How much does haematuria affect UPCR?

RE: How much does haematuria affect UPCR?

Mellora Sharman — Wed, 06 Sep 2023 09:11:42 GMT

Good question Rob,

Factors that I might consider would be

- Is there any hint of pyuria - ie is the WBCC 0 / hpf, or borderline or high suggesting more of an active sediment - ie 4-5 / hpf or more.

- If culture is positive what is the bacteria - is it a more pathogenic type bacteria such as an E.coli, or something that might be more benign - ie an Enterococcus spp might be less significant.

Interestingly in this study - https://journals.sagepub.com/doi/epdf/10.1177/1098612X12469522?src=getftr - although subclinical UTI was relatively common in cats with CKD (and 87% of the positive cultures were associated with active sediment), The presence of an occult UTI, when treated, did not influence survival, and survival was linked mainly to creatinine concentration, regardless of infection or treatment.

That's not to say that these cases shouldn't be treated however, and I'm inclined to treat where active sediment is documented.

I hope that answers the question!

Mellora

RE: How much does haematuria affect UPCR?

Roger Powell — Wed, 06 Sep 2023 08:55:43 GMT

Interpreting these in the lab over the years was/is also consistent with those papers (given you don't have other canine urogenital factors especially).

The cysto technique could then inadvertently account for the (microscopic?) RBC presence, a voided sample confirming no significant/persistent haematuria for investigations or monitoring?

Culture wise, many seem to advocate antibacterial therapy even if culture negative given the potential increased risk. Whilst I personally wouldn't necessarily advocate this, it raises several questions in terms of why 'waste time or money' on the culture but is hard/impossible to reliably tease apart from the too limited studies on any apparent NPV/PPV when the method to call pyuria is unclear and extrapolating from human to vet/cat is a little more fraught with voided vs cysto sampling and boric acid preserved etc etc

Personally the UPC and pattern fits well with CKD and IRIS assessment, without waffling anymore on analytical factors for the UPCs etc

Hope it goes well and the neuro is not something else etc - good luck!

RE: How much does haematuria affect UPCR?

Rob Loxley — Wed, 06 Sep 2023 07:15:30 GMT

[quote userid="15006" url="~/f/clinical-questions/30759/how-much-does-haematuria-affect-upcr/242310#242310"]However, even where sediment is fairly unremarkable in a cat with documented CKD, and a USG of 1.018 - I'd still perform urine culture to ensure pyelonephritis is not present and a contributing factor.[/quote]

Hi, how do you pull apart pyelonephritis and subclinical bateriuria in such cases, or would you always treat a positive culture in a CKD cat?

RE: How much does haematuria affect UPCR?

Mellora Sharman — Tue, 05 Sep 2023 10:06:25 GMT

Hi Yantha,

Haematuria is documented to affect UPC. However...

This paper - https://pubmed.ncbi.nlm.nih.gov/30517829/ - showed that although haematuria affects UPC at all contamination levels, microscopic haematuria does not drive UPC > 0.5, at least in the samples in this study. Overall they concluded that unless haematuria is grossly visible, microscopic haematuria is unlikely to affect UPC. This study shows similar findings - 10.1111/j.1939-165x.2004.tb00343.x.

Pyuria might be expected to have more of an affect on UPC.

Overall for your case, if the urine was grossly yellow, and sediment inactive - I'd be inclined to consider the UPC as real.

However, even where sediment is fairly unremarkable in a cat with documented CKD, and a USG of 1.018 - I'd still perform urine culture to ensure pyelonephritis is not present and a contributing factor.

I hope this helps!

Best Wishes,
Mellora

RE: Haematuria effect on UPCR

Kate Richardson — Mon, 04 Sep 2023 08:36:10 GMT

Possibly. I would see if you can get owners to collect a voided sample at home and recheck it.