Hepatic hepcidin gene expression in dogs with a congenital portosystemic shunt

Comparison of hematologic variables between dogs with congenital intrahepatic and extrahepatic portosystemic shunts

BACKGROUND

Dogs with congenital intrahepatic portosystemic shunt (IHPSS) are predisposed to gastrointestinal inflammation, ulceration, and bleeding, unlike dogs with congenital extrahepatic portosystemic shunt (EHPSS). Limited information is available about hematologic differences between dogs with IHPSS and dogs with EHPSS.

OBJECTIVE

Compare hemogram variables between dogs with IHPSS and EHPSS. We hypothesized that hematologic variables would differ between the 2 populations, with a higher frequency and severity of anemia and microcytosis in dogs with IHPSS.

ANIMALS

Twenty-six client-owned dogs with IHPSS and 35 client-owned dogs with EHPSS.

METHODS

Retrospective cross-sectional study. Dogs were included if a CBC was performed before shunt attenuation. Contingency analysis was performed to determine if the frequency of clinical signs and of hematologic variables below the reference range differed between groups. Hematologic and selected biochemical variables were compared between groups using an analysis of covariance with age as a covariate.

RESULTS

Gastrointestinal clinical signs (IHPSS, 81% vs EHPSS, 34%; P = .01), anemia (31% vs 6%; P = .01), microcytosis (77% vs 29%; P = .002), and hypochromia (77% vs 49%; P = .03) were more common in dogs with IHPSS than in dogs with EHPSS. Dogs with IHPSS had lower packed cell volume (34% vs 41%, P = .04), hemoglobin concentration (11.5 g/dL vs 13.7 g/dL, P = .03), mean corpuscular volume (57 fL vs 65 fL; P = .001), and mean corpuscular hemoglobin concentration (32 g/dL vs 33 g/dL; P = .04) than dogs with EHPSS.

CONCLUSIONS AND CLINICAL IMPORTANCE

Dogs with IHPSS had a higher frequency of anemia, microcytosis, and hypochromia and exhibited more gastrointestinal clinical signs.

Evaluation of the Blood Neutrophil-to-Lymphocyte Ratio (NLR) as a Diagnostic and Prognostic Biomarker in Dogs with Portosystemic Shunt

The neutrophil-to-lymphocyte ratio (NLR) can help in assessing inflammatory diseases, sepsis, and chronic hepatic conditions in humans. Dogs with congenital portosystemic shunts (PSSs) have signs of generalized inflammation, and the clinical signs can overlap with other conditions, including hypoadrenocorticism (HOC). Thus, the potential diagnostic and prognostic value of leukocyte ratios as surrogate markers was assessed in a retrospective case-control study including 106 dogs diagnosed with PSSs. The disease control groups were dogs with parenchymal hepatopathy (PH; n = 22) or HOC (n = 31). In the PSS dogs, the blood NLRs were associated with the severity of systemic inflammation but not with the shunt type, hepatoencephalopathy, systemic infection, or hypoglycemia. The baseline NLRs did not differ between the three disease groups, between medically and surgically treated PSS dogs, or between those with successful PSS ligation and dogs experiencing peri-/post-surgical complications. However, dogs requiring two consecutive surgical interventions had significantly higher NLRs, and an NLR of <2.53 distinguished dogs with successful shunt ligation in one surgery from those requiring two consecutive surgeries for PSS closure. The blood NLR might be a useful clinicopathologic variable in PSS, but its value in helping differentiate PSS from HOC cases appears low. Integrating the NLR into a diagnostic algorithm may allow for a prediction of the number of surgical interventions required.

Congenital Portosystemic Shunts in Dogs and Cats: Classification, Pathophysiology, Clinical Presentation and Diagnosis

Congenital portosystemic shunts (CPSS) are abnormal vascular communications between the portal and the systemic circulation, bypassing the hepatic parenchyma and resulting in liver hypoplasia and hepatic insufficiency. Such connections develop in utero and persist postnatally. CPSS are among the two most common congenital vascular anomalies of the liver in small animals, along with primary hypoplasia of the portal vein without portal hypertension (PHPV without PH). CPSS can be extrahepatic (ECPSS), most commonly diagnosed in small and toy breed dogs and cats, or intrahepatic (ICPSS), most commonly seen in large breed dogs. Single ECPSS is the most common type encountered in both dogs and cats. Clinical signs of CPSS are non-specific and may wax and wane, while laboratory findings can raise clinical suspicion for CPSS, but they are also not specific. Definitive diagnosis will be established by evaluation of liver function tests, such as determination of fasting plasma ammonia (FA) levels, and pre- and postprandial serum bile acids concentrations, and diagnostic imaging. The purpose of this article is to review the definition, classification, pathogenesis, clinical presentation, and diagnosis of CPSS in dogs and cats, highlighted by the authors' clinical experience.

Iron status and erythropoiesis response to darbepoetin alfa in dogs with chronic kidney disease

Iron metabolism, hepcidin and some blood profiles were investigated in 13 healthy and 31 chronic kidney disease (CKD) dogs. The study consisted of 2 experiments, experiment I included healthy dogs (CONT) and CKD dogs (stage 2, 3 and 4), while experiment II consisted of anemic CKD dogs subjected to 28-day darbepoetin alfa treatment. The response to darbepoetin alfa could divide anemic CKD dogs into responder (RP) and non-responder (NRP) subgroups. The results from experiment I showed that packed cell volume (PCV) and plasma albumin concentration were significantly lower in CKD dogs of all stages while the total iron binding capacity (TIBC) was lower in only CKD stage 3 and 4 compared with dogs in CONT group. The PCV was related to both TIBC and albumin when considering among all dogs or only in CKD dogs. The hepcidin concentration in CKD dogs with anemia was lower than those without anemia (P<0.05). In experiment II before darbepoetin alfa treatment, RP subgroup had significantly higher iron and TIBC compared with NRP subgroup (P<0.05), the iron concentration was decreased only in RP subgroup after darbepoetin alfa treatment (P<0.05). The percent increase in PCV was correlated with initial TIBC (P<0.01). Plasma hepcidin concentration was not different between CONT and CKD groups and between RP and NRP subgroups both before and after darbepoetin alfa treatment. It is concluded that TIBC and plasma iron concentration play role on anemia and erythropoietic response to darbepoetin alfa treatment in CKD dogs.

Identification of The Canidae Iron Regulatory Hormone Hepcidin

Hepcidins are an evolutionarily conserved class of liver-expressed peptide, from which the twenty-five amino acid hormone, hepcidin-25 (herein hepcidin), has gained significant notoriety as the master regulator of iron homeostasis in mammals. Hepcidin maintains iron homeostasis by controlling the dietary absorption of iron and the mechanisms of recycling cellular iron stores. With the physiological significance of this hormone well established, it has emerged as an informative biomarker. In a comparison of the genome, transcriptome and peptidome of Canis lupis familiaris, we reveal the size of the hepcidin peptide in the canine, previous reports of which were contradictory to the evolutionary conservation predicted by genome annotation. Here, measurement of the peptide by mass spectrometry, following isolation from greyhound blood serum, revealed an amino acid sequence and peptide mass, differing from all accounts to date, yet demonstrating perfect sequence identity to that of the greater Canidae lineage of the Carnivora. Importantly, in the greyhound, the measured hepcidin peptide showed a similar temporal pattern to total serum iron, consistent with our understanding of hepcidin regulating iron homeostasis, in agreement with human diagnostics, and providing added translational evidence of the measured peptide being the iron regulatory hormone of the Canidae.

Haematology and coagulation profiles in cats with congenital portosystemic shunts

Objectives

The objectives of this study were, first, to report the haematological parameters and coagulation times for cats with a congenital portosystemic shunt (CPSS) and the influence of surgical shunt attenuation on these parameters; and, second, to identify any association between prolongation in coagulation profiles and incidence of perioperative haemorrhage.

Methods

This was a retrospective clinical study using client-owned cats with a CPSS. Signalment, shunt type (extra- or intrahepatic), degree of shunt attenuation (complete or partial), haematological parameters, prothrombin time (PT) and activated partial thromboplastin time (aPTT) test results, and occurrence of any perioperative clinical bleeding complications were recorded for cats undergoing surgical treatment of a CPSS at the Royal Veterinary College, UK, between 1994 and 2011.

Results

Forty-two cats were included. Thirty-six (85.7%) had an extrahepatic CPSS and six (14.3%) had an intrahepatic CPSS. Preoperatively, mean cell volume (MCV) and mean cell haemoglobin (MCH) were below the reference interval (RI) in 32 (76.2%) and 31 (73.8%) cats, respectively. Red blood cell count and mean cell haemoglobin concentration (MCHC) were above the RI in 10 (23.8%) and eight (19.1%) cats, respectively. Postoperatively, there were significant increases in haematocrit ( P = 0.044), MCV ( P = 0.008) and MCH ( P = 0.002). Despite the significant increase in MCV postoperatively, the median MCV postoperatively was below the RI, indicating persistence of microcytosis. Preoperatively, PT was above the upper RI in 14 cats (87.5%), and aPTT was above the upper RI in 11 cats (68.8%). No cat demonstrated a perioperative clinical bleeding complication.

Conclusions and relevance

Cats with a CPSS are likely to present with a microcytosis, but rarely present with anaemia, leukocytosis or thrombocytopenia. Surgical attenuation of the CPSS results in a significant increase in the HCT and MCV. Coagulation profiles in cats with a CPSS are likely to be prolonged, irrespective of shunt type, but do not appear to be associated with an increased risk of clinical bleeding.