Sorted By Test Name - Mayo Medical Laboratories

BILID
81787
AFBIL
8390
(non-PSC versus PSC patient). This information is then provided in the interpretive portion of the final
report.
Reference Values:
An interpretive report will be provided.
Clinical References: 1. Kipp BR, Stadheim LM, Halling SA, et al: A comparison of routine
cytology and fluorescence in situ hybridization for the detection of malignant bile duct strictures. Am J
Gastroenterol 2004 September;99(9):1675-1681 2. Moreno Luna LE, Kipp BR, Halling KC, et al:
Advanced cytologic techniques for the detection of malignant pancreatobiliary strictures.
Gastroenterology 2006 October;131(4):1064-1072 3. Barr Fritcher EG, Kipp BR, Slezak JM, et al:
Correlating routine cytology, quantitative nuclear morphometry by digital image analysis, and genetic
alterations by fluorescence in situ hybridization to assess the sensitivity of cytology for detecting
pancreatobiliary tract malignancy. Am J Clin Pathol 2007 August;128(2):272-279
Bilirubin Direct, Serum
Clinical Information: Approximately 85% of the total bilirubin produced is derived from the heme
moiety of hemoglobin while the remaining 15% is produced from the red blood cell precursors destroyed
in the bone marrow and from the catabolism of other heme-containing proteins. After production in
peripheral tissues, bilirubin is rapidly taken up by hepatocytes where it is conjugated with glucuronic acid
to produce mono- and diglucuronide, which are excreted in the bile. Direct bilirubin is a measurement of
conjugated bilirubin. Jaundice can occur as a result of problems at each step in the metabolic pathway.
Disorders may be classified as those due to: increased bilirubin production (e.g. hemolysis and ineffective
erythropoiesis), decreased bilirubin excretion (e.g. obstruction and hepatitis), and abnormal bilirubin
metabolism (e.g. hereditary and neonatal jaundice). Inherited disorders in which direct bilirubinemia
occurs include Dubin-Johson syndrome and Rotor Syndrome. Jaundice of the newborn where direct
bilirubin is elevated includes idiopathic neonatal hepatitis and biliary atresia. The most commonly
occurring form of jaundice of the newborn, physiological jaundice, results in unconjugated (indirect)
hyperbilirubinemia. Elevated unconjugated bilirubin in the neonatal period may result in brain damage
(kernicterus). Treatment options are phototherapy and, if severe, exchange transfusion. The increased
production of bilirubin that accompanies the premature breakdown of erythrocytes and ineffective
erythropoiesis results in hyperbilirubinemia in the absence of any liver abnormality. In hepatobiliary
diseases of various causes, bilirubin uptake, storage and excretion are impaired to varying degrees. Thus
both conjugated and unconjugated bilirubin is retained and a wide range of abnormal serum
concentrations of each form of bilirubin may be observed. Both conjugated and unconjugated bilirubin are
increased in hepatocellular diseases, such as hepatitis and space-occupying lesions of the liver; and
obstructive lesions such as carcinoma of the head of the pancreas, common bile duct, or ampulla of Vater.
Useful For: Evaluation of jaundice and liver functions.
Interpretation: Direct bilirubin levels must be assessed in conjunction with total and indirect levels
and the clinical setting.
Reference Values:
> or =12 months: 0.0-0.3 mg/dL
Reference values have not been established for patients that are less than 12 months of age.
Clinical References: 1. Tietz Textbook of Clinical Chemistry. Edited by Burtis and Ashwood.
Philadelphia, PA, WB Saunders Co, 1994 2. Roche/Hitachi Modular Analytics Reference Guide, Vol 7
Bilirubin, Amniotic Fluid
Clinical Information: The presence of bilirubin in amniotic fluid, which results in a yellow color, is
an indicator of fetal erythroblastosis. Visual inspection of amniotic fluid is unreliable because bilirubin is
not the only cause of an excessive yellow color; therefore, the presence of bilirubin must be confirmed
with spectrophotometric methods. Meconium may contribute a green color (biliverdin) that can obscure
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