Distinctive EBV infection characteristics in children from a developing country

Abstract

Background: In developing countries, Epstein-Barr virus (EBV) infection is mostly asymptomatic in early childhood. EBV persistence may lead to different malignancies, such as B cell derived lymphomas. In Argentina, most children are seropositive at three years and an increased association between EBV and lymphoma was proved in children under 10 years old by our group. Objective: Our aim was to characterize EBV infection at the site of entry and reactivation of viral infection -the tonsils-in order to better understand the mechanism of viral persistence in pediatric patients. Methods: A cohort of 54 patients was described. We assessed specific antibodies profiles in sera; viral proteins presence by IHC on FFPE samples and EBV type from fresh tissue. Results: EBV type 1 was prevalent, mostly in the youngest patients. Asymptomatic primary infected patients presented higher viral loads and Latency 0/I or II patterns, whereas the Latency III pattern was observed mostly in healthy carriers. There were no differences between groups in the expression of viral lytic antigens. This study discloses new features in patients undergoing primary infection from a developing population. Low viral inoculum and restricted viral antigen expression may be responsible for the lack of symptoms in children from our country.

Neonatal and Children’s Immune System and COVID-19: Biased Immune Tolerance versus Resistance Strategy

“…Similarly, in early childhood, EBV infection is asymptomatic or associated with a middisease, whereas it often manifests as an acute infectious mononucleosis in adults because of an exaggerated immune response (27,28). The mechanism underlying the lack of EBV symptoms in early life is not well defined; however, a lower number of new infectious virions is reported to be associated with mild and subclinical symptoms (29). Mechanistically, limited viral Ags because of fewer infectious particles results in immune surveillance avoidance and is subsequently associated with EBV persistence (29).…”

“…The mechanism underlying the lack of EBV symptoms in early life is not well defined; however, a lower number of new infectious virions is reported to be associated with mild and subclinical symptoms (29). Mechanistically, limited viral Ags because of fewer infectious particles results in immune surveillance avoidance and is subsequently associated with EBV persistence (29). As such, the occurrence of asymptomatic EBV in early childhood elicits limited virusspecific CD8 + T cells, whereas excessive expansion of CD8 + T cells is the cause of symptoms in adolescents (e.g., acute infectious mononucleosis) (30).…”

Prognosis of EBV Infection in Children with Tonsillitis

“…For instance, bacterial infectioninduced tonsillitis is primarily treated via antibiotics clinically [19,20], although, EBV induced tonsillitis should be given antiviral therapy [21]. Recent findings have shown that EBV is asymptomatic in many children and varies in pathogenicity depending on the degree of virus infection [22].…”

PD-L1 is upregulated in CD163+ tonsillar macrophages from children undergoing EBV primary infection

“…For the surgery to be performed, patients must be completely asymptomatic, without signs or symptoms of acute inflammation or infection such as fever, sore throat, or cough. At surgery, a concomitant blood sample was obtained and serum was separated to determine the EBV infection status using indirect immunofluorescence assay, as previously reported ( 16 ). A portion of the tissue was preserved at −70°C for later nucleic acid extraction, and the remaining biopsy tissue was formalin-fixed paraffin-embedded (FFPE) at the Pathology Division of Ricardo Gutierrez Children’s Hospital (Buenos Aires, Argentina).…”