The high burden of hospitalizations for primary EBV infection: a 6-year prospective survey in a French hospital

Risk of multiple sclerosis in individuals with infectious mononucleosis: a national population-based cohort study using hospital records in England, 2003-2023

BACKGROUND

Epstein-Barr virus (EBV) is thought to be a necessary causative agent in the development of multiple sclerosis (MS). Infectious mononucleosis (IM), which occurs up to 70% of adolescents and young adults with primary EBV infection, appears to be a further risk factor but few studies have been highly powered enough to explore this association by time since IM diagnosis.

OBJECTIVE

The objective was to quantify the risk of MS in individuals with IM compared with the general population, with particular focus on time since IM diagnosis.

METHODS

In this retrospective cohort study using English national Hospital Episode Statistics from 2003 to 2023, patients with a hospital diagnosis of IM were compared with the general population for MS incidence.

RESULTS

MS incidence in patients with IM was nearly three times higher than the general population after multivariable adjustment (adjusted hazard ratio = 2.8, 95% confidence interval (CI = 2.3-3.4), driven by strong associations at long time intervals (>5 years) between IM diagnosis and subsequent MS diagnosis.

CONCLUSION

While EBV infection may be a prerequisite for MS, the disease process of IM (i.e. the body's defective immune response to primary EBV infection) seems to be, in addition, implicated over the long term.

Are corticosteroids safe in adolescent and adult patients with infectious mononucleosis? A retrospective cohort study

BACKGROUND AND AIM

The use of systemic corticosteroids during Epstein-Barr virus (EBV)-induced infectious mononucleosis is a controversial but widespread practice. We aimed to investigate the frequency of complications in adolescents and adults with infectious mononucleosis in relation to the use of corticosteroids.

METHODS

We reviewed the clinical records of 396 patients admitted to the hospital with infectious mononucleosis (52.0% male; median age, 19 years; range, 15-87 years), with a focus on both short-term (infectious and non-infectious) and long-term (hematological malignancies) complications in relation to corticosteroid use.

RESULTS

A total of 155 (38.6%) patients received corticosteroids at some point during infectious mononucleosis. Corticosteroid use was significantly (P≤0.002) associated with sore throat, lymphadenopathy, leukocytosis, and with antibiotics use (mainly indicated after suspicion of tonsillar bacterial superinfection). Overall, 139/155 (89.7%) patients who were treated with corticosteroids also received antibiotics either before or during hospitalization, compared with 168/241 (69.7%) patients who did not. The frequency of short-term severe complications, either infectious (peritonsillar-parapharyngeal abscess or bacteremia) or non-infectious (splenic rupture, severe thrombocytopenia, myopericarditis, or lymphocytic meningitis) were similar in patients receiving and not receiving corticosteroids. After a median of 15 years of follow-up, only one Hodgkin's lymphoma was diagnosed, in a patient who was not treated with corticosteroids during infectious mononucleosis.

CONCLUSIONS

The use of systemic corticosteroids during EBV-induced infectious mononucleosis is generally safe, at least with concomitant antibiotic therapy. However, this should not encourage the use of corticosteroids in this context, given that their efficacy has yet to be demonstrated.

HLA-E-restricted immune responses are crucial for the control of EBV infections and the prevention of PTLD

Primary Epstein-Barr virus (EBV) infections may cause infectious mononucleosis (IM), whereas EBV reactivations in solid organ and hematopoietic stem cell transplant recipients are associated with posttransplantation lymphoproliferative disorders (PTLDs). It is still unclear why only a minority of primary EBV-infected individuals develop IM, and why only some patients progress to EBV+PTLD after transplantation. We now investigated whether nonclassic human leukocyte antigen E (HLA-E)-restricted immune responses have a significant impact on the development of EBV diseases in the individual host. On the basis of a large study cohort of 1404 patients and controls as well as on functional natural killer (NK) and CD8+ T-cell analyses, we could demonstrate that the highly expressed HLA-E∗0103/0103 genotype is protective against IM, due to the induction of potent EBV BZLF1-specific HLA-E-restricted CD8+ T-cell responses, which efficiently prevent the in vitro viral dissemination. Furthermore, we provide evidence that the risk of symptomatic EBV reactivations in immunocompetent individuals as well as in immunocompromised transplant recipients depends on variations in the inhibitory NKG2A/LMP-1/HLA-E axis. We show that EBV strains encoding for the specific LMP-1 peptide variants GGDPHLPTL or GGDPPLPTL, presented by HLA-E, elicit strong inhibitory NKG2A+ NK and CD8+ T-cell responses. The presence of EBV strains encoding for both peptides was highly associated with symptomatic EBV reactivations. The further progression to EBV+PTLD was highly associated with the presence of both peptide-encoding EBV strains and the expression of HLA-E∗0103/0103 in the host. Thus, HLA-E-restricted immune responses and the NKG2A/LMP-1/HLA-E axis are novel predictive markers for EBV+PTLD in transplant recipients and should be considered for future EBV vaccine design.

Virological Markers in Epstein–Barr Virus-Associated Diseases

Epstein–Barr virus (EBV) is an oncogenic virus infecting more than 95% of the world’s population. After primary infection—responsible for infectious mononucleosis in young adults—the virus persists lifelong in the infected host, especially in memory B cells. Viral persistence is usually without clinical consequences, although it can lead to EBV-associated cancers such as lymphoma or carcinoma. Recent reports also suggest a link between EBV infection and multiple sclerosis. In the absence of vaccines, research efforts have focused on virological markers applicable in clinical practice for the management of patients with EBV-associated diseases. Nasopharyngeal carcinoma is an EBV-associated malignancy for which serological and molecular markers are widely used in clinical practice. Measuring blood EBV DNA load is additionally, useful for preventing lymphoproliferative disorders in transplant patients, with this marker also being explored in various other EBV-associated lymphomas. New technologies based on next-generation sequencing offer the opportunity to explore other biomarkers such as the EBV DNA methylome, strain diversity, or viral miRNA. Here, we review the clinical utility of different virological markers in EBV-associated diseases. Indeed, evaluating existing or new markers in EBV-associated malignancies or immune-mediated inflammatory diseases triggered by EBV infection continues to be a challenge.

Impact of Epstein-Barr virus serological status on clinical outcomes in adult patients with inflammatory bowel disease

BACKGROUND

Little is known about the impact of Epstein-Barr virus (EBV) infection on clinical outcomes in adults with inflammatory bowel disease (IBD).

AIM

To evaluate seroprevalence, seroconversion rate and complications associated with EBV infection in an adult IBD cohort attending a tertiary care hospital in Spain between 2006 and 2016.

METHODS

EBV serological status was determined. In seronegative patients, the seroconversion rate was evaluated. The complications associated with primary and latent EBV infection are described.

RESULTS

One thousand four hundred and eighty-three patients over the age of 17 were included in the study (mean age at EBV serological status determination was 48.3). Overall seroprevalence of EBV was 97.4% (95% CI: 96.6%-98.2%). The seroconversion rate was 29.7% (95% CI: 16.2-45.9) after a mean of 47.5 months. There were no differences in seroconversion rates between patients 35 years or younger and patients older than 35 years. A 66-year-old man, on treatment with thiopurines, developed lymphoma and a hemophagocytic syndrome during a primary EBV infection. Overall, six patients (one with primary infection and five with prior EBV infection) developed lymphoma. In three of five patients with lymphoma and thiopurine use, EBV was associated to the development of lymphoma.

CONCLUSIONS

There is a small percentage of adults with IBD at risk of primary EBV infection. The risks of seroconversion and its complications remain through adulthood. Our results suggest that, when considering the use of thiopurines in IBD, the information on EBV serological status should be taken into account at any age.

Severe infectious mononucleosis in immunocompetent adults

OBJECTIVES

To determine the risk factors for severe infectious mononucleosis (IM) occurrence in immunocompetent adults.

METHODS

We performed a multicenter, retrospective case series including immunocompetent adults presenting with confirmed IM between 2001 and 2011. Severe presentations were compared with uncomplicated presentations using Stata^® 9 software. The significance level was set at 5%.

RESULTS

In univariate analysis, age over 30 years (n=13 or 41.9% vs. n=5 or 12.8%; P=0.006), prior use of non-steroidal anti-inflammatory drugs (NSAIDs) (n=7 or 87.5% vs. n=1 or 12.5%; P=0.009), and smoking (n=13 or 68.4% vs. n=6 or 31.6%; P=0.013) were associated with severe IM onset. In multivariate analysis, only age over 30 years (OR=3.55; P=0.05) and prior use of NSAIDs (OR=15; P=0.05) remained associated with severe IM onset, without reaching significance level (P=0.05).

CONCLUSION

Our study confirmed that age over 30 years is a risk factor for severe IM onset. Prior use of NSAIDs also seems to be correlated with severe presentations. This new data needs to be confirmed in a prospective study.

Evolution of EBV seroprevalence and primary infection age in a French hospital and a city laboratory network, 2000-2016

BACKGROUND

According to rare studies, the age at EBV primary infection (PI) has recently risen in some developed countries. A later age at infection is generally considered a risk factor for severe EBV PI, although few studies exist on this subject. Our investigation aimed to determine whether EBV seroprevalence and EBV PI epidemiology have evolved in France, and to what extent age and infection intensity (regarding biological parameters) are correlated.

METHODS AND FINDINGS

We conducted a retrospective study of the following EBV serological tests databases: tests carried out at Grenoble University Hospital (2000-2016) (n = 53,553); and tests carried out by a network of city laboratories in Grenoble area (2008-2015) (n = 27,485). The hospital population showed a continuous, significant decrease in EBV seroprevalence over the studied period for patients aged 20 and over (p<0.01). The seroprevalence also decreased for different age classes (<10, 15-19, 20-30, and 30-40 years old) over the periods 2001-2005, 2006-2010, and 2011-2015. Consistently, the age at PI was significantly higher in the years 2008-2015 than in the years 2001-2007 (15.6±12.0 vs. 13.7±11.0; p = 0.03). The city laboratory population showed the same trend of decreasing seroprevalence (p = 0.06); no significant variations in age at PI were observed. The age at PI was positively correlated with ASAT, ALAT, γGT, and bilirubin blood levels (p<0.01) and negatively correlated with platelet counts (p<0.05).

CONCLUSION

In the last 15 years, the age at EBV PI has increased, whereas seroprevalence has decreased. Moreover, our findings confirm the positive correlation between age and biological abnormalities. Taken together, these results suggest that the incidence of severe EBV PI will increase in the future.