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Test ID: CI
Inherited Conjugated Hyperbilirubinemias, Urine

Secondary ID A test code used for billing and in test definitions created prior to November 2011

8652

NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.

Conditional

Useful For Suggests clinical disorders or settings where the test may be helpful

Differential diagnosis of hyperbilirubinemia syndromes between Dubin-Johnson syndrome and Rotor syndrome in patients > or =1 year of age

Genetics Test Information Provides information that may help with selection of the correct test or proper submission of the test request

Investigation of inherited conjugated hyperbilirubinemia syndromes (Dubin-Johnson syndrome, Rotor syndrome) only.

Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test

Method Name A short description of the method used to perform the test

High-Performance Liquid Chromatography (HPLC)

Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name

Inher Conj Hyperbilirubinemias, U

Aliases Lists additional common names for a test, as an aid in searching

Dubin-Johnson syndrome
Hyperbilirubinemia
Rotor syndrome

Specimen Type Describes the specimen type needed for testing

Urine

Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.

Container/Tube: Amber, 60-mL urine bottle (Supply T596)

Specimen Volume: 20-50 mL

Collection Instructions:

1. Patient should abstain from alcohol for at least 24 hours before as well as during the collection period.

2. Collect urine for 24 hours.

3. Add 5 g of sodium carbonate as preservative at start of collection. This preservative is intended to achieve a pH of >7. Do not substitute sodium bicarbonate for sodium carbonate.

4. The container should be refrigerated and protected from light as much as possible during collection.

5. Protect specimen from light.

Additional Information:

1. 24-Hour volume is required.

2. Include a list of medications the patient is currently taking.

3. The pH will generally fall between 7 and 10 if the proper preservative (5 g sodium carbonate) was added to the container before the collection was started.

4. See Urine Preservatives in Special Instructions for multiple collections.

 

Urine Preservative Collection Options

 Ambient

No

Refrigerated

No

Frozen

No

6N HCl

No

50% Acetic Acid

No

Na2CO3

Required

Toluene

No

6N HNO3

No

Boric Acid

No

Thymol

No

Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.

10 mL

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected

 

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

Specimen not light protected

Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.

Specimen TypeTemperatureTime
UrineFrozen7 days

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Dubin-Johnson syndrome (DJS) and Rotor syndrome are 2 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 <80%, is most consistent with Rotor syndrome. In patients with DJS the percentage of coproporphyrin I to total coproporphyrin is typically >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.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

COPROPORPHYRIN ISOMERS I AND III

Males

25-150 mcg/24 hours

Females  

 8-110 mcg/24 hours

 

% COPROPORPHYRIN I

20-45%

Interpretation Provides information to assist in interpretation of the test results

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.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

This test is not useful for the evaluation of individuals <1 year of age suspected of having Dubin-Johnson syndrome or Rotor syndrome. Due to normal liver development, coproporphyrin I is primarily excreted in infant urine and cannot be interpreted in the scope of hyperbilirubinemia syndromes.

 

This test is not useful for evaluating patients with suspected porphyrias. For measurement of urine coproporphyrin and uroporphyrin, see PQNU/8562Porphyrins, Quantitative, Urine or PQNRU/60597 Porphyrins, Quantitative, Random, Urine.

 

 

Failure to maintain low temperature and correct pH may allow analyte degradation and result in falsely-decreased coproporphyrin III values (ie, false positives).

Clinical Reference Provides recommendations for further in-depth reading of a clinical nature

1. Koskelo P, Mustajoki P: Altered coproporphyrin-isomer excretion in patients with the Dubin-Johnson syndrome. Int J Biochem 1980;12:975-978

2. Chowdhury JR, Wolkoff AW, Chowdhury NR, et al: Hereditary jaundice and disorders of bilirubin metabolism. In Metabolic and Molecular Basis of Inherited Disease, Eighth edition. Edited by CR Scriver, AL Beaudet, WS Sly, et al. New York, McGraw-Hill Medical Publishing Division, 2001, pp 3063-3101, Available from URL: www.ommbid.com

 

Method Description Describes how the test is performed and provides a method-specific reference

After the urine specimen is acidified, the isomers are separated by HPLC.(Lim CK, Peters TJ: High-performance liquid chromatography of uroporphyrin and coproporphyrin isomers. Methods Enzymol 1986;123:383-389)

Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.

Varies

Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.

3 days (not reported on Saturday or Sunday)

Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result

5 days

Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

7 days

Performing Laboratory Location The location of the laboratory that performs the test

Rochester

Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

84120

LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.

Result IDReporting NameLOINC Code
8652Copro I + IIIIn Process
2394% Copro IIn Process
TM74Collection DurationIn Process
VL57Urine VolumeIn Process
30216Interpretation (CI)59462-2