients -a retrospective study in a tertiary children's hospital in China

BACKGROUND

The primary aim of the study was to assess the nutritional status of pediatric liver transplant outpatients in nutrition clinic, particularly the nutritional status of their bones.  METHODS: One hundred thirty-eight pediatric liver transplant outpatients, who had visited the nutrition clinic in Shanghai Children's Medical Center between January 2017 and December 2019, were recruited. The bone mineral density (BMD) z-scores were determined by dual energy X-ray absorptiometry (DXA). Nutritional assessment was performed, and their corresponding height-for-age z-scores (HAZs)/weight-for-age z-scores (WAZs)/BMI-for-age z-scores (BMIZs) were obtained.

RESULTS

A total of 138 patients came to our nutrition outpatient clinic, including 68 boys (49.3%) and 70 girls (50.7%). The median age was 0.87y (0.68y, 1.71y). Among these patients, 44 (31.9%) had acute malnutrition with WAZ/BMIZ value -1.14 (-2.38, -0.18), 55 (38.4%) had chronic malnutrition with HAZ value -1.51 (-2.39, -0.38), and 96 (69.6%) had a BMD lower than normal. The BMD z-score was significantly correlated with the WAZ/BMIZ value (Spearman's correlation coefficient = 0.334, p < 0.001). A total of 37 infants re-visited the nutrition clinic for a follow-up after (147 ± 127) days. The WAZ/BMIZ value of the re-visiting patients and the BMD z-score of the re-visiting patients were significantly improved compared to those of the first-visit patients (p = 0.004 and p = 0.001 respectively).

CONCLUSIONS

There were different rates of malnutrition before and after liver transplantation. At the same time, BMD Z-score and serum vitamin D level of patients decreased. There was a significant correlation between BMD z-scores and WAZ/BMIZ values. Proper and professional nutrition guidance significantly improved the WAZ/BMIZ-values and BMD Z-score of liver transplantation patients.

Bone demineralization in a cohort of Egyptian pediatric liver transplant recipients: Single center pilot study

Liver transplantation (LT) is the definitive treatment of end-stage liver disease. The long-term survival following LT spurred more interest in improving the quality of life of patients. This was a cohort study that included 23 pediatric liver transplant recipients who underwent LT due to hereditary or metabolic liver diseases. Bone health assessment was performed at their last follow up clinically (anthropometric measures), biochemically and radiologically (Dual Energy X-ray Absorptiometry [DEXA] scans). Poor bone health was defined as z-score <-1. Mean age at LT was 5.77 years (standard deviation [SD] 3.64) and 43% were males. Biliary atresia was the most common cause of end stage liver disease (35%). Mean age at follow up was 14 years (SD 5.48) and mean follow up was 8 years (SD 4.12 years). Eleven patients (48%) had poor bone health (osteopenia 22% and osteoporosis 26%). On univariate analysis, being on steroids at last follow up (odds ratio [OR] 13.2, 95% confidence interval [CI] 1.23-140.67, P = .03), weight at last follow up (OR 0.45, 95% CI 0.20-0.99, P = .04), platelets at last follow up (OR 0.98, 95% CI 0.96-s0.99, P = .02), hemoglobin at last follow up (OR 0.33, 95% CI 0.12-0.89, P = .03) were significantly associated with poor bone health. None of the variables were significant on multivariate analysis. At most recent follow up, 48% of patients demonstrated poor bone health by DEXA scans. More studies are required to evaluate predictors of poor bone health after LT in children.

Impaired Bone Health in Children With Biliary Atresia

OBJECTIVES

The aim of the study was to examine the frequency of rickets and bone fractures and to assess areal bone mineral density (aBMD) in childhood among patients with biliary atresia (BA).

METHODS

We gathered data on all patients diagnosed with BA in Finland that survived to ≥1 year of age between 1 January 2000 to 30 June 2018. Data on gestational age, birth weight, postsurgical medications, and history of rickets and bone fractures were collected retrospectively. Serum levels of 25-hydroxyvitamin D [25(OH)D] postportoenterostomy (PE) were collected. Plain radiographs and dual energy X-ray absorptiometry (DXA) measurements of study subjects were reviewed.

RESULTS

Out of 49 patients, 7 (14%) were diagnosed with rickets during infancy. Clearance of jaundice [odds ratio 0.055, 95% confidence interval [CI] 0.00266-0.393; P < 0.01] was a protective factor against rickets. Sufficient 25(OH)D levels were reached 3 months post-PE. Eleven (22%) patients suffered at least one bone fracture (range 1-9) during childhood and adolescence. In DXA measurements, median lumbar spine aBMD anthropometrically adjusted z-scores were as follows: in native liver survivors 0.8 (interquartile range [IQR] -1.9 to 1.4) at 5 and -0.3 (IQR -1.3 to 0.8) at 10 years and for liver transplanted patients 0.4 (IQR -0.2 to 1.1) at 5 and 0.6 (IQR -0.1 to 1.3) at 10 years.

CONCLUSIONS

BA patients have an increased risk for rickets and bone fractures compared with the normal population. Most BA patients have aBMD within normal range between 5 and 10 years of age irrespective of liver transplantation status.

Nutrition Support of Children With Chronic Liver Diseases: A Joint Position Paper of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition

Chronic liver disease places patients at increased risk of malnutrition that can be challenging to identify clinically and treat. Nutrition support is a key aspect of the management of these patients as it has an impact on their quality of life, morbidity, and mortality. There are significant gaps in the literature regarding the optimal nutrition support for patients with different types of liver diseases and the impact of these interventions on long-term outcomes. This Position Paper summarizes the available literature on the nutritional aspects of the care of patients with chronic liver diseases. Specifically, the challenges associated with the nutritional assessment of these subjects are discussed, and recently investigated approaches to determining the patients' nutritional status are reviewed. Furthermore, the pathophysiology of the malnutrition seen in the context of chronic liver disease is summarized and monitoring, as well as treatment, recommendations are provided. Lastly, suggestions for future research studies are described.

International Liver Transplantation Society Consensus Statement on Immunosuppression in Liver Transplant Recipients

Effective immunosupression management is central to achieving optimal outcomes in liver transplant recipients. Current immunosuppression regimens and agents are highly effective in minimizing graft loss due to acute and chronic rejection but can also produce a substantial array of toxicities. The utilization of immunosuppression varies widely, contributing to the wide disparities in posttransplant outcomes reported between transplant centers. The International Liver Transplantation Society (ILTS) convened a consensus conference, comprised of a global panel of expert hepatologists, transplant surgeons, nephrologists, and pharmacologists to review the literature and experience pertaining to immunosuppression management to develop guidelines on key aspects of immunosuppression. The consensus findings and recommendations of the ILTS Consensus guidelines on immunosuppression in liver transplant recipients are presented in this article.

Growth, body composition, and bone density following pediatric liver transplantation

Patients transplanted for cholestatic liver disease are often significantly fat-soluble vitamin deficient and malnourished pretransplant, with significant corticosteroid exposure post-transplant, with increasing evidence of obesity and metabolic syndrome post-LT. Our study aimed to assess growth, body composition, and BMD in patients post-pediatric LT. Body composition and bone densitometry scans were performed on 21 patients. Pre- and post-transplant anthropometric data were analyzed. Bone health was assessed using serum ALP, calcium, phosphate, and procollagen-1-N-peptide levels. Median ages at transplant and at this assessment were 2.7 and 10.6 years, respectively. Physiological markers of bone health, median z-scores for total body, and lumbar spine aBMD were normal. Bone area was normal for height and BMAD at L3 was normal for age, indicating, respectively, normal cortical and trabecular bone accrual. Median z-scores for weight, height, and BMI were 0.6, -0.9, 1.8 and 0.6, 0.1, 0.8 pre- and post-transplant, respectively. Total body fat percentages measured on 21 body composition scans revealed 2 underweight, 7 normal, 6 overweight, and 6 obese. Bone mass is preserved following pediatric LT with good catch-up height. About 52% of patients were either overweight/obese post-transplant, potentially placing them at an increased risk of metabolic syndrome and its sequelae in later life. BMI alone is a poor indicator of nutritional status post-transplant.

Bone Mineral Density of Very Long-term Survivors After Childhood Liver Transplantation

OBJECTIVES

Liver transplant patients are at risk of osteopenia and fractures but limited information is available in long-term survivors after childhood transplantation. This study aimed to assess bone mineral density (BMD) of very long-term, >5 years, survivors after liver transplantation in childhood.

METHODS

Patients aged <18 years at transplant, having survived >5 years after transplant were potentially eligible but only those with ongoing review in our state were included. Dual-energy x-ray absorptiometry (DXA) was used to measure BMD. Patients aged <20 years had lumbar spine (LS) and total body (TB) measurements whereas those aged 20 years or more had LS and femoral neck but not TB. BMD z-scores for LS and TB, if available, were used in this study. BMD z-score ≤-2.0 was considered reduced. Pre-pubertal children had radiologic bone age assessment.

RESULTS

Forty-two patients, 17 boys, participated of whom 64% had biliary atresia. Median age at transplant was 2.22 (range 0.38-14.25) years; time since transplant 10.10 (5.01-25.98) years; and age at DXA 14.64 (6.59-38.07) years. Mean BMD z-scores were LS -0.15 ± 1.07, and TB -0.76 ± 1.14, with no sex difference noted. Four (9.5%) patients had reduced LS BMD, and although ongoing steroid use was more frequent in these patients, other comorbidities were likely important. Age at transplant, time since transplant, height, weight, and body mass index at DXA did not predict LS BMD. Pathologic fractures occurred in 2 of 42 (5%) patients; all within 18 months of transplant.

CONCLUSIONS

Very long-term survivors after childhood liver transplant have LS BMD within the normal range.

Osteoporosis in Pediatric Liver Transplantation

Liver transplantation provides an important, often life-saving treatment for end-stage liver disease. Osteoporosis post-liver transplantation has been described in adults; however, this has not been described in the pediatric population to date. We present a case of a 13-year-old female patient who underwent an orthotopic liver transplant for cryptogenic liver cirrhosis. Her immunosuppressants were tacrolimus and prednisone. Four months posttransplant, she started complaining of bilateral lower limb pain and limping while walking, progressing to a point where she was almost immobile. Magnetic resonance imagining of the pelvis showed bilateral avascular necrosis involving the weight-bearing surfaces of both femoral heads, in addition to the extensive edema involving both hip joints. Bone mineral densitometry was below normal for her age at the hip and forearm. She was started on high-dose calcium and vitamin D supplement, as well as zoledronic acid with a remarkable symptomatic and functional improvement.

Vitamin D deficiency and insufficiency after pediatric liver transplantation

Vitamin D deficiency and insufficiency are increasingly recognized in the general population, including healthy children. There is also an increasing emphasis on the importance of vitamin D status following pediatric liver transplantation and specifically its relationship to metabolic bone disease and growth retardation. Vitamin D insufficiency has also been associated with multiple immunological and metabolic disorders in adults. To our knowledge, this has not been systematically evaluated in children undergoing liver transplantation to date. Between October 2004 and August 2008, serum 25-(OH)-vitamin D levels were measured in 199 children who had undergone liver transplantation at Birmingham Children's Hospital. Potential factors contributing to vitamin D levels were evaluated. Additionally, we evaluated a possible relationship between vitamin D levels and immunological phenomena and metabolic complications. Median 25-(OH)-vitamin D level was 19.5 ng/mL (range: 4.4-71.4 ng/mL). A total of 105 children (53%) had insufficient vitamin D levels and 28 children (14%) showed vitamin D deficiency. The only factors found to be associated with vitamin D deficiency were season of sample, ethnicity, and PTH levels. Vitamin D deficiency was more prevalent during the first year after transplantation. We did not find a significant relationship between vitamin D levels and graft function or any other immunological and metabolic complications. Vitamin D insufficiency and deficiency are common in children after liver transplantation, especially in winter and spring and in non-white patients. Initial post-transplant period and high PTH are significantly associated with vitamin D deficiency. Vitamin D status should be monitored following pediatric liver transplantation and vitamin D supplementation provided as required.