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The correction notice in the "Frontiers in Veterinary Science" journal addresses errors in Figure 1, Table 1, Table 2, Table 3, and Table 6 of an article on dogs with acute myeloid leukemia. The correction involves changing CD1c to CD1a in the figures and tables due to an error in the original publication. The corrected figures and tables provide criteria and results for diagnosing and classifying acute myeloid leukemia in dogs based on morphologic, flow cytometric, and cytochemical analyses. [Extracted from the article]

Clonality testing for rearrangements in the complementarity-determining region 3 of the immunoglobulin heavy chain of B lymphocytes (B cell receptor) and the T cell receptor of T lymphocytes helps distinguish between clonal and non-clonal expansions of lymphocytes. There are rare reports of clonally rearranged T and B cell receptors in dogs with acute myeloid leukemia (AML). Our objective was to determine the frequency of clonally rearranged T and B cell receptors in dogs with AML. Archived slides from historical cases of AML (from January 2010 to June 2013) and slides or liquid specimens [blood, bone marrow (BM), body cavity fluid, or tissue aspirates] from cases of AML diagnosed between June 2013 and February 2017 were used in the study. A diagnosis of AML was made on the basis of more than 20% immature neoplastic cells ("blasts") in blood, BM, or extramedullary tissues, displaying features of myeloid differentiation. Myeloid differentiation was based on a combination of morphologic criteria, positive flow cytometric labeling for surface antigens typical of myeloid origin (e.g., CD11b, CD11c, CD14 with a general lack of expression of T or B cell markers), or positive cytochemical staining reactions for myeloid-associated enzymes (e.g., alkaline phosphatase, chloroacetate esterase). There were 63 cases of AML diagnosed during this period; however, slides or liquid specimens with sufficient DNA for testing were only obtained from 25 dogs. Affected dogs represented various breeds and were a median of 8 years old, with more male (64%) than female (36%) dogs. Common clinical signs were peripheral or internal lymphadenopathy (10/25 dogs, 40%) and hepatomegaly or splenomegaly (10/25 dogs combined, 40%). Typical hematologic findings were bi- or pancytopenia (23/25 dogs, 92%), with circulating blasts (21/25, 84%). Solitary clonal (4 B cell, 6 T cell) and biclonal (6 B and T cell) rearrangements in B or T cell receptors were found in 16 dogs (64%). Our results indicate that dogs with AML can have a high frequency of clonally rearranged T or B cell receptors, including biclonality, and clonality testing should not be used as a tool to distinguish between acute leukemia of myeloid or lymphoid origin. [ABSTRACT FROM AUTHOR]

Introduction: CD80, a co-stimulatory molecule required for optimal T cell activation, is expressed on antigen-presenting cells, including monocytes and dendritic cells, in dogs and humans. We hypothesized that CD80 would be expressed on tumor cells in dogs from acute myeloid leukemia (AML) but not dogs with lymphoid neoplasms. Methods and results: We first evaluated the cellular staining pattern of a hamster anti-murine CD80 antibody (clone 16-10A1, ThermoFisher Scientific Cat# 17– 0801-82, RRID: AB_469417) in blood and bone marrow aspirates from healthy dogs. Using flow cytometric analysis and examination of modified Wright’sstained cytologic smears of unsorted and flow cytometric or immunomagnetic bead-sorted leukocytes, we show that the antibody binds to mature and immature neutrophils and monocytes, but not lymphocytes or eosinophils, in blood and bone marrow. We then added the antibody to routine flow cytometric panels for immunophenotyping hematopoietic neoplasms in dogs. We found that the antibody labeled tumor cells in 72% of 39 dogs with AML and 36% of 11 dogs with acute leukemia expressing lymphoid and myeloid markers (“mixed lineage”) but none of the dogs with B (n  =  37) or T (n  =  35) lymphoid neoplasms. A higher proportion of tumor cells in dogs with AML were labeled with the anti-CD80 antibody vs antibodies against other myeloid-associated antigens, including CD4 (36%, p  =  0.003), CD11b (44%), CD11c (46%), CD14 (38%, p  =  0.006) and CD18 (59%, clone YFC118). In contrast, antibodies against CD11b and CD11c bound to tumor cells in 8–32% of the lymphoid neoplasms. Discussion: We show that CD80, as detected by antibody clone 16-10A1, is a sensitive and specific marker for AML and would be useful to include in flow cytometric immunophenotyping panels in dogs. [ABSTRACT FROM AUTHOR]

Reptile white blood cell (WBC) morphological features are strikingly variable across species. In the Argentine black and white tegu (Salvator merianae), red tegu (Salvator rufescens), and Savannah monitor (Varanus exanthematicus), previous reports described a WBC type with a single distinct, clear, linear- to ovoid- to crescent-shaped inclusion of presumptive monocytic origin. The objective of this study was to further investigate the origin of this unique WBC type with crescent-shaped inclusions. Blood samples from two Argentine black and white tegus, tegu 1, a 4-year-old female, and tegu 2, a 2-year-old presumed male, were submitted for routine hematological evaluation. Additional blood films were prepared and stained with these cytochemical stains: alkaline phosphatase (ALP; naphthol AS-MX phosphate substrate), alpha-naphthyl butyrate esterase, alphachloroacetate esterase, myeloperoxidase, Periodic acid-Schiff, and Sudan black B. Blood films from tegu 1 were also stained with a second ALP stain (5-bromo- 4-chloro-3-indoxyl-phosphate and nitroblue tetrazolium substrate), Luna, luxol fast blue, and toluidine blue. The blood from tegu 1 was cytocentrifuged to isolate and fix the buffy coat in glutaraldehyde 2.5% aqueous solution for transmission electron microscopy. Six morphologically distinct WBC types were identified from tegu 1, including heterophils, basophils, monocytes, azurophils, lymphocytes, and the unique WBC type, which were identified as eosinophils with inclusions. WBC types in tegu 2 were similar; however, eosinophils lacked a discernable inclusion. Proper WBC identification will be useful in obtaining accurate hemogram data for this species. [ABSTRACT FROM AUTHOR]

Background: Liver analyte measurement is important in the evaluation of sick animals. Liver injury in horses is recognized by increased glutamate dehydrogenase (GLDH), sorbitol dehydrogenase (SDH), and aspartate aminotransferase (AST) activities, whereas biliary pathology is identified by increased alkaline phosphatase and γ‐glutamyl transferase (GGT) activities or bilirubin concentrations. We have observed high GLDH, but not SDH, activities in neonatal foals admitted for conditions other than liver disease. Only one previous study have evaluated GLDH activity over time in healthy neonatal foals; however, SDH activity was not measured. Objective: We aimed to evaluate changes in liver analytes in neonatal foals over time. Methods: We measured serum liver analytes (GLDH, SDH, GGT, AST, total, direct, and indirect bilirubin) and creatine kinase activity of 11 clinically healthy foals before and at various times after suckling until 46 days of age. Analytes were also measured in colostrum and mare serum. Results: Median GLDH activities increased after birth to peak at 3‐4 days of age (106 U/L, reference interval, 0‐8 U/L). Median SDH activities had a lower peak at 3‐4 days (15 U/L, reference interval, 0‐11 U/L) and were frequently discordant with GLDH. There was no association between foal and mare serum or colostral enzyme activities. AST activity plateaued at 5‐6 days, whereas GGT activity and total and indirect bilirubin concentrations peaked at 14 and 3‐4 days of age, respectively. Conclusions: Transient increases in GLDH, SDH, and GGT activities and total and indirect bilirubin concentrations occur in clinically healthy neonatal foals and do not necessarily indicate relevant liver disease. [ABSTRACT FROM AUTHOR]

A 16‐year‐old female spayed domestic shorthaired cat was examined for lameness and a mass on the fourth digit of the right hindlimb. Cytologic examination of an aspirate of the mass revealed large discrete cells admixed with low numbers of well‐granulated mast cells. The discrete cells contained single to many variably sized light pink to purple granules in their cytoplasm and had pleomorphic nuclei, with intranuclear cytoplasmic inclusions. Karyomegalic, binucleated and multinucleated cells were seen. Histologic examination of formalin‐fixed sections of the excised mass showed a mildly infiltrative, unencapsulated, multinodular dermal mass that extended into the subcutis and consisted of similar discrete cells. On immunohistochemical staining, the tumor cells expressed ionized calcium‐binding adapter molecule 1 (Iba1) and CD18. The tumor cells did not express CD3, CD20, CD117, pancytokeratin (AE1/AE3), melanoma antigen (Melan‐A), multiple myeloma oncogene‐1 (MUM1), melanoma‐associated antigen (PNL‐2), and S‐100. Low numbers of tumor cells expressed CD204 and protein gene product 9.5 (PGP9.5). Granules were variably positive for Periodic‐acid Schiff (PAS) and Alcian blue. On transmission electron microscopy, the cells contained filopodia, abundant endoplasmic reticulum, and moderate numbers of low‐density membrane‐bound granules. This case documents a previously undescribed granular variant of a histiocytic tumor in a cat. [ABSTRACT FROM AUTHOR]

Background: High serum γ‐glutamyl‐transferase (GGT) activity syndrome in racehorses has been associated with maladaption to exercise. Investigation of affected horses before and immediately after standard exercise may provide critical insight into the syndrome's pathophysiology. Objectives: To investigate blood biomarker changes in actively competing racehorses with high GGT activity associated with an exercise challenge. Study design: Case–control study. Methods: High GGT case (age: 2–3 years) and normal GGT control (age: 2–7 years) pairs (3 Thoroughbred, 4 Standardbred pairs) at least 3 months into their training/racing season were included. Horses with a recent history of high GGT activity (≥50 IU/L) without additional biochemical evidence of liver disease were identified by veterinarians. Horses were tested again in the week prior to a planned exercise challenge to confirm persistent increases in GGT activity. Controls from the same stable with similar training/racing intensity and serum GGT activity ≤36 IU/L were matched with each case. Blood samples were obtained immediately before, 15 and 120 min after exercise. Pre‐exercise serum samples were analysed for baseline select serum chemistries, selenium and vitamin E concentrations. Cortisol concentration and markers of oxidative status were measured in serum or plasma for all time points. Individual serum bile acid and coenzyme Q10 concentrations, plasma lipid mediator (fatty acids, oxylipids, isoprostanes) concentrations and targeted metabolomics analyses were performed using liquid chromatography‐mass spectrometry. Serum viral PCR for equine hepaci‐ and parvovirus was performed in each animal. Results: Cases had higher baseline concentrations of total glutathione, taurocholic acid, cortisol and cholesterol concentrations and higher or lower concentrations of specific oxylipid and isoprostane mediators, but there were no case‐dependent changes after exercise. Main limitations: Small sample size. Conclusions: Results indicated that glutathione metabolism was altered in high GGT horses. Enhanced glutathione recycling and mild cholestasis are possible explanations for the observed differences. [ABSTRACT FROM AUTHOR]