Effects of different drying methods on smears of canine blood and effusion fluid.

BACKGROUND: Glass slide preparations from a variety of specimens (blood, masses, effusions) are commonly made as part of the diagnostic work-up, however the effects of various drying methods in veterinary practice and diagnostic laboratory settings is not clear. OBJECTIVE: Compare the effects of four drying methods on results of microscopic examination of canine blood smears and direct smears of pleural or peritoneal effusion fluid. METHODS: Twelve canine blood samples (6 from healthy dogs, 6 from sick dogs) and 6 canine peritoneal or pleural effusion samples. Four smears were prepared from each of the 18 samples and dried using the following methods: air-dry, hair dryer with or without heat, and heat block at 58 °C. Observers, blinded to the drying method, independently reviewed the slides microscopically, using a scoring system to evaluate cell morphology and (for blood smears) echinocyte numbers; scoring results were analyzed statistically. RESULTS: For blood smears, several comparisons showed more adverse effects on morphology using the heat block method than for one or more other drying methods. For effusion fluid smears, RBCs dried with the heat block or air-dry methods had more poorly preserved morphology than RBCs dried by the hair dryer method without heat. CONCLUSIONS AND CLINICAL RELEVANCE: The results (1) indicate that different drying methods had a significant effect, (2) support using a hair dryer without heat for both blood smears and effusion fluid smears, and (3) discourage using a 58 °C heat block.

Effect of time and storage on toxic or pseudo-toxic change in canine neutrophils.

BACKGROUND: The presence of toxic change in neutrophils is frequently used as a biomarker of inflammation in dogs. OBJECTIVE: We aimed to evaluate the effect of time and storage on toxic change in canine neutrophils. METHODS: One hundred and fifty microliters of EDTA blood were obtained from eight dogs with no toxic neutrophil changes observed on fresh blood smears (T0). Blood was stored at room temperature (RT), in a box with an icepack (ICE), and at 4°C. For each storage condition, smears were prepared 2 (T2), 4 (T4), 8 (T8), and 24 (T24) hours post blood draw. Smears were randomized, and each smear was evaluated for the presence of toxic neutrophil change. RESULTS: A statistically significant effect of time and storage on the presence of toxic neutrophil change was observed. Compared with T0, the number of neutrophils containing Döhle bodies was significantly higher at T8 and T24 for the RT (P < 0.0001) and ICE (P < 0.0001) samples and at T24 for 4°C samples (P < 0.0001). Additionally, smears were falsely classified as having 1+ toxic change in 0/8 (T2), 1/8 (T4), 3/8 (T8), and 8/8 (T24) for RT samples; 0/8 (T2 and T4), 2/8 (T8), and 5/7 (T24) smears for ICE samples; and 0/8 (T2, T4, and T8) and 2/8 (T24) for 4°C samples. CONCLUSIONS: Smears can be falsely classified as having neutrophils with toxic change as early as 4 hours post blood draw in samples stored at RT, 8 hours when stored with icepacks, and 24 hours when stored at 4°C. Canine blood smears should be prepared and evaluated for toxic neutrophil change as early as possible.

Customization of Advia 120 thresholds for canine erythrocyte volume and hemoglobin concentration, and effects on morphology flagging results.

This study sought to develop customized morphology flagging thresholds for canine erythrocyte volume and hemoglobin concentration [Hgb] on the ADVIA 120 hematology analyzer; compare automated morphology flagging with results of microscopic blood smear evaluation; and examine effects of customized thresholds on morphology flagging results. Customized thresholds were determined using data from 52 clinically healthy dogs. Blood smear evaluation and automated morphology flagging results were correlated with mean cell volume (MCV) and cellular hemoglobin concentration mean (CHCM) in 26 dogs. Customized thresholds were applied retroactively to complete blood (cell) count (CBC) data from 5 groups of dogs, including a reference sample group, clinical cases, and animals with experimentally induced iron deficiency anemia. Automated morphology flagging correlated more highly with MCV or CHCM than did blood smear evaluation; correlation with MCV was highest using customized thresholds. Customized morphology flagging thresholds resulted in more sensitive detection of microcytosis, macrocytosis, and hypochromasia than default thresholds.

Adaptation des seuils d'Advia 120 pour le volume d'érythrocytes et la concentration d'hémoglobines des chiens et les effets sur le signalement des résultats de la morphologie. Cette étude a cherché à développer des seuils de signalement adaptés à la morphologie pour le volume des érythrocytes et la concentration d'hémoglobines [Hgb] des chiens sur l'analyseur d'hématologie ADVIA 120; à comparer le signalement automatique de la morphologie avec les résultats de l'évaluation microscopique des frottis sanguins; et à examiner les effets des seuils adaptés sur les résultats de signalement de la morphologie. Des seuils adaptés ont été déterminés à l'aide de données de 52 chiens cliniquement en santé. L'évaluation des frottis sanguins et les résultats de signalement automatiques de la morphologie ont été corrélés avec le volume cellulaire moyen (VCM) et la concentration d'hémoglobines cellulaires moyennes (CHCM) chez 26 chiens. Les seuils adaptés ont été appliqués rétroactivement à des données d'hémogramme provenant de 5 groupes de chiens, y compris un groupe de référence, de cas cliniques et d'animaux avec une anémie ferriprive induite expérimentalement. Il y avait une corrélation supérieure du signalement automatique de la morphologie avec le VCM ou le CHCM par rapport à l'évaluation des frottis sanguins; la corrélation avec le VCM était supérieure en utilisant des seuils adaptés. Des seuils de signalement adaptés à la morphologie ont produit une détection plus sensible de la microcytose, de la macrocytose et de l'hypochromasie que les seuils par défaut.(Traduit par Isabelle Vallières).

Role of hepcidin in iron metabolism and potential clinical applications.

The relatively recent discovery of hepcidin has stimulated renewed research interest in iron metabolism and iron-related disorders, emphasizing the importance of this hormone in many normal and pathologic processes. Important questions still remain to be answered; however, research to date offers promising diagnostic and therapeutic implications for both humans and veterinary species.