T Cells and Subgroups in Children with COVID-19

Year 2022, Volume: 8 Issue: 3, 239 - 243, 03.10.2022

Mehmet Fatih Orhan , Öner Özdemir , Gülay Trak

https://doi.org/10.30934/kusbed.951540

Abstract

Objective: In COVID-19 disease, it was observed that T lymphocytes decreased numerically, both CD4+ and CD8+ could decrease, and sometimes the CD8+ level increased significantly. The virus-specific CD8+ T-cells are thought to be TEM or TEMRA cells. However, the characteristics of these cells, particularly their role in the pathogenesis of SARS-CoV-2 infection or COVID-19 disease, are unclear. Therefore, this study aimed to examine the flow cytometric changes observed in T helper, T cytotoxic cells, and subtypes during diagnosis in pediatric patients diagnosed with COVID-19 infection with SARS-CoV-2 PCR positivity.
Methods: Twenty-two children aged 0-18, diagnosed with COVID-19, with flow cytometry; T Helper Cell (TH), T Cytotoxic Cell (TC), T Naive Cells (TN), Central Memory (TCM), Effector Memory (TEM), RA + Effector memory (TEMRA) and Recent Thymic Emigrants (RTEs) were studied.
Results: T cell counts were found to be expected in all age groups. The CD4/CD8 ratio increased in the under-five and over 16 age group. While TCM among CD4+T cells decreased in the group above 16 years of age, TEM decreased in all age groups. RTEs decreased in all except the age group 16+. Naive CD8+ T cells (TN) were found to be high in all age groups.
Conclusion: A low number of CD4+ and CD8+ lymphocytes have been reported as a distinctive laboratory finding in 2019 Coronavirus disease (COVID-19). Having enough naive T cells is essential for the immune system to respond consistently to unknown pathogens. This study found that these cells were higher than expected in children.

Keywords

Child, Immunology, COVID-19, Flow Cytometry, T-Lymphocyte Subsets

COVID-19 Tanılı Çocuklarda T Hücreleri ve Alt Grupları

Abstract

Amaç: COVID-19 hastalığında, T lenfositlerin sayısal olarak azaldığı, hem CD4+ hem de CD8+’in azalabildiği, bazen de CD8+ düzeyinin anlamlı arttığı görülmüştür. Virüse spesifik CD8+ T-hücrelerin Efektör bellek (TEM) veya RA+ Terminal diferansiye efektör bellek (TEMRA) hücrelerinin olduğu düşünülmektedir. Ancak bu hücrelerin özellikleri, özellikle SARS-CoV-2 enfeksiyonu veya COVID-19 hastalığının patogenezindeki rolleri belirsizdir. Bu araştırmada, SARS-CoV-2 PCR pozitifliği ile COVID -19 hastalığı tanısı alan çocuk hastalarda tanı sırasında yardımcı T, sitotoksik T hücreleri ve alt tiplerinde gözlenen değişiklikleri akım hücre ölçer ile irdelemeyi amaçladık.
Yöntem: COVID-19 tanısı alan, 0-18 yaş arası 22 çocuğa flow sitometri ile; T Yardımcı Hücresi (TH), T Sitotoksik Hücresi (TC), T Naif Hücreleri (TN), Santral bellek (TCM), Efektör bellek (TEM), RA+ Terminal diferansiye efektör bellek (TEMRA) ve Son timik göçmen T hücreleri (RTEs) çalışılmıştır.
Bulgular: T hücre sayıları tüm yaş gruplarında normal bulundu. CD4/CD8 oranı 5 yaş altı ve 16 yaş üstü grupta arttı. CD4+T hücreler içinde TCM 16 yaş üstü grupta azalırken, TEM tüm yaş gruplarında azaldı. RTEs, 16 yaş üstü grup hariç diğerlerinde azaldı. Naif CD8+T hücreleri (TN) tüm yaş gruplarında yüksek bulundu.
Sonuç: Düşük sayıda saptanan CD4+ ve CD8+ lenfosit sayısı, 2019 Coronavirus hastalığında (COVID-19) ayırt edici bir laboratuvar bulgusu olarak bildirilmiştir. Yeterli sayıda naif T hücresine sahip olmak, bağışıklık sisteminin bilinmeyen patojenlere sürekli yanıt vermesi için gereklidir. Çocuklarda bu hücrelerin normalden yüksek olduğu bu çalışma tespit edilmiştir.

Keywords

Çocuk, İmmünoloji, COVID-19, T-lenfosit alt grupları, Akım hücre ölçer

References

• Altmann DM, Boyton RJ. SARS-CoV-2 T cell immunity: Specificity, function, durability, and role in protection. Sci Immunol. 2020;5(49):eabd6160.
• Ganji A, Farahani I, Khansarinejad B, Ghazavi A, Mosayebi G. Increased expression of CD8 marker on T-cells in COVID-19 patients. Blood Cells Mol Dis. 2020;83:102437.
• Deng Z, Zhang M, Zhu T, et al. Dynamic changes in peripheral blood lymphocyte subsets in adult patients with COVID-19. Int J Infect Dis. 2020;98:353-358.
• Chen G, Wu D, Guo W, et al. Clinical and immunological features of severe and moderate coronavirus disease 2019. J Clin Invest. 2020;130(5):2620-2629.
• Zhao Q, Meng M, Kumar R, et al. Lymphopenia is associated with severe coronavirus disease 2019 (COVID-19) infections: A systemic review and meta-analysis. Int J Infect Dis. 2020;96:131-135.
• Weiskopf D, Schmitz KS, Raadsen MP, et al. Phenotype and kinetics of SARS-CoV-2-specific T cells in COVID-19 patients with acute respiratory distress syndrome. Sci Immunol. 2020;5(48):eabd2071.
• Tan M, Liu Y, Zhou R, et al. Immunopathological characteristics of coronavirus disease 2019 cases in Guangzhou, China. Immunology. 2020;160(3):261-268.
• Mathew D, Giles JR, Baxter AE, et al. Deep immune profiling of COVID-19 patients reveals distinct immunotypes with therapeutic implications. Science. 2020;369(6508):eabc8511.
• Özdemir Ö. İmmün Sistemin COVID-19 Hastalığındaki Rolü: Patogenezden Tedaviye. Türkiye Klinikleri COVID-19. 2020;1(16):14-21.
• Özdemir Ö, Erkun O. Solving puzzle of the immunopathogenesis for management of COVID-19 disease. MOJ Immunol. 2020;7(1):13‒15.
• Shearer WT, Rosenblatt HM, Gelman RS, 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):973-980.
• Comans-Bitter WM, de Groot R, van den Beemd R, et al. Immunophenotyping of blood lymphocytes in childhood. Reference values for lymphocyte subpopulations. J Pediatr. 1997;130(3):388-393.
• Schatorjé EJH, Gemen EFA, Driessen GJA, et al. Age-matched Reference Values for B-lymphocyte Subpopulations and CVID Classifications in Children. Scand J Immunol. 2011;74(5):502-510.
• Schatorjé EJ, Gemen EF, Driessen GJ, et al. Age-matched reference values for B-lymphocyte subpopulations and CVID classifications in children. Scand J Immunol. 2011;74(5):502-510.
• Tan L, Wang Q, Zhang D, et al. Lymphopenia predicts disease severity of COVID-19: a descriptive and predictive study. Signal Transduct Target Ther. 2020;5(1):33.
• Liu J, Li S, Liu J, et al. Longitudinal characteristics of lymphocyte responses and cytokine profiles in the peripheral blood of SARS-CoV-2 infected patients. EBioMedicine. 2020;55:102763.
• Wang F, Nie J, Wang H, et al. Characteristics of Peripheral Lymphocyte Subset Alteration in COVID-19 Pneumonia. J Infect Dis. 2020;221(11):11762-11769.
• Wang F, Hou H, Luo Y, et al. The laboratory tests and host immunity of COVID-19 patients with different severity of illness. JCI Insight. 2020;5(10):e137799.
• Wu Y, Huang X, Sun J, et al. Clinical Characteristics and Immune Injury Mechanisms in 71 Patients with COVID-19. mSphere. 2020;5(4):e00362-20.
• Melek Arsoy HE, Özdemir Ö. Mysterious Side of COVID-19 Pandemic: Children. Istanbul Medical Journal. 2020;21(4):242-257.
• Ozdemir Oner. Coronavirus Disease 2019 (COVID-19): Diagnosis and Management. Erciyes Med J. 2020;42(3):242-247.
• Martin MD, Badovinac VP. Defining Memory CD8 T Cell. Front Immunol. 2018;9:2692.