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

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.

Treatment for cholangiohepatitis in cats

Acute bacterial cholangiohepatitis of cats is a common disease associated with the inflammation of bile ducts and liver parenchyma, characterized by development of a pronounced hepatodepressive syndrome (hypoalbuminemia), cytolysis (increase in serum activity of alanine and asparagine transaminase), cholestasis (increase in serum concentration of bilirubin, cholesterol, activity of alkaline phosphatase and gamma-glutamyltranspeptidase), intoxication, dehydration, mesenchymal-inflammatory and pain syndromes. The aim of the research was to study the effectiveness of treatment for acute bacterial cholangiohepatitis in cats with average severity of the pathology course. According to inclusion and exclusion criteria, the study included a cohort of cats (n = 12) with acute bacterial cholangiohepatitis. Clinical, hematological, ultrasonographic, statistical methods of investigation were used in this work. For sick cats with medium severity form of cholangiohepatitis, when administered as a complex therapy the combination of marbofloxacin, metronidazole, ursodeoxycholic acid, cyancobolamine, tocopherol acetate, infusion therapy also had a good therapeutic effect, which was accompanied by improved clinical and laboratory performance. In the blood of cats with cholangiohepatitis, in the background of intensive therapy, there was a significant decrease in white blood cell count, erythrocyte sedimentation rate, and in serum, there was an increase in albumin concentration, reduction of creatinine, aminotransferase activity, alkaline phosphatase, gamma-glutamyltranspeptidase, lipase.

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.

Immunohistochemical evaluation of hepatic progenitor cells in different types of feline liver diseases

Hepatic progenitor cells are periportally resident cells capable of differentiating into mature hepatocytes or cholangiocytes to ensure hepatic regeneration. This reaction is termed a ductular reaction. In the present study, regenerative response of the feline liver to different hepatic diseases was investigated immunohistochemically. Regeneration of the liver through hepatocellular replication and proliferation of progenitor cell compartment were comparatively evaluated. Histological and immunohistochemical stainings were conducted on feline liver samples (n=40) representing various hepatobiliary diseases. Cytokeratin (CK) 7, CK19, Proliferating cell nuclear antigen (PCNA), Ki67, and Human hepatocyte marker 1 (Hep Par-1) were used. The presence of progenitor cells within feline livers was proved, both as passive cells in normal liver and as active cells (ductular reaction) in hepatic lesions. CK7 was found to be a suitable antibody for immunohistochemically detecting feline progenitor cells. In acute events, regeneration was predominantly shaped by the division of hepatocytes. In chronic events and severe acute events, hepatocytes lost their ability to divide and regeneration mainly occurred through progenitor cells. Location of the ductular reaction varied between different hepatic diseases. Parenchymal ductular reaction was detected in fulminant hepatitis, chronic hepatitis, hepatocellular lipidosis and metastatic lymphoma, whereas septal ductular reaction was detected in chronic hepatitis and metastatic lymphoma. Ductular reaction exhibited positive staining for Hep Par-1 in chronic and severe acute events. This study indicates the major role played by hepatic progenitor cells in regeneration of the feline liver. Moreover, it shows how the activation pattern of ductular reaction varies according to the hepatobiliary disease type.

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.

A histopathological study on adrenal cysts in ferrets

Adrenal disorders are common in ferrets, but there are few studies on cystic lesions of the adrenal gland. The present study describes pathological and immunohistochemical features of adrenal cysts in eleven ferrets and discusses their histogenesis. In nine of eleven cases examined, which included seven, one, and one right, left, and bilateral cases, respectively, cysts were in the adrenal cortex and lined with epithelial cells. These epithelial cells contained an Alcian blue-negative/PAS-positive material and were positive for cytokeratin (CK) 7. The staining pattern was similar to that of biliary epithelial cells in the ferret. In five of the cases, there were small ducts adjacent to the cysts that were positive for CK7 and CK20 and negative for CK19. Based on the anatomical proximity between the right adrenal and liver, the immunohistochemical features of the small duct cells were comparable to those of hepatic oval cells. These results indicate the possibility that these adrenocortical cysts in the ferret originated from the biliary system. In the other two cases, the cysts lacked an epithelial cell lining, and there were dilated lymphoid vessels around the cysts. These cysts were assumed to have developed in the adrenal medulla, because the cyst wall was positive for glial fibrillary acidic protein and there were adrenal medullary cells positive for synaptophysin in the cyst wall. Therefore, the medullary cysts may have been associated with dilated vasculatures.

Reference limits for hepatic bile duct-to-arteriole and bile duct-to-portal tract ratios in healthy cats

OBJECTIVE To establish reference limits for hepatic bile duct-to-arteriole ratio (BD:A) and bile duct-to-portal tract ratio (BD:PT) in healthy cats and assess whether these parameters could be used to support a diagnosis of biliary ductopenia in cats. SAMPLE Hepatic biopsy samples from healthy cats (n = 20) and cats with ductopenia (2). PROCEDURES Hepatic biopsy samples from healthy cats were used to count the number of bile ducts and hepatic arterioles in 20 portal tracts for each cat. Mean BD:A and mean BD:PT for each cat were calculated, and these values were used to determine reference limits for mean BD:A and mean BD:PT. Results of histologic evaluation, including immunohistochemical staining in some instances, were compared for healthy cats versus cats with ductopenia. RESULTS Of the 400 portal tracts from healthy cats, 382 (95.5%) and 396 (99.0%) had BD:A and BD:PT, respectively, ≥ 1.0, with less variability in BD:A. Mean BD:A and BD:PT were markedly lower in both cats with ductopenia, compared with values for healthy cats. However, only mean BD:A for cats with ductopenia was below the reference limit of 0.59. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that systematic evaluation of BD:A, with a lower reference limit of 0.59 to define biliary ductopenia in cats, may be a discrete and easily applied morphometric tool to enhance detection of ductopenia in cats. However, application of this ratio required evaluation of ≥ 20 portal tracts with cross-sectioned portal elements to determine a mean BD:A value.

Immunohistochemical characterisation of the hepatic stem cell niche in feline hepatic lipidosis: a preliminary morphological study

OBJECTIVES

The aim of this study was to describe the cellular and stromal components of the hepatic progenitor cell niche in feline hepatic lipidosis (FHL).

METHODS

Immunohistochemical staining for the progenitor/bile duct marker (K19), activated Kupffer cells (MAC387), myofibroblasts (alpha-smooth muscle actin [α-SMA]) and the extracellular matrix component laminin were used on seven liver biopsies of cats with FHL and three healthy cats. Double immunofluorescence stainings were performed to investigate co-localisation of different cell types in the hepatic progenitor cell (HPC) niche.

RESULTS

HPCs, Kupffer cells, myofibroblasts and laminin deposition were observed in the liver samples of FHL, although with variability in the expression and positivity of the different immunostainings between different samples. When compared with the unaffected cats where K19 positivity and minimal α-SMA and laminin positivity were seen mainly in the portal area, in the majority of FHL samples K19 and α-SMA-positive cells and laminin positivity were seen also in the periportal and parenchymatous area. MAC387-positive cells were present throughout the parenchyma.

CONCLUSIONS AND RELEVANCE

This is a preliminary morphological study to describe the activation and co-localisation of components of the HPC niche in FHL. Although the HPC niche in FHL resembles that described in hepatopathies in dogs and in feline lymphocytic cholangitis, the expression of K19, α-SMA, MAC387 and lamin is more variable in FHL, and a common pattern of activation could not be established. Nevertheless, when HPCs were activated, a spatial association between HPCs and their niche could be demonstrated.

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.

Dose dependent treatment with isotretinoin induces more changes in the ileum than in the duodenum and jejunum in Wistar rats

Acne is the most common skin disorder and can directly affect the patients' self-esteem. Systemic treatment has been indicated for nodular, cystic or persistent acne rather than another type of treatment, such as a topic one. Isotretinoin is an analogue of vitamin A and by suppressing the sebaceous glands the disease can be controlled. This study was designed to mimic the treatment performed in young patients using the dosage of 1mg/kg, and a higher one of 10mg/kg, for 60days in young male Wistar rats. 24 Wistar rats were divided into four groups: control(water), D0(soybean oil, control group), D1(1mg/kg of Isotretinoin solution), D10(10mg/kg of Isotretinoin solution). Using the morphometry tool and histochemical techniques we evaluated the villus, intestinal crypts, and goblet cells to find signs of possible alterations of the duodenum, jejunum and ileum segments of the small intestine. We found no signs of changes in the jejunum mucosa after 60 days of treatment with 1mg/kg and 10mg/kg. The duodenum is also less affected, whereas significant modifications were found in the ileum. The goblet cell frequency was altered, indicating a proliferative potential for the substance. Although some patients have described intestinal symptoms, no important alterations were found with this protocol, reaffirming the security involved in the treatment with this substance.