Vol. 59, 2020

(update: 2020.09.22; 11.10)
 

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 Yu^1,*

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: +886-227396828. Fax: +886-227323817.
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. E-mail: 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

Heterophil toxic change (TC) and left-shifting (LS) are widely used as indicators of accelerated granulopoiesis. However, the ultrastructure of heterophil TC and LS in sea turtles remain poorly understood. This study aimed to describe the ultrastructural characteristics of sea turtle TC and LS heterophils, compare the staining quality of accessible staining methods, and provide a better understanding of the clinical applications and limitations of heterophil TC and LS examinations. 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 heterophils were performed, and the qualities of three staining methods (Wright-Giemsa stain, Diff-Quik stain and Liu’s stain) were analyzed to diagnose TC and LS heterophils. In addition, the diagnostic values of TC and LS heterophils were examined. Diff-Quik stain was significantly inferior in the assessment of heterophil TC and/or LS comparing to the Wright-Giemsa stain and Liu’s stain (Mann-Whitney test, P < 0.001). Microscopic examinations of heterophil TC and/or LS were comparable to transmission electron microscopy examinations (Cohen’s kappa coefficient, κ = 1). The correlation between the presence of heterophil TC and/or LS and clinical inflammatory state was weak (Spearman’s rank correlation coefficient, rs = 0.171, p = 0.445). In conclusion, this is the first study to describe the ultrastructural characteristics of reptile TC and LS heterophils. Wright-Giemsa stain and Liu’s stain were suitable staining methods for the microscopic observations of TC and LS heterophil in sea turtles. Given the poor correlation between TC and/or LS and clinical findings, TC and LS are not a suitable diagnostic indicator of 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 59:52. doi:10.6620/ZS.2020.59-52.