Several problems in Rotor's syndrome were studied with respect to the effects of aging on the pigment metabolism, and its differences from Dubin-Johnson syndrome.
In six cases of Rotor's syndrome examined at least twice at an average interval of 10.5±6.5 years, no significant increase was found in the total (TB) and direct (DB) bilirubin in the serum between the initial and the last examination. However, indirect bilirubin increased from 1.21±0.72 mg/dl to 2.28±1.00 mg/dl (p<0.05), the DB/TB ratio decreased from 77.3±6.6% to 64.4±8.7% (p<0.05) and BSP retentions at 45 minutes increased from 26.8±10.9% to 45.3±14.9% (p<0.05). A significant positive correlation between the values of BSP retained at 45 minutes and the age of the patients was observed (p <0.01) in a total of 10 cases of Rotor's syndrome, including four other cases that were examined only once.
No reelevation of BSP on the disappearance curves was observed in 17 examinations of these 10 cases of Rotor's syndrome. However, reelevation of BSP was noted in all of the 10 cases of Dubin-Johnson syndrome examined separately.
Five cases of Dubin-Johnson syndrome and one case of Rotor's syndrome were loaded intravenously with dehydrocholic acid following 45. minute BSP tests. Fifteen minutes later the values of retained BSP increased in all of the 5 cases of Dubin-Johnson syndrome but decreased in a single case of Rotor's syndrome.
These results imply that abnormalities in pigment metabolism intensify with age in Rotor's syndrome, and that Rotor's syndrome is a distinct pathophysiological entity different from Dubin-Johnson syndrome.