Itsuji Y, Tanaka K, Tanabe T, Takahashi H
Central Laboratory, Kanasi Medical University Hospital, Moriguchi.
Rinsho Byori. 1997 Mar;45(3):265-70.
Since urine contains cross-reacting substances to anti-cortisol(F) antibody, we extracted F from urine samples with dichloromethane. Using this specific assay system for F with TDX dynapack(fluorescence polarization immunoassay system), clinical significance of urinary F was tested by measuring urine samples from normal subjects, patients with pituitary-adrenal diseases and liver cirrhosis, and pregnant. The circadian rhythm of urinary F was evaluated by using samples collected every 4-hour period. The amount of urinary excretions of F during 4 hours were the highest during between 4 a.m. to 8 a.m. and then gradually decreased reaching at the lowest level at between 0 a.m. and 4 a.m. in normal volunteers. Such circadian rhythm was not found in 6 patients with Cushing's syndrome. The urinary F levels in pregnant women started to increase in the samples from between 21 to 30 weeks of gestation, and the level was maintained even at the 5th day of post-partum. The urinary F levels in patients with liver cirrhosis were significantly lower than those for age-matched healthy volunteers. In patients with abnormal steroidogenesis, the urinary F levels in patients with Cushing's syndrome were extremely high, 165-3358 micrograms/day. On the other hands, those in patients with deficient steroid synthetase were 2.8-26.5 micrograms/day, and those in patients with neuroblastoma and pheochromocytoma were 7.8-43.8 micrograms/day. The urinary F levels were about 50-fold higher in the patients with Cushing's syndrome than those in the normal reference interval, whereas serum F and urinary 17-OHCS levels were only 2.5-fold and 7-fold higher than those healthy volunteers, respectively. These results indicate that the assay of urinary F extracted with dichloromethane is the most useful test for the diagnosis of Cushing's syndrome.
