Primary Epstein-Barr Virus Infection in Healthy Children in Saudi Arabia: A Single Hospital-Based Study

Immunological evidence of an early seroconversion to oncogenic Merkel cell polyomavirus in healthy children and young adults

Oncogenic Merkel cell polyomavirus (MCPyV) provokes a widespread and asymptomatic infection in humans. Herein, sera from healthy children and young adults (HC, n = 344) aged 0-20 years old were evaluated for anti-MCPyV immunoglobulin G (IgG) and IgM antibodies employing a recently developed immunoassay. Serum MCPyV IgG data from healthy subjects (HS, n = 510) and elderlies (ES, n = 226), aged 21-65/66-100 years old, from our previous studies, were included. The anti-MCPyV IgG and IgM rates in HC sera were 40.7% and 29.7%, respectively. A lower prevalence of anti-MCPyV IgGs was found in HC aged 0-5 years old (13%) compared to 6-10 (52.3%), 11-15 (60.5%) and 16-20 years old (61.6%) cohorts. Age-stratified HCs exhibited similar anti-MCPyV IgM rates (27.9%-32.9%). Serological profiles indicated that anti-MCPyV IgGs and IgMs had low optical densities (ODs) during the first years of life, while IgM ODs appeared to decrease throughout young adulthood. A lower anti-MCPyV IgGs rate was found in HC (40.7%) than HS (61.8%) and ES (63.7%). Upon the 5-years range age-stratification, a lower anti-MCPyV IgGs rate was found in the younger HC cohort aged 0-5 years old compared to the remaining older HC/HS/ES cohorts (52.3%-72%). The younger HC cohort exhibited the lowest anti-MCPyV IgG ODs than the older cohorts. Low anti-MCPyV IgMs rates and ODs were found in the 21-25 (17.5%) and 26-30 (7.7%) years old cohorts. Our data indicate that, upon an early-in-life seroconversion, the seropositivity for oncogenic MCPyV peaks in late childhood/young adulthood and remains at high prevalence and relatively stable throughout life.

Increased Prevalence of EBV Infection in Nasopharyngeal Carcinoma Patients: A Six-Year Cross-Sectional Study

Epstein Barr Virus (EBV) is implicated in the carcinogenesis of nasopharyngeal carcinoma (NPC) and currently associated with at least 1% of global cancers. The differential prognosis analysis of NPC in EBV genotypes remains to be elucidated. Medical, radiological, pathological, and laboratory reports of 146 NPC patients were collected retrospectively over a 6-year period between 2015 and 2020. From the pathology archives, DNA was extracted from tumor blocks and used for EBV nuclear antigen 3C (EBNA-3C) genotyping by nested polymerase chain reaction (PCR). We found a high prevalence of 96% of EBV infection in NPC patients with a predominance of genotype I detected in 73% of NPC samples. Histopathological examination showed that most of the NPC patients were in the advanced stages of cancer: stage III (38.4%) or stage IV-B (37.7%). Only keratinized squamous cell carcinoma was significantly higher in EBV negative NPC patients compared with those who were EBV positive (OR = 0.01, 95%CI = (0.004-0.32; p = 0.009)), whereas the majority of patients (91.8%) had undifferentiated, non-keratinizing squamous cell carcinoma, followed by differentiated, non-keratinizing squamous cell carcinoma (7.5%). Although NPC had metastasized to 16% of other body sites, it was not associated with EBV infection, except for lung metastasis. A statistically significant reverse association was observed between EBV infection and lung metastasis (OR = 0.07, 95%CI = (0.01-0.51; p = 0.008)). Although 13% of NPC patients died, the overall survival (OS) mean time was 5.59 years. Given the high prevalence of EBV-associated NPC in our population, Saudi could be considered as an area with a high incidence of EBV-associated NPC with a predominance of EBV genotype I. A future multi-center study with a larger sample size is needed to assess the true burden of EBV-associated NPC in Saudi Arabia.

Analysis of two laboratory tests for determination of EBV-IM in children

This study aimed to explore the application value of two laboratory tests in the diagnosis of Epstein-Barr virus-associated infectious mononucleosis (EBV-IM) in children. From January 2018 to December 2020, 166 patients with EBV-IM were included in this study. Two methods were used in the analysis. The results of both tests were compared and analyzed. The age of onset of EBV-IM is mainly distributed in the range of 0-6 years, and no difference by gender is observed. The sensitivity and specificity of EBV testing by PCR were 49.4% and 89.8%, respectively, and the area under the receiver operating characteristic curve (AUC) was 0.714 (0.662-0.762). When using the immunofluorescence method to detect EBV antibodies, the two indices with the highest diagnostic efficacy were low-affinity EBV-CA IgG and EBV-CA IgM, and their AUC values were 0.798 (0.751-0.840) and 0.663 (0.609-0.713), respectively. When combining the two indices for testing, the AUC values of EBV-CA IgM + low-affinity EBV-CA IgG, EBV-DNA+EBV-CA IgM, and EBV-DNA+low-affinity EBV-CA IgG were 0.904 (0.867-0.933), 0.768 (0.719-0.812), and 0.963 (0.937-0.981), respectively. The diagnostic efficacy of the combined EBV-DNA+EBV-CA IgM + low-affinity EBV-CA IgG test was optimal compared with that of a single index or the combination of two indices, with an AUC of 0.999 (0.986-1.000; p < 0.05), sensitivity of 100%, and specificity of 89.8%. The combined immunofluorescence and real-time PCR methods have high sensitivity and specificity and good application value in the clinical diagnosis of EBV-IM.