No abstract

Exercise-induced pulmonary hemorrhage (EIPH) is a relevant respiratory disease in sport horses, which can be diagnosed by examination of bronchoalveolar lavage fluid (BALF) cells using the total hemosiderin score (THS). The aim of this study was to evaluate the diagnostic accuracy and reproducibility of annotators and to validate a deep learning-based algorithm for the THS. Digitized cytological specimens stained for iron were prepared from 52 equine BALF samples. Ten annotators produced a THS for each slide according to published methods. The reference methods for comparing annotator’s and algorithmic performance included a ground truth dataset, the mean annotators’ THSs, and chemical iron measurements. Results of the study showed that annotators had marked interobserver variability of the THS, which was mostly due to a systematic error between annotators in grading the intracytoplasmatic hemosiderin content of individual macrophages. Regarding overall measurement error between the annotators, 87.7% of the variance could be reduced by using standardized grades based on the ground truth. The algorithm was highly consistent with the ground truth in assigning hemosiderin grades. Compared with the ground truth THS, annotators had an accuracy of diagnosing EIPH (THS of < or ≥ 75) of 75.7%, whereas, the algorithm had an accuracy of 92.3% with no relevant differences in correlation with chemical iron measurements. The results show that deep learning-based algorithms are useful for improving reproducibility and routine applicability of the THS. For THS by experts, a diagnostic uncertainty interval of 40 to 110 is proposed. THSs within this interval have insufficient reproducibility regarding the EIPH diagnosis.

ZusammenfassungDieses Fallbeispiel zeigt ein bisher selten beschriebenes Myxosarkom in der ventrolateralen Halsregion eines 1-jährigen Teddy-Hamsters. Die zytologische Beurteilung eines Feinnadelaspirats aus der Umfangsvermehrung zeigte zahlreiche pleomorphe Spindelzellen, die in hohen Mengen in einer muzinösen Matrix gelegen waren. Zytologisch wurde aufgrund der ausgeprägten Malignitätskriterien der Spindelzellpopulation der Verdacht auf eine maligne mesenchymale Neoplasie geäußert. Die Matrix war dabei hinweisend auf ein zugrundeliegendes Myxosarkom. Der Hamster verstarb im Rahmen der operativen Entfernung der Zubildung. Die Histopathologie zeigte eine vollständige Übereinstimmung mit den zytologischen Befunden. In der Immunhistochemie stellte sich der Tumor Vimentin-positiv mit Alzianblau-positiver Matrix dar und bestätigte die zytologische Verdachtsdiagnose. Der Fall zeigt, dass die Zytologie als minimalinvasives Diagnostikum auch beim Kleinsäuger angewendet werden kann und Rückschlüsse auf die zugrundeliegende Pathologie von Zubildungen ermöglicht. Zum biologischen Verhalten des Myxosarkoms beim Hamster ist aufgrund der seltenen Fallbeschreibungen jedoch bislang wenig bekannt.

No abstract

Point-of-care analyzers (POCAs) for quantitative assessment of bile acids (BAs) are scarce in veterinary medicine. We evaluated the Fuji Dri-Chem Immuno AU10V analyzer and v-BA test kit (Fujifilm) for detection of feline and canine total serum BA concentration. Results were compared with a 5th-generation assay as reference method and a 3rd-generation assay, both run on a bench-top analyzer. Analytical performance was assessed at 3 different concentration ranges, and with interferences. For method comparison, samples of 60 healthy and diseased cats and 64 dogs were included. Linearity was demonstrated for a BA concentration up to 130 µmol/L in cats ( r = 0.99) and 110 µmol/L in dogs ( r = 0.99). The analyzer showed high precision near the lower limit of quantification of 2 µmol/L reported by the manufacturer. Intra- and inter-assay coefficients of variation were < 5% for both species and all concentrations. Interferences were observed for bilirubin (800 mg/L) and lipid (4 g/L). There was excellent correlation with the reference method for feline ( rs = 0.98) and canine samples ( rs = 0.97), with proportional biases of 6.7% and −1.3%, respectively. However, a large bias (44.1%) was noted when the POCA was compared to the 3rd-generation assay. Total observed error was less than total allowable error at the 3 concentrations. The POCA reliably detected feline and canine BA in clinically relevant concentrations.