EBV-related lymphoproliferative disease in Wiskott-Aldrich Syndrome patient

Case: Wiskott-Aldrich Syndrome (WAS) is a rare X-linked inborn error of immunity caused by mutations in the WAS gene. It is classically characterized by immunodeficiency, eczema, and micro-thrombocytopenia. It has been known since the 1960s that patients with WAS have an increased risk of lymphoproliferative disease though the exact incidence remains unknown in the American population. Limited case reports have discussed EBV-related lymphoproliferative disease in patients with WAS. We present a case of a 9-year-old boy with known WAS complicated by eczematous rash, thrombocytopenia, recurrent ear infections, and monoclonal gammopathy who was found to have submandibular EBV-associated lymphoid hyperplasia with associated lung and retroperitoneal lymphadenopathy. Family had been offered treatment with hematopoietic stem cell transplant but declined multiple times in the past. Earlier in the year, he presented with possible MIS-C with negative SARS-CoV-2 PCR. He presented to our hospital with mastoiditis and lymphadenopathy. Physical examination showed severe eczema on hands and tender right mastoid. Laboratory evaluation showed thrombocytopenia, elevated IgG of 6290, IgA of 744, IgE of 827, low IgM of 41, and 14% response to pneumococcal titers. He was empirically treated with intravenous antibiotics. ENT performed right postauricular incision and drainage and the culture grew Hemophilus influenza. Throughout his hospital stay, his submandibular lymphadenopathy became more prominent despite treatment. Core needle biopsy of right submandibular lymph node was suggestive of EBV-associated lymphoid hyperplasia. EBV PCR and antibodies were both positive. CT chest, abdomen, and pelvis revealed multifocal pulmonary lymphadenopathy and a diffuse, bilateral nodularity as well as retroperitoneal and mesenteric lymphadenopathy. He was given four doses of weekly Rituximab, which successfully decreased EBV viremia below linear detectability. Immunoglobulin replacement therapy (IgRT) was initiated. Bronchoalveolar lavage and lung biopsy were performed and are results are currently pending. Discussion(s): We present a case of a 9-year-old boy with known WAS awaiting transplant who was found to have submandibular EBV-associated lymphoid hyperplasia with associated lung and retroperitoneal lymphadenopathy. While lymphoproliferative disease is a known complication of WAS, EBV-related lymphoproliferative disease in WAS patients has only been reported as case reports and remains a rare but known complication of patient with WAS.Copyright © 2023 Elsevier Inc.

Lymphoproliferation- a clue towards an underlying monogenic disorder of immune dysregulation- a retrospective analysis from a single center in India

Background: Lymphoproliferation is the persistent proliferation of lymphoid cells and it's incidence in inborn errors of immunity varies from 0.7 to 18%. Material(s) and Method(s): This is a retrospective analysis of patients referred to the department of Immunology, B. J. Wadia Hospital for Children, Mumbai between March 2017 to December 2022. Inclusion criteria consisted of 3 months duration of significant lymphadenopathy and/or splenomegaly or history of lymphoma. The clinical characteristics, laboratory and molecular findings of the included patients were analyzed. Result(s): A total of 66 patients were included. There was a male preponderance with male:female ratio of 25:8. Median age of onset of lymphoproliferation was 4.75 years(Range 1 year to 60 years). Splenomegaly was seen in 75%. Infections included recurrent pneumonia (14/66), recurrent ear infections(5/66), COVID(4/66), one episode of pneumonia(6/66), herpes zoster(3/66), recurrent subcutaneous abscess (3/66), abdominal koch(3/66), chronic sinusitis(2/66), dermatophytosis(2/66), esophageal candidiasis(2/66), recurrent malaria(1/66), recurrent varicella(1/66), cryptococcal meningitis(1/66), gram negative sepsis(1/66), BCG adenitis(1/66), pseudomonas osteomyelitis(1/66), impetigo (1/66), pseudomonas urinary tract infection (1/66), chicken pox(1/66), herpes keratitis(1/66), dengue(1/66), Other manifestations included Evans plus phenotype(10/66), Evans phenotype(8/66), Autoimmune hemolytic anemia(5/66), bronchiectasis(5/66), Type 1 diabetes(3/66), hyper reactive airway disease(2/66), inflammatory bowel disease(4/66), autoimmune thrombocytopenia(2/66), stroke(3/66), hemophagocytic lymphohistiocytosis(2/66), hypertriglyceridemia(2/66), hypothyroidism(2/66), celiac disease(1/66), Type 2 diabetes(1/66), autoimmune encephalitis(1/66), autoimmune hepatitis(2/66), anti-parietal cell antibody(1/66), arthritis(1/66), autoimmune enteropathy(1/66), systemic lupus erythromatosus(1/66), primary biliary cirrhosis requiring liver transplant(1/66), nephrotic syndrome(1/66), lymphoedema(1/66), hypersplenism(1/66), recurrent oral ulcers(1/66), gout(1/66), dermatitis(1/66), ovarian teratoma(1/66), alopecia areata(1/66). Hodgkin's lymphoma(HL) was the most common malignancy(9/66), followed by non Hodgkin lymphoma(NHL)(6/66), transformation from NHL to HL(1/66), Burkitt to T-cell lymphoma(1/66), HL to DLBCL(1/66), HL to anaplastic T-cell lymphoma(1/66). EBV driven lymphoproliferation was seen in biopsy of21/66. Genetic testing showed mutations in LRBA(11/66), PIK3CD(5/66), CTLA4(3/66), TET2(2/66), IL2RA (1/66), IL12RB1(1/66), BACH2(1/66), PRKCD(1/66), TNFSFR13B(1/66), TNFAIP3(1/66), FAS(2/66), FASL(1/66), Caspase8(1/66), CARD11(1/66), RTEL1(1/66), AICD(1/66), PIK3R1(1/66), IKBKB(1/66). Treatment included IVIG, chemotherapy, rituximab, sirolimus, abatacept, HSCT. Conclusion(s): All children with persistent lymphoproliferation, with or without autoimmunity and/or infections should be worked up for an underlying monogenic disorder of immune dysregulation. Lymphomas presenting at abnormal site and/or age, relapse and EBV driven lymphomas require further evaluation. Presence of monogenic cause helps in providing targeted therapy.Copyright © 2023 Elsevier Inc.

Epstein-Barr virus and cytomegalovirus coinfection in Egyptian COVID-19 patients.

Background: Reactivation of herpesviruses such as Epstein-Barr virus (EBV) and cytomegalovirus (CMV) in COVID-19 patients reported in many studies in different countries during the pandemic. We aimed to measure prevalence of this coinfection in Egyptian COVID-19 patients with elevated liver enzymes and its relation to the severity and the outcome of COVID-19 infection in those patients. Methods: A cross-sectional study was carried out on 110 COVID-19 patients with elevated liver enzymes regardless the severity of COVID-19 disease. All patients were subjected to medical history, clinical examination, laboratory investigations, high-resolution computed tomography chest (HRCT chest). Epstein-Barr virus (EBV) and Human cytomegalovirus (HCMV) were determined by VCA IgM and CMV IgM respectively by enzyme-linked immunosorbent assay (ELISA). Results: Of the included 110 patients with COVID-19 illness, 5 (4.5%) were Epstein-Barr virus seropositive and 5 (4.5%) were human cytomegalovirus seropositive. Regarding the symptoms, the incidence of fever in the EBV and CMV seropositive group was apparently higher than that in the EBV and CMV seronegative group. In lab tests, the platelets and albumin of EBV and CMV seropositive group decreased more significantly than EBV and HCMV seronegative group, and serum ferritin, D-dimer, and C-reactive protein show higher values in seropositive group than in seronegative group but not statistically significant. Seropositive group had received higher doses of steroids than seronegative group. The median of hospital stay in seropositive group was (15 days) nearly double that of seronegative group with statistically significant difference between both groups. Conclusion: Coinfection of EBV and CMV in COVID-19 Egyptian has no effect on the disease severity or the clinical outcome of the disease. But those patients had higher hospital stay duration.

Specific cytokine patterns in Epstein-Barr virusassociated hemophagocytic lymphohistiocytosis compared to Kawasaki disease in children.

The aim of the study was to test whether the cytokine profile could be used as a marker to differentiate between Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) and Kawasaki disease (KD). A total of 70 hospitalized children with HLH and KD admitted to hospital for the first time from March 2017 to December 2021 were enrolled in this study. Fifty-five healthy children were enrolled as normal controls. All patients and normal controls were tested for the six cytokines including interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-α), and interferon-γ (IFN-γ) by flow cytometry. IL-10 and IFN-γ levels were significantly higher in children with EBV-HLH than in the KD, IL-6 was lower in EBV-HLH patients than in the KD. IL-10/IL-6 ratio, IFN-γ/IL-6 ratio and IL10/IFN-γ ratio in children with EBV-HLH were significantly much higher than children in the KD group. When the diagnostic cutoff values of IL-10, IFN-γ, IL-10/IL-6 ratio and IFN-γ/IL-6 ratio were >13.2 pg/ml, >71.0 pg/ml, >0.37 and >1.34, respectively, the sensitivity and specificity of the diagnosis of EBV-HLH disease were 91.7% and 97.1%, 72.2% and 97.1%, 86.1% and 100.0%, and 75.0% and 97.1%, respectively. Notably high IL-10 and IFN-γ and moderately elevated IL-6 suggest the diagnosis of EBV-HLH, while high IL-6 levels with low IL-10 or IFN-γ concentration would suggest KD. Additionally, IL-10/IL-6 ratio or IFN-γ/IL-6 ratio could be used as an index to differentiate between EBV-HLH and KD.

Reduced exercise capacity, chronotropic incompetence, and early systemic inflammation in cardiopulmonary phenotype Long COVID.

BACKGROUND: Mechanisms underlying persistent cardiopulmonary symptoms following SARS-CoV-2 infection (post-acute sequelae of COVID-19 "PASC" or "Long COVID") remain unclear. This study sought to elucidate mechanisms of cardiopulmonary symptoms and reduced exercise capacity. METHODS: We conducted cardiopulmonary exercise testing (CPET), cardiac magnetic resonance imaging (CMR) and ambulatory rhythm monitoring among adults > 1 year after confirmed SARS-CoV-2 infection in a post-COVID cohort, compared those with or without symptoms, and correlated findings with previously measured biomarkers. RESULTS: Sixty participants (median age 53, 42% female, 87% non-hospitalized) were studied at median 17.6 months following SARS-CoV-2 infection. On CPET, 18/37 (49%) with symptoms had reduced exercise capacity (<85% predicted) compared to 3/19 (16%) without symptoms (p = 0.02). Adjusted peak VO2 was 5.2 ml/kg/min lower (95%CI 2.1-8.3; p = 0.001) or 16.9% lower percent predicted (95%CI 4.3-29.6; p = 0.02) among those with symptoms. Chronotropic incompetence was common. Inflammatory markers and antibody levels early in PASC were negatively correlated with peak VO2 more than 1 year later. Late-gadolinium enhancement on CMR and arrhythmias were absent. CONCLUSIONS: Cardiopulmonary symptoms >1 year following COVID-19 were associated with reduced exercise capacity, which was associated with elevated inflammatory markers early in PASC. Chronotropic incompetence may explain exercise intolerance among some with cardiopulmonary Long COVID.

Systematic review with meta-analysis of active herpesvirus infections in patients with COVID-19: Old players on the new field.

OBJECTIVES: Herpesviruses are ubiquitous and after primary infection they establish lifelong latency. The impairment of maintaining latency with short-term or long-term consequences could be triggered by other infection. Therefore, reactivation of herpesviruses in COVID-19 patients represents an emerging issue. DESIGN AND METHODS: This study provided the first systematic review with meta-analysis of studies that evaluated active human herpesvirus (HHV) infection (defined as the presence of IgM antibodies or HHV-DNA) in COVID-19 patients and included 36 publications collected by searching through PubMed, SCOPUS, and Web of science until November 2022. RESULTS: The prevalence of active EBV, HHV6, HSV, CMV, HSV1, and VZV infection in COVID-19 population was 41% (95% CI =27%-57%), 3% (95% CI=17%-54%), 28% (95% CI=1%-85%), 25% (95% CI=1%-63%), 22% (95% CI=10%-35%), and 18% (95% CI=4%-34%), respectively. There was a 6 times higher chance for active EBV infection in patients with severe COVID-19 than in non-COVID-19 controls (OR=6.45, 95% CI=1.09-38.13, p=0.040), although there was no difference in the prevalence of all evaluated active herpesvirus infections between COVID-19 patients and non-COVID-19 controls. CONCLUSIONS: Future research of herpesvirus and SARS-CoV-2 coinfections must be prioritized to define: who, when and how to be tested, as well as how to effectively treat HHVs reactivations in acute and long COVID-19 patients.

Hemophagocytic Lymphohistiocytosis Caused by a Severe Epstein-Barr Virus Infection in a Young Patient Presenting With Hiccups.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome characterized by a pathologic immune response in the setting of infection, malignancy, acute illness, or any immunological stimulus. Infection is the most common etiology of HLH. HLH involves aberrant activation of lymphocytes and macrophages with resultant hypercytokinemia due to an inappropriately stimulated and ineffective immune response. Here, we present the case of a previously healthy 19-year-old male presenting with hiccups and scleral icterus, who was found to have HLH due to a severe Epstein-Barr virus infection. Despite a morphologically normal bone marrow biopsy, the patient met the diagnostic criteria for HLH, including a low natural killer cell count and elevated soluble interleukin-2 receptor. Notably, ferritin was severely elevated at 85,810 ng/mL. The patient was treated with an induction course of dexamethasone intravenously for eight weeks. Since HLH can progress into multi-organ failure, timely diagnosis and prompt initiation of treatment are critical. Novel disease-modifying therapies and further clinical trials are warranted to treat this potentially fatal immunological disease with multisystem ramifications.

Viral Hepatitis and Acute-on-Chronic Liver Failure.

Acute-on-chronic liver failure (ACLF) is a potentially reversible syndrome that develops in patients with cirrhosis or with underlying chronic liver disease (CLD) and is characterized by acute decompensation, organ failure, and high short-term mortality. Hepatitis A and hepatitis E are major causes of ACLF. Hepatitis B may also cause ACLF through a flare of hepatitis B, acute infection, or reactivation. Besides supportive care, nucleoside/nucleotide analog therapy should also be initiated in this setting. Nonhepatotropic viruses may rarely also cause ACLF with the severe acute respiratory syndrome coronavirus 2 virus recently being identified with poorer outcomes in those with underlying CLD.

An Unusual Case of Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type Masquerading as Dacryocystitis and Sinusitis.

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (NNKTL) is a rare and highly aggressive non-Hodgkin lymphoma originating from NK or γδ T cells infected by Epstein-Barr virus (EBV). In the United States, NNKTL is usually noted in people of Asian or Hispanic descent. Natural killer/T-cell lymphoma, nasal type commonly involves the upper aerodigestive tract, including the nasopharynx, nasal cavity, Waldeyer's ring, and oropharynx. Extensive local destruction and invasion has been noted, especially of the paranasal sinuses, hard palate, and central nervous system; involvement of the nasolacrimal duct with dacryocystitis is yet to be reported. We report a rare case of a Hispanic man with extranodal NNKTL masquerading as persistent dacryocystitis and necrotizing sinusitis unresponsive to antibiotics and surgical intervention. An extensive background of necrosis and inflammation was noted on pathology, and additional analysis with immunohistochemistry and in situ hybridization after repeat biopsy were necessary for accurate diagnosis.

Antiviral Potential of the Genus Panax: An updated review on their effects and underlying mechanism of action.

Viral infections are known as one of the major factors causing death. Ginseng is a medicinal plant that demonstrated a wide range of antiviral potential, and saponins are the major bioactive ingredients in the genus Panax with vast therapeutic potential. Studies focusing on the antiviral activity of the genus Panax plant-derived agents (extracts and saponins) and their mechanisms were identified and summarized, including contributions mainly from January 2016 until January 2022. P. ginseng, P. notoginseng, and P. quinquefolius were included in the review as valuable medicinal herbs against infections with 14 types of viruses. Reports from 9 extracts and 12 bioactive saponins were included, with 6 types of protopanaxadiol (PPD) ginsenosides and 6 types of protopanaxatriol (PPT) ginsenosides. The mechanisms mainly involved the inhibition of viral attachment and replication, the modulation of immune response by regulating signaling pathways, including the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, cystathionine γ-lyase (CSE)/hydrogen sulfide (H2S) pathway, phosphoinositide-dependent kinase-1 (PDK1)/ protein kinase B (Akt) signaling pathway, c-Jun N-terminal kinase (JNK)/activator protein-1 (AP-1) pathway, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway. This review includes detailed information about the mentioned antiviral effects of the genus Panax extracts and saponins in vitro and in vivo, and in human clinical trials, which provides a scientific basis for ginseng as an adjunctive therapeutic drug or nutraceutical.

New Presentation of CD27 Deficiency; Coronary Ectasia and COVID-19.

CD27 is a costimulatory receptor involved in the maturation of the innate and adaptive immunity. CD27, through interaction with CD70, plays a role in the control of Epstein-Barr virus (EBV) infection. CD27 deficiency leads to an immune dysregulation disease characterized by EBV susceptibility. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) might put patients with primary immunodeficiency at risk for adverse outcomes. Chromogenic in situ hybridization (CISH) study was performed to detect EBV in the lymphoma tissue. Genetic analysis of the patient was done with Whole Exome Sequencing and detected variant was confirmed with PCR-Sanger sequencing. Here we report a 20-month-old boy with CD27 deficiency who developed lymphoma and coronary artery ectasia and had been infected with SARS-CoV-2. Clinical and laboratory findings were incompatible with atypical Kawasaki syndrome or multisystem inflammatory syndrome in children (MIS-C). As CD27 deficiency is a rare immune defect, publishing clinical data about the identified patient(s) can shed light on our knowledge about the related phenotype and the spectrum of clinical manifestations associated with CD27 deficiency. Thus, our findings expanded the spectrum of manifestations beyond EBV infection, highlighting this unusual cardiac sequela that could be related to EBV infection, lymphoma, or an underlying disease.

Human genetic and immunological determinants of SARS-CoV-2 and Epstein-Barr virus diseases in childhood: Insightful contrasts.

There is growing evidence to suggest that severe disease in children infected with common viruses that are typically benign in other children can result from inborn errors of immunity or their phenocopies. Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a cytolytic respiratory RNA virus, can lead to acute hypoxemic COVID-19 pneumonia in children with inborn errors of type I interferon (IFN) immunity or autoantibodies against IFNs. These patients do not appear to be prone to severe disease during infection with Epstein-Barr virus (EBV), a leukocyte-tropic DNA virus that can establish latency. By contrast, various forms of severe EBV disease, ranging from acute hemophagocytosis to chronic or long-term illnesses, such as agammaglobulinemia and lymphoma, can manifest in children with inborn errors disrupting specific molecular bridges involved in the control of EBV-infected B cells by cytotoxic T cells. The patients with these disorders do not seem to be prone to severe COVID-19 pneumonia. These experiments of nature reveal surprising levels of redundancy of two different arms of immunity, with type I IFN being essential for host defense against SARS-CoV-2 in respiratory epithelial cells, and certain surface molecules on cytotoxic T cells essential for host defense against EBV in B lymphocytes.

The Influence of Herpes Family Viruses on the Course of Novel Coronavirus Infection

We have analyzed the impact of herpes virus infection on the course of a new coronavirus infection (NCVI). Infection of the examined contingent with herpes family viruses reached 95.3-100%. An association of NCVI with herpes simplex viruses 1, 2 types (HSV 1, 2 types) was found, but no correlation was found between the positivity coefficient (CP) of HSV 1, type 2 and the severity of NCVI. This can be explained by the fact that the sampling was carried out in the remote period after the transferred NKVI. Considering that both herpes viruses and the SARS-CoV-2 virus cause multiple organ damage and can aggravate each other, the study of co-infection seems to be very relevant.

Dynamics of Viral and Host 3D Genome Structure upon Infection.

Eukaryotic chromatin is highly organized in the 3D nuclear space and dynamically regulated in response to environmental stimuli. This genomic organization is arranged in a hierarchical fashion to support various cellular functions, including transcriptional regulation of gene expression. Like other host cellular mechanisms, viral pathogens utilize and modulate host chromatin architecture and its regulatory machinery to control features of their life cycle, such as lytic versus latent status. Combined with previous research focusing on individual loci, recent global genomic studies employing conformational assays coupled with high-throughput sequencing technology have informed models for host and, in some cases, viral 3D chromosomal structure re-organization during infection and the contribution of these alterations to virus-mediated diseases. Here, we review recent discoveries and progress in host and viral chromatin structural dynamics during infection, focusing on a subset of DNA (human herpesviruses and HPV) as well as RNA (HIV, influenza virus and SARS-CoV-2) viruses. An understanding of how host and viral genomic structure affect gene expression in both contexts and ultimately viral pathogenesis can facilitate the development of novel therapeutic strategies.

Use of rituximab in SARS-CoV-2-positive renal transplant recipient with EBV reactivation and probable haemophagocytic lymphohistiocytosis.

We present a case of a rapid clinical recovery in a critically ill kidney transplant recipient with SARS-CoV-2 positivity, Epstein-Barr virus (EBV) reactivation and probable secondary hemophagocytic lymphohistiocytosis (HLH) treated with etoposide-free regimen, based on dexamethasone and a single dose of rituximab. Although rituximab is often a part of EBV-HLH treatment strategy, its use in simultaneous Coronavirus 2019 disease (COVID-19) and solid-organ transplantation has not been reported yet. We review the current evidence for the potential of SARS-CoV-2 to trigger EBV reactivation, leading to a severe clinical illness. Finally, we compare the clinical features of hyper-inflammatory response typical for severe COVID-19 and classical secondary HLH and discuss the benefits of therapeutic B-cell depletion in both conditions.

Bronchoscopic Endobronchial Valve Therapy for Persistent Air Leaks in COVID-19 Patients Requiring Veno-Venous Extracorporeal Membrane Oxygenation.

COVID-19 acute respiratory distress syndrome (ARDS) can be associated with extensive lung damage, pneumothorax, pneumomediastinum and, in severe cases, persistent air leaks (PALs) via bronchopleural fistulae (BPF). PALs can impede weaning from invasive ventilation or extracorporeal membrane oxygenation (ECMO). We present a series of patients requiring veno-venous ECMO for COVID-19 ARDS who underwent endobronchial valve (EBV) management of PAL. This is a single-centre retrospective observational study. Data were collated from electronic health records. Patients treated with EBV met the following criteria: ECMO for COVID-19 ARDS; the presence of BPF causing PAL; air leak refractory to conventional management preventing ECMO and ventilator weaning. Between March 2020 and March 2022, 10 out of 152 patients requiring ECMO for COVID-19 developed refractory PALs, which were successfully treated with bronchoscopic EBV placement. The mean age was 38.3 years, 60% were male, and half had no prior co-morbidities. The average duration of air leaks prior to EBV deployment was 18 days. EBV placement resulted in the immediate cessation of air leaks in all patients with no peri-procedural complications. Weaning of ECMO, successful ventilator recruitment and removal of pleural drains were subsequently possible. A total of 80% of patients survived to hospital discharge and follow-up. Two patients died from multi-organ failure unrelated to EBV use. This case series presents the feasibility of EBV placement in severe parenchymal lung disease with PAL in patients requiring ECMO for COVID-19 ARDS and its potential to expedite weaning from both ECMO and mechanical ventilation, recovery from respiratory failure and ICU/hospital discharge.

Persistent SARS-CoV-2 Infection, EBV, HHV-6 and Other Factors May Contribute to Inflammation and Autoimmunity in Long COVID.

A novel syndrome called long-haul COVID or long COVID is increasingly recognized in a significant percentage of individuals within a few months after infection with SARS-CoV-2. This disorder is characterized by a wide range of persisting, returning or even new but related symptoms that involve different tissues and organs, including respiratory, cardiac, vascular, gastrointestinal, musculo-skeletal, neurological, endocrine and systemic. Some overlapping symptomatologies exist between long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Very much like with long ME/CFS, infections with herpes family viruses, immune dysregulation, and the persistence of inflammation have been reported as the most common pattern for the development of long COVID. This review describes several factors and determinants of long COVID that have been proposed, elaborating mainly on viral persistence, reactivation of latent viruses such as Epstein-Barr virus and human herpesvirus 6 which are also associated with the pathology of ME/CFS, viral superantigen activation of the immune system, disturbance in the gut microbiome, and multiple tissue damage and autoimmunity. Based on these factors, we propose diagnostic strategies such as the measurement of IgG and IgM antibodies against SARS-CoV-2, EBV, HHV-6, viral superantigens, gut microbiota, and biomarkers of autoimmunity to better understand and manage this multi-factorial disorder that continues to affect millions of people in the world.

Antibody Levels Poorly Reflect on the Frequency of Memory B Cells Generated following SARS-CoV-2, Seasonal Influenza, or EBV Infection.

The scope of immune monitoring is to define the existence, magnitude, and quality of immune mechanisms operational in a host. In clinical trials and praxis, the assessment of humoral immunity is commonly confined to measurements of serum antibody reactivity without accounting for the memory B cell potential. Relying on fundamentally different mechanisms, however, passive immunity conveyed by pre-existing antibodies needs to be distinguished from active B cell memory. Here, we tested whether, in healthy human individuals, the antibody titers to SARS-CoV-2, seasonal influenza, or Epstein-Barr virus antigens correlated with the frequency of recirculating memory B cells reactive with the respective antigens. Weak correlations were found. The data suggest that the assessment of humoral immunity by measurement of antibody levels does not reflect on memory B cell frequencies and thus an individual's potential to engage in an anamnestic antibody response against the same or an antigenically related virus. Direct monitoring of the antigen-reactive memory B cell compartment is both required and feasible towards that goal.

Saliva antibody-fingerprint of reactivated latent viruses after mild/asymptomatic COVID-19 is unique in patients with myalgic-encephalomyelitis/chronic fatigue syndrome.

Background: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic disease considered to be triggered by viral infections in a majority of cases. Symptoms overlap largely with those of post-acute sequelae of COVID-19/long-COVID implying common pathogenetic mechanisms. SARS-CoV-2 infection is risk factor for sustained latent virus reactivation that may account for the symptoms of post-viral fatigue syndromes. The aim of this study was first to investigate whether patients with ME/CFS and healthy donors (HDs) differed in their antibody response to mild/asymptomatic SARS-CoV-2 infection. Secondly, to analyze whether COVID-19 imposes latent virus reactivation in the cohorts. Methods: Anti-SARS-CoV-2 antibodies were analyzed in plasma and saliva from non-vaccinated ME/CFS (n=95) and HDs (n=110) using soluble multiplex immunoassay. Reactivation of human herpesviruses 1-6 (HSV1, HSV2, VZV, EBV, CMV, HHV6), and human endogenous retrovirus K (HERV-K) was detected by anti-viral antibody fingerprints in saliva. Results: At 3-6 months after mild/asymptomatic SARS-CoV-2 infection, virus-specific antibodies in saliva were substantially induced signifying a strong reactivation of latent viruses (EBV, HHV6 and HERV-K) in both cohorts. In patients with ME/CFS, antibody responses were significantly stronger, in particular EBV-encoded nuclear antigen-1 (EBNA1) IgG were elevated in patients with ME/CFS, but not in HDs. EBV-VCA IgG was also elevated at baseline prior to SARS-infection in patients compared to HDs. Conclusion: Our results denote an altered and chronically aroused anti-viral profile against latent viruses in ME/CFS. SARS-CoV-2 infection even in its mild/asymptomatic form is a potent trigger for reactivation of latent herpesviruses (EBV, HHV6) and endogenous retroviruses (HERV-K), as detected by antibody fingerprints locally in the oral mucosa (saliva samples). This has not been shown before because the antibody elevation is not detected systemically in the circulation/plasma.

Association of delayed chemoradiotherapy with elevated Epstein-Barr virus DNA load and adverse clinical outcome in nasopharyngeal carcinoma treatment during the COVID-19 pandemic: a retrospective study.

BACKGROUND: To summarize the impact of radiotherapy (RT) and chemotherapy delays on patients with nasopharyngeal carcinoma (NPC) during the COVID-19 pandemic. METHODS: We retrospectively included 233 patients with stage II-IVa NPC treated with RT and chemotherapy between December 11, 2019 and March 11, 2020. The outcomes were elevation in the EBV DNA load between two adjacent cycles of chemotherapy or during RT, and 1-year disease-free survival (DFS). RESULTS: RT delay occurred in 117 (50%) patients, and chemotherapy delay occurred in 220 (94%) patients. RT delay of ≥ 6 days was associated with a higher EBV DNA elevation rate (20.4% vs. 3.6%, odds ratio [OR] = 6.93 [95% CI = 2.49-19.32], P < 0.001), and worse 1-year DFS (91.2% vs. 97.8%, HR = 3.61 [95% CI = 1.37-9.50], P = 0.006), compared with on-schedule RT or delay of < 6 days. Chemotherapy delay of ≥ 10 days was not associated with a higher EBV DNA elevation rate (12.5% vs. 6.8%, OR = 1.94 [95% CI = 0.70-5.40], P = 0.20), or worse 1-year DFS (93.8% vs. 97.1%, HR = 3.73 [95% CI = 0.86-16.14], P = 0.059), compared with delay of < 10 days. Multivariable analyses showed RT delay of ≥ 6 days remained an independent adverse factor for both EBV DNA elevation and DFS. CONCLUSION: To ensure treatment efficacy for patients with nonmetastatic NPC, initiation of RT should not be delayed by more than 6 days; the effect of chemotherapy delay requires further investigation.