The diagnostic performance of point-of-care tests for serum amyloid A and C-reactive protein in lame sows

TL;DR

This study evaluated two portable tests for measuring inflammation markers in lame pregnant pigs but found them unreliable compared to a standard lab test.

Contribution

The study provides new evidence on the diagnostic reliability of point-of-care tests for acute phase proteins in lame sows.

Findings

The CRP point-of-care test showed poor agreement with ELISA and significant underestimation.

The SAA point-of-care test agreed with ELISA in only two out of 49 samples and overestimated levels.

Both tests are currently unreliable for determining acute phase protein levels in blood samples from lame sows.

Abstract

For acute phase proteins to be implemented in routine diagnostics for pig herds, a fast, reliable, and portable point-of-care test is required. Therefore, this study aimed to evaluate the diagnostic performance of two point-of-care tests on lame gestating sows. The two tests were the Cobas b101 CRP test for C-reactive protein and OmniChekTM-SAA for serum amyloid A. The reference test was an enzyme-linked immunosorbent assay (ELISA).

The C-reactive protein point-of-care test had a concordance with the ELISA results of 0.12 (95% confidence limits: 0.12–0.23) and a mean difference of − 30.98 µg/mL (Limits of agreement: 27.45 and − 89.40 µg/mL), with a clear proportional bias. The serum amyloid A point-of-care test was only in agreement with the ELISA results in two out of 49 samples. The serum amyloid A test overestimated the serum amyloid A levels, whereas the C-reactive protein point-of-care test underestimated the C-reactive protein levels.

Currently, the two point-of-care tests cannot be reliably used to determine acute phase protein levels in blood samples from lame gestating sows.

The online version contains supplementary material available at 10.1186/s13028-026-00857-6.

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