Distinguishing between chylous and nonchylous effusions
Measurement of triglycerides in body fluids as a surrogate for chylomicrons
Colorimetry
Chylothorax Analysis, Abnormal Body Fluid
Chylothorax Lipid Analysis, Abnormal Body Fluid
Fat, Body Fluids
Triglyceride, Body Fluids
TGLBF
Body Fluid
For help distinguishing between chylous and nonchylous effusions, order BFLA1 / Lipid Analysis, Body Fluid. The body fluid will be tested for cholesterol and triglyceride concentrations and undergo lipoprotein electrophoresis.
1. Date and time of collection is required.
2. Specimen source is required.
Question ID | Description | Answers |
---|---|---|
FLD25 | Fluid Type: |
Specimen Type: Body fluid
Preferred Source:
-Peritoneal fluid (peritoneal, abdominal, ascites, paracentesis)
-Pleural fluid (pleural, chest, thoracentesis)
-Drain fluid (drainage, Jackson Pratt [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.
0.5 mL
Gross hemolysis | Reject |
Gross lipemia | OK |
Gross icterus | Reject |
Anticoagulant or additive, amniotic fluid, breast milk, saliva, sputum, synovial fluid, bronchoalveolar lavage (BAL) or bronchial washings, colostomy, ostomy, feces, cerebrospinal fluid, gastric secretions, nasal secretions, urine, vitreous | Reject |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Body Fluid | Frozen (preferred) | 30 days | |
Refrigerated | 7 days | ||
Ambient | 24 hours |
Distinguishing between chylous and nonchylous effusions
Measurement of triglycerides in body fluids as a surrogate for chylomicrons
Triglyceride concentration in body fluids is correlated to the presence of chylomicrons and can be useful when diagnosing chylous effusion or differentiating from pseudochylous effusion.(1) Chylous effusions are characterized by the presence of chyle which contains chylomicrons circulating through the lymphatic system. Pseudochylous effusions do not have chylomicrons. These fluids have a milky appearance and can be confused with chylous effusions. While chylous effusions often have elevated triglyceride concentrations and decreased cholesterol concentrations, identification of chylomicrons is considered the gold standard for the diagnosis.
Pleural fluid:
Chylothorax is the name given to pleural effusions containing chylomicrons. They develop when chyle accumulates from disruption of the lymphatic system, often the thoracic duct, caused mainly by malignancy or trauma.(1) Lymph contains chylomicron rich chyle characterized by high concentrations of triglycerides. Pseudochylous effusions are the name given to milky appearing effusions that do not contain lymphatic contents but rather form 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.(2) Differentiation of pseudochylothorax from chylothorax is important as their milky or opalescent appearance is similar, however therapeutic management strategies differ.
Peritoneal fluid:
Chylous ascites is the name given to peritoneal effusions containing chylomicrons. Obstruction of lymph flow causing leakage from dilated subserosal lymphatics, exudation through the walls of retroperitoneal megalymphatics, and direct leakage of chyle due to a lymphoperitoneal fistula have been proposed as possible mechanisms causing chylous ascites.(3) Elevated triglyceride concentrations have the best correlation with detection of chylomicrons, while cholesterol is not useful at predicting the presence or absence of chylomicrons.
An interpretive report will be provided
Pleural fluid triglyceride concentrations over 110 mg/dL are consistent with a chylous effusion. Triglyceride concentrations below 50 mg/dL are usually not due to chylous effusions.(1)
Peritoneal fluid triglyceride concentrations over 187 mg/dL are most consistent with chylous effusion.(3)
Dicynone (Etamsylate) at therapeutic concentrations may lead to false-low results.
Acetaminophen intoxications are frequently treated with N-acetylcysteine.
N-acetylcysteine at a plasma concentration above 166 mg/L and the acetaminophen metabolite, N-acetyl-p-benzoquinone imine may independently cause falsely low results.
In very rare cases, gammopathy, in particular type IgM (Waldenstrom macroglobulinemia), may cause unreliable results.
1. 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;65(Suppl2):ii4-17. doi:10.1136/thx.2010.136978
2. 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
3. Thaler MA, Bietenbeck A, Schulz C, Luppa PB. Establishment of triglyceride cut-off values to detect chylous ascites and pleural effusions. Clin Biochem. 2017;50(3):134-138. doi:10.1016/j.clinbiochem.2016.10.008
4. McGrath EE, Blades Z, Anderson PB. Chylothorax: aetiology, diagnosis, and therapeutic options. Respir Med. 2010;104(1):1-8. doi:10.1016/j.rmed.2009.08.010
Samples analyzed for triglycerides are measured by an automated enzymatic method. The chemistry includes hydrolysis of the triglycerides and phosphorylation of the resulting glycerol.(Package insert: Roche Triglycerides Reagent. Roche Diagnostics Corp; V13.0, 03/2022)
Monday through Sunday
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.
84478
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
TGLBF | Triglycerides, BF | 12228-3 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
BFTGL | Triglycerides (BF) | 12228-3 |
FLD25 | Fluid Type: | 14725-6 |