Zoological Studies

Vol. 59, 2020

(update: 2020.09.22)

Light Microscopic and Ultrastructural Characteristics of Heterophil Toxicity and Left-shifting in Green Sea Turtles (Chelonia mydas) from Taiwan

Yi-Fan Wang1, Tsung-Hsien Li2, Yi-Fan Jiang3, Chau-Hwa Chi1, I-Jiunn Cheng4, Chiung-Hsiang Cheng3, Ray Sun5, and Pin-Huan Yu1,*


1Institute of Veterinary Clinical Science, School of Veterinary Medicine, National Taiwan University, No.153, Sec. 3, Keelung Rd, Da-an district, 10672 Taipei city, Taiwan. *Correspondence: E-mail: pinhuan@ntu.edu.tw (Yu). Tel: +886227396828. Fax: +886227323817.
E-mail: r04643011@ntu.edu.tw (Wang), chie@ntu.edu.tw (Chi)
2National Museum of Marine Biology and Aquarium. No. 2 Houwan Road, Checheng, Pingtung, 94450, Taiwan. E-mail: lith@nmmba.gov.tw (Li)

3Graduate Institute of Molecular and Comparative Pathology, School of Veterinary Medicine, National Taiwan University, No.1, Sec. 4, Roosevelt Rd., Da-An district, Taipei city, Taipei, Taiwan emcheng@ntu.edu.tw (Cheng), yfjiang@ntu.edu.tw (Jiang)
4Institute of Marine Biology, National Taiwan Ocean University, No.2, Beining Rd., Zhongzheng Dist., Keelung City 20224, Taiwan. E-mail:  b0107@mail.ntou.edu.tw (Cheng)
5Joint Center for Instruments and Researches, College of Bioresources and Agriculture, National Taiwan University, No.1, Sec. 4, Roosevelt Rd., Da-An district, Taipei city, Taiwan. E-mail: raymsun@ntu.edu.tw (Sun)

Received 10 May 2020 / Accepted 20 August 2020
Communicated by Jian-Nan Liu

Widely used as indicators of accelerated granulopoiesis, heterophil toxic change (TC) and left-shifting (LS) remains poorly understood in sea turtles which include ultrastructural descriptions. This study aims to describe ultrastructural characteristics of sea turtle TC and LS heterophils, compare the staining quality of accessible staining methods, and to provide a better understanding of the clinical applications and limitations of heterophil TC and LS examination. Blood samples were collected from 21 rescued sea turtles from January 2017 to September 2018. Morphologic (n = 22) and ultrastructural (n = 15) examination of TC and LS heterophil were performed, and the quality of three staining methods (Wright Giemsa stain, Diff-Quik stain and Liu’s stain) for diagnosis of heterophil TC and LS was analyzed. In addition, the diagnostic value of TC and LS heterophils was examined. Diff-Quik stain was significantly inferior in the assessment of heterophil TC and/or LS comparing with Wright Giemsa stain and Liu’s stain (Mann-Whitney test, P < 0.001). Microscopic examination of heterophil TC and/or LS is comparable to transmission electron microscopy examination (Cohen’s kappa coefficient, κ =1). The correlation of the presence of heterophil TC and/or LS with clinical inflammatory state is weak (Spearman’s rank correlation coefficient, rs =0.171, p =0.445). In conclusion, this is the first study describing ultrastructural characteristics of reptile TC and LS heterophils. Wright-Giemsa stain and Liu’s stain were suitable staining methods for microscopic observation of TC and LS heterophil in sea turtles. Given the poor correlation of TC and/or LS with clinical findings, TC and LS is not a suitable diagnostic indicator in green sea turtles’ inflammation status.

Key words: Green sea turtle, Heterophil toxic change, Left shift, Staining methods, Ultrastructure.

Citation: Wang YF, Li TH, Jiang YF, Chi CH, Cheng IJ, Cheng CH, Sun R, Yu PH. 2020. Light microscopic and ultrastructural characteristics of heterophil toxicity and left-shifting in green sea turtles (Chelonia mydas) from Taiwan. Zool Stud 59:0jj. doi:-.