Growth hormone/insulin-like growth factor 1 axis recovery after liver transplantation: a preliminary prospective study

Disruption of the circadian clock component BMAL1 elicits an endocrine adaption impacting on insulin sensitivity and liver disease

SignificanceWhile increasing evidence associates the disruption of circadian rhythms with pathologic conditions, including obesity, type 2 diabetes, and nonalcoholic fatty liver diseases (NAFLD), the involved mechanisms are still poorly described. Here, we show that, in both humans and mice, the pathogenesis of NAFLD is associated with the disruption of the circadian clock combined with perturbations of the growth hormone and sex hormone pathways. However, while this condition protects mice from the development of fibrosis and insulin resistance, it correlates with increased fibrosis in humans. This suggests that the perturbation of the circadian clock and its associated disruption of the growth hormone and sex hormone pathways are critical for the pathogenesis of metabolic and liver diseases.

Donor CYP3A5 genotype influences tacrolimus disposition on the first day after paediatric liver transplantation

AIM

The aim of the present study was to investigate the influence of the cytochrome P450 (CYP) 3A4/5 genotype in paediatric liver transplant recipients and donors, and the contribution of age and gender to tacrolimus disposition on the first day after transplantation.

METHODS

The contribution of the CYP3A4/5 genotype in paediatric liver transplant recipients and donors to the tacrolimus blood trough concentrations (C0 ) and the tacrolimus concentration/weight-adjusted dose ratio on day 1 was evaluated in 67 liver-transplanted children: 33 boys and 34 girls, mean age 4.5 years.

RESULTS

Donor CYP3A5 genotype appears to be significantly associated with tacrolimus disposition on the first day after liver transplantation (P < 0.0002). Other physiological factors, such as recipient age and donor gender may also play a role and lead to significant differences in tacrolimus C0 and tacrolimus concentration/weight-adjusted dose ratio on day 1. However, according to the general linear model, only recipient age appears to be independently associated with tacrolimus disposition on the first day after liver transplantation (P < 0.03). Indeed, there was a faster tacrolimus metabolism in children under 6 years of age (P < 0.02).

CONCLUSIONS

Donor CYP3A5 genotype, recipient age and, to a lesser extent, donor gender appear to be associated with tacrolimus disposition on day 1 after transplant. This suggests that increasing the starting tacrolimus doses in paediatric patients under 6 years of age who receive a graft from a male extensive metabolizer may enhance the possibility of their tacrolimus levels reaching the therapeutic range sooner.

Prognostic significance of insulin-like growth factor-I serum levels in acute decompensation of cirrhosis

CONTEXT

IGF-I serum levels are suppressed in cirrhosis, but its prognostic significance is unknown.

OBJECTIVES

To investigate the prognostic value of IGF-I in patients admitted for acute decompensation of cirrhosis.

MATERIALS AND METHODS

Cohort study that included 103 patients. IGF-I was measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Ninety-day mortality was 26.2% and it was independently associated with MELD, age and IGF-I. The Kaplan-Meier survival probability at 90 days was 94.3% in patients with IGF-I ≥13 ng/mL and 63.2% for patients with IGF-I <13 ng/mL (p = .001).

DISCUSSION AND CONCLUSION

IGF-I levels are independently associated with mortality in acute decompensation of cirrhosis.

Effects of liver transplantation on endocrine function: a systematic review

Patients with chronic liver disease (CLD) often experience secondary endocrine dysfunction. Therefore, because the liver plays a major role in endocrine function, liver transplantation (LT) may also be beneficial for the restoration of hormonal regulation. This systematic review collects and interprets the available literature on the effect of LT on endocrine and sexual function in adult patients. A systematic review was conducted by searching Pubmed (including Medline) and EMBASE for studies published from database inception until November 2015. We collected all relevant studies that discussed changes in hormonal and sexual function after LT. Studies were included if they assessed the effect of LT on sexual function or one of the following components of the hormone/endocrine axis: the hypothalamus-pituitary-gonadal axis, growth hormone (GH), insulin-like growth factor-1 (IGF-1) or thyroid function. The results are reported according to the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines. Twenty-one studies with a total of 1274 patients were included. The results collected from the included studies suggested that LT improves the hormonal perturbation associated with CLD by restoring physiological levels of circulating GH, IGF-1, testosterone, estradiol, prolactin, follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Thyroid function was not affected by LT, and sexual function was partially improved after LT. This systematic review suggests that LT is associated with an improvement in endocrine and sexual function in patients with CLD. This information should encourage clinicians who treat CLD patients to identify endocrine disturbances in this population, inform their patients of the effects of LT and assess post-transplantation improvements.

Predictive factors of short term outcome after liver transplantation: A review

Liver transplantation represents a fundamental therapeutic solution to end-stage liver disease. The need for liver allografts has extended the set of criteria for organ acceptability, increasing the risk of adverse outcomes. Little is known about the early postoperative parameters that can be used as valid predictive indices for early graft function, retransplantation or surgical reintervention, secondary complications, long intensive care unit stay or death. In this review, we present state-of-the-art knowledge regarding the early post-transplantation tests and scores that can be applied during the first postoperative week to predict liver allograft function and patient outcome, thereby guiding the therapeutic and surgical decisions of the medical staff. Post-transplant clinical and biochemical assessment of patients through laboratory tests (platelet count, transaminase and bilirubin levels, INR, factor V, lactates, and Insulin Growth Factor 1) and scores (model for end-stage liver disease, acute physiology and chronic health evaluation, sequential organ failure assessment and model of early allograft function) have been reported to have good performance, but they only allow late evaluation of patient status and graft function, requiring days to be quantified. The indocyanine green plasma disappearance rate has long been used as a liver function assessment technique and has produced interesting, although not univocal, results when performed between the 1(th) and the 5(th) day after transplantation. The liver maximal function capacity test is a promising method of metabolic liver activity assessment, but its use is limited by economic cost and extrahepatic factors. To date, a consensual definition of early allograft dysfunction and the integration and validation of the above-mentioned techniques, through the development of numerically consistent multicentric prospective randomised trials, are necessary. The medical and surgical management of transplanted patients could be greatly improved by using clinically reliable tools to predict early graft function.

Postoperative Insulin-Like Growth Factor 1 Levels Reflect the Graft's Function and Predict Survival after Liver Transplantation

BACKGROUND

The reduction of insulin-like growth factor 1 (IGF-1) plasma levels is associated with the degree of liver dysfunction and mortality in cirrhotic patients. However, little research is available on the recovery of the IGF-1 level and its prognostic role after liver transplantation (LT).

METHODS

From April 2010 to May 2011, 31 patients were prospectively enrolled (25/6 M/F; mean age±SEM: 55.2±1.4 years), and IGF-1 serum levels were assessed preoperatively and at 15, 30, 90, 180 and 365 days after transplantation. The influence of the donor and recipient characteristics (age, use of extended criteria donor grafts, D-MELD and incidence of early allograft dysfunction) on hormonal concentration was analyzed. The prognostic role of IGF-1 level on patient survival and its correlation with routine liver function tests were also investigated.

RESULTS

All patients showed low preoperative IGF-1 levels (mean±SEM: 29.5±2.1), and on postoperative day 15, a significant increase in the IGF-1 plasma level was observed (102.7±11.7 ng/ml; p<0.0001). During the first year after LT, the IGF-1 concentration remained significantly lower in recipients transplanted with older donors (>65 years) or extended criteria donor grafts. An inverse correlation between IGF-1 and bilirubin serum levels at day 15 (r = -0.3924, p = 0.0320) and 30 (r = -0.3894, p = 0.0368) was found. After multivariate analysis, early (within 15 days) IGF-1 normalization [Exp(b) = 3.913; p = 0.0484] was the only prognostic factor associated with an increased 3-year survival rate.

CONCLUSION

IGF-1 postoperative levels are correlated with the graft's quality and reflect liver function. Early IGF-1 recovery is associated with a higher 3-year survival rate after LT.

Growth hormone/insulin-like growth factor 1 dynamics in adult living donor liver transplantation

End-stage liver disease is accompanied by decreased serum levels of insulin-like growth factor 1 (IGF1) and inversely increased serum levels of growth hormone (GH). Previous reports have demonstrated rapid GH/IGF1 axis recovery after orthotopic liver transplantation. This study investigated the effect in an adult-to-adult living donor liver transplantation (LDLT) model and characterized GH/IGF1 alterations and liver regeneration in both donors and recipients. Sequential blood samples were prospectively collected from 30 donor-recipient pairs during the perioperative course of LDLT. A distinct set of biochemical parameters, including serum GH, serum IGF1, and standard liver blood tests, was analyzed at different time points (preoperatively and during 12 months of follow-up after surgery). Recipients showed significantly higher GH serum levels and lower IGF1 serum levels in comparison with donors before surgery and throughout the first postoperative days (PODs). The GH serum levels of recipients declined, whereas donor levels inversely increased during the early postoperative period to a normal range. Recipients' IGF1 serum levels were restored within the first operative week. In parallel, donor IGF1 levels decreased by 50% after living donation, and preoperative serum levels were restored after 6 months. Donors showed delayed recovery of liver function in comparison with recipients. The dynamics of IGF1 strongly correlated with routine laboratory parameters of liver function. In conclusion, recipients showed a rapid recovery of the GH/IGF1 hormonal axis and liver function after LDLT, whereas donors showed altered GH signaling and regenerative delay in the early PODs after living donation.

Primary graft dysfunction after liver transplantation

BACKGROUND

Primary graft dysfunction (PGD) causes complications in liver transplantation, which result in poor prognosis. Recipients who develop PGD usually experience a longer intensive care unit and hospital stay and have higher mortality and graft loss rates compared with those without graft dysfunction. However, because of the lack of universally accepted definition, early diagnosis of graft dysfunction is difficult. Additionally, numerous factors affect the allograft function after transplantation, making the prediction of PGD more difficult. The present review was to analyze the literature available on PGD and to propose a definition.

DATA SOURCE

A search of PubMed (up to the end of 2012) for English-language articles relevant to PGD was performed to clarify the characteristics, risk factors, and possible treatments or interventions for PGD.

RESULTS

There is no pathological diagnostic standard; many documented definitions of PGD are different. Many factors, such as donor status, procurement and transplant process and recipient illness may affect the function of graft, and ischemia-reperfusion injury is considered the direct cause. Potential managements which are helpful to improve graft function were investigated. Some of them are promising.

CONCLUSIONS

Our analyses suggested that the definition of PGD should include one or more of the following variables: (1) bilirubin ≥ 10 mg/dL on postoperative day 7; (2) international normalized ratio ≥ 1.6 on postoperative day 7; and (3) alanine aminotransferase or aspartate aminotransferase >2000 IU/L within 7 postoperative days. Reducing risk factors may decrease the incidence of PGD. A majority of the recipients could recover from PGD; however, when the graft progresses into primary non-function, the patients need to be treated with re-transplantation.

Relationship between GH/IGF-1 axis, graft recovery, and early survival in patients undergoing liver transplantation

BACKGROUND

High levels of IGF-1 have been reported in patients with initial poor function of the graft after liver transplantation (LT). Correlation with other clinical variables or early survival has not been extensively investigated.

AIM

To evaluate the GH/IGF-1 profile as a function of liver recovery and patients' early survival after LT.

METHODS

30 transplanted patients (23 survivors and 7 nonsurvivors), were retrospectively enrolled in the study. GH and IGF-1 serum levels were assessed at baseline, graft reperfusion, and 1, 7, 15, 30 , 90, and 360 days after LT. Individual biochemical variables were also recorded.

RESULTS

After grafting, IGF-1 in blood linearly correlated with cholesterol (r = 0.6, P = 0.001). IGF-1 levels from day 15 after surgery were statistically higher in survivors as compared to nonsurvivors. ROC curves analysis identified an IGF-1 cut-off >90 μg/L, from day 15 after surgery, as a good predictor of survival (sensitivity 86%, specificity 95%, and P < 0.001).

CONCLUSIONS

After LT, GH levels correlate with the extent of cytolysis, while IGF-1 is an indicator of liver synthetic function recovery. IGF-1 levels >90 μg/L (day 15-30) seem to be an indicator of short-term survival.

[Biomarkers in endocrinology]

TSH assay is the best parameter of the thyroid function. For adults, the normal interval of TSH concentrations range from 0.4 to 4 mUI/L. At the first trimester of pregnancy, TSH levels must be <2.5 mUI/L. Normal TSH levels increase with aging and obesity. The biological diagnosis relies on the identification of excessive secretion of the metanephrines which are more sensitive and specific than those of catecholamines. The concentrations of the free plasmatic metanephrines reflect the ongoing production of tumor. Plasma methoxytyramine is a novel biomarker of metastatic pheochromocytomas and paragangliomas. Serum IGF1 is a reliable measure of integrated GH concentrations in patients with acromegaly. Accurate assessment of IGF1 concentrations requires age and sex-matched control values. IGF1 is a sensitive tool for the diagnosis of acromegaly and efficacy of therapies. Serum AMH assay is more sensitive, more specific and more reproducible that counting of ovarian follicles by ultrasound. AMH level above 5 ng/mL (35 pmol/L) could be chosen as one of the diagnostic criteria for the polycystic ovary syndrome. In early or "incipiens" ovarian failure, the decrease in serum AMH is far ahead of the increase in FSH. Thyroglobulin (TG) and calcitonin (CT) are the sensitive and specific markers of respectively well-differentiated thyroid cancers of follicular origin and of the medullary thyroid cancers. The same tumour marker assay should be used to monitor a given patient. Chromogranin A (CgA) is a highly efficient biomarker for diagnosis and follow-up of various endocrine tumours. Despite the lack of international standardisation, some CgA assays are reliable.

Evaluation of growth after liver transplantation in Turkish children

AIMS

Currently, the main interest in childhood liver transplantation (LT) is to prevent long-term complications and optimize growth. The aim of this study is to analyze (1) nutritional status in the pretransplantation period, and (2) posttransplantation growth and associated factors in children.

PATIENTS AND METHODS

Eighty children were included in the study. Height (Z (H)) and weight (Z (W)) Z scores were calculated before transplantation and postoperatively at the 6th month and 1st, 2nd, 3rd, 4th, and 5th year.

RESULTS

Patients' Z (H) and Z (W) scores at LT were -1.6 ± 1.3 and -1.5 ± 1.4, respectively. Both Z (H) and Z (W) scores increased after LT, especially in the first 6 months, and then continued to rise gradually. Both reached beyond -1 Z score at 2nd year and -0.5 at 4th year. Age, primary diagnosis, total steroid dose (<1,000 mg), and absence of rejection episodes had positive impact on posttransplantation growth, whereas gender, immunosuppression type, surgical complications, and presence of tumor had no impact on posttransplantation growth. Age at time of LT was negatively correlated with Z (W) score at 5th year (P = 0.02, r = -0.43). Both Z (W) and Z (H) scores at time of LT were positively correlated with Z (W) and Z (H) scores and negatively correlated with ∆Z (W) and ∆Z (H) scores at 5th year.

CONCLUSIONS

LT is not only a modern, life-saving treatment technique but also an efficient method of facilitating growth, an indispensable component of childhood and the best indicator of health.

Rescue of fertility in homozygous mice for the urokinase plasminogen activator transgene by the transplantation of mouse hepatocytes

Development of the urokinase plasminogen activator/SCID (uPA/SCID) transgenic mouse model has opened new perspectives for the study of different biological mechanisms such as liver regeneration, stem cell differentiation, and human hepatic pathogens. We observed that homozygous uPA/SCID mice (uPA+/+/SCID) had a small offspring, indicating a fertility defect. The goal of this study was thus to rescue the fertility of homozygous uPA mice. A deregulation of ovarian function with an absence of corpus luteum was observed in female uPA+/+/SCID mice. In male uPA+/+/SCID mice, a decrease of the weight of the testes, epididymis, seminal vesicle, and prostate was measured. This was associated with an absence of seminal and prostatic secretions and a reduction in testicular sperm production. We hypothesized that the infertility of mice was the consequence of uPA-induced liver injury. Thus, in order to rescue liver function, hepatocytes from mice negative for the uPA transgene were transplanted into uPA+/+/SCID mice. Thirty days after cell transplantation, the livers of transplanted uPA+/+/SCID mice were totally repopulated and presented a normal morphology. Furthermore, transplantation restored normal body weight, life span, and reproductive organ function. In conclusion, we demonstrated that the transplantation of uPA+/+/SCID mice with healthy hepatocytes was sufficient to rescue the reproductive capacity of female and male uPA homozygous animals, highlighting the importance of normal liver function to reproductive capability.

Syngeneic living-donor liver transplantation for hemangioendothelioma: a clinical model for studying liver regeneration

A 22-year-old Caucasian patient underwent living-donor liver transplantation (LDLT) for hepatic hemangioendothelioma in a healthy liver. The organ donor was his monozygotic twin brother. Surgery was uneventful in both donor and recipient, who received the same postoperative treatment (i.e. no immunosuppression for the recipient). Although both donor and recipient achieved a full liver function recovery, the volume of the recipient's graft increased much more than the donor's residual liver in the first postoperative month (1.6-fold vs. 1.2-fold). This different growth rate correlated with growth hormone (GH)/insulin growth factor (IGF) axis dynamics: the donor had significantly lower insulin-like growth factor 1 (IGF-1), insulin-like growth factor 2 (IGF-2) and insulin-like growth factor binding protein 3 (IGFBP-3) values than the recipient on postoperative days (POD) 3-30, although they had similar GH values. Other potential regenerative factors, e.g. tumor necrosis alpha, interleukin 6 (IL-6), insulin and C peptide did not correlate with liver regeneration rate. The particular endocrine picture of the graft may be explained by a modified GH-hepatocyte interaction due to cold ischemia during preservation resulting in a higher IGF production. Whether this is a potential molecular tool by means of which transplanted partial livers promote their regeneration remains to be seen in a larger number of patients.