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

ObjectivesIt 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.MethodsA total of 21 client-owned cats with a suspicion of pancreatitis were followed up over a median of 6 weeks (range 1-130). The median number of rechecks was two (range 1-9). Lipase activity (LIPC, Roche Diagnostics; reference interval [RI] 8-26 U/l) and PLI (Spec fPL; RI 0-4.4 µg/l) were measured at each examination and compared with the clinical status of cats expressed as a clinical disease activity score (CDAS).ResultsNo 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 (76 U/l, range 20-421), PLI (23 µg/l, range 1.3-50) and CDAS (5, range 1-9) were significantly higher at initial presentation compared with follow-up visits (lipase activity 33 U/l, range 9-357; PLI 7 µg/l, range 0.7-50; CDAS 2, range 0-10). In total, 17 cats had concurrent chronic enteropathy. Immunomodulatory therapy was administered during 31/50 (62%) follow-up visits compared with four (19%) cats at initial presentation. Discordant results relative to respective RIs were rare (n = 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 three cats.Conclusions and relevanceBoth 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.