TLI |
B9 |
B12 |
Interpretation |
|---|---|---|---|
| N | N | N | TLI usually rules out EPI. No symptoms of malabsorption or dysbiosis were observed. Normal folate and vitamin B12 concentrations also do not allow for a definitive exclusion of intestinal disease. |
| ↓ | N or ↓ | N or ↓ | EPI and/or SIBO. |
| ↑ | N or ↓ | N or ↓ | Intestinal disease or pancreatitis (further evaluation required). |
| N | ↓ | ↓ | Proximal or distal small-intestinal disease and/or SIBO. |
| N | ↓ | N | Disease of the proximal small intestine (duodenum, jejunum). |
| N | N | ↓ | Distal small-intestinal disease and/or SIBO. |
| N | ↑ | ↓ | SIBO (and possibly distal small-intestinal disease). |
| N | ↑ | N | SIBO, vitamin B6 supplementation, or hemolysis in the sample. |
| N | ↑ | ↑ | Vitamin B6 and B12 supplementation |
| N | N | ↑ | Vitamin B12 supplementation, liver disease, cancer. |
LEGEND
N – normal, ↓ – decreased, ↑ – increased
EPI – exocrine pancreatic insufficiency
SIBO – small intestinal bacterial overgrowth
Sample: 2 ml serum (IMPORTANT: the patient should be fasted for 12 hours prior to blood collection)
Further details
TLI (trypsin-like immunoreactivity)
Amylase, lipase and trypsinogen are produced by pancreatic cells and secreted into the blood in small amounts in healthy dogs and cats. Trypsin-like factors (trypsinogen, trypsin) are produced exclusively in the pancreas (unlike amylase and lipase), which is why TLI is considered a specific marker for pancreatic function.
The most common cause of chronic exocrine pancreatic insufficiency (EPI) is progressive pancreatic atrophy, which leads to a decrease in blood TLI concentration. This is associated with a reduced ability of the pancreas to produce trypsinogen, resulting in digestive disorders. Once clinical symptoms appear, TLI values are usually clearly below the reference range for healthy dogs.
Markedly elevated TLI values, especially in cats, may indicate pancreatitis; however, this parameter is not specific enough to confirm the disease. To confirm suspected pancreatitis, lipase measurements (using the DGGR method) or pancreatic-specific lipase (cPL), as well as imaging diagnostics, are used.
Folate (vitamin B9) and cobalamin (vitamin B12)
Measuring folate and vitamin B12 concentrations in serum is a simple test that can provide valuable information in patients with gastrointestinal diseases. Both vitamins are absorbed in different sections of the small intestine, so detecting an abnormal level of either substance can allow precise localization of the affected intestinal segment.
When interpreting the measurement results of these vitamins, it is important to rule out exocrine pancreatic insufficiency, as it can cause both impaired cobalamin absorption and excessive bacterial growth in the intestine. Therefore, it is recommended to measure TLI at the same time.
Diseases of the proximal small intestine can lead to decreased folate concentrations, while pathological processes in the ileum may be responsible for a reduction in cobalamin levels. If the disease affects the entire small intestine, both folate and cobalamin levels may decrease.
Excessive bacterial overgrowth (SIBO) in dogs can lead to increased folate levels, which may be accompanied by decreased or unchanged cobalamin levels.
