Retrospective comparison of prednisolone and ursodeoxycholic acid for the treatment of feline lymphocytic cholangitis

Feline Cholangitis

Inflammatory biliary tract disease (cholangitis) is the commonest liver disease in cats but remains poorly understood. There are chronic lymphocytic and acute neutrophilic forms together with chronic neutrophilic cholangitis which may overlap both these categories. Acute suppurative cholangitis is often associated with bacterial infections and interruptions to bile flow. Lymphocytic forms may be immune-mediated but there is evidence of heterogenicity in histologic and clinical appearance and response to treatment which may suggest several distinct diseases. This review discusses current knowledge, presentation, and diagnosis of feline cholangitis and suggests avenues for future research.

Fecal bile acid dysmetabolism and reduced ursodeoxycholic acid correlate with novel microbial signatures in feline chronic kidney disease

Background

Microbial-derived secondary bile acids (SBAs) are reabsorbed and sensed via host receptors modulating cellular inflammation and fibrosis. Feline chronic kidney disease (CKD) occurs with progressive renal inflammation and fibrosis, mirroring the disease pathophysiology of human CKD patients.

Methods

Prospective cross-sectional study compared healthy cats (n = 6) with CKD (IRIS Stage 2 n = 17, Stage 3 or 4 n = 11). Single timepoint fecal samples from all cats underwent targeted bile acid metabolomics. 16S rRNA gene amplicon sequencing using DADA2 with SILVA taxonomy characterized the fecal microbiota.

Results

CKD cats had significantly reduced fecal concentrations (median 12.8 ng/mg, Mann-Whitney p = 0.0127) of the SBA ursodeoxycholic acid (UDCA) compared to healthy cats (median 39.4 ng/mg). Bile acid dysmetabolism characterized by <50% SBAs was present in 8/28 CKD and 0/6 healthy cats. Beta diversity significantly differed between cats with <50% SBAs and > 50% SBAs (PERMANOVA p < 0.0001). Twenty-six amplicon sequence variants (ASVs) with >97% nucleotide identity to Peptacetobacter hiranonis were identified. P. hiranonis combined relative abundance was significantly reduced (median 2.1%) in CKD cats with <50% SBAs compared to CKD cats with >50% SBAs (median 13.9%, adjusted p = 0.0002) and healthy cats with >50% SBAs (median 15.5%, adjusted p = 0.0112). P. hiranonis combined relative abundance was significantly positively correlated with the SBAs deoxycholic acid (Spearman r = 0.5218, adjusted p = 0.0407) and lithocholic acid (Spearman r = 0.5615, adjusted p = 0.0156). Three Oscillospirales ASVs and a Roseburia ASV were also identified as significantly correlated with fecal SBAs.

Clinical and translational importance

The gut-kidney axis mediated through microbial-derived SBAs appears relevant to the spontaneous animal CKD model of domestic cats. This includes reduced fecal concentrations of the microbial-derived SBA UDCA, known to regulate inflammation and fibrosis and be reno-protective. Microbes correlated with fecal SBAs include bai operon containing P. hiranonis, as well as members of Oscillospirales, which also harbor a functional bai operon. Ultimately, CKD cats represent a translational opportunity to study the role of SBAs in the gut-kidney axis, including the potential to identify novel microbial-directed therapeutics to mitigate CKD pathogenesis in veterinary patients and humans alike.

Diagnostic and predictive ability of hyperbilirubinemia severity in cats: A multicenter retrospective study

BACKGROUND

Total serum bilirubin concentration (TBIL) can provide useful information on several pathophysiological conditions in cats. Nevertheless, whether the variable severity classification of hyperbilirubinemia can reliably indicate certain disease processes or predict a biliary obstruction (BO) has not been investigated.

HYPOTHESIS/OBJECTIVE

Determine if hyperbilirubinemia of variable severity can assist clinicians to identify BO, which often is considered a surgical emergency.

ANIMALS

Two-hundred sixteen client-owned cats.

METHODS

Data were retrospectively collected from all cats (January 2015-August 2022) with an increased TBIL (>0.58 mg/dL [>10 μmol/L]) presented to 3 referral centers in the United Kingdom (UK). Presenting clinical features and diagnostic outcomes were collected. The predictive ability of TBIL to indicate BO was evaluated by multivariable binary logistic regression modeling and receiver operating characteristic (ROC) curves.

RESULTS

Median TBIL was 1.73 mg/dL (range, 0.59-26.15; 29.5 μmol/L; range, 10.1-447.1) with severity classification of hyperbilirubinemia categorized as mild (>0.58-2.92 mg/dL; >10-50 μmol/L; 68.1%), moderate (>2.92-5.85 mg/dL; >50-100 μmol/L; 17.6%), severe (>5.85-11.70 mg/dL; >100-200 μmol/L; 9.7%) and very severe (>11.70 mg/dL; >200 μmol/L; 4.6%). Biliary obstruction was present in 17 (7.9%) cats, all of which received recommendation for emergency surgery. Median TBIL in cats with BO (9.69 mg/dL; 165.7 μmol/L) differed significantly from those without obstruction (1.51 mg/dL; 25.8 μmol/L; P < .01). The optimal TBIL cut-off to discriminate between cats with and without BO was ≥3.86 mg/dL (≥66 μmol/L) with a sensitivity of 94.1% and specificity of 82.4%. Using multivariable logistic regression, as age increased, the odds of BO increased significantly (odds ratio, 1.20; 95% confidence interval, 1.01-1.42; P = .04).

CONCLUSIONS AND CLINICAL IMPORTANCE

As part of a thorough clinical assessment, the severity classification of hyperbilirubinemia has the potential to predict the likelihood of a BO and to discriminate between cats that may or may not require surgery for BO at a suggested cut-off of ≥3.86 mg/dL (≥66 μmol/L). Alongside TBIL, age is also useful when assessing for the likelihood of BO in a cat presented with hyperbilirubinemia.

Surgical Management Of Feline Biliary Tract Disease: Decision-making and techniques

PRACTICAL RELEVANCE

Diseases of the hepatobiliary system are not uncommon in first-opinion practice. The anatomy of the feline hepatobiliary tract differs from that of dogs and may predispose cats to inflammatory hepatobiliary disease. Case management can be challenging, and the prognosis is variable and dependent on the underlying disease process.

CLINICAL CHALLENGES

Biliary tract disease in the cat has non-specific clinical signs that overlap with those of diseases of other body systems. Diagnostic tests of the hepatobiliary system are widely available, but interpretation of results can be challenging. Deciding on medical or surgical management can also be challenging; for example, various degrees of cholestasis may be seen with different diseases and disease severities, and will influence the decision to manage the patient medically or surgically. Surgery is indicated in cases of bile peritonitis, severe cholestasis, focal neoplasia or disease that is refractory to medical management. Intensive perioperative and postoperative management, with 24 h hospitalisation facilities, is essential.

AUDIENCE

This review article is written for the small animal general/primary care practitioner, with an emphasis on decision-making in the surgical management of feline hepatobiliary disease.

EVIDENCE BASE

Evidence available in the published literature is reviewed and presented, and the inherent limitations are discussed.

Feline Cyst-like Lymphocytic Cholangiohepatitis in a Cat: First Case Report

A 5-year-old female neutered domestic short-haired cat presented with abdominal enlargement. An abdominal ultrasound revealed that large multiple hepatic cysts with irregular walls, hypoechoic fluid, and internal septations occupied most of the liver parenchyma. Serum liver enzymes, bilirubin, and bile acids concentrations were within normal limits. A fecal examination using simple floatation and formalin-ether sedimentation techniques was negative for liver fluke (Platynosomum fastosum), intestinal protozoa, and other helminth eggs. Praziquantel was prescribed for two distinct courses one month apart without obvious improvement of the hepatic cysts. An abdominal laparotomy and histopathological examination finally enabled diagnosis of cyst-like lymphocytic cholangiohepatitis of the liver tissue. Twelve weeks of oral prednisolone resulted in marked ultrasonographic improvement of the hepatic cysts. The liver parenchyma was heterogeneous and filled with multiple small anechoic cavities. Twenty-three months after ceasing the prednisolone, there was no recurrence of hepatic cysts.

Feline cholangitis/cholangiohepatitis complex - what have we learned?

Cholangitis/cholangiohepatitis complex in cats is commonly encountered in clinical practice worldwide. Diagnosis and management of cats with this complex is difficult because of the ambiguity of clinical signs, diagnostic test results and commonality of comorbid disorders. These impediments can delay disease identification and treatment, which can increase morbidity and mortality. ​In this narrative review, we aimed to provide a thorough review of the unique physioanatomic features of the biliary system as well as clinically relevant updates on cholangitis/cholangiohepatitis complex in cats.

Clinical features and outcomes in 38 dogs with cholelithiasis receiving conservative or surgical management

Background

Ursodeoxycholic acid is used in human medicine for litholytic management of choleliths, but the efficacy of medical management in dogs with cholelithiasis is unknown.

Objectives

To describe the clinical features and outcomes of dogs with cholelithiasis, focusing on cases that received medical treatment, and to identify patient factors that influenced decision‐making for surgical or medical management.

Animals

Thirty‐eight dogs with cholelithiasis identified on abdominal ultrasonography (AUS).

Methods

Medical records of dogs with cholelithiasis on AUS between 2010 and 2019 were retrospectively reviewed. Cases were classified as symptomatic (n = 18) or incidental (n = 20) and divided into medically treated (n = 13), surgically treated (n = 10), and no treatment (n = 15) groups. Biochemical variables and cholelith location were compared between symptomatic and incidental groups using Mann‐Whitney U and chi‐squared tests, respectively. Survival times were compared using Kaplan‐Meier survival analysis.

Results

Symptomatic cases had higher alkaline phosphatase (P = .03), gamma‐glutamyl transferase (P = .03), and alanine transferase (P = .02) activities than did incidental cases. A higher proportion of symptomatic cases (44.4%) had choledocholithiasis than did incidental cases (0%; P = .003). Seventy percent of surgically managed dogs, 7.7% of medically managed dogs, and 0% of nontreated dogs had choledocholiths at presentation. Seventeen dogs had follow‐up AUS: cholelithiasis completely resolved in 4/8 medically treated, 5/7 of surgically treated, and 1/2 nontreated dogs. Median survival time was 457.4 days, with no significant difference between incidental and symptomatic dogs.

Conclusions and Clinical Importance

Medical treatment can be effective for management of cholelithiasis in dogs, with clinical presentation and cholelith location playing important roles in treatment decision‐making.

Challenging diagnostic work-up of a massive fluid-filled structure in the cranial abdomen of a cat

A 9-year-old female, neutered European shorthair cat was presented with acute vomiting, obvious jaundice and painful enlargement of the abdomen. Icteric skin and mucous membranes in addition to severe bilirubinaemia (mainly direct bilirubin) and a large increase in liver enzyme activities were the main findings at the initial examination. Radio- and ultrasonographic evaluation revealed a massive fluid-filled structure caudal to the liver displacing abdominal organs, in particular the stomach. As this structure with a diameter of 8-10 cm occupied considerable space in the cranioventral abdomen, a detailed ultrasonographic examination of the liver and the gallbladder, and determination of the structure's association with a particular abdominal organ was initially impossible. Via ultrasound-assisted puncture under general anaesthesia 300 ml of an almost clear fluid could be aspirated. Cytological examination revealed a cyst content-like fluid with cell detritus.Further ultrasonographic and computed tomographic diagnostics followed by abdominal laparotomy finally enabled diagnosis of a cystic dilatation of the entire common bile duct and accumulation of white bile. Histopathological examination after euthanasia (requested by the owner) identified lymphoplasmacytic cholangitis and necrosis of the duodenal papilla. The massive dilatation of the common bile duct complicated its definite diagnosis by diagnostic imaging methods. It was most likely caused by a longer-standing obstruction of the bile flow by lymphoplasmacytic cholangitis with necrosis and granulation tissue formation in the area of the duodenal papilla. An interesting but initially misleading feature was the presence of white bile. The etiology of this extremely rare condition remains obscure but in the described case a manifestation of impaired hepatocyte function secondary to biliary stasis is suspected to be the cause.

Platynosomum fastosum in domestic cats in Cuiabá, Midwest region of Brazil

Platynosomum fastosum, which is distributed in tropical and subtropical regions, is the main parasite in the biliary system of domestic cats. Cats can be asymptomatic or show severe signs of cholangitis. Although the infection is reported throughout Brazil, only post-mortem studies are available from the Midwest region of the country. This cross-sectional study investigated the frequency of P. fastosum parasitism in domestic cats treated at the University Veterinary Hospital in Cuiabá city, Mato Grosso, Brazil, by three coproparasitological techniques (formalin-ether sedimentation, Faust, and Hoffmann), associating clinical, laboratory (haematological, biochemical) and ultrasonographic alterations. Based on the sample calculation, 171 cats were evaluated in the clinical and laboratory and a semi-structured epidemiological questionnaire was designed and used by the tutors. The prevalence observed was 26.90%, with no significant association with sex, reproductive status, age, hunting habit, access to the street, recent anthelmintic treatment, and the guardian's lack of knowledge regarding parasitism. Of the 171 cats evaluated, 55 (32.16%) showed clinical signs suggestive of cholangitis, with a significant association of this variable. Regarding the clinical and pathological variables, mild neutrophilia and elevated serum activity of alanine amino transferase and alkaline phosphatase was observed (but not significantly), while the mean values of eosinophils, leucocytes, total protein, albumin, and globulin were normal. The ultrasound findings were like those previously described. Thus, it was observed that P. fastosum occurs in moderate prevalence in cats from Cuiabá-MT, with a significant association with clinical signs and a regular agreement between the parasitological techniques employed.

Tissue-Engineered Bile Ducts for Disease Modeling and Therapy

Recent biotechnical advances in the in vitro culture of cholangiocytes and generation of bioengineered biliary tissue have a high potential for creating biliary tissue to be used for disease modeling, drug screening, and transplantation. For the past few decades, scientists have searched for a source of cholangiocytes, focused on primary cholangiocytes or cholangiocytes derived from hepatocytes or stem cells. At the same time, the development of scaffolds for biliary tissue engineering for transplantation and modeling of cholangiopathies has been explored. In this review, we provide an overview on the current understanding of cholangiocytes sources, the effect of signaling molecules, and transcription factors on cell differentiation, along with the effects of extracellular matrix molecules and scaffolds on bioengineered biliary tissues, and their application in disease modeling and drug screening. Impact statement Over the past few decades, biliary tissue engineering has acquired significant attention, but currently a number of factors hinder this field to eventually generate bioengineered bile ducts that mimic in vivo physiology and are suitable for transplantation. In this review, we present the latest advances with respect to cell source selection, influence of growth factors and scaffolds, and functional characterization, as well as applications in cholangiopathy modeling and drug screening. This review is suited for a broad spectrum of readers, including fundamental liver researchers and clinicians with interest in the current state and application of bile duct engineering and disease modeling.

Feline comorbidities: What do we really know about feline triaditis?

PRACTICAL RELEVANCE

Feline triaditis describes concurrent pancreatitis, cholangitis and inflammatory bowel disease (IBD). The reported prevalence is 17-39% in ill referral patients. While the aetiology is poorly understood, it is known to include infectious, autoimmune and physical components. What is not known is whether different organs are affected by different diseases, or the same process; indeed, triaditis may be part of a multiorgan inflammatory disease. Feline gastrointestinal tract anatomy plays its role too. Specifically, the short small intestine, high bacterial load and anatomic feature whereby the pancreatic duct joins the common bile duct before entering the duodenal papilla all increase the risk of bacterial reflux and parenchymal inflammation. Inflammation may also be a sequela of bowel bacterial translocation and systemic bacteraemia.

DIAGNOSTIC CHALLENGES

Cholangitis, pancreatitis and IBD manifest with overlapping, vague and non-specific clinical signs. Cholangitis may be accompanied by increased serum liver enzymes, total bilirubin and bile acid concentrations, and variable ultrasonographic changes. A presumptive diagnosis of pancreatitis is based on increased serum pancreatic lipase immunoreactivity or feline pancreas-specific lipase, and/or abnormal pancreatic changes on ultrasonography, though these tests have low sensitivity. Diagnosis of IBD is challenging without histopathology; ultrasound findings vary from normal to mucosal thickening or loss of layering. Triaditis may cause decreased serum folate or cobalamin (B12) concentrations due to intestinal disease and/or pancreatitis. Triaditis can only be confirmed with histopathology; hence, it remains a presumptive diagnosis in most cases.

EVIDENCE BASE

The literature on feline triaditis, pancreatitis, cholangitis and IBD is reviewed, focusing on histopathology, clinical significance and diagnostic challenges. Current management recommendations are provided. Further studies are needed to understand the complex pathophysiology, and in turn improve diagnosis and treatment.

Serum vitamin D status in sick cats with and without cholestatic liver disease

OBJECTIVES

Vitamin D deficiency accompanies chronic cholestatic liver disease (CLD) in humans. The vitamin D status of cats with CLD is unknown. The objectives of this study were to describe serum vitamin D concentrations in cats with CLD and to determine if they correlated with indices of liver disease severity.

METHODS

Thirty-six cats with CLD, defined by increases in serum bilirubin and serum alanine aminotransferase, and 23 sick cats with non-hepatobiliary diseases were prospectively enrolled. Serum 25-hydroxyvitamin D (25[OH]D), parathyroid hormone (PTH) and ionized calcium were measured. Signalment, clinical signs, comorbidities, diet history, serum bilirubin, liver enzyme activity, albumin, phosphorus, white blood cell count, prothrombin time and final hepatic cytologic/histopathologic diagnosis, when available, were recorded.

RESULTS

Median serum 25(OH)D levels were similar in cats with CLD (89.5 nmol/l; range 21-112 nmol/l) and sick cats (89.0 nmol/l; range 49-115 nmol/l). Overall 12/36 (33%) cats with CLD and 4/23 (17%) sick cats had 25(OH)D levels below the lower limit of the reference interval (<65 nmol/l). Median PTH concentrations in cats with CLD were significantly higher (0.95 pmol/l; range 0-11.3 pmol/l) than in sick cats (0.70 pmol/l; range 0.5-6 pmol/l). In cats with CLD, 6/36 (17%) had high PTH levels in contrast to only 1/23 (4%) sick cats. In cats with CLD, 25(OH)D concentrations did not correlate with serum bilirubin, albumin or serum liver enzymes but were moderately negatively correlated with white blood cell count (r = - 0.402, P = 0.013). Cats with hepatic lipidosis had the highest prevalence of 25(OH)D concentrations that fell below the reference interval.

CONCLUSIONS AND RELEVANCE

Many cats with CLD have serum 25(OH)D concentrations below the lower limit of the reference interval. Further study is warranted to determine the clinical relevance and whether supplementation would provide benefits.

Triaditis: Truth and Consequences

Clinical findings with triaditis and individual disease components overlap and may include hyporexia, weight loss, lethargy, vomiting, diarrhea, dehydration, icterus, abdominal pain, thickened bowel loops, pyrexia, dyspnea, and shock. A definitive diagnosis of triaditis requires histologic confirmation of inflammation in each organ, but this may not be possible because of financial or patient-related constraints. Evidence-based data indicate that histologic lesions of triaditis are present in 30% to 50% of cats diagnosed with pancreatitis and cholangitis/inflammatory liver disease. Treatment of triaditis is based on the overall health status of the patient and the type and severity of disease in component organs.

Feline biliary tree and gallbladder disease: Aetiology, diagnosis and treatment

Practical relevance Diseases of the biliary tree and gallbladder are more common in cats than diseases of the liver parenchyma. The parenchyma is usually affected secondarily to systemic illnesses, while the biliary system is the prime target for infectious agents (eg, bacteria and flukes) and non-infectious conditions (eg, neoplasia and cysts). Clinical approaches Cats with biliary disease are evaluated because of common feline clinical signs such as anorexia, nausea, vomiting and lethargy. Icterus may or may not be obvious. Biopsies for histological evaluation, and bile aspirates for culture and cytological evaluation are helpful diagnostically. Antibiotics and immunosuppressive drugs have been used successfully. Hepatosupportive drugs may help in liquefying thick bile and protecting hepatic tissue from damage. Ultrasound is a noninvasive diagnostic tool that may help in identifying dilated bile ducts, liver cysts and choleliths. It is also used to guide percutaneous bile aspiration. Audience This review, written for all veterinarians who treat cats, describes the various conditions that can affect the feline biliary tree and gallbladder. Treatment options are discussed, and brief summaries provided of surgical techniques and diagnostic approaches. Evidence base The veterinary literature pertaining to feline biliary disease is comprehensively reviewed. When appropriate, data on dogs and humans has been included to provide background information. Based on the available literature, more research into feline biliary diseases is needed.

Immunohistochemical evaluation of the activation of hepatic progenitor cells and their niche in feline lymphocytic cholangitis

Objectives The aim of the study was to compare the hepatic progenitor cell niche in healthy feline livers and the liver tissue of cats with lymphocytic cholangitis. Methods Immunohistochemical stainings for vimentin, laminin, beta (β)-catenin and Notch1 intracellular domain (NICD) were used on formalin-fixed liver biopsies from affected (n = 12) and unaffected cats (n = 2). Results All immunohistochemical markers used were expressed in more cells, or more intensely, in the liver tissue of cats with lymphocytic cholangitis than in the liver tissue of unaffected cats. Conclusions and relevance Enhanced expression of vimentin, laminin, cytoplasmic/nuclear β-catenin and NICD in liver biopsies from cats with lymphocytic cholangitis indicates that the hepatic progenitor cell (HPC) niche is remodelled and activated. HPCs might provide insights into new regenerative treatment options for lymphocytic cholangitis in cats in the future.

A morphological and immunohistochemical study of the effects of prednisolone or ursodeoxycholic acid on liver histology in feline lymphocytic cholangitis

Feline lymphocytic cholangitis (LC) has been commonly treated with prednisolone, and more recently with ursodeoxycholic acid (UDCA). Previously, we found that prednisolone treatment resulted in a statistically longer survival time than treatment with UDCA. In order to explain this difference, we compared the effects of prednisolone and UDCA treatment on hepatic tissue by evaluating consecutive liver biopsies. Archival serial biopsy materials from cats with LC treated with prednisolone (n = 5) or UDCA (n = 4) were evaluated. We employed haematoxylin and eosin staining to evaluate inflammation, and reticulin staining for fibrosis. Immunohistochemical stainings for Ki-67, K19 (Cytokeratin 19) and α-smooth muscle actin were used to evaluate cell type-specific proliferation and activation of hepatic stellate cells. Inflammation decreased more in the group treated with prednisolone, while the number of cholangiocytes, progenitor cells and fibroblasts did not differ between the treatment groups. Additionally, no difference was found for the amount of fibrosis in both treatment groups.