Definition
- � �-Trace protein is also known as BTP or lipocalin-type prostaglandin D synthase. This test is currently not widely available in commercial laboratories. Research use only test. BTP, a low molecular weight glycoprotein freely filtered through the glomerular basement membrane and with minimal nonrenal elimination, is an ideal marker for GFR. BTP has been shown to be a more sensitive marker of GFR than creatinine in patients with chronic kidney disease, in kidney transplant recipients, and in children.
- Normal range: 0.40 " �0.74 mg/L.
Use
- Alternative marker for GFR in children as well as in DM and various renal diseases.
- The early diagnosis of fistulas leaking CSF is an accurate marker of CSF leakage (CSF rhinorrhea).
Limitations
- Patients with renal insufficiency and bacterial meningitis have increase serum and decreased CSF levels.
- There are no clear cut and accurate cutoff values available, which is a major determinant of diagnostic significance.
Suggested Reading
1P � �ge � �U, Gerhardt � �TM, Stoffel-Wagner � �B � �-Trace protein is an alternative marker for GFR in renal transplantation patients. Clin Chem. 2005;51:1531.