Well Preserved Renal Function in Children With Untreated Chronic Liver Disease

Preserved renal function during long-term follow-up in children with chronic liver disease

AIM

We have previously found well-maintained renal function in children with new-onset chronic liver disease. In this study, we investigated their renal function during long-term follow-up of the disease.

METHODS

In a study of 289 children with chronic liver disease, renal function was investigated as glomerular filtration rate (GFR) measured as clearance of inulin or iohexol. Yearly change in GFR was calculated based on a linear mixed model. The data were analysed with regard to different subgroups of liver disease and with regard to the outcome.

RESULTS

The initially well-preserved renal function remained so in most patients during the observation period, even in children with progressive liver disease leading to decompensation. The greatest fall in GFR occurred in patients with initial hyperfiltration. Cholestasis seemed to have a nephroprotective effect.

CONCLUSION

Chronic liver disease in childhood seems to have less impact on renal function than believed earlier, at least as long as the liver function remains compensated. Regular renal check-ups remain an essential tool for optimal patient care. Hyperfiltration seems to predict decline in renal function. Otherwise no further reliable prognostic markers were found in patients whose liver disease was not decompensated.

Cystatin C: best biomarker for acute kidney injury and estimation of glomerular filtration rate in childhood cirrhosis

The objective of the study was to evaluate the diagnostic and prognostic role of serum cystatin C, urinary neutrophil gelatinase-associated lipocalin (NGAL), and renal resistive index (RRI) in AKI among pediatric cirrhotics. The study included cirrhotic children under 18 years of age. AKI was diagnosed as per Kidney Diseases-Improving Global Outcomes (KDIGO) guidelines. All patients underwent measurement of serum cystatin C, urinary NGAL, and RRI at baseline, 3 months, and 6 months. eGFR was calculated using both creatinine- and cystatin-based equations. Of the 247 cirrhotics admitted during the study, 100 gave consent and were included. Forty-one fulfilled the KDIGO definition of AKI of whom 22 showed resolution. Two of these children had a repeat AKI at 2 and 4 months after initial AKI; both resolved with medical management. On logistic regression analysis, serum cystatin C (OR: 544.8, 95% CI: 24.4-12170, p < 0.0005) and urinary NGAL (OR: 1.006, 95% CI: 1001-1.012, p = 0.019) were found to be significantly associated with AKI. Cystatin C alone was the best biomarker for diagnosing AKI in children with decompensation (OR: 486.7, p < 0.0005) or spontaneous bacterial peritonitis (p = 0.02). eGFR calculated by serum cystatin C-based formulas was more reliable than that calculated by creatinine-based equations.Conclusion: Serum cystatin C is the best biomarker for diagnosis of AKI in pediatric cirrhotics, especially with decompensation and SBP. eGFR calculated on serum cystatin C-based equations is more reliable than creatinine-based ones. What is Known: • Acute kidney injury (AKI) is a common complication in cirrhotic adults. • Newer biomarkers have diagnostic and prognostic role in adult cirrhotics. What is New: • Serum cystatin C is a useful biomarker to identify acute kidney injury in cirrhotic children with decompensation. • Glomerular filtration rate calculation is more accurate by cystatin-based equations than creatinine-based equations.

Cardiac and renal effects of liver cirrhosis in a growing animal model

PURPOSE

To assess the biochemical, histological, histomorphometric and molecular effects of biliary duct ligation (BDL) induced liver cirrhosis in the heart and kidneys.

METHODS

Thirty-two weaning rats (21 days old, 50-70 g) underwent BDL and were divided in four groups (euthanasia after two, four, six, and eight weeks, respectively) and compared to control groups.

RESULTS

The animals' hearts of group 3 were bigger than those of the control group (p=0.042), including thinner right ventricle wall, decreased internal diameter of ventricles, and increased perivascular collagen deposition in left ventricle, as well as increased interstitial collagen in right ventricle after six weeks. In the kidneys of groups 3 and 4, bilirubin impregnation in the tubules, hydropic degeneration, loss of nuclei and lack of plasmatic membrane limits were noted. Nitric oxide synthase (NOS) gene expressions were higher in group 1 (p=0.008), and endothelial nitric oxide synthase (eNOS) gene expressions were elevated in all experimental groups (p=0.008, p=0.001, p=0.022, and p=0.013, respectively). In the heart, a decreased expression of eNOS in group 1 (p=0.04) was observed.

CONCLUSIONS

Liver cirrhosis leads to histological and histomorphometric alterations in the heart and kidneys, with changes in the NOS and eNOS gene expressions, that may suggest a role in the associated myocardial and renal manifestations.

Hepatorenal syndrome in children: a review

Hepatorenal syndrome (HRS) occurs in patients with cirrhosis or fulminant hepatic failure and is a kind of pre-renal failure due to intense reduction of kidney perfusion induced by severe hepatic injury. While other causes of pre-renal acute kidney injury (AKI) respond to fluid infusion, HRS does not. HRS incidence is 5% in children with chronic liver conditions before liver transplantation. Type 1 HRS is an acute and rapidly progressive form that often develops after a precipitating factor, including gastrointestinal bleeding or spontaneous bacterial peritonitis, while type 2 is considered a slowly progressive form of kidney failure that often occurs spontaneously in chronic ascites settings. HRS pathogenesis is multifactorial. Cirrhosis causes portal hypertension; therefore, stasis and release of vasodilator substances occur in the hepatic vascular bed, leading to vasodilatation of splanchnic arteries and systemic hypotension. Many mechanisms seem to work together to cause this imbalance: splanchnic vasodilatation; vasoactive mediators; hyperdynamic circulation states and subsequent cardiac dysfunction; neuro-hormonal mechanisms; changes in sympathetic nervous system, renin-angiotensin system, and vasopressin. In patients with AKI and cirrhosis, fluid expansion therapy needs to be initiated as soon as possible and nephrotoxic drugs discontinued. Once HRS is diagnosed, pharmacological treatment with vasoconstrictors, mainly terlipressin plus albumin, should be initiated. If there is no response, other options can include surgical venous shunts and kidney replacement therapy. In this regard, extracorporeal liver support can be a bridge for liver transplantation, which remains as the ideal treatment. Further studies are necessary to investigate early biomarkers and alternative treatments for HRS.

Risk factors and associated outcomes of early acute kidney injury in pediatric liver transplant recipients: A retrospective study

BACKGROUND

Acute kidney injury (AKI) may contribute to high mortality rates after liver transplantation. Few studies have investigated AKI in pediatric liver transplantation. This retrospective study was conducted to investigate the risk factors for and associated outcomes of AKI in pediatric liver transplant recipients.

METHODS

Eighty pediatric liver transplant patients were included. The occurrence of AKI was defined by the KDIGO Clinical Practice Guidelines for Acute Kidney Injury. A multivariate regression analysis model was used to investigate risk factors for AKI in the pediatric liver recipients.

RESULTS

The final multivariable regression model showed that biliary atresia (odds ratio [OR] = 0.097, p = 0.03), increased time of the anhepatic phase (OR = 0.871, p = 0.005) and lower postoperative jaundice clearance (OR = 13.936, p = 0.02) were independently associated with the development of AKI in pediatric patients. Additionally, cumulative 3-year patient (p = 0.15) and graft (p = 0.26) survival rates between the non-acute kidney injury (NAKI) and AKI groups were 95.2% vs 86.8% and 90.5% vs 84.2%, respectively.

CONCLUSION

Pediatric liver transplant recipients with a presence of biliary atresia, increased time of anhepatic phase, and a lower postoperative jaundice clearance had an increased risk of AKI. The long-term outcomes of patients who developed AKI appears to be worse compared with those having NAKI.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

Level III.