Fecal acute phase proteins in cats with chronic enteropathies

BACKGROUND

Chronic enteropathies (CE) are common in cats and reliable biomarkers that can distinguish different causes and predict or monitor response to treatment are currently lacking.

HYPOTHESIS

To evaluate certain acute phase proteins in feces that could potentially be used as biomarkers in cats with CE.

ANIMALS

Twenty-eight cats with either inflammatory bowel disease (IBD; n = 13), food-responsive enteropathy (FRE; n = 3) or small cell gastrointestinal lymphoma (SCGL; n = 12) and 29 healthy control cats were prospectively enrolled.

METHODS

Fecal concentrations of haptoglobin, alpha-1-acid-glycoprotein (AGP), pancreatitis-associated protein-1 (PAP-1), ceruloplasmin, and C-reactive protein (CRP) were measured using Spatial Proximity Analyte Reagent Capture Luminescence (SPARCL) immunoassays before and after initiation of treatment. Cats were treated with diet and/or prednisolone (IBD cats), plus chlorambucil (SCGL cats).

RESULTS

Compared with controls, median fecal AGP concentrations were significantly lower (25.1 vs 1.8 μg/g; P = .003) and median fecal haptoglobin (0.17 vs 0.5 μg/g), PAP-1 (0.04 vs 0.4 μg/g) and ceruloplasmin (0.15 vs 4.2 μg/g) concentrations were significantly higher (P < .001) in cats with CE. Median fecal AGP concentrations were significantly lower (P = .01) in cats with IBD and FRE (0.6 μg/g) compared with cats with SCGL (10.75 μg/g). A significant reduction was found in CE cats after treatment for median fecal ceruloplasmin concentrations (6.36 vs 1.16 μg/g; P = .04).

CONCLUSIONS

Fecal AGP concentration shows promise to differentiate cats with SCGL from cats with IBD and FRE. Fecal ceruloplasmin concentrations may be useful to objectively monitor response to treatment in cats with CE.

Acute phase proteins in cats: Diagnostic and prognostic role, future directions, and analytical challenges

While clinical studies on acute phase proteins (APPs) have significantly increased in the last decade, and most commercial labs are now offering major APPs in their biochemical profiles, APP testing has not been widely adopted by veterinary clinical pathologists and veterinarians. Measurement of APP concentration is a useful marker for detecting the presence or absence of inflammation in cats with various diseases. APPs can also be reliably measured in different biological fluids (eg, effusions and urine) to improve their diagnostic utility. Measurement of APPs can be extremely beneficial in cats with feline infectious peritonitis (FIP) to discriminate between FIP and non-FIP cats with similar clinical presentations. Additional benefits come from multiple and sequential measurements of APPs, particularly in the assessment of therapeutic efficacy. APPs are more sensitive than WBC counts for early detection of inflammation and to demonstrate an early remission or recurrence of the diseases. Given the potential utility of APPs, more studies are warranted, with a particular focus on the applications of APPs to guide the length of antimicrobial therapies, as suggested by the antimicrobial stewardship policy. New inflammatory markers have been discovered in human medicine, with a higher specificity for distinguishing between septic versus nonseptic inflammatory diseases. It is desirable that these new markers be investigated in veterinary medicine, to further test the power of APPs in diagnostic setting.

Impact of radioiodine treatment on acute phase proteins in hyperthyroid cats

OBJECTIVES

The aim of this study was to investigate the impact of radioiodine treatment (RIT) on the acute phase proteins (APPs) serum amyloid A (SAA), alpha-1-acid glycoprotein (AGP) and haptoglobin (Hp) in hyperthyroid cats.

METHODS

Between June 2013 and November 2014, 33 hyperthyroid cats without clinical or laboratory signs of inflammatory or neoplastic disease and a body weight >2.5 kg were enrolled. Immediately before, and 12, 36, 72 h and 6 days after RIT, serum samples were obtained for determination of APP concentrations.

RESULTS

Both SAA and AGP concentrations changed significantly after RIT. The concentration of AGP increased gradually after treatment with a maximum concentration at the end of the study period (median baseline 398 μg/ml; median 6 days post-RIT 562 μg/ml [P = 0.001]). A relevant >two-fold increase in AGP was seen in 8/33 (24%) cats. SAA concentration increased significantly within 12 h (baseline 9.2 μg/ml; 12 h post-RIT 22.5 μg/ml [P = 0.012]). In 7/33 (21%) cats, a clinically relevant >10-fold increase in SAA was observed. Hp concentration showed no significant change (P = 0.12).

CONCLUSIONS AND RELEVANCE

RIT induced a mild, mainly not clinically relevant acute phase reaction (APR). AGP and SAA were useful APPs to determine RIT-induced APR.