MO096: Chronic Liver Disease and Hepatic Calcium-Oxalate Deposition in Patients with Primary Hyperoxaluria Type I

Abstract

Abstract BACKGROUND AND AIMS Patients with primary hyperoxaluria type I (PH I) are prone to develop early end-stage kidney failure (ESKF). Systemic deposition of calcium-oxalate (CaOx) crystals starts when renal function declines and plasma oxalate (Pox) increases >30 µmol/L. It is anticipated that all parenchymal organs, but also bone (marrow), retina and the central nervous system can be involved. However, liver involvement, either as CaOx deposition or as chronic hepatitis/fibrosis, was never reported. METHOD We now examined liver involvement in 19 patients with PH I aged 1.5–52 years. Liver specimen was obtained by biopsy for diagnostic purposes (1), at autopsy (1) or at the time of combined or sequential liver kidney transplantation (17). RESULTS With polarization microscopy, crystals with the typical star-like appearance of CaOx were found in 3/19 patients. The crystals were located in small arteries but not within hepatocytes. Cirrhosis was seen in one patient. Fibrosis was seen in 10/19 patients, with porto-portal and nodular fibrosis (n = 1), and a limitation of fibrosis to the portal field in eight and/or to central areas in five patients. Unspecific hepatitis features were observed in seven patients. Fiber proliferations were detectable in 10 cases, and in one sample, transformed Ito-cells (myofibroblasts) were found. Iron deposition but also megakaryocytes as a sign of extramedullary erythropoiesis were found in nine and three patients, respectively. CONCLUSION Overall, liver involvement in patients with PH I was more pronounced, as previously described. However, compared with CaOx deposition in other organs/tissue, such crystal accumulations were only minimal in the liver, although the oxalate concentration must be the highest.