Tierarztl Prax Ausg K Kleintiere Heimtiere 2022; 50(01): 67
DOI: 10.1055/s-0041-1741163
Abstracts | DVG

Evaluation of a commercial in-house analyser for semi-quantitative assessment of urinary protein: creatinine ratio in cats

F Mortier
1   Small Animal Department, Ghent University, Ghent, Belgium
,
S Hamelink
1   Small Animal Department, Ghent University, Ghent, Belgium
,
G Schils
1   Small Animal Department, Ghent University, Ghent, Belgium
,
S Daminet
1   Small Animal Department, Ghent University, Ghent, Belgium
,
L Duchateau
2   Department of Nutrition, Genetics and Ethology, Ghent University, Ghent, Belgium
,
D Paepe
1   Small Animal Department, Ghent University, Ghent, Belgium
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    Introduction Proteinuria is an important prognostic factor and therapeutic target in cats with chronic kidney disease. Reliable in-house assessment of proteinuria substages would provide an easy, cheaper and faster determination method than UPC measurement by an external laboratory. This prospective study aimed to assess the agreement between proteinuria substage results (NP = non-proteinuric, UPC <0.2; BP = borderline proteinuric, UPC 0.2-0.4; P = proteinuric, UPC >0.4) from a commercial in-house colorimetric automated analyser and those from a commercial external lab. Furthermore, results for microalbuminuria of the in-house analyser (negative, albumin <2.5 mg/dL; positive, albumin ≥2.5 mg/dL) were compared with proteinuria substage results of the in-house analyser and external lab.

    Material and Methods Urine of 53 client-owned cats (26 healthy, 27 diseased) was collected by cystocentesis or via a subcutaneous ureteral bypass device. Both UPC and MA were assessed semi-quantitatively with the in-house analyser within 30 minutes. The remaining urine was sent to the external lab.

    Results In the external lab, mean ± SD UPC was 0.30±0.32. 24 cats were classified as NP, 19 as BP, 10 as P. Semi-quantitative results from the in-house analyser indicated 32 cats were NP, 15 BP and 6 P. The same substage was assigned by both methods in 25/53 cats and fair agreement was found (weighted kappa coefficient 0.21 (95% CI 0.00–0.43)). In-house analysis showed negative MA result for 20 cats that were all classified as NP by the same analyser, but 9 of these cats were BP and 2 were P according to the external lab. The 33 cats with positive MA result were distributed over all 3 proteinuria substages by the in-house analyser (12 NP, 15 BP, 6 P) and the external lab (15 NP, 10 BP, 8 P).

    Conclusion This study demonstrated discrepancies between IRIS proteinuria substage results from an in-house analyser and those from an external laboratory in 53% of cats. No gold standard exists for UPC determination in cats, but the differences observed here must be taken into account in clinical decision-making.


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    Publication History

    Article published online:
    08 March 2022

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