Serum bile salts as an aid to oral cholecystogram interpretation

A radioimmunoassay for glycocholate was used as an estimate of serum bile salts in patients with serum bilirubin levels less than 5 mg/dl undergoing oral cholecystography. Most subjects also had a percutaneous liver biopsy. Intravenous cholangiography was performed in most subjects who had a nonvisualized gallbladder after receiving single doses of iopanoic acid on two consecutive days. The pathologic status of nonvisualized gallbladders was ascertained by surgery, prospective follow-up, necropsy and/or ultrasound. In 20 subjects with well-visualized gallbladders, the serum cholate conjugates (CC) were lower than 3.5 μM in all but two subjects, both of whom had inflammatory liver disease (chronic active hepatitis, alcoholic hepatitis). Those with faintly or poorly visualized gallbladders, but with no evidence of gallbladder or gallstone disease by other criteria, also had levels less than 3.5 μM, except for one subject with inflammatory liver disease. By contrast, 11 subjects with nonvisualized, although normal gallbladders by the above clinical criteria, exhibited serum CC greater than 3.5 μM. Six subjects had diminished gallbladder visualization, but normal gallbladders on clinicopathological grounds; all but one with chronic active hepatitis had serum CC greater than 3.5 μM. In conclusion, when the serum cholate conjugates are less than 3.5 μM, nonvisualization of the gallbladder with oral cholecystography supports a diagnosis of a diseased gallbladder. In addition, a serum CC level greater than 3.5 μM may predict insufficient hepatic capacity to secrete iopanoic acid adequate for gallbladder visualization in noninflammatory liver disease. The serum cholate conjugates appear to provide greater information on this hepatic function than the serum bilirubin or bromsulfophthalein retention.