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Peripheral blood smear, Covid-19, Severity
Data about the morphological changes of Covid-19 infection in peripheral blood smear are limited and association with clinical severity of the disease are not known yet. We aimed to examine the characteristics of the cells detected in the pathological rate and / or appearance and whether these findings are related to the clinical course by evaluating the peripheral blood smear at the time of diagnosis in Covid-19 patients.
Clinical features, laboratory data, peripheral blood smear of fifty patients diagnosed with Covid-19 by PCR was evaluated at diagnosis. Peripheral smear samples of the patients were compared with the age and sex matched 30 healthy controls. Pictures were taken from the paitients’peripheral blood smear. Patients were divided into two groups. Early and advanced stage patient groups were compared in terms of laboratory data and peripheral smear findings. The relationship between the laboratory values of all patients and the duration of hospitalization was analyzed.
Pseudo pelger-huet, atypical lymphocytes, vacuole monocytes and pycnotic neutrophils rates were high in the patient group. Increased pseudo pelger-huet anomaly, psodo-pelger huet/mature lymphocyte ratio, decreased number of mature lymphocytes, and eosinophils in peripheral blood smear were observed in the advanced stage patients (p <0.05). A negative correlation was observed between the duration of hospitalization and mature lymphocyte, and monocytes with vacuoles rates (p <0.05).
Peripheral smear is a cheap, easily performed, and rapid test. Increased pseudo-pelger huet anomaly/mature lymphocytes rate is suggesting advanced stage disease, while high initial monocytes with vacuoles and mature lymphocyte rates at the time of diagnosis may be an indicator of shortened duration of hospitalization.
2. Pal M, Berhanu G, Desalegn C, Kandi V. Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2): An Update. Cureus. 2020;12(3):e7423. Published 2020 Mar 26. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7182166/
3. World Health Organization Press Conference. The World Health Organization (WHO) Has Officially Named the Disease Caused by the Novel Coronavirus as COVID-19. Available online: (accessed on 18 May 2020). URL:https://www.who.int/emergencies/diseases/novel-coronavirus-2019/technical-guidance/naming-the-coronavirus-disease-(covid-2019)-and-the-virus-that-causes-it
4. Chan JF, Yuan S, Kok KH, To KK, Chu H, Yang J, Xing F, Liu J, Yip CC, Poon RW, Tsoi HW, Lo SK, Chan KH, Poon VK, Chan WM, Ip JD, Cai JP, Cheng VC, Chen H, Hui CK, Yuen KY. A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: a study of a family cluster. Lancet. 2020 Feb 15;395(10223):514-523. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7159286/
5. Zhu N, Zhang D, Wang W, Li X, Yang B, Song J, Zhao X, Huang B, Shi W, Lu R, Niu P, Zhan F, Ma X, Wang D, Xu W, Wu G, Gao GF, Tan W; China Novel Coronavirus Investigating and Research Team. A Novel Coronavirus from Patients with Pneumonia in China, 2019. N Engl J Med. 2020 Feb 20;382(8):727-733. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7092803/
6. Pascutti MF, Erkelens MN, Nolte MA. Impact of Viral Infections on Hematopoiesis: From Beneficial to Detrimental Effects on Bone Marrow Output. Front Immunol. 2016 Sep 16;7:364.URL: https://pubmed.ncbi.nlm.nih.gov/27695457/
7. Ponder E, Ponder RV. Cytology of polymorphonuclear leucocyte in toxic conditions. J Lab Clin Med. 1942; 28:316-322. URL:
8. Gordin R. Toxic granulation in leukocytes; development and relation to cloudy swelling. Acta Med Scand. 1952;143(Suppl 270):1-50. URL: https://pubmed.ncbi.nlm.nih.gov/14943431/
9. Jordans GHW. The familial occurrence of fat containing vacuoles in the leucocytes diagnosed in 2 brothers suffering from dystrophia musculorum progressiva. Acta Med Scand. 1953;145:419-423. URL: https://pubmed.ncbi.nlm.nih.gov/13079655/
10. Harald T, Heinz D, Torsten H. Color Atlas of Hematology. 2004. URL: https://www.bookdepository.com/Color-Atlas-Hematology-Harald-Klaus-Theml/9783136731024
11. Löffler H, Rastetter J, Haferlach T. Atlas of Clinical Hematology. Sixth Revised Edition. 2005 URL: https://www.springer.com/gp/book/9783540210139
12. Aydogdu I, Kuku I, Kaya E, Gödekmerdan A. Kan Hastal?klar? Atlas?. 2003 URL: https://www.nadirkitap.com/kan-hastaliklari-atlasi-i-aydogdu-i-kuku-e-kaya-a-godekmerdan-kitap7534815.html
13. Tassin F, Dewé W, Schaaf N, Herens C, Ravoet C, Albert A, Beguin Y, Paulus JM. A four-parameter index of marrow dysplasia has predictive value for survival in myelodysplastic syndromes. Leuk Lymphoma. 2000 Feb;36(5-6):485-96. URL: https://www.tandfonline.com/doi/abs/10.3109/10428190009148396
14. Gogia A, Raina V, Gupta R, Gajendra S, Kumar L, Sharma A, Kumar R, Vishnubhatla S. Prognostic and predictive significance of smudge cell percentage on routine blood smear in chronic lymphocytic leukemia. Clin Lymphoma Myeloma Leuk. 2014 Dec;14(6):514-7. URL: https://pubmed.ncbi.nlm.nih.gov/24656596/
15. Anderson G, Smith VV, Malone M, Sebire NJ. Blood film examination for vacuolated lymphocytes in the diagnosis of metabolic disorders; retrospective experience of more than 2,500 cases from a single centre. J Clin Pathol. 2005 Dec;58(12):1305-10. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1770783/
16. Lauer SA, Grantz KH, Bi Q, Jones FK, Zheng Q, Meredith HR, Azman AS, Reich NG, Lessler J. The Incubation Period of Coronavirus Disease 2019 (COVID-19) From Publicly Reported Confirmed Cases: Estimation and Application. Ann Intern Med. 2020 May 5;172(9):577-582. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7081172/
17. Neil M Ferguson, Daniel Laydon, Gemma Nedjati-Gilani, Natsuko Imai, Kylie Ainslie, Marc Baguelin, Sangeeta Bhatia, Adhiratha Boonyasiri, Zulma Cucunubá, Gina Cuomo-Dannenburg, Amy Dighe, Ilaria Dorigatti, Han Fu, Katy Gaythorpe, Will Green, Arran Hamlet, Wes Hinsley, Lucy C Okell, Sabine van Elsland, Hayley Thompson, Robert Verity, Erik Volz, Haowei Wang, Yuanrong Wang, Patrick GT Walker, Caroline Walters, Peter Winskill, Charles Whittaker, Christl A Donnelly, Steven Riley, Azra C Ghani Impact of non-pharmaceutical interventions (NPIs) to reduce COVID-19 mortality and healthcare demand. Imperial College COVID-19 Response Team. 2020;10:77482. URL: https://www.imperial.ac.uk/media/imperial-college/medicine/sph/ide/gida-fellowships/Imperial-College-COVID19-NPI-modelling-16-03-2020.pdf
18. Ahnach M, Ousti F, Nejjari S, Houssaini MS, Dini N. Peripheral Blood Smear Findings in COVID-19. Turk J Haematol. 2020 Jun 26. URL: https://www.journalagent.com/tjh/pdfs/TJH-25902-AHNACH.pdf
19. Cantu MD, Towne WS, Emmons FN, Mostyka M, Borczuk A, Salvatore SP, Yang HS, Zhao Z, Vasovic LV, Racine-Brzostek SE. Clinical significance of blue-green neutrophil and monocyte cytoplasmic inclusions in SARS-CoV-2 positive critically ill patients. Br J Haematol. 2020 Jul;190(2):e89-e92. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7283650/
20. Salib C, Teruya-Feldstein J. Hypersegmented granulocytes and COVID-19 infection. Blood. 2020;135(24):2196. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7290095/
21. Mitra A, Dwyre DM, Schivo M, Thompson GR 3rd, Cohen SH, Ku N, Graff JP. Leukoerythroblastic reaction in a patient with COVID-19 infection. Am J Hematol. 2020 Aug;95(8):999-1000. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7228283/
22. Li H, Wang B, Ning L, Luo Y, Xiang S. Transient appearance of EDTA dependent pseudothrombocytopenia in a patient with 2019 novel coronavirus pneumonia. Platelets. 2020 Aug 17;31(6):825-826. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7212537/
23. Zini G, Bellesi S, Ramundo F, d'Onofrio G. Morphological anomalies of circulating blood cells in COVID-19. Am J Hematol. 2020 Jul;95(7):870-872. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7262044/
24. Kong M, Zhang H, Cao X, Mao X, Lu Z. Higher level of neutrophil-to-lymphocyte is associated with severe COVID-19. Epidemiol Infect. 2020 Jul 9;148:e139. URL: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7360950/