Circulating Oxalate Levels in Short Bowel Syndrome as a Severity Marker of CKD.

Introduction: Patients with short bowel syndrome (SBS) may exhibit enteric hyperoxaluria (EH), and the prevalence of oxalate nephropathy in SBS is likely underestimated. Plasma oxalate (POx) is a surrogate of systemic oxalate deposition and, consequently, may increase the risk of developing chronic kidney disease (CKD). The main objective of this study was to explore the distribution of POx levels in patients with SBS.

[Oxalate: from physiology to pathology].

Hyperoxaluria is defined by an increase of urinary oxalate, leading to kidney stones, nephrocalcinosis and/or chronic kidney disease. There are different diseases related to hyperoxaluria: (1) kidney stones, 50% of them being explained by intermittent hyperoxaluria, secondary to dietary mistakes such as low hydration, excess of oxalate consumption and/or low calcium consumption; (2) primary hyperoxaluria, a genetic orphan disease inducing a massive production of oxalate by the liver, leading to increased plasma oxalate increase and saturation, and further systemic oxalosis with oxalate deposition, nephrocalcinosis and ultimately kidney failure, the management of this disease being currently dramatically modified by the onset of new therapeutic tools such as RNA interference; and (3) enteric hyperoxaluria, resulting from increased intestinal oxalate absorption because of intestinal malabsorption (short bowel syndrome, bariatric surgery, exocrine pancreatic insufficiency, etc.).