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Unraveling avian and reptilian hematology: An optical and electron microscopic study of the buffy coat
Author(s) -
Fontes Pinto Filipe,
Lopes Célia,
Malhão Fernanda,
Marcos Ricardo
Publication year - 2018
Publication title -
veterinary clinical pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.537
H-Index - 51
eISSN - 1939-165X
pISSN - 0275-6382
DOI - 10.1111/vcp.12640
Subject(s) - buffy coat , coat , biology , staining , platelet , peripheral blood mononuclear cell , hematology , pathology , virology , immunology , medicine , in vitro , genetics , paleontology
Background Blood centrifugation and buffy coats are at the cornerstone of hematology. In mammals, the buffy coat has a layered disposition (from bottom to top) with neutrophils on top of erythrocytes, followed by monocytes/lymphocytes, and platelets. In nonmammals, this distribution is unknown. Recently, the cell tube block ( CTB ) technique was developed to study the buffy coat, but it was never applied to nonmammal buffy coats. Objectives This study aimed to evaluate using the CTB technique to study reptilian and avian buffy coats and to propose its use for clinical applications. Methods Blood from five birds and eight reptiles of different species was obtained to make CTB s that were processed for optical/electron microscopy. H&E, Sirius red, and immunohistochemistry staining against CD 3 (to label T lymphocytes) were applied to the CTB s. Results In birds, the buffy coat had a layered appearance with the granulocyte layer containing granulocytes (heterophils and eosinophils) and nucleated erythrocytes followed by a mononuclear cell layer containing lymphocytes, monocytes, and thrombocytes. In some animals, a nucleated erythrocyte layer was observed admixed with the granulocyte/mononuclear cell layer. A small clot within the buffy coat was seen in seven reptiles, and less definition of layers occurred in reptiles, with only one or two layers. Lymphocytes appeared toward the top of the buffy coat. Conclusions From a comparative hematology perspective, the buffy coat of mammals differs from that of birds and more from that of reptiles. The CTB technique can be used to study these differences in avian and reptilian hematology, especially to study atypical circulating cells, hemoparasites, or blood cell proportions in health and disease.