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Epic Code LAB1230081 Cholesterol, Body Fluid

Additional Codes

Mayo Code: CHLBF

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Aiding in the diagnosis of a cholesterol effusion or cholesterol-rich pseudochylous effusion in body fluids

 

Distinguishing between chylous and pseudochylous pleural effusions 

 

Distinguishing between malignant and nonmalignant ascites

Specimen Type

Body Fluid


Ordering Guidance


This test provides a measurement of cholesterol in body fluids, which is useful for screening of a cholesterol effusion or cholesterol-rich pseudochylous effusion. To distinguish between chylous and nonchylous effusions, order BFLA1 / Lipid Analysis, Body Fluid; which measures cholesterol and triglyceride concentrations, as well as chylomicrons and plasma lipoproteins.



Necessary Information


1. Date and time of collection are required.

2. Specimen source is required.



Specimen Required


Preferred Source:

-Peritoneal fluid (peritoneal, abdominal, ascites, paracentesis)

-Pleural fluid (pleural, chest, thoracentesis)

-Drain fluid (drainage, JP drain)

-Pericardial fluid

Acceptable Source: Write in source name with source location (if appropriate)

Collection Container/Tube: Sterile container

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Centrifuge to remove any cellular material and transfer into a plastic vial.

2. Indicate the specimen source and source location on label.


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Body Fluid Frozen (preferred) 30 days
  Refrigerated  7 days
  Ambient  24 hours

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus Reject
Anticoagulant or additive, amniotic fluid, breast milk, saliva, nasal secretions, sputum, synovial fluid, bronchoalveolar lavage (BAL) or bronchial washings, colostomy, ostomy, feces, spinal fluid, gastric secretions, urine, vitreous fluid Reject

Day(s) Performed

Monday through Sunday

Reference Values

An interpretive report will be provided

Clinical Information

Serum cholesterol is measured to determine the concentration of circulating lipoprotein particles when screening for cardiovascular disease. The concentration is affected by genetic and lifestyle factors. Cholesterol concentrations in serous effusions increase due to exudative processes that cause cell lysis or increased vascular permeability. Measurement of cholesterol in body fluids is used for the diagnosis of a cholesterol effusion or cholesterol-rich pseudochylous effusion. Pseudochylous effusions contain low triglycerides and high cholesterol and occur from chronic pleural effusions such as rheumatic pleurisy and tuberculosis. Malignant effusions may become enriched with cholesterol due to increased synthesis and release from neoplastic cells or lymphatic obstruction.(1)

 

Pleural fluid:

Chylothorax is the name given to pleural effusions containing chylomicrons with accordingly high triglyceride and low cholesterol concentrations, which occurs when chyle accumulates from a disruption of the thoracic duct caused mainly by malignancy or trauma.(2)

 

Pseudochylous effusions accumulate gradually through the breakdown of cellular lipids in long-standing effusions such as rheumatoid pleuritis, tuberculosis, or myxedema, and by definition the effluent contains high concentrations of cholesterol, while chylous effusions contain high concentrations of triglycerides in the form of chylomicrons.(3)

 

Differentiation of pseudochylothorax from chylothorax is important as their milky or opalescent appearance is similar; however, therapeutic management strategies differ.

 

Measurement of pleural fluid cholesterol has also been investigated in multiple studies for the purpose of differentiating exudates from transudates.(4) Most of these studies concluded that cholesterol performs as well as measurement of lactate dehydrogenase and total protein applying Light's criteria, but does not add much value beyond that.

 

Peritoneal fluid:

Ascites is the pathologic accumulation of excess fluid in the peritoneal cavity. Cholesterol analysis in peritoneal fluid may be a useful index to separate malignant ascites from nonmalignant, often cirrhotic ascites. Studies report concentrations ranging from greater than 32 to 70 mg/dL are greater than 88% sensitive and greater than 80% specific for malignant ascites, outperforming cytology.(4)

Cautions

In very rare cases, gammopathy, in particular type IgM (Waldenstrom macroglobulinemia), may cause unreliable results.

 

Acetaminophen intoxications are frequently treated with N-acetylcysteine.

 

N-acetylcysteine, at the therapeutic concentration when used as an antidote, and the acetaminophen metabolite N-acetyl-p-benzoquinone imine (NAPQI), may independently cause falsely low results.

Interpretation

Pleural fluid cholesterol concentrations between 45 to 65 mg/dL are consistent with exudative effusions. Cholesterol concentrations above 200 mg/dL suggest a pseudochylous effusion.(2)

 

Peritoneal fluid cholesterol concentrations between 32 to 70 mg/dL suggest a malignant cause of ascites.(4)

Reporting Name

Cholesterol, BF

Method Name

Colorimetry

Method Description

Cholesterol is measured by an automated enzymatic method. The reagents include cholesterol ester hydrolase, cholesterol oxidase, and a coupled colorimetric end-point chemistry system.(Package insert: Roche Cholesterol Reagent, c501. Roche Diagnostics Corp; V 13.0, 02/2019)

CPT Code Information

84311-Spectrophotometry, analyte not specified (cholesterol)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
CHLBF Cholesterol, BF 12183-0

 

Result ID Test Result Name Result LOINC Value
FLD25 Fluid Type: 14725-6
BFCHL Cholesterol (BF) 12183-0

Report Available

Same day/1 to 2 days

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

Clinical Reference

1. Gulyas M, Kaposi AD, Elek G, Szollar LG, Hjerpe A: Value of carcinoembryonic antigen (CEA) and cholesterol assays of ascitic fluid in cases of inconclusive cytology. J Clin Pathol. 2001 Nov;54(11):831-5. doi: 10.1136/jcp.54.11.831

2. Hooper C, Lee YC, Maskell N: BTS Pleural Guideline Group. Investigation of a unilateral pleural effusion in adults: British Thoracic Society Pleural Disease Guideline 2010. Thorax. 2010 Aug;65 Suppl 2:ii4-17. doi: 10.1136/thx.2010.136978

3. Staats BA, Ellefson RD, Budahn LL, et al: The lipoprotein profile of chylous and nonchylous pleural effusions. Mayo Clin Proc. 1980;55(11):700-704

4. Block DR, Algeciras-Schimnich A: Body fluid analysis: clinical utility and applicability of published studies to guide interpretation of today's laboratory testing in serous fluids. Crit Rev Clin Lab Sci. 2013;50:107-124. doi: 10.3109/10408363.2013.844679