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# A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Serum Trypsin-Like Immunoreactivity, Cobalamine & Folate, Canine or Feline
Test Code: VTCFSO
Synonyms/Keywords
​TLI, Vitamin B12, EPI (Exocrine Pancreatic Insufficiency)
Test Components
​TLI, Cobalamin, Folate
Species
Canine, Feline
Test Category
Specimen Requirements
Fasting Required ​Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Yes
 
12-18 hour fast for non-diabetic animals
6 hour fast for diabetic animals
​Serum​ ​Red Top Tube (RTT) ​Serum Separator Tube (SST) ​1 mL ​0.9 mL
Collection Processing Instructions

Pancreatic function must be assessed before these results can be interpreted since they may be abnormal in animals with Exocrine Pancreatic Insufficiency (EPI). 

Samples should be frozen as soon as possible.

Specimen Stability Information
Specimen Type Temperature Time
Serum​ ​ Room Temperature ​<24 hours
Refrigerated 48 hours
​Frozen (preferred) Indefinitely
Interference
​Hemolysis and non-fasting status may interfere with results.  Serum folate shows limited stability at room temperature.  Therefore, serum samples for folate analysis should be kept at ​4º C (refrigerator temperature) for no longer than 48 hours, freezing is preferred.
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Texas A&M Gastrointestinal Lab ​Monday through Friday ​1-2 days

​TLI-RIA

Cobalamin/Folate-Chemiluminescence

Marshfield Center Laboratory Section
Reference Lab
Reference Lab Information
Address Telephone Website Link Marshfield Lab Account #

Gastroinestinal Laboratory
4474 TAMU
College of Veterinary Medicine
Texas A&M University
​College Station, TX 77843-4474

​Ph 979-862-2861

Fax 979-862-2864

​vetmed.tamu.edu/gilab ​68-026314
Test Information

In dogs,TLI  values below 2.5 µg/L are diagnostic for EPI. Values between 3.5 and 5.7 µg/L are rarely if ever associated with signs of EPI but may reflect subclinical pancreatic disease such as subtotal pancreatic acinar cell destruction secondary to on-going immune-mediated lymphocytic pancreatitis. Progression of the disease in such patients may ultimately lead to EPI. Values between 2.5 and 3.5 µg/L are sometimes (but rarely) associated with clinical signs due to EPI. In these cases the TLI assay should be repeated after one month paying particular attention to ensuring that food is withheld for 12 to 15 hours before the blood sample is collected.

In cats, TLI values equal to or below 8.0 µg/L are diagnostic for EPI, with values between 8.0 and 12.0 being equivocal. As in the dog, repeating the assay one month later should be considered.

Serum TLI values above 50.0 µg/L (dogs) and 100.0 µg/L (cats) are consistent with either acute or chronic pancreatitis or decreased renal excretion due to severe renal insufficiency, although our experience suggests that serum TLI is often minimally increased even in severe renal failure. Elevated serum TLI concentrations are also seen in some malnourished patients (dogs usually) without evidence of pancreatitis, and in some cats with patchy pancreatic hypertrophy/atrophy (generally considered to be a benign age-related change). Serum TLI is increased in approximately 30-40% of cats and dogs with pancreatitis; it is important to recognize that normal test results do not rule out the possibility of pancreatic inflammation. We believe that in acute pancreatitis testing of samples obtained as soon as possible after the onset of clinical signs is most likely to yield an abnormal test result. If pancreatitis is suspected, a PLI test should be performed. In cats increased serum TLI is often also observed with small intestinal disease. In these cases serum concentrations of cobalamin and folate should be determined for evaluation of the small intestine.

Reference Intervals
Performing Location Canine Reference Intervals Feline Reference Intervals​
​Texas A&M Gastrointestinal Lab

​TLI:  5.7-45.2 ug/L

Cobalamin:  251-908 ng/L

Folate:  7.7-24.4 ug/L

​TLI:  12.0-82.0 ug/L

Cobalamin:  290-1500 ng/L

Folate:  9.7-21.6 ug/L

Synonyms/Keywords
​TLI, Vitamin B12, EPI (Exocrine Pancreatic Insufficiency)
Test Components
​TLI, Cobalamin, Folate
Species
Canine, Feline
Test Category
Specimen Requirements
Fasting Required ​Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Yes
 
12-18 hour fast for non-diabetic animals
6 hour fast for diabetic animals
​Serum​ ​Red Top Tube (RTT) ​Serum Separator Tube (SST) ​1 mL ​0.9 mL
Collection Processing Instructions

Pancreatic function must be assessed before these results can be interpreted since they may be abnormal in animals with Exocrine Pancreatic Insufficiency (EPI). 

Samples should be frozen as soon as possible.

Specimen Stability Information
Specimen Type Temperature Time
Serum​ ​ Room Temperature ​<24 hours
Refrigerated 48 hours
​Frozen (preferred) Indefinitely
Interference
​Hemolysis and non-fasting status may interfere with results.  Serum folate shows limited stability at room temperature.  Therefore, serum samples for folate analysis should be kept at ​4º C (refrigerator temperature) for no longer than 48 hours, freezing is preferred.
Test Information

In dogs,TLI  values below 2.5 µg/L are diagnostic for EPI. Values between 3.5 and 5.7 µg/L are rarely if ever associated with signs of EPI but may reflect subclinical pancreatic disease such as subtotal pancreatic acinar cell destruction secondary to on-going immune-mediated lymphocytic pancreatitis. Progression of the disease in such patients may ultimately lead to EPI. Values between 2.5 and 3.5 µg/L are sometimes (but rarely) associated with clinical signs due to EPI. In these cases the TLI assay should be repeated after one month paying particular attention to ensuring that food is withheld for 12 to 15 hours before the blood sample is collected.

In cats, TLI values equal to or below 8.0 µg/L are diagnostic for EPI, with values between 8.0 and 12.0 being equivocal. As in the dog, repeating the assay one month later should be considered.

Serum TLI values above 50.0 µg/L (dogs) and 100.0 µg/L (cats) are consistent with either acute or chronic pancreatitis or decreased renal excretion due to severe renal insufficiency, although our experience suggests that serum TLI is often minimally increased even in severe renal failure. Elevated serum TLI concentrations are also seen in some malnourished patients (dogs usually) without evidence of pancreatitis, and in some cats with patchy pancreatic hypertrophy/atrophy (generally considered to be a benign age-related change). Serum TLI is increased in approximately 30-40% of cats and dogs with pancreatitis; it is important to recognize that normal test results do not rule out the possibility of pancreatic inflammation. We believe that in acute pancreatitis testing of samples obtained as soon as possible after the onset of clinical signs is most likely to yield an abnormal test result. If pancreatitis is suspected, a PLI test should be performed. In cats increased serum TLI is often also observed with small intestinal disease. In these cases serum concentrations of cobalamin and folate should be determined for evaluation of the small intestine.

Reference Intervals
Performing Location Canine Reference Intervals Feline Reference Intervals​
​Texas A&M Gastrointestinal Lab

​TLI:  5.7-45.2 ug/L

Cobalamin:  251-908 ng/L

Folate:  7.7-24.4 ug/L

​TLI:  12.0-82.0 ug/L

Cobalamin:  290-1500 ng/L

Folate:  9.7-21.6 ug/L

Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Texas A&M Gastrointestinal Lab ​Monday through Friday ​1-2 days

​TLI-RIA

Cobalamin/Folate-Chemiluminescence

Laboratory Section
Reference Lab
Reference Lab Information
Address Telephone Website Link Marshfield Lab Account #

Gastroinestinal Laboratory
4474 TAMU
College of Veterinary Medicine
Texas A&M University
​College Station, TX 77843-4474

​Ph 979-862-2861

Fax 979-862-2864

​vetmed.tamu.edu/gilab ​68-026314
For most current information refer to the Marshfield Laboratory online reference manual.