Metabolomic differences between exanthematous drug eruption and infectious mononucleosis.

BACKGROUND: Exanthematous drug eruption and infectious mononucleosis (IM) are both exanthematous diseases. Current research on exanthematous drug eruption and IM mainly targets identifying these disorders, the resulting differences at the metabolism level have not yet been systematically analyzed. MATERIALS AND METHODS: A total of 30 cases of exanthematous drug eruption and IM, 10 patients without exanthema and 10 healthy volunteers were enrolled, 3 mL of fasting venous blood was collected, the serum metabolite content was detected by gas chromatography-mass spectrometry metabolomics. RESULTS: A total of 165 metabolites were identified, exhibiting significant differences in plasma metabolic trends between exanthematous drug eruption and IM, and pinpointed 28 potential biomarkers. Notable changes were seen in the metabolic activities of the pentose phosphate pathway (PPP), tricarboxylic acid cycle (TCA-cycle), and galactose metabolism, characterized by increased levels of gluconate, gluconolactone, glucose, galactaric acid, and mannose, along with decreased amounts of pyruvic acid, succinic acid, malic acid, and glycerol, indicating an impairment in the exanthematous drug eruption group's capacity to endure oxidative stress and regulate energy metabolism. In contrast to its medication without rash counterpart, the exanthematous drug eruption group's plasma displayed distinct metabolic routes, predominantly in the processing of arginine and proline, along with the TCA. This resulted in a marked reduction in urea levels and a rise in pyruvate, citrate, and ornithine, indicating hypoxic stress as the primary cause of these rashes. In contrast to the healthy control group, the IM group showed 26 potential biomarkers, marked by increased levels of ketoglutaric acid, malic acid, pyruvic acid, and oxoglutaric acid, and reduced amounts of glutamine, galacturonic acid, arachidonic acid, trimethylphosphonic acid ester, gluconolactone, and indole acetic acid. Mainly, the metabolic pathways included the TCA, breaking down alanine, aspartate and glutamate metabolism, and the processing of D-glutamine and D-glutamate metabolism, underscoring the body's crucial role in generating energy and inflammatory agents through the citric acid cycle. CONCLUSIONS: The comparison of serum metabolomic features of exanthematous drug eruptions and IM outlines a unique pattern closely related to the differences in the pathogenesis of these two exanthematous diseases.

Constructing a predictive model based on peripheral blood signs to differentiate infectious mononucleosis from chronic active EBV infection.

OBJECTIVE: To develop a prediction model based on peripheral blood signs to distinguish between infectious mononucleosis and chronic active EBV infection. METHODS: Retrospective data was collected for 60 patients with IM (IM group) and 20 patients with CAEBV infection (CAEBV group) who were hospitalized and diagnosed at the General Hospital of Tianjin Medical University between December 2018 and September 2022. The analyses used were univariate and LASSO (least absolute shrinkage and selection operator) logistic regression. RESULTS: Univariate analyses revealed that both IM and CAEBV-infected patients displayed overlapping and intersecting clinical manifestations, such as fever, sore throat, enlarged lymph nodes, and enlargement of the liver and spleen, and that in contrast to inflammatory responses in peripheral blood, CAEBV-infected patients had more severe inflammatory responses. Nine biomarkers-HGB, lymphocyte count, percentage of lymphocytes, ALB, fibrinogen, CRP, IFN-, IL-6, and EBV-DNA load-were subsequently selected by LASSO logistic regression modeling to serve as discriminatory models. CONCLUSIONS: Our investigation offers a solid foundation for diagnosing IM and CAEBV infection using the LASSO logistic regression model based on the significance and availability of peripheral blood indicators. Infected patients with CAEBV require early medical attention.

Clinical analysis of 163 pediatric patients with infectious mononucleosis: a single-center retrospective analysis.

OBJECTIVE: This study aims to enhance the management of Epstein-Barr Virus (EBV) infections by analyzing the correlation between laboratory indicators and clinical manifestations in children, thereby proposing more precise diagnostic and treatment strategies. METHODS: In this retrospective study included 163 pediatric patients with EBV infections treated at the Children's Hospital of Soochow University from December 2017 to December 2019. Data collected through retrospective analysis included gender, age, clinical symptoms, signs, liver function tests, T-cell subset distribution, EBV-DNA copy numbers in plasma, and treatment outcomes. Patients were grouped based on EBV-DNA copy numbers in plasma and hospital stay duration to compare clinical indicators across different groups. RESULTS: The dichotomous results of EBV-DNA copy numbers in plasma showed that the two groups of children were significantly different in the number of days of fever (p = .0022), platelet count (p = .0212), ALT (p = .001), immunoglobulin IgM (p = .0039), IgG (p = .0195), TBiL (p = .025), LDH (p = 0.0001), and length of hospital stay (p < .001) were significantly different, indicating that EBV-DNA copy numbers in plasma may be correlated with these characteristic variables. The dichotomous results of the length of hospital stay showed that the two groups were significantly increased in tonsil enlargement (p = .0024), platelet count (p = .0059), LDH (p = .0394), and ferritin (p = .0106) and EBV-DNA copy numbers in plasma (p = 0.0361) were significantly different, This suggests a potential correlation between EBV-DNA copy numbers in plasma and these clinical indicators. CONCLUSION: Variations in platelet counts and lactate dehydrogenase (LDH) levels in children with EBV infections may serve as indicators of clinical outcomes.

Risk of inflammatory bowel disease following hospitalisation with infectious mononucleosis: nationwide cohort study from Denmark.

Infectious mononucleosis (IM) is suspected to be associated with inflammatory bowel disease (IBD) development. Using a Danish nationwide cohort of people developing severe IM and their age-, sex-, and socioeconomic (SES) index-matched counterparts, we investigated the subsequent risk of IBD, Crohn's disease (CD), or ulcerative colitis (UC) development from 1977 to 2021. Among 39,684 severe IM patients we find a sex-, age-, and SES index-adjusted HR for IBD of 1.35 (95% CI: 1.22-1.49). This significantly increased risk was seen for both CD (HR: 1.56; 95% CI: 1.34-1.83) and to a lesser extent UC (HR: 1.23; 95% CI: 1.08-1.40) and remains following negative control matching with a cohort diagnosed with Chlamydia trachomatis infection (HR: 1.39; 95% CI: 1.01-1.91). Those with severe IM at 0-9 years had a particularly increased risk for CD (HR: 1.77; 95% CI: 1.26-2.49). Here we show an increased risk for IBD diagnosis following IM hospitalisation, indicating an association between severe EBV disease and later IBD development. Further exploration of the potential factors contributing to IBD susceptibility following EBV disease is warranted.

[Cold agglutinin syndrome associated with infectious mononucleosis: A case report]. / Síndrome por aglutininas frías secundario a mononucleosis infecciosa: reporte de un caso.

Background: Cold agglutinin syndrome (CAS) is a hemolytic anemia mediated by antibodies, mainly IgM, whose maximum activity occurs at 4 °C. It happens secondary to infectious, autoimmune or neoplastic diseases, due to the formation of antibodies that cross-react against erythrocyte antigens, particularly of the I system. Here, we describe a case of CAS associated to Epstein-Barr virus (EBV) reactivation in a patient with primary human immunodeficiency virus (HIV) infection. Clinical case: 22-year old man with no medical history, hospitalized due to mononucleosis and anemic syndrome. Hemoglobin of 3.7 g/dL and elevation of lactate dehydrogenase were documented. In the peripheral blood smear it was observed spherocytosis, polychromasia and nucleated erythrocytes. EBV infection was confirmed with serology and viral load, as well as seronegative HIV infection with positive viral load. The C3d monospecific direct antiglobulin test was positive and an irregular antibody screening revealed the presence of an anti-I antibody. The patient received transfusion support and conservative treatment, with remission of the symptoms 2 weeks after admission. Conclusions: Cold agglutinin syndrome is a rare, potentially fatal complication of infectious mononucleosis, which should be considered in the face of findings suggestive of hemolysis in order to initiate support measures in a timely manner.

Introducción: el síndrome por aglutininas frías (SAF) es una anemia hemolítica mediada por anticuerpos principalmente de tipo IgM, cuya máxima actividad se da a 4 °C. Se presenta en el contexto de enfermedades infecciosas, autoinmunes o neoplásicas por la formación de anticuerpos que tienen reacción cruzada contra antígenos eritrocitarios, particularmente del sistema I. En este trabajo presentamos un caso de SAF asociado a reactivación del virus de Epstein-Barr (VEB) en un paciente con primoinfección por el virus de la inmunodeficiencia humana (VIH). Caso clínico: hombre de 22 años, sin antecedentes patológicos, hospitalizado por síndrome mononucleósico y anémico. Presentó hemoglobina de 3.7 g/dL y elevación de lactato deshidrogenasa. En el frotis de sangre periférica se observó esferocitosis, policromasia y eritrocitos nucleados. Se confirmó infección por VEB con serología y carga viral, así como infección por VIH seronegativa, con carga viral positiva. La prueba de antiglobulina directa monoespecífica a C3d fue positiva y el rastreo de anticuerpos irregulares demostró un anticuerpo anti-I. El paciente recibió soporte transfusional y tratamiento conservador, con remisión del cuadro a las 2 semanas de su ingreso. Conclusiones: el SAF es una complicación poco frecuente de la mononucleosis infecciosa, potencialmente mortal, la cual debe ser considerada ante hallazgos sugestivos de hemólisis con la finalidad de iniciar medidas de soporte de forma oportuna.

Infectious mononucleosis complicated by transitory Epstein-Barr virus infection of T and natural killer cells.

Epstein-Barr virus (EBV) typically infects B cells in infectious mononucleosis (IM), but a rare case shows EBV infection in T cells. Seven cases of lymphoproliferative disorder caused by EBV-positive cytotoxic T/natural killer (NK) cell proliferation in the lymph nodes, termed IM with transient EBV infection of T and NK cells (EBV + T/NK cells in IM), are reported here. The purpose of the study is to describe clinicopathological features of EBV + T/natural killer (NK) cells in IM of the lymph node. We retrospectively analysed seven cases of Chinese children and young people adults with EBV + T/NK cells in IM. We used morphological observation, immunohistochemical staining, EB virus in situ hybridisation detection, and analysis of T-cell receptor gene rearrangement. The patients were healthy prior to illness, experiencing sudden onset occurring in all the patients, with high fever as the first symptom, followed by lymphadenopathy and hepatosplenomegaly. Diagnosis occurred < 1.5 months of symptom onset. Most lymphocytes in lesions expressed CD3 and Granzyme B or TIA-1 and lacked CD5. CD56 was expressed in numerous cells in 5 of the 7 cases. EBV-encoded RNA (EBER) was detected in medium-to-large-sized cells (50-100 cells per cell/high-power field). T-cell receptor (TCR) gene rearrangement was seen in six cases, with monoclonal rearrangement in four cases. Treatment was conservative treatment but not chemotherapy. Four received anti-HLH therapy and others anti-inflammatory treatment. All patients survived with relapse after long-term clinical observation and follow-up. EBV + T/NK cells in IM can elicit malignant features that mimic T/NK-cell lymphoma pathologically and benign features mimicking IM clinically. These findings indicate that EBV + T/NK cells in IM could serve as valuable diagnosis. Additional clinical information, including age of onset (children and young people), nature of onset (sudden), disease course (short), symptoms (systemic), EBV infection status (acute), and lymph node involvement, is crucial for accurate diagnosis and prognostic evaluation.

Histopathology of peritonitis due to infectious mononucleosis with background Chlamydia trachomatis infection: A case report and literature review.

Epstein-Barr virus (EBV) is a major cause of infectious mononucleosis (IM), characterized by fever, fatigue, sore throat, lymphadenopathy, atypical lymphocytosis, and elevated liver enzymes. However, ascites is a rare complication associated with IM. We present a rare case of IM with ascites and peritonitis in a patient who underwent a peritoneal biopsy. A 20-year-old woman presented with fatigue and abdominal distension. Laboratory examination revealed atypical lymphocytes in peripheral blood (54%) and elevated liver enzymes. EBV serological tests revealed a recent primary infection (EBV VCA IgM 1:160). Computed tomography revealed moderate ascites and peritonitis. Adenocarcinoma was suspected based on the ascites' cytology. Considering possible complications of IM and adenocarcinoma, a laparoscopic biopsy was performed. Histological findings of biopsy specimens from the peritoneum, omentum, and fimbria of the fallopian tube demonstrated severe inflammatory cell infiltration and focal aggregation of large EBV-encoded RNA-1 (EBER1)-positive B cells, mimicking EBV-positive polymorphous B-cell lymphoproliferative disorder. Furthermore, intracytoplasmic inclusion bodies of Chlamydia trachomatis were observed by immunohistochemistry. Real-time polymerase chain reaction detected C. trachomatis in cervical secretions. Two months after laparoscopy, ascites decreased, and the diagnosis was IM-associated peritonitis with C. trachomatis infection. IM should be considered as a differential diagnosis in young patients with ascites.

Evaluation of novel Epstein-Barr virus-derived antigen formulations for monitoring virus-specific T cells in pediatric patients with infectious mononucleosis.

BACKGROUND: Infection with the Epstein-Barr virus (EBV) elicits a complex T-cell response against a broad range of viral proteins. Hence, identifying potential differences in the cellular immune response of patients with different EBV-associated diseases or different courses of the same disorder requires interrogation of a maximum number of EBV antigens. Here, we tested three novel EBV-derived antigen formulations for their ability to reactivate virus-specific T cells ex vivo in patients with EBV-associated infectious mononucleosis (IM). METHODS: We comparatively analyzed EBV-specific CD4+ and CD8+ T-cell responses to three EBV-derived antigen formulations in 20 pediatric patients during the early phase of IM: T-activated EBV proteins (BZLF1, EBNA3A) and EBV-like particles (EB-VLP), both able to induce CD4+ and CD8+ T-cell responses ex vivo, as well as an EBV-derived peptide pool (PP) covering 94 well-characterized CD8+ T-cell epitopes. We assessed the specificity, magnitude, kinetics, and functional characteristics of EBV-specific immune responses at two sequential time points (v1 and v2) within the first six weeks after IM symptom onset (Tonset). RESULTS: All three tested EBV-derived antigen formulations enabled the detection of EBV-reactive T cells during the early phase of IM without prior T-cell expansion in vitro. EBV-reactive CD4+ and CD8+ T cells were mainly mono-functional (CD4+: mean 64.92%, range 56.15-71.71%; CD8+: mean 58.55%, range 11.79-85.22%) within the first two weeks after symptom onset (v1) with IFN-γ and TNF-secreting cells representing the majority of mono-functional EBV-reactive T cells. By contrast, PP-reactive CD8+ T cells were primarily bi-functional (>60% at v1 and v2), produced IFN-γ and TNF and had more tri-functional than mono-functional components. We observed a moderate correlation between viral load and EBNA3A, EB-VLP, and PP-reactive CD8+ T cells (rs = 0.345, 0.418, and 0.356, respectively) within the first two weeks after Tonset, but no correlation with the number of detectable EBV-reactive CD4+ T cells. CONCLUSIONS: All three EBV-derived antigen formulations represent innovative and generic recall antigens suitable for monitoring EBV-specific T-cell responses ex vivo. Their combined use facilitates a thorough analysis of EBV-specific T-cell immunity and allows the identification of functional T-cell signatures linked to disease development and severity.

Genetic and early life factors influence on time-to-multiple sclerosis diagnosis: A UK Biobank study.

BACKGROUND: Previous investigations into multiple sclerosis (MS) risk factors predominantly relied on retrospective studies, which do not consider different follow-up times and assume a constant risk effect throughout lifetime. OBJECTIVE: We aimed to evaluate the impact of genetic and early life factors on MS diagnosis by employing a time-to-event analysis in a prospective cohort. METHODS: We used the UK Biobank data, considering the observation period from birth up to 31 December 2022. We considered genetic risk, using a multiple sclerosis polygenic risk score (MS-PRS), and various early life factors. Tobacco smoking and infectious mononucleosis diagnosis were also considered as time-varying variables along the follow-up. Using a Cox proportional hazards model, we examined the associations between these factors and MS diagnosis instantaneous risk. RESULTS: We analyzed 345,027 participants, of which 1669 had an MS diagnosis. Our analysis revealed age-dependent effects for sex (females vs males) and higher MS-PRS, with greater hazard ratios observed in young adults. CONCLUSION: The age-dependent effects suggest that retrospective studies could have underestimated sex and genetic variants' risk roles during younger ages. Therefore, we emphasize the importance of a time-to-event approach using longitudinal data to better characterize age-dependent risk effects.

[The Role of Notch Signaling Pathway in Adult Patients with Epstein-Barr Virus-induced Infectious Mononucleosis].

OBJECTIVE: To investigate the changes of Notch signaling molecules and Th22 cells in adult patients with infectious mononucleosis (IM), and assess the regulatory function of Notch signaling inhibition to Th22 cells. METHODS: Forty-two IM patients and twenty-one healthy controls were enrolled in this study. Their peripheral blood was collected, from which plasma and peripheral blood mononuclear cells (PBMCs) were isolated. Plasma interleukin (IL)-17 and IL-22 were measured by enzyme-linked immunosorbent assay. The percentages of CD3+ CD4+ IL-17+ Th17 cells and CD3+ CD4+ IL-22+ Th22 cells were investigated by flow cytometry. The mRNA relative levels corresponding to Th17 transcription factor retinoic acid related orphan receptor γt (RORγt), Th22 transcription factor aryl hydrocarbon receptor (AhR), and Notch signaling pathway molecules (including Notch receptors, Notch ligands, Notch downstream molecules) were semi-quantified by real-time PCR. CD4+ T cells were purified and stimulated with γ-secretase inhibitor (GSI). Cellular proliferation, Th17 and Th22 percentage, IL-17 and IL-22 secretion, transcription factor mRNA were measured in response to GSI stimulation. RESULTS: The relative expression levels of Notch1 and Notch2 mRNA in PBMCs of IM group were 13.58±3.18 and 4.73±1.16, respectively, which were significantly higher than 1.09±0.12 and 1.07±0.15 in PBMCs of control group (both P < 0.001). However, there were no significant differences in relative expression levels of Notch3 and Notch4 mRNA between IM group and control group (P >0.05). The relative expression levels of Notch ligands (including DLL1 and Jagged1 ) mRNA and Notch downstream molecules (including Hes1, Hes5, and Hey1 ) were increased in IM group compared with control group (all P < 0.001). In IM group, the Th17 and Th22 percentage were 5.03%±1.15% and 4.48%±1.29%, respectively, which were both higher than 4.36%±0.82% and 3.83%±0.55% in control group (both P < 0.05). In IM group, the IL-17 and IL-22 level were (301.1±53.82) and (101.2±16.45) pg/ml, respectively, which were both higher than (237.2±72.18) and (84.75±11.83) pg/ml in control group (both P < 0.001). In IM group, the relative expression levels of RORγt and AhR mRNA were 1.25±0.22 and 1.21±0.12, respectively, which were both higher than 0.99±0.15 and 1.04±0.11 in control group (both P < 0.001). There were no remarkable differences in CD4+ T cell proliferation, Th17 percentage, IL-17 secretion, and relative expression level of RORγt mRNA between cells with GSI stimulation and without GSI stimulation (P >0.05). GSI stimulation reduced Th22 percentage, IL-22 secretion, and relative expression level of AhR mRNA compared with non-stimulation (all P < 0.05). CONCLUSION: Notch signaling pathway regulates IL-22 secretion by CD4+ T cells via AhR in IM patients. Notch-AhR-Th22 pathway may take part in the pathogenesis of IM.

Flow Cytometry as the Tool to Define Peripheral Blood Leukocyte Signatures in Acute EBV Infection.

Primary Epstein-Barr virus (EBV) infection which can manifest as infectious mononucleosis (IM) is commonly acquired during childhood. EBV primarily invades B cells leading to a lytic reaction; the control of the infection is handled by natural killer and T cells in immunocompetent individuals. The infection has a wide spectrum of clinical findings and can lead to serious complications in patients with certain underlying immunological dysfunctions. We retrospectively investigated peripheral white blood cell populations' surface marker characteristics in IM using a comprehensive flow cytometry marker panel. Twenty-one cases of IM and seventeen EBV-seropositive cases without IM serving as controls were included. We observed novel alterations in lymphocyte, neutrophil, and monocyte populations. In addition to increased activated cytotoxic T cells and low B cells, we demonstrated high T-large granular lymphocyte (T-LGL) populations in IM cases. Furthermore, despite T cells' increased HLA-DR expression, another activation marker, CD11b, was lower in T-LGL populations. Monocytes showed increased CD16 expression; CD64 was higher in neutrophils. Our findings point to monocyte and neutrophil activation which may account for acute clinical features and may contribute to the understanding of IM immunobiology. Furthermore, they may serve as a useful tool in investigating inherited and post-transplant conditions characterized by deficiencies in controlling EBV infection.

Heightened Epstein-Barr virus immunity and potential cross-reactivities in multiple sclerosis.

BACKGROUND: Epstein-Barr virus (EBV) is a likely prerequisite for multiple sclerosis (MS) but the underlying mechanisms are unknown. We investigated antibody and T cell responses to EBV in persons with MS (pwMS), healthy EBV-seropositive controls (HC) and post-infectious mononucleosis (POST-IM) individuals up to 6 months after disease resolution. The ability of EBV-specific T cell responses to target antigens from the central nervous system (CNS) was also investigated. METHODS: Untreated persons with relapsing-remitting MS, POST-IM individuals and HC were, as far as possible, matched for gender, age and HLA-DRB1*15:01. EBV load was determined by qPCR, and IgG responses to key EBV antigens were determined by ELISA, immunofluorescence and Western blot, and tetanus toxoid antibody responses by multiplex bead array. EBV-specific T cell responses were determined ex vivo by intracellular cytokine staining (ICS) and cross-reactivity of in vitro-expanded responses probed against 9 novel Modified Vaccinia Ankara (MVA) viruses expressing candidate CNS autoantigens. RESULTS: EBV load in peripheral blood mononuclear cells (PBMC) was unchanged in pwMS compared to HC. Serologically, while tetanus toxoid responses were unchanged between groups, IgG responses to EBNA1 and virus capsid antigen (VCA) were significantly elevated (EBNA1 p = 0.0079, VCA p = 0.0298) but, importantly, IgG responses to EBNA2 and the EBNA3 family antigens were also more frequently detected in pwMS (EBNA2 p = 0.042 and EBNA3 p = 0.005). In ex vivo assays, T cell responses to autologous EBV-transformed B cells and to EBNA1 were largely unchanged numerically, but significantly increased IL-2 production was observed in response to certain stimuli in pwMS. EBV-specific polyclonal T cell lines from both MS and HC showed high levels of autoantigen recognition by ICS, and several neuronal proteins emerged as common targets including MOG, MBP, PLP and MOBP. DISCUSSION: Elevated serum EBV-specific antibody responses in the MS group were found to extend beyond EBNA1, suggesting a larger dysregulation of EBV-specific antibody responses than previously recognised. Differences in T cell responses to EBV were more difficult to discern, however stimulating EBV-expanded polyclonal T cell lines with 9 candidate CNS autoantigens revealed a high level of autoreactivity and indicate a far-reaching ability of the virus-induced T cell compartment to damage the CNS.

Characteristics of Virology and Immune Inflammation of Epstein-Barr Virus Infection Related Non-Neoplastic Diseases in Children.

BACKGROUND: The goal was to study the difference of virological, immunologic, and inflammatory indicators between Epstein-Barr associated infectious mononucleosis (EBV-IM) and EBV associated hemophagocytic lymphohistiocytosis (EBV-HLH) and to explore the evaluation indicators for monitoring the therapeutic efficacy of EBV-HLH. METHODS: Twenty children with EBV-IM (IM group) and 10 children with EBV-HLH (HLH group) were selected. Virology indicators were detected; the absolute count of lymphocyte, and lymphocyte subsets were detected; the levels of immunoglobulin and ferritin were assayed. RESULTS: Compared to the IM group, the HLH group showed a decrease in EBV-specific VCA-IgM antibody levels (U = 29.0, p = 0.006) and an increase in EBV-specific NA-IgG antibody levels (U = 17.0, p = 0.001), while there was no significant difference in EB-DNA loads (t = 0.417, p = 0.680). The counts of lymphocytes, and various lymphocyte subsets in the HLH group were lower than those in the IM group. Inflammatory markers in the HLH group were significantly higher than those in IM group. Dynamic monitoring of virological, immunological, and inflammatory indicators in HLH patients during treatment showed that EBV DNA gradually decreased in patients with good prognosis. Inflammatory indicators significantly decreased and returned to normal, lymphocyte count significantly increased and returned to normal during treatment. However, patients with poor prognosis showed rebound increase in EBV DNA and inflammatory indicators in the later stage of treatment, while lymphocyte count further decreased with the recurrence of the disease. CONCLUSIONS: Exhausted and damaged immune function in host by persistent stimulation of EB viral antigen is one of the main pathogeneses of EB-HLH. Lymphocyte count and serum ferritin level are effective indicators to monitor the therapeutic efficacy during the treatment to HLH.

Genetics of immune response to Epstein-Barr virus: prospects for multiple sclerosis pathogenesis.

Epstein-Barr virus (EBV) infection has been advocated as a prerequisite for developing multiple sclerosis (MS) and possibly the propagation of the disease. However, the precise mechanisms for such influences are still unclear. A large-scale study investigating the host genetics of EBV serology and related clinical manifestations, such as infectious mononucleosis (IM), may help us better understand the role of EBV in MS pathogenesis. This study evaluates the host genetic factors that influence serological response against EBV and history of IM and cross-evaluates them with MS risk and genetic susceptibility in the Swedish population. Plasma IgG antibody levels against EBV nuclear antigen-1 [EBNA-1, truncated = amino acids (aa) (325-641), peptide = aa(385-420)] and viral capsid antigen p18 (VCAp18) were measured using bead-based multiplex serology for 8744 MS cases and 7229 population-matched control subjects. The MS risk association for high/low EBV antibody levels and history of IM was compared to relevant clinical measures along with sex, age at sampling, and associated HLA allele variants. Genome-wide and HLA allele association analyses were also performed to identify genetic risk factors for EBV antibody response and IM history. Higher antibody levels against VCAp18 [odds ratio (OR) = 1.74, 95% confidence interval (CI) = 1.60-1.88] and EBNA-1, particularly the peptide (OR = 3.13, 95% CI = 2.93-3.35), were associated with an increased risk for MS. The risk increased with higher anti-EBNA-1 IgG levels up to 12× the reference risk. We also identified several independent HLA haplotypes associated with EBV serology overlapping with known MS risk alleles (e.g. DRB1*15:01). Although there were several candidates, no variants outside the HLA region reached genome-wide significance. Cumulative HLA risk for anti-EBNA-1 IgG levels, particularly the peptide fragment, was strongly associated with MS. In contrast, the genetic risk for high anti-VCAp18 IgG levels was not as strongly associated with MS risk. IM history was not associated with class II HLA genes but negatively associated with A*02:01, which is protective against MS. Our findings emphasize that the risk association between anti-EBNA-1 IgG levels and MS may be partly due to overlapping HLA associations. Additionally, the increasing MS risk with increasing anti-EBNA-1 levels would be consistent with a pathogenic role of the EBNA-1 immune response, perhaps through molecular mimicry. Given that high anti-EBNA-1 antibodies may reflect a poorly controlled T-cell defence against the virus, our findings would be consistent with DRB1*15:01 being a poor class II antigen in the immune defence against EBV. Last, the difference in genetic control of IM supports the independent roles of EBNA-1 and IM in MS susceptibility.

The Impact of Infectious Mononucleosis History on the Risk of Developing Lymphoma and Nasopharyngeal Carcinoma: A Retrospective Large-Scale Cohort Study Using National Health Insurance Data in South Korea.

PURPOSE: This study aimed to assess the long-term risks associated with a history of infectious mononucleosis (IM), primarily caused by the Epstein-Barr virus (EBV). Specifically analyzing the potential increase in developing nasopharyngeal cancer (NPC) and lymphoma in patients with a history of IM and exploring the prevalence of other EBV-associated conditions. MATERIALS AND METHODS: The Korean National Health Insurance Service (NHIS) database was utilized for a retrospective analysis, covering data from 2002 to 2021. A total of 25,582 IM patients and controls were included, with 1:1 propensity score matching. The study monitored outcomes, including lymphoma, NPC, gastric cancer, multiple sclerosis, and all-cause mortality. RESULTS: Patients with a history of IM demonstrated a significantly higher incidence of lymphoma (hazard ratio [HR], 5.320; 95% confidence interval [CI], 3.208 to 8.820; p < 0.001) and NPC (HR, 7.116; 95% CI, 1.617 to 31.314; p=0.009) during the follow-up period compared with the control group. Additionally, the IM group showed an increased rate of all-cause mortality (HR, 2.225; 95% CI, 1.858 to 2.663; p < 0.001). CONCLUSION: This study suggests that individuals with a history of IM have an elevated risk of developing lymphoma and NPC in South Korea, emphasizing the importance of vigilant follow-up and monitoring. The results advocate for heightened awareness and potential national monitoring policies to address the long-term health implications of EBV infection and to implement preventive measures.

Infectious mononucleosis due to Epstein-Barr virus reactivation in an immunocompromised 60-year-old patient with COVID-19.

Epstein-Barr virus (EBV) reactivation in COVID-19 patients has been reported, but studies on its clinical significance are lacking. We herein report the occurrence of infectious mononucleosis (IM) due to EBV reactivation in a 60-year-old man with rheumatoid arthritis being treated with methotrexate and tocilizumab. The patient presented with a fever and tested positive for COVID-19. Laboratory findings revealed an increased atypical lymphocyte count, decreased platelet count, and elevated liver enzyme levels. Flow cytometry showed predominant expansion of reactive T cells. EBV reactivation was confirmed using real-time polymerase chain reaction. The patient was treated with remdesivir, and clinical improvement was observed after 10 days of treatment. Follow-up showed a gradual decrease in the EBV-DNA load with no recurrence of atypical lymphocytes. These findings suggest that COVID-19 in immunocompromised patients may lead to unexpected EBV reactivation and IM, even for patients outside the age at which IM is likely to occur.

Infectious mononucleosis: new concepts in clinical presentation, epidemiology, and host response.

PURPOSE OF REVIEW: Infectious mononucleosis (IM) is an infectious disease that presents clinically in only a small percentage of individuals despite almost universal infection with the causative agent. Here, we review the latest concepts in the clinical presentation, epidemiology, and host response of this disease. RECENT FINDINGS: Several recently published papers/reviews describe IM as a condition caused by one of several etiologic agents including, cytomegalovirus (HHV-5), Roseola virus (HHV-6) and Toxoplasmosis amongst others; this review focuses on IM as solely caused by the human herpes virus 4 (HHV-4). Since the initial discovery of the virus in the 1960s and its subsequent discovery as the primary etiologic agent for IM it has been associated with several human cancers and autoimmune disorders. Recent published findings show a correlation between HHV-4 and the autoimmune disorder, multiple sclerosis (MS), suggesting earlier IM could possibly act as a causative factor. Considering the important links being made with IM to so many cancers and autoimmune disorders it is surprising that a standard investigative procedure has yet to be determined for this disease. A standard approach to the investigation of IM would ensure more cases are diagnosed, particularly atypical cases, this would benefit epidemiological studies, and more immediately help practitioners distinguish viral from bacterial throat infections, enabling them to treat accordingly. SUMMARY: The understanding of the latest concepts in clinical presentation, epidemiology and host response to IM would benefit greatly from the introduction of a standard procedure for its investigation and diagnosis.

Role of IL-27 in Epstein-Barr virus infection revealed by IL-27RA deficiency.

Epstein-Barr virus (EBV) infection can engender severe B cell lymphoproliferative diseases1,2. The primary infection is often asymptomatic or causes infectious mononucleosis (IM), a self-limiting lymphoproliferative disorder3. Selective vulnerability to EBV has been reported in association with inherited mutations impairing T cell immunity to EBV4. Here we report biallelic loss-of-function variants in IL27RA that underlie an acute and severe primary EBV infection with a nevertheless favourable outcome requiring a minimal treatment. One mutant allele (rs201107107) was enriched in the Finnish population (minor allele frequency = 0.0068) and carried a high risk of severe infectious mononucleosis when homozygous. IL27RA encodes the IL-27 receptor alpha subunit5,6. In the absence of IL-27RA, phosphorylation of STAT1 and STAT3 by IL-27 is abolished in T cells. In in vitro studies, IL-27 exerts a synergistic effect on T-cell-receptor-dependent T cell proliferation7 that is deficient in cells from the patients, leading to impaired expansion of potent anti-EBV effector cytotoxic CD8+ T cells. IL-27 is produced by EBV-infected B lymphocytes and an IL-27RA-IL-27 autocrine loop is required for the maintenance of EBV-transformed B cells. This potentially explains the eventual favourable outcome of the EBV-induced viral disease in patients with IL-27RA deficiency. Furthermore, we identified neutralizing anti-IL-27 autoantibodies in most individuals who developed sporadic infectious mononucleosis and chronic EBV infection. These results demonstrate the critical role of IL-27RA-IL-27 in immunity to EBV, but also the hijacking of this defence by EBV to promote the expansion of infected transformed B cells.