Evaluation of the diagnostic value of plasma copper levels in cattle.
Copper (Cu) is an essential trace element. Depletion of liver-Cu stores leads to clinical or sub-clinical Cu deficiency. Our objective was to evaluate plasma-Cu levels as a diagnostic test for the assessment of Cu status in cattle. We used liver-Cu levels as the gold standard. The chosen cutoff for plasma Cu was 9 mmol/l; two different cutoffs were chosen for liver-Cu: 20 and 10 microg/g dry matter (DM). When 20 microg/g DM of liver Cu was the cutoff, plasma Cu had sensitivity=69% (58, 79) and specificity=84% (74, 93). The same values if the cutoff in liver was 10 microg/g were 92 (82, 100) and 73% (64, 82), respectively. ROC curves showed that the best cutoff to be used for plasma Cu was 8.26 mmol/l; however, no significant improvement was found in sensitivity or specificity. We concluded that interpretation of plasma-Cu levels significantly varies with the liver-Cu cutoff.
Minatel
L
L
Area de Patología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Capital Federal, Argentina. patolbas@fvet.uba.ar
Carfagnini
J C
JC
D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000175:diagnosis*; D003300:Copper / Q000097:blood / Q000172:deficiency*; D003955:Diagnostic Tests, Routine / Q000592:standards / Q000662:veterinary; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity
D003300:Copper