Do Biliary Salts Have Role on Acute Kidney Injury Development?

Abstract

Acute kidney injury (AKI) is a major complication in patients with acute liver failure and chronic liver disease. Hemodynamic changes appear to be the principal alterations in these conditions, therefore there should be no known structural abnormalities responsible for AKI. On the other hand, several authors have published data on structural changes known as bile cast nephropathy or cholemic nephrosis, which basically consist of the presence of bile casts in tubular lumen analogous to those observed in myeloma. Although these findings are well documented, there is a lack of reproducibility by other authors. This paper aims to discuss, through evidence-based medical literature, the role of biliary salts on kidney injury development.

Bile cast nephropathy: when the kidneys turn yellow

“…Pathological features include loss of tubular brush borders, attenuated cytoplasm of tubular cells, dilatation of the tubular lumen, cytoplasmic vacuolization, apical blebbing, and tubular necrosis and desquamation [2,4,19,28]. In the study done by van Slambrouck, ATN was noted in 76% of the biopsies [3,5,15,26].…”

“…Many case reports of kidney biopsies have demonstrated bilirubin cast deposition mainly in the distal renal tubules and minimally in the proximal tubules [12,15,27]. A clinico-pathologic study done by van Slambrouck et al on 3 renal biopsies and 41 autopsy studies of patients with jaundice showed distal deposition of bile casts in more than 50% of them, while only 6 biopsies had proximal tubular involvement [1,3,5]. The degree of bile cast formation correlated significantly with the severity of jaundice [1,3].…”

“…It was initially described by Qunicke in 1899 in autopsy studies of patients with acute jaundice and renal insufficiency [2,4]. Later in 1922, Haessler et al showed that biliary salt sediments were found in the urine of dogs and humans with jaundice, and that the amount of sediments decreased as jaundice resolved [1,[3][4][5]. The gold standard for diagnosing this entity is renal biopsy.…”

“…The prevalence of bile cast nephropathy is probably underestimated as pathological diagnosis is often missing considering the increased bleeding risk of renal biopsy in coagulopathic patients with liver disease; however, it has been recognized more frequently lately with the utilization of transjugular renal biopsy [1,2,5,6]. Nonetheless, Nayak et al conducted a study on postmortem kidney biopsy [7].…”

Bile Nephropathy in Flucloxacillin-Induced Cholestatic Liver Dysfunction

“…Other studies reported hyperbilirubinemia to be renoprotective in both animals and humans through anti-inflammatory and antioxidative effects [ 18 – 20 ]. Guo et al have shown that higher bilirubin levels were independently associated with lower levels of late graft failure in a prospective study in renal transplant recipients [ 14 ].…”