Sorted By Test Name - Mayo Medical Laboratories

CI
8652
Useful For: Rapid detection of influenza virus types A and B in upper respiratory tract specimens.
Interpretation: Positive results are diagnostic of influenza A or influenza B. Negative results do not
rule out infection with influenza virus.
Reference Values:
Negative for influenza A nucleic acid
If positive, reported as influenza A nucleic acid detected
Negative for influenza B nucleic acid
If positive, reported as influenza B nucleic acid detected
Clinical References: 1. Pachucki CT: The diagnosis of influenza. Semin Resp Infect 1992;7:46-53
2. Wendt CH: Community respiratory viruses: organ transplant recipients. Am J Med 1997;102:31-36;
42-43
Inherited Conjugated Hyperbilirubinemias, Urine
Clinical Information: Dubin-Johnson syndrome (DJS) and Rotor syndrome are two of the inherited
disorders of bilirubin metabolism which result in conjugated hyperbilirubinemia. DJS is inherited as an
autosomal recessive trait that is rarely detected before puberty. It is characterized by chronic,
nonhemolytic jaundice. Most patients are asymptomatic and the liver typically shows abnormal black
pigmentation. The gene responsible for this disorder is a member of the family of ATP-binding cassette
transporters located on chromosome 10q24, called MRP2 or cMOAT. This defect impairs liver excretion
of conjugated bilirubin and several organic anions from the hepatocytes into the bile. Other liver function
tests are normal. Rotor syndrome is a rare condition of the liver and very similar to DJS. It is inherited as
an autosomal recessive trait caused by digenic inheritance of homozygous mutations in the SLCO1B1 and
SLCO1B3 genes. Biochemically, Rotor syndrome can be distinguished from DJS by a normal functioning
gallbladder, normal liver histology, and the different pattern of coproporphyrin isomers excretion. In
healthy individuals, the percent of coproporphyrin I excreted relative to the total coproporphyrin excreted
in urine is approximately 20% to 45%. In DJS and Rotor syndrome, retention of coproporphyrin III by the
liver causes diminished urinary excretion. Consequently the percent of coproporphyrin I to the total
coproporphyrin excreted in the urine exceeds the normal range. When the total urinary excretion of
coproporphyrin is elevated and the percent of coproporphyrin I to total coproporphyrin exceeds 60% but
is less than 80%, is most consistent with Rotor syndrome. In patients with DJS the percentage of
coproporphyrin I to total coproporphyrin is typically greater than 80% and the total urinary
coproporphyrin excretion is within normal limits. Some overlap may exist so the ratio alone should not be
used to distinguish Rotor or DJS.
Useful For: Differential diagnosis of hyperbilirubinemia syndromes between Dubin-Johnson syndrome
and Rotor syndrome in patients > or =1 year of age
Interpretation: Abnormal results are reported with a detailed interpretation including an overview of
the results and their significance, a correlation to available clinical information provided with the
specimen, differential diagnosis, and recommendations for additional testing when indicated and
available, and a phone number to reach one of the laboratory directors in case the referring physician has
additional questions.
Reference Values:
COPROPORPHYRIN ISOMERS I AND III
Males
or =16 years: 25-150 mcg/24 hours
Females
or =16 years: 8-110 mcg/24 hours
% COPROPORPHYRIN I