Case summary
A 2-year-old spayed female domestic longhair cat was presented for evaluation of chronic ocular discharge and occasional vomiting. While physical examination findings were consistent ...with an upper respiratory infection (URI), serum chemistry results revealed increased liver enzyme activities. Histopathologic examination of a liver biopsy identified substantial centrilobular accumulation of copper in hepatocytes – strongly suggestive of primary copper hepatopathy (PCH). Retrospective cytologic examination of a liver aspirate also identified copper aggregates in hepatocytes. After transitioning to a low-copper diet, 1 year of chelation therapy with D-penicillamine achieved normalization of liver enzyme activities and resolution of persistent ocular signs. Subsequently, a long-term regimen of zinc gluconate has been successfully managing the cat’s PCH for almost 3 years. Sanger sequencing of the cat’s ATP7B gene, which encodes a copper-transporting protein, revealed a novel, ‘likely pathogenic’, single nucleotide variation (c.3670t/a p.Trp1224Arg), for which the cat is heterozygous.
Relevance and novel information
Recommendations are described for the long-term clinical management of feline PCH – a previously attainable but unreported outcome – with considerations for mitigating the speculated oxidation-exacerbated ocular risks of concurrent URI. This report is the first to include identification of copper aggregates in a liver aspirate from a cat – evidence that liver aspirates from cats could be routinely examined for copper as is standard practice for those from dogs. The cat is also the first reported with PCH and a ‘likely pathogenic’ heterozygous ATP7B genotype, which suggests that normal ATP7B alleles could be recessive to or incompletely/co- dominant with deleterious ATP7B alleles in cats, as has been reported in other species.
Tissue factor (TF)-expressing tumor-derived extracellular vesicles (EVs) can promote metastasis and pre-metastatic niche formation, but the mechanisms by which this occurs remain largely unknown. We ...hypothesized that generation of activated factor X (FXa) by TF expressed on tumor-derived EV could activate protease-activated receptors (PARs) on non-activated endothelial cells to induce a pro-adhesive and pro-inflammatory phenotype. We obtained EV from TF-expressing breast (MDA-MB-231) and pancreatic (BxPC3 and Capan-1) tumor cell lines. We measured expression of E-selectin and secretion of interleukin-8 (IL-8) in human umbilical vein endothelial cells after exposure to EV and various immunologic and chemical inhibitors of TF, FXa, PAR-1, and PAR-2. After 6 h of exposure to tumor-derived EV (pretreated with factor VIIa and FX)
, endothelial cells upregulated E-selectin expression and secreted IL-8. These changes were decreased with an anti-TF antibody, FXa inhibitors (FPRCK and EGRCK), and PAR-1 antagonist (E5555), demonstrating that FXa generated by TF-expressing tumor-derived EV was signaling through endothelial PAR-1. Due to weak constitutive PAR-2 expression, these endothelial responses were not induced by a PAR-2 agonist peptide (SLIGKV) and were not inhibited by a PAR-2 antagonist (FSLLRY) after exposure to tumor-derived EV. In conclusion, we found that TF-expressing cancer-derived EVs activate quiescent endothelial cells, upregulating E-selectin and inducing IL-8 secretion through generation of FXa and cleavage of PAR-1. Conversion of resting endothelial cells to an activated phenotype by TF-expressing cancer-derived EV could promote cancer metastases.
Background
Prognostic indicators for equine multinodular pulmonary fibrosis (EMPF), an interstitial fibrosing lung disease, are poorly described.
Hypothesis/Objectives
Describe diagnostic findings ...and outcome predictors for EMPF.
Animals
Forty‐six adult horses with EMPF.
Methods
Retrospective multicenter case series from 2009 to 2019. Radiographic (n = 27) and ultrasonographic studies (n = 19) from EMPF horses and bronchoalveolar lavage fluid (BALF) cytology from 6 EMPF and 13 asthma cases were independently reviewed and blinded to diagnosis and outcome. Associations between predictor variables and survival were assessed by predictor screening followed by Fisher's exact and Wilcoxon rank sum tests.
Results
Primary clinical findings were weight loss (36/46, 78%), increased respiratory effort (33/46, 72%), tachypnea (32/46, 70%), and fever (18/46, 39%). Macrophage atypia was seen in more EMPF than asthmatic horse BALF (67% vs. 8%; P = .02). Equine herpesvirus 5 (EHV‐5) was detected in 24 of 30 (80%) and hyperfibrinogenemia in 25 of 28 (89%) cases. Twenty‐seven of 46 horses (59%) and 11 of 45 (24%) survived to discharge and to 3 months, respectively. Three‐month survival was associated with lower median (range) respiratory rates (30 24‐36 vs. 41 30‐60 breaths per minute; P = .04), and higher BALF lymphocyte:neutrophil ratios (4.7 1.4‐22 vs. 0.47 0.11‐1.9; P = .01) and blood lymphocyte counts (1.25 0.93‐2.55 vs. 0.90 0.70‐1.24 × 109/L; P = .03). Imaging findings, EHV‐5 detection, and corticosteroid treatment were not associated with survival.
Conclusions and Clinical Importance
Fever is not a sensitive clinical sign of EMPF. Diagnostic testing should be pursued for horses with increased respiratory rate and effort and weight loss. The prognosis for EMPF horses is poor. Corticosteroid treatment does not improve 3‐month survival.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Equid herpesvirus type 1 (EHV-1) causes outbreaks of abortion and neurological disease in horses. One of the main causes of these clinical syndromes is thrombosis in placental and spinal cord ...vessels, however the mechanism for thrombus formation is unknown. Platelets form part of the thrombus and amplify and propagate thrombin generation. Here, we tested the hypothesis that EHV-1 activates platelets. We found that two EHV-1 strains, RacL11 and Ab4 at 0.5 or higher plaque forming unit/cell, activate platelets within 10 minutes, causing α-granule secretion (surface P-selectin expression) and platelet microvesiculation (increased small events double positive for CD41 and Annexin V). Microvesiculation was more pronounced with the RacL11 strain. Virus-induced P-selectin expression required plasma and 1.0 mM exogenous calcium. P-selectin expression was abolished and microvesiculation was significantly reduced in factor VII- or X-deficient human plasma. Both P-selectin expression and microvesiculation were re-established in factor VII-deficient human plasma with added purified human factor VIIa (1 nM). A glycoprotein C-deficient mutant of the Ab4 strain activated platelets as effectively as non-mutated Ab4. P-selectin expression was abolished and microvesiculation was significantly reduced by preincubation of virus with a goat polyclonal anti-rabbit tissue factor antibody. Infectious virus could be retrieved from washed EHV-1-exposed platelets, suggesting a direct platelet-virus interaction. Our results indicate that EHV-1 activates equine platelets and that α-granule secretion is a consequence of virus-associated tissue factor triggering factor X activation and thrombin generation. Microvesiculation was only partly tissue factor and thrombin-dependent, suggesting the virus causes microvesiculation through other mechanisms, potentially through direct binding. These findings suggest that EHV-1-induced platelet activation could contribute to the thrombosis that occurs in clinically infected horses and provides a new mechanism by which viruses activate hemostasis.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This article uses a case-based approach, complemented with diagnostic algorithms and images, to highlight hematologic changes of pathologic relevance in horses, namely, marked erythrocytosis, anemia ...or leukocytosis, inflammatory leukograms, lymphocytosis in adult horses, thrombocytopenia, and pancytopenia. These hematologic abnormalities occur with certain diseases and their identification can help clinicians narrow to down differential diagnostic lists. This article highlights the importance of blood smear examination, particularly, but not only, when numerical red flags are identified on automated blood counts.
Background
Crossmatching is used to prevent life‐threatening transfusion reactions in horses. Laboratory methods are laborious and technically challenging, which is impractical during emergencies.
...Hypothesis/Objectives
Evaluate agreement between a stall‐side crossmatch kit (KIT) and a laboratory method (LAB) in horses with known and unknown blood types.
Animals
Twenty‐four blood‐typed and alloantibody‐screened healthy adult horses (Aim 1) and 156 adult horses of unknown blood type (Aim 2).
Methods
Prospective, blinded study. Expected positive (n = 35) and negative (n = 36) crossmatches among 24 antibody and blood‐typed horses were used to determine sensitivity and specificity of KIT and LAB against the reference method. Agreement in 156 untyped horses was evaluated by reciprocal crossmatch (n = 156).
Results
Sensitivity (95% confidence interval CI) for LAB and KIT compared with expected reactions was 77.1% (59.9%‐90.0%) and 91.4% (77.0%‐98.2%), and specificity 77.8% (60.9%‐89.9%) and 73.5% (55.6%‐87.1%), respectively. The KIT was 100% sensitive for Aa reactions; LAB was 100% sensitive for Qab; and both were 100% sensitive for Ca. Cohen's κ agreement for LAB and KIT with expected positive and negative reactions (n = 71) was moderate (0.55 0.36‐0.74) and substantial (0.65 0.47‐0.82), respectively. Agreement was fair comparing LAB with KIT in Aim 1 (0.30 0.08‐0.52) and in untyped horses in Aim 2 (0.26 0.11‐0.41).
Conclusions and Clinical Importance
Agreement between KIT and LAB with expected reactions was blood type dependent. Performance of both methods depends on blood type prevalence.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Since the publication of the dog genome and the construction of high-quality genome-wide SNP arrays, thousands of dogs have been genotyped for disease studies. For many of these dogs, additional ...clinical phenotypes are available, such as hematological and clinical chemistry results collected during routine veterinary care. Little is known about the genetic basis of variation in blood phenotypes, but this variation may play an important role in the etiology and progression of many diseases. From a cohort of dogs that had been previously genotyped on a semi-custom Illumina CanineHD array for various genome-wide association studies (GWAS) at Cornell University Hospital for Animals, we chose 353 clinically healthy, adult dogs for our analysis of clinical pathologic test results (14 hematological tests and 25 clinical chemistry tests). After correcting for age, body weight and sex, genetic associations were identified for amylase, segmented neutrophils, urea nitrogen, glucose, and mean corpuscular hemoglobin. Additionally, a strong genetic association (P = 8.1×10-13) was evident between a region of canine chromosome 13 (CFA13) and alanine aminotransferase (ALT), explaining 23% of the variation in ALT levels. This region of CFA13 encompasses the GPT gene that encodes the transferase. Dogs homozygous for the derived allele exhibit lower ALT activity, making increased ALT activity a less useful marker of hepatic injury in these individuals. Overall, these associations provide a roadmap for identifying causal variants that could improve interpretation of clinical blood tests and understanding of genetic risk factors associated with diseases such as canine diabetes and anemia, and demonstrate the utility of holistic phenotyping of dogs genotyped for disease mapping studies.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK