A FLOW CYTOMETRIC EVALUATION OF B LYMPHOCYTE CELLS AND SUBGROUPS OF CHILDREN DIAGNOSED WITH COVID-19

Öz

Objective: During viral infections, antibody production of B cells are critical for protective immunity. It is known that the COVID-19 disease has a milder course in children. It is crucial to evaluate the causes of this situation from a pediatrician’s perspective to determine the treatment goals of the disease. We aimed to examine the flow cytometric changes in B cells and subtypes observed in children diagnosed with the COVID-19 infection.
Materials and Methods: This is a prospective cohort study including 22 children aged 0-18 who had been diagnosed with COVID-19. CD19+B cells, CD27-IgD+ naive B, CD21low immature B, CD21lowCD38low active B, CD27-IgD- double-negative B, CD27- non-memory B, CD27+ memory B, CD27+IgD- switched memory B, and CD27+IgD+ non-switched memory B cells were studied using flow cytometry.
Results: B cells counts decreased as a percentage in the 2-5 years age group and the 10-16 age group as an absolute number. Naive and non-memory B cell frequencies increased in the 5-10 years old and over 16 years old groups. Double negative B cells were normal in all age groups. Non-memory B cells increased in the 5-10 and over 16 years old groups, whereas memory B cells decreased. In all groups, switched memory B cells decreased. Non-switched memory B cell counts were within reference ranges in all groups except for the over 16 years group.
Conclusion: Although the decrease in B cell count is associated with the severity of the disease, naive B cell subgroups did not decrease in the pediatric patients included in the study. All groups showed increased switched memory B cell counts, in accordance with the literature. Unlike adults, naive B cells, non-switched memory B cells, and double-negative B cells were normal in children.

Anahtar Kelimeler

• COVID-19
• child
• immunology
• flow cytometry
• B-lymphocyte subgroups

COVİD-19 TANISI ALAN ÇOCUKLARIN B LENFOSİT HÜCRELERİNİN VE ALT GRUPLARININ AKIŞ SİTOMETRİK DEĞERLENDİRİLMESİ

Öz

Amaç: Viral enfeksiyonlar sırasında B hücrelerinin antikor üretimi, koruyucu bağışıklık için kritiktir. Çocuklarda COVID-19 hastalığının daha hafif seyrettiği bilinmektedir. Bu durumun nedenlerini çocuk doktoru gözüyle değerlendirmek, hastalığın tedavi hedeflerini belirlemek açısından çok önemlidir. COVID-19 enfeksiyonu tanısı alan çocuklarda gözlenen B hücre ve alt tiplerinde akım sitometrik değişiklikleri incelemeyi amaçladık.
Gereç ve Yöntem: Çalışmamız 0-18 yaş arası COVID-19 teşhisi konulan 22 çocuğu içeren prospektif kohort bir araştırmadır. CD19+B hücreleri, CD27-IgD+ saf B, CD21düşük olgunlaşmamış B, CD21düşükCD38düşük aktif B, CD27-IgD- çift negatif B, CD27- bel- lek B, CD27+ bellek B, CD27+IgD- dönüşmüş (switched) bellek B, CD27+IgD+ dönüşmemiş (non-switched) bellek B hücreleri akış sitometrisi ile incelenmiştir.
Bulgular: B hücre sayısı 2-5 yaş grubunda yüzde olarak, 10-16 yaş grubunda ise mutlak sayı olarak azaldı. 5-10 yaş ve 16 yaş üstü gruplarda naif ve hafıza dışı B hücrelerinin oranları arttı. Çift negatif B hücreleri tüm yaş gruplarında normaldi. Bellek dışı B hücreleri 5-10 yaş arasında ve 16 yaş üzerinde artarken, aynı gruplarda bellek B hücreleri azaldı. Dönüşmüş bellek B hücreleri tüm yaş gruplarında azaldı. Dönüşmemiş bellek B hücreleri, 16 yaşın üzerinde azaldı ve diğer tüm yaş gruplarında normal görünüyordu.
Sonuç: B hücre sayısındaki azalma hastalığın şiddeti ile ilişkili olmasına rağmen, çalışmaya dâhil edilen çocuk hastalarımızda naif B hücre alt gruplarında azalma olmadı. Literatüre uygun olarak tüm gruplarda dönüşmüş bellek B hücreleri arttı. Çocuklarda yetişkinlerden farklı olarak naif B hücreleri, dönüşmemiş bellek B hücreleri ve çift negatif B hücreleri normaldi.

Anahtar Kelimeler

• Çocuk
• İmmünoloji
• COVID-19
• Akış sitometrisi
• B-lenfosit alt grupları

Kaynakça

1. 1. Baker D, Roberts CA, Pryce G, Kang AS, Marta M, Reyes S, et al. COVID-19 vaccine-readiness for anti-CD20-depleting therapy in autoimmune diseases. Clin Exp Immunol 2020;202(2):149-61. [CrossRef] google scholar
2. 2. Chiappelli F. COVID-19 Immunopathology & Immunotherapy. Bioinformation 2020;16(3):219-22. [CrossRef] google scholar
3. 3. Comans-Bitter WM, De Groot R, Van den Beemd R, Neijens HJ, Hop WCJ, Groeneveld K, et al. Immunophenotyping of blood lymphocytes in childhood: Reference values for lymphocyte subpopulations. J Pediatr 1997;130(3):388-93. [CrossRef] google scholar
4. 4. Deng Z, Zhang M, Zhu T, Zhili N, Liu Z, Xiang R, et al. Dynamic changes in peripheral blood lymphocyte subsets in adult patients with COVID-19. Int J Infect Dis 2020;98:353-8. [CrossRef] google scholar
5. 5. Devogelaere J, D’hooghe MB, Vanderhauwaert F, D’haeseleer M. Coronavirus disease 2019: favorable outcome in an immunosuppressed patient with multiple sclerosis. Neurol Sci 2020;41(8):1981-3. [CrossRef] google scholar
6. 6. He R, Lu Z, Zhang L, Fan T, Xiong R, Shen X, et al. The clinical course and its correlated immune status in COVID-19 pneumonia. J Clin Virol 2020;127:104361. [CrossRef] google scholar
7. 7. Huang W, Berube J, McNamara M, Saksena S, Hartman M, Arshad T, et al. Lymphocyte Subset Counts in COVID-19 Patients: A Meta-Analysis. Cytom Part A 2020;97(8):772-6. [CrossRef] google scholar
8. 8. Kebudi R, Kurucu N, Tuğcu D, Hacısalihoğlu Ş, Fışgın T, Ocak S, et al. COVID-19 infection in children with cancer and stem cell transplant recipients in Turkey: A nationwide study. Pediatr Blood Cancer 2021;68(6):e28915. [CrossRef] google scholar

9. 9. Li H, Chen K, Liu M, Xu H, Xu Q. The profile of peripheral blood lymphocyte subsets and serum cytokines in children with 2019 novel coronavirus pneumonia. J Infect 2020;81(1):115-20. [CrossRef] google scholar
10. 10. Liu J, Li S, Liu J, Liang B, Wang X, Wang H, et al. Longitudinal characteristics of lymphocyte responses and cytokine profiles in the peripheral blood of SARS-CoV-2 infected patients. EBioMedicine 2020;55:1027633. [CrossRef] google scholar
11. 11. Machura E, Mazur B, Pienişzek W, Karczewska K. Expression of naive/memory (CD45RA/CD45RO) markers by peripheral blood CD4 + and CD8 + T cells in children with asthma. Arch Immunol Ther Exp (Warsz) 2008;56(1):55-62. [CrossRef] google scholar
12. 12. Mathew D, Giles JR, Baxter AE, Oldridge DA, Greenplate AR, Wu JE, et al. Deep immune profiling of COVID-19 patients reveals distinct immunotypes with therapeutic implications. Science 2020;369(6508):eabc8511. [CrossRef] google scholar
13. 13. Melek Arsoy HE, Özdemir Ö. Mysterious Side of COVID-19 Pandemic: Children. Istanbul Med J 2020;21(4):242-57. [CrossRef] google scholar
14. 14. Nielsen S, Fang Y, Jackson K, Hoh R, Röltgen K, Stevens B, et al. Human B cell clonal expansion and convergent antibody responses to SARS-CoV-2. Cell Host Microbe 2020;28(4):516-525.e5. [CrossRef] google scholar
15. 15. Orhan MF, Büyükavcı M. COVID-19’un Tanı ve Tedavi Sürecinde Hematolojik Parametreler. J Biotechnol Strateg Heal Res 2020;4:123-7. [CrossRef] google scholar
16. 16. Özdemir Ö. Coronavirus Disease 2019 (COVID-19): Diagnosis and Management (narrative review). Erciyes Med J 2020;42(3):242-7. [CrossRef] google scholar
17. 17. Özdemir Ö. İmmün sistemin COVID-19 hastalığındaki rolü: Patogenezden tedaviye. Bostancı İ, editör. Çocuk Sağlığında SARSCoV- 2 (COVID-19). 1. Baskı. Ankara: Türkiye Klinikleri; 2020. p.14-21. google scholar
18. 18. Özdemir Ö, Erkun O. Solving puzzle of the immunopathogenesis for management of COVID-19 disease. MOJ Immunol 2020;7(1):13-5. google scholar
19. 19. Schatorje EJH, Gemen EFA, Driessen GJA, Leuvenink J, van Hout RWNM, et al. Age-matched reference values for B-lymphocyte subpopulations and CVID classifications in children. Scand J Immunol 2011;74(5):502-10. [CrossRef] google scholar
20. 20. Schatorje EJH, Gemen EFA, Driessen GJA, Leuvenink J, van Hout RWNM, de Vries E. Paediatric reference values for the peripheral T cell compartment. Scand J Immunol 2012;75(4):436-44. [CrossRef] google scholar
21. 21. Shearer WT, Rosenblatt HM, Gelman RS, Oyomopito R, Plaeger S, Stiehm ER, et al. Lymphocyte subsets in healthy children from birth through 18 years of age: The Pediatric AIDS Clinical Trials Group P1009 study. J Allergy Clin Immunol 2003;112(5):973-80. [CrossRef] google scholar
22. 22. Tan M, Liu Y, Zhou R, Deng X, Li F, Liang K, et al. Immunopathological characteristics of coronavirus disease 2019 cases in Guangzhou, China. Immunology 2020;160(3):261-8. [CrossRef] google scholar
23. 23. Wang F, Hou H, Luo Y, Tang G, Wu S, Huang M, et al. The laboratory tests and host immunity of COVID-19 patients with different severity of illness. JCI Insight 2020;5(10):e137799. [CrossRef] google scholar
24. 24. Wang F, Nie J, Wang H, Zhao Q, Xiong Y, Deng L, et al. Characteristics of peripheral lymphocyte subset alteration in COVID-19 Pneumonia. J Infect Dis 2020;221(11):11762-9. [CrossRef] google scholar
25. 25. Wen W, Su W, Tang H, Le W, Zhang X, Zheng Y, et al. Immune cell profiling of COVID-19 patients in the recovery stage by single-cell sequencing. Cell Discov 2020;6(1):31. [CrossRef] google scholar