EXPRESS: Longitudinal comparison of serum pancreatic lipase activity and pancreatic lipase immunoreactivity with clinical signs in cats with suspicion of pancreatitis.

Abstract

Objectives It remains unclear whether pancreatic lipase immunoreactivity (PLI) and lipase activity similarly reflect clinical status and disease severity in cats with suspected pancreatitis. This retrospective cohort study aimed to directly compare their association with clinical disease severity over time Methods Twenty-one client-owned cats with suspicion of pancreatitis were followed up over a median of 6 weeks (range, 1-130). The median number of re-checks was 2 (range, 1-9). Lipase activity (LIPC Roche; RI, 8-26 U/L) and PLI (Spec fPL; RI, 0-4.4 µg/L ) were measured at each examination and compared to clinical status of cats expressed as a clinical disease activity score (CDAS). Results No significant correlation between CDAS and either lipase assay was detected at the initial evaluation. During 50 follow-up visits, both lipase assays showed moderate correlations of similar magnitude with CDAS (lipase activity, rₛ = 0.486, P = 0.0003; PLI, rₛ = 0.432, P = 0.0017). Median lipase activity (46 U/L, range 20-421) and PLI (23 µg/L, range, 1.3-50), as well as CDAS (5, range 1-9) at initial presentation were significantly higher compared to follow-up visits (lipase activity 33 U/L, range 9-357; PLI 7 µg/L, range 0.7-50; CDAS 2, range 0-10). Seventeen cats had concurrent chronic enteropathy. Immunomodulatory therapy was administered during 31/50 (62%) follow-up visits compared to 4 (19%) cats at initial presentation. Discordant results relative to RIs were rare (3/72 visits, 4%), with normal lipase activity and mildly increased PLI; CDAS was 0 (n=2) or 1 (n=1) because of minimal weight loss in these 3 cats. Conclusions and relevance Both lipase assays provide clinically equivalent information, however a moderate correlation with clinical status was only seen during follow-up visits. The lack of correlation with clinical status in sicker cats may reflect the limited spectrum of clinical signs in feline pancreatitis.