Hepatorenal syndrome: a historical appraisal of its origins and conceptual evolution

Cholemic Nephropathy: Role in Acute Kidney Injury in Cholestasis and Cirrhosis

The concept of structural kidney damage and renal dysfunction as a result of jaundice attracted attention in the medical community in the early and mid-20th century. The postulated doctrine of the time was that the excretion of elevated concentrations of bile results in bile-stained casts occupying collecting and distal convoluted tubules, degeneration of tubular epithelium, and decreased renal function. Compared to the hepatorenal syndrome, the poster child of hepatology and nephrology collaboration, the notion of structural kidney damage and renal dysfunction as a result of cholemia lost its traction and has almost disappeared from modern textbooks. Today, cholemic nephropathy is experiencing a renaissance, with multiple case reports and case series of jaundiced patients with kidney dysfunction and evidence of bile acid casts upon histologic examination. Published cases include acute hepatitis, chronic liver injury, cirrhosis, and obstructive etiologies. Diagnosis of cholemic nephropathy is based on histological examination, typically showing intraluminal bile casts predominantly located in the distal tubules. In common bile duct-ligated mice, the histomorphological and functional alterations of cholemic nephropathy mimic those seen in humans. Some argue against the concept of cholemic nephropathy and postulate that bile casts are a secondary phenomenon. What we need are carefully designed trials to establish diagnostic criteria and subsequently translate this knowledge into evidence-based therapies.

Regional Citrate Anticoagulation versus No Anticoagulation for CKRT in Patients with Liver Failure with Increased Bleeding Risk

BACKGROUND

The opinions on the efficacy and safety of no anticoagulation versus regional citrate anticoagulation for continuous KRT (CKRT) were controversial in patients with severe liver failure with a higher bleeding risk. We performed a randomized controlled trial to assess no anticoagulation versus regional citrate anticoagulation for CKRT in these patients.

METHODS

Adult patients with liver failure with a higher bleeding risk who required CKRT were considered candidates. The included participants were randomized to receive regional citrate anticoagulation or no-anticoagulation CKRT. The primary end point was filter failure.

RESULTS

Of the included participants, 44 and 45 were randomized to receive regional citrate anticoagulation and no-anticoagulation CKRT, respectively. The no-anticoagulation group had a significantly higher filter failure rate (25 [56%] versus 12 [27%], P = 0.003), which was confirmed by cumulative incidence function analysis and sensitive analysis including only the first CKRT sessions. In the cumulative incidence function analysis, the cumulative filter failure rates at 24, 48, and 72 hours of the no-anticoagulation and regional citrate anticoagulation groups were 31%, 58%, and 76% and 11%, 23%, and 35%, respectively. Participants in the regional citrate anticoagulation group had significantly higher incidences of Ca 2+tot /Ca 2+ion >2.5 (7% versus 57%, P < 0.001), hypocalcemia (51% versus 82%, P = 0.002), and severe hypocalcemia (13% versus 77%, P < 0.001). However, most (73%) of the increased Ca 2+tot /Ca 2+ion ratios were normalized after the upregulation of the calcium substitution rate. In the regional citrate anticoagulation group, there was no significant additional increase in the systemic citrate concentration after 6 hours.

CONCLUSIONS

For patients with liver failure with a higher bleeding risk who required CKRT, regional citrate anticoagulation resulted in significantly longer filter lifespan than no anticoagulation. However, regional citrate anticoagulation in patients with liver failure was associated with a significantly higher risk of hypocalcemia, severe hypocalcemia, and Ca 2+tot /Ca 2+ion >2.5.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

RCA for CRRT in Liver Failure and High Risk Bleeding Patients, NCT03791190 .

Clinical and pathophysiological understanding of the hepatorenal syndrome: Still wrong or still not exactly right?

The hepatorenal syndrome (HRS) is one major extrahepatic complication of end-stage liver diseases. While circulatory dysregulation is considered as primary etiology for HRS, cirrhosis-related (systemic) inflammation and/or cardial dysfunction may also play a key pathogenic role in HRS development. Exclusion of other causes of acute kidney injury (AKI) is required for diagnosis of HRS-AKI by the definition of the International Club of Ascites. However, the pathophysiology of HRS is not understood completely and there are still limited therapeutic options. Reversibility of renal dysfunction after liver transplantation indicates that HRS-AKI is a functional disorder caused by altered cellular function. The interplay between systemic inflammation and the onset of kidney-related hypometabolism may have a key role and needs to be studied in depth. This minireview challenges simplified views of the HRS in the context of diagnostics and therapy stressing the need for further evidence to advance the knowledge on this syndrome.

Reversal of hepatorenal syndrome and kidney recovery: When renal has more to offer

Hepatorenal syndrome (HRS) is one of the most severe complications in advanced cirrhosis. Type-1 HRS is relatively uncommon, yet carries considerably higher mortality rate. Effective treatment for HRS, especially therapy towards survival benefits, is still limited. However, the role for dialysis in HRS has been questioned over the years. The initiation of dialysis remains controversial for those who aren't transplant candidates. Meanwhile, there's a growing attention towards the successful use of peritoneal dialysis (PD) in cirrhotic patients. Herein, we report a case of HRS-1 in a 76-year-old male patient with decompensated cirrhosis. Through a series of adjustments of hemodialysis regimens and pharmacological prescriptions, patient stabilized and the opportunity for transjugular intrahepatic portosystemic shunt (TIPS) insertion was gained. PD was initiated after TIPS placement. With a gradual decrease of dialysis dose, patient successfully weaned off PD and achieved both reversal of HRS and kidney recovery. Markedly improved nutritional status and quality of life were reported. The potential role of dialysis and TIPS in HRS may be worth revisiting. Further studies regarding the optimal timing of dialysis initiation, choices of dialysis modality, and efficacy of dialysis therapy in combination with TIPS in HRS patients are warranted.