Bilirubin and Paranitrophenol Glucuronyl Transferase Activities of the Liver in Patients with Gilbert’s Syndrome. An Attempt at a Biochemical Breakdown of the Gilbert’s Syndrome

Abstract

Hepatic bilirubin (Bil-GT) and paranitrophenol glucuronyl transferase (PNP-GT) activities were measured in 26 subjects with Gilbert’s syndrome (GS) and in one subject with a Crigler-Najjar type 2. Firstly, the results allowed us to distinguish three groups of patients in GS. In the first group, Bil-GT activity decreased by 25% of that of the controls and PNP-GT activity was normal. In the second group, Bil-GT decreased by 25% of that of the controls and PNP-GT decreased by 50% of that of the controls. In the third group, Bil-GT decreased by 50% of that of the controls and PNP-GT activity was normal. Secondly, the results showed in the Crigler-Najjar type 2 that Bil-GT activity was 25% of that of the controls and PNP-GT was 10% of that of the controls. From these results the following hypothesis has been raised: (1) the subjects of the third GS group were probably heterozygous to the homozygous disease which affected the subjects of the first GS group, and (2) the subjects of the second GS group were most likely heterozygous to the homozygous disease which affected our Crigler-Najjar type 2. However, in the present state of our knowledge, the scheme of GS classification which we propose requires confirmation.

Prolonged Neonatal Jaundice

“…The limited amount of liver available led us to use a method allowing accurate duplicated measurements in homogenates dialyzed against EDT A (I). The values obtained in controls and in the 10 patients with type I Crigler-Najjar disease were in the same range as those measured with different methods by others (6)(7)(8).…”

Inherited disorders of bilirubin clearance

“…It is typically associated with at least 50% decrease in hepatic bilirubin UGT activity (29). GS is now regarded as an autosomal recessive disorder, with affected patients being either homozygotes or compound heterozygotes (i.e.…”

Gilbert's syndrome: evidence of morphological heterogeneity.

“…Since indocyanine green does not require conjugation, this would require a second defect in addition to the glucuronyl transferase defect demonstrated by Black and Billing (1969). There have also been other reports of the heterogeneity of Gilbert's syndrome on the basis of bilirubin kinetic studies (Okolicsanyi et al, 1978) and studies of the conjugating enzymes (Auclair et al, 1976). It would thus be of interest to perform kinetic and enzyme studies on the two ultrastructual subpopulations to assess if the various subpopulations coincide, or whether they themselves are heterogeneous.…”