Effects of Oral Prednisone Administration on Serum Cystatin C in Dogs

Hypothalamic-pituitary-adrenal axis recovery after intermediate-acting glucocorticoid treatment in client-owned dogs

BACKGROUND

In dogs, duration of hypothalamic-pituitary-adrenal (HPA) axis suppression after systemic glucocorticoid treatment is reported to vary from a few days to up to 7 weeks after glucocorticoid discontinuation. These data are derived mainly from experimental studies in healthy dogs and not from animals with spontaneous disease.

HYPOTHESIS AND OBJECTIVE

To determine the timeline for recovery of the HPA axis in a group of ill dogs treated with intermediate-acting glucocorticoids (IAGCs).

ANIMALS

Twenty client-owned dogs that received IAGC for at least 1 week.

METHODS

Single-center prospective observational study. An ACTH stimulation test, endogenous ACTH concentration, serum biochemistry profile, and urinalysis were performed at T0 (2-6 days after IAGC discontinuation) and then every 2 weeks (eg, T1, T2, T3) until HPA axis recovery was documented (post-ACTH cortisol concentration > 6 μg/dL).

RESULTS

The median time of HPA axis recovery was 3 days (range, 2-133 days). Eleven of 20 dogs showed recovery of the HPA axis at T0, 6/20 at T1, and 1 dog each at T2, T5, and T9. Dose and duration of treatment were not correlated with timing of HPA axis recovery. Activities of ALT and ALP were significantly correlated with the post-ACTH cortisol concentration (rs = -0.34, P = .03; rs = -0.31, P = .05). Endogenous ACTH concentration was significantly correlated with pre (r = 0.72; P < .0001) and post-ACTH cortisol concentrations (r = 0.35; P = .02). The timing of HPA axis recovery of the dogs undergoing an alternate-day tapering dose was not different compared to dogs that did not (3.5 vs 3 days, P = .89).

CONCLUSION AND CLINICAL IMPORTANCE

Most dogs experienced HPA axis recovery within a few days after IAGC discontinuation. However, 2/20 dogs required >8 weeks.

Urinary cystatin C and N-acetyl-beta-D-glucosaminidase (NAG) as early biomarkers for renal disease in dogs with leishmaniosis

Canine leishmaniasis (CanL) is a disease caused by Leishmania infantum that can vary from a subclinical infection to a severe disease. Dogs affected with CanL present varying degrees of renal dysfunction. Unfortunately, traditional biomarkers such as urea and creatinine detect renal damage in advanced stages of the disease, so more accurate biomarkers are needed. Hence, we aimed to study how urinary cystatin C (CysC) and N-acetyl-beta-D-glucosaminidase (NAG), behave in dogs with CanL at different stages of the disease. Eighty-six CanL infected dogs were classified according to LeishVet stages: LI (16 dogs), LIIa (12 dogs), LIIb (12 dogs), LIII (16 dogs) and LIV (30 dogs); as a control, 17 healthy dogs were studied. Blood samples were collected for complete haematological and biochemistry analysis including plasma cystatin C. Urine analysis included urine specific gravity (USG), urine protein to creatinine ratio (UPC), CysC and NAG expressed as a ratio with creatinine uCysCc (μg/g) and uNAGc (IU/g). The haematological, biochemical and urinary analysis coincided with the LeishVet guidelines. The statistical study of the uCysCc ratio and the uNAGc, showed significant increase when compared against control starting from group LI (p < 0.05). Interestingly, when the cut-off values were calculated using the ROC curve, uCysCc (258.85 µg/g) and uNAGc (2.25 IU/g) 75 % of the dogs included in LI groups surpassed the threshold. Hence our study indicates that uCysCc and uNAGc, could help to detect early renal damage in CanL affected dogs.

Drug-Dosing Adjustment in Dogs and Cats with Chronic Kidney Disease

Chronic kidney disease is a common kidney disorder in adult and aged dogs and cats; the management of associated complications and comorbidities generally requires a life-long medical treatment to ensure a good quality of life of affected patients. However, indications and the literature on drug dosing in dogs and cats with chronic kidney disease are often lacking. The aim of this review is to revise the current literature on drug dosing in canine and feline patients with renal impairment, with a special focus on the most commonly used medications to manage chronic kidney disease and possible comorbidities.

Serum cystatin C concentration can be used to evaluate glomerular filtration rate in small dogs

Serum cystatin C levels (CysC) are used in human medicine to document progressive kidney failure. Although CysC are not thought to be useful for the diagnosis of kidney dysfunction in dogs, there has been no specific consideration of body weight as a confounding issue. The aim of this study was to assess that the utility of CysC for the diagnosis of decreased glomerular filtration rate (GFR) in smaller vs. larger dogs. In clinically healthy dogs, serum creatinine (Cre) and CysC correlate directly with body weight; we found that dogs weighing <20 kg had significantly lower CysC than those weighing ≥20 kg (0.27 ± 0.07 vs. 0.34 ± 0.05 mg/l, respectively, P<0.001). In dogs weighing <20 kg, CysC had superior diagnostic accuracy for the detection of mildly decreased plasma iohexol clearance (PCio) (<1.8 ml/min/kg) compared with Cre (sensitivity 100% vs. 80.9% and specificity 100% vs. 85.7%); this was not true for dogs weighing ≥20 kg. Additionally, using a cut-off PCio of <1.8 ml/min/kg, the area under receiver-operating characteristics curve (AUC) of CysC was significantly higher than that of Cre in dogs weighing <20 kg (P<0.05); this was not true for dogs weighing ≥20 kg (P=0.695). In conclusion, CysC is a useful marker for the detection of a mild decreasing GFR compared with Cre in dogs weighing <20 kg.

The effect of glucocorticoids on serum cystatin C in identifying acute kidney injury: a propensity-matched cohort study

BACKGROUND

Glucocorticoids may impact the accuracy of serum cystatin C (sCysC) in reflecting renal function. We aimed to assess the effect of glucocorticoids on the performance of sCysC in detecting acute kidney injury (AKI) in critically ill patients.

METHODS

A prospective observational cohort study was performed in a general intensive care unit (ICU). Using propensity score matching, we successfully matched 240 glucocorticoid users with 960 non-users among 2716 patients. Serum creatinine (SCr) and sCysC were measured for all patients at ICU admission. Patients were divided into four groups based on cumulative doses of glucocorticoids within 5 days before ICU admission (Group I: non-users; Group II: 0 mg < prednisone ≤50 mg; Group III: 50 mg < prednisone ≤150 mg; Group IV: prednisone > 150 mg). We compared the performance of sCysC for diagnosing and predicting AKI in different groups using the area under the receiver operator characteristic curve (AUC).

RESULTS

A total of 240 patients received glucocorticoid medication within 5 days before ICU admission. Before and after matching, the differences of sCysC levels between glucocorticoid users and non-users were both significant (P <  0.001). The multiple linear regression analysis revealed that glucocorticoids were independently associated with sCysC (P <  0.001). After matching, the group I had significantly lower sCysC levels than the group III and group IV (P <  0.05), but there were no significant differences in sCysC levels within different glucocorticoids recipient groups (P > 0.05). Simultaneously, we did not find significant differences in the AUC between any two groups in the matched cohort (P > 0.05).

CONCLUSIONS

Glucocorticoids did not impact the performance of sCysC in identifying AKI in critically ill patients.

Mathematical Modelling Using Predictive Biomarkers for the Outcome of Canine Leishmaniasis upon Chemotherapy

Prediction parameters of possible outcomes of canine leishmaniasis (CanL) therapy might help with therapeutic decisions and animal health care. Here, we aimed to develop a diagnostic method with predictive value by analyzing two groups of dogs with CanL, those that exhibited a decrease in parasite load upon antiparasitic treatment (group: responders) and those that maintained high parasite load despite the treatment (group: non-responders). The parameters analyzed were parasitic load determined by q-PCR, hemogram, serum biochemistry and immune system-related gene expression signature. A mathematical model was applied to the analysis of these parameters to predict how efficient their response to therapy would be. Responder dogs restored hematological and biochemical parameters to the reference values and exhibited a Th1 cell activation profile with a linear tendency to reach mild clinical alteration stages. Differently, non-responders developed a mixed Th1/Th2 response and exhibited markers of liver and kidney injury. Erythrocyte counts and serum phosphorus were identified as predictive markers of therapeutic response at an early period of assessment of CanL. The results presented in this study are highly encouraging and may represent a new paradigm for future assistance to clinicians to interfere precociously in the therapeutic approach, with a more precise definition in the patient's prognosis.