Positive Epstein-Barr virus and cytomegalovirus IgM assays in primary HIV infection

Sustained false-positive results for hepatitis A virus immunoglobulin M: A case report and literature review

Hepatitis A virus immunoglobulin M (HAV-IgM) is often used to diagnose acute hepatitis A virus (HAV) infection serologically. However, false-positive test results can interfere with the diagnosis. A 56-year-old woman was readmitted to the hospital owing to abnormal liver function tests for the last 18 months. She had been diagnosed with acute HAV and was hospitalized in isolation based on a positive HAV-IgM test 18 months ago. Regular follow-up after discharge showed abnormal liver function and an elevated level of antinuclear antibodies and immunoglobulin G. For the last 15 days, the patient had fatigue, decreased appetite, and yellow urine, signaling recrudescence. Liver function tests were also abnormal. Liver biopsy revealed histological changes consistent with typical autoimmune hepatitis. After 2 months of methylprednisolone treatment, liver function returned to normal, and HAV-IgM turned negative. The diagnosis of acute HAV in nonendemic areas requires a comprehensive analysis of epidemic history, clinical characteristics, etiology, etc.

Diagnostic performance of four SARS-CoV-2 antibody assays in patients with COVID-19 or with bacterial and non-SARS-CoV-2 viral respiratory infections

SARS-CoV-2 antibody assays are used for epidemiological studies and for the assessment of vaccine responses in highly vulnerable patients. So far, data on cross-reactivity of SARS-CoV-2 antibody assays is limited. Here, we compared four enzyme-linked immunosorbent assays (ELISAs; Vircell SARS-CoV-2 IgM/IgA and IgG, Euroimmun SARS-CoV-2 IgA and IgG) for detection of anti-SARS-CoV-2 antibodies in 207 patients with COVID-19, 178 patients with serological evidence of different bacterial infections, 107 patients with confirmed viral respiratory disease, and 80 controls from the pre-COVID-19 era. In COVID-19 patients, the assays showed highest sensitivity in week 3 (Vircell-IgM/A and Euroimmun-IgA: 78.9% each) and after week 7 (Vircell-IgG: 97.9%; Euroimmun-IgG: 92.1%). The antibody indices were higher in patients with fatal disease. In general, IgM/IgA assays had only limited or no benefit over IgG assays. In patients with non-SARS-CoV-2 respiratory infections, IgG assays were more specific than IgM/IgA assays, and bacterial infections were associated with more false-positive results than viral infections. The specificities in bacterial and viral infections were 68.0 and 81.3% (Vircell-IgM/IgA), 84.8 and 96.3% (Euroimmun-IgA), 97.8 and 86.0% (Vircell-IgG), and 97.8 and 99.1% (Euroimmun-IgG), respectively. Sera from patients positive for antibodies against Mycoplasma pneumoniae, Chlamydia psittaci, and Legionella pneumophila yielded particularly high rates of unspecific false-positive results in the IgM/IgA assays, which was revealed by applying a highly specific flow-cytometric assay using HEK 293 T cells expressing the SARS-CoV-2 spike protein. Positive results obtained with anti-SARS-CoV-2 IgM/IgA ELISAs require careful interpretation, especially if there is evidence for prior bacterial respiratory infections.

Primary Epstein-Barr virus infection shortly after primary Cytomegalovirus infection: a case report

Background

Infectious mononucleosis (IM) and mononucleosis-like illnesses are common viral infectious diseases which are often accompanied by a high fever, pharyngitis and lymphadenopathy in adults, although such infection in childhood is generally subclinical. Most cases of IM are caused by the Epstein–Barr virus (EBV) or Cytomegalovirus (CMV). However, it is difficult to diagnose IM only with subjective symptoms, and thus EBV and CMV are nearly indistinguishable in clinical practice.

Case presentation

A 20-year-old healthy Japanese woman had a 2-day history of high fever and consulted us. She had sex for the first time 6 months earlier. Her virus antibodies showed that she was infected with primary CMV. About 5 months later, she again experienced high fever and lymph node enlargement at the posterior cervical region. Her virus antibodies showed that she was infected with primary EBV at that time.

Conclusion

Herein, we report a healthy adult Japanese woman with primary EBV infection relatively soon after primary CMV infection. It is very interesting to compare the symptoms and/or clinical data after EBV and CMV infection in the same patient within a short period of time. Our patient was diagnosed based only on subjective symptoms, physical examination and laboratory data, without tests of such virus-related antibodies. Therefore, clinicians should bear in mind that primary EBV infection and/or primary CMV infection is possible when patients have symptoms such as high fever, pharyngitis and lymphadenopathy, even in healthy adults.

FcγRIIb Expression Is Decreased on Naive and Marginal Zone-Like B Cells From Females With Multiple Sclerosis

B cells are critical to the development of multiple sclerosis (MS), but the mechanisms by which they contribute to the disease are poorly defined. We hypothesised that the expression of CD32b (FcγRIIb), a receptor for the Fc region of IgG with inhibitory activities in B cells, is lower on B cell subsets from people with clinically isolated syndrome (CIS) or MS. CD32b expression was highest on post-naive IgM⁺ B cell subsets in healthy controls. For females with MS or CIS, significantly lower CD32b expression was identified on IgM⁺ B cell subsets, including naive and IgM^hi MZ-like B cells, when compared with control females. Lower CD32b expression on these B cell subsets was associated with detectable anti-Epstein Barr Virus viral capsid antigen IgM antibodies, and higher serum levels of B cell activating factor. To investigate the effects of lower CD32b expression, B cells were polyclonally activated in the presence of IgG immune complexes, with or without a CD32b blocking antibody, and the expression of TNF and IL-10 in B cell subsets was assessed. The reduction of TNF but not IL-10 expression in controls mediated by IgG immune complexes was reversed by CD32b blockade in naive and IgM^hi MZ-like B cells only. However, no consequence of lower CD32b expression on these cells from females with CIS or MS was detected. Our findings highlight a potential role for naive and marginal zone-like B cells in the immunopathogenesis of MS in females, which requires further investigation.

The vagaries of IgM: a case report of EBV infection with concomitantly false-positive IgM for CMV, VZV, and HSV

Background

Serum IgM (immunoglobulin M) testing is commonly used to diagnose acute viral infections. However, most clinicians are unaware of the vagaries of IgM testing, including antigenic cross-reactivity between multiple viruses and risk misdiagnosis.

Case presentation

We report a case of infectious mononucleosis with concomitantly positive IgM for EBV, CMV, VZV, and HSV.

A 26-year-old man presented with acute infectious mononucleosis picture. His blood work showed a total bilirubin level of 7.7 mg/dl, ALT 1077 U/L, AST 806 U/L, ALP 325 U/L, and INR 1.0. Monospot was positive; peripheral blood smear showed atypical lymphocytes; however, because EBV infectious mononucleosis does not typically cause elevation of liver enzymes over 1000, other etiologies were explored. Tests for hepatitis A, B, C, HIV, ANA, and ASMA returned negative. IgM for EBV-VCA, CMV, HSV, and VZV all returned positive, and the diagnosis of EBV IM was called into question. Subsequent tests of CMV and HSV PCR for viral load were negative (VZV was not clinically suspected), and later on, EBV-EBNA returned negative and EBV-VCA IgM and IgG returned positive, confirming the diagnosis of acute EBV infection.

Conclusion

We believe that IgM seropositivity can result from cross-reactivity among several viruses (especially herpes viruses), and although often relied on, a positive IgM should not serve as the sole determinant for diagnosis of acute viral infections.

Identifying missed clinical opportunities for the earlier diagnosis of HIV in Australia, a retrospective cohort data linkage study

Background

Treatment as prevention approaches for HIV require optimal HIV testing strategies to reduce undiagnosed HIV infections. In most settings, HIV testing strategies still result in unacceptably high rates of missed and late diagnoses. This study aimed to identify clinical opportunities for targeted HIV testing in persons at risk to facilitate earlier HIV diagnosis in New South Wales, Australia; and to assess the duration between the diagnosis of specific conditions and HIV diagnosis.

Methods

The Australian National HIV registry was linked to cancer diagnoses, notifiable condition diagnoses, emergency department presentations and hospital admissions for all HIV diagnoses between 1993 and 2012 in NSW. Date of HIV acquisition was estimated from back-projection models and people with a likely duration from infection to diagnosis of less than 180 days were excluded. Risk factors associated with clinical opportunities for the earlier diagnosis of HIV were identified.

Results

Sexually transmitted infection diagnoses (particularly gonorrhoea and syphilis) and some hospital admissions (mental health and drug-related diagnoses, and non-infective digestive disorder diagnoses) were prominent among people estimated to be living with undiagnosed HIV. The length of time between a clinical opportunity for the earlier HIV diagnosis and actual HIV diagnosis was 13.3 months for notifiable conditions, and 15.2 months for hospital admissions. People with lower CD4+ cell count at diagnosis, and older people were significantly less likely to have a missed opportunity for earlier HIV diagnosis.

Conclusions

Additional targeted clinical HIV testing strategies are warranted for people with gonorrhoea and syphilis; and hospital presentations or admissions for mental health, drug-related and gastrointestinal diagnoses.

Immunoglobulin M for Acute Infection: True or False?

Immunoglobulin M (IgM) tests have clear clinical utility but also suffer disproportionately from false-positive results, which in turn can lead to misdiagnoses, inappropriate therapy, and premature closure of a diagnostic workup. Despite numerous reports in the literature, many clinicians and laboratorians remain unaware of this issue. In this brief review, a series of virology case examples is presented. However, a false-positive IgM can occur with any pathogen. Thus, when an accurate diagnosis is essential for therapy, prognosis, infection control, or public health, when the patient is sick enough to be hospitalized, or when the clinical or epidemiologic findings do not fit, IgM detection should not be accepted as a stand-alone test. Rather, whenever possible, the diagnosis should be confirmed by other means, including testing of serial samples and the application of additional test methods.

Severe Thrombocytopenia and Acute Cytomegalovirus Colitis during Primary Human Immunodeficiency Virus Infection

We herein report the case of a 25-year-old man who was referred to our hospital due to acute cytomegalovirus (CMV) colitis. The initial blood tests showed that the patient had concurrent primary human immunodeficiency virus (HIV) infection and severe thrombocytopenia. Raltegravir-based antiretroviral therapy (ART) was initiated without the use of ganciclovir or corticosteroids and resulted in a rapid clinical improvement. Platelet transfusions were only necessary for a short period, and subsequent colonoscopy revealed a completely healed ulcer. This case implies that ART alone could be effective for treating severe thrombocytopenia during primary HIV and CMV coinfection.

Performance of the architect EBV antibody panel for determination of Epstein-Barr virus infection stage in immunocompetent adolescents and young adults with clinical suspicion of infectious mononucleosis

The Architect EBV antibody panel is a new chemiluminescence immunoassay system used to determine the stage of Epstein-Barr virus (EBV) infection based on the detection of IgM and IgG antibodies to viral capsid antigen (VCA) and IgG antibodies against Epstein-Barr nuclear antigen 1 (EBNA-1). We evaluated its diagnostic accuracy in immunocompetent adolescents and young adults with clinical suspicion of infectious mononucleosis (IM) using the RecomLine EBV IgM and IgG immunoblots as the reference standard. In addition, the use of the antibody panel in a sequential testing algorithm based on initial EBNA-1 IgG analysis was assessed for cost-effectiveness. Finally, we investigated the degree of cross-reactivity of the VCA IgM marker during other primary viral infections that may present with an EBV IM-like picture. High sensitivity (98.3% [95% confidence interval {CI}, 90.7 to 99.7%]) and specificity (94.2% [95% CI, 87.9 to 97.8%]) were found after testing 162 precharacterized archived serum samples. There was perfect agreement between the use of the antibody panel in sequential and parallel testing algorithms, but substantial cost savings (23%) were obtained with the sequential strategy. A high rate of reactive VCA IgM results was found in primary cytomegalovirus (CMV) infections (60.7%). In summary, the Architect EBV antibody panel performs satisfactorily in the investigation of EBV IM in immunocompetent adolescents and young adults, and the application of an EBNA-1 IgG-based sequential testing algorithm is cost-effective in this diagnostic setting. Concomitant testing for CMV is strongly recommended to aid in the interpretation of EBV serological patterns.

Anti-N-methyl-D-aspartate receptor encephalitis with serum anti-thyroid antibodies and IgM antibodies against Epstein-Barr virus viral capsid antigen: a case report and one year follow-up

Background

Anti-N-methyl-D-aspartate receptor encephalitis is an increasingly common autoimmune disorder mediated by antibodies to certain subunit of the N-methyl-D-aspartate receptor. Recent literatures have described anti-thyroid and infectious serology in this encephalitis but without follow-up.

Case presentation

A 17-year-old Chinese female patient presented with psychiatric symptoms, memory deficits, behavioral problems and seizures. She then progressed through unresponsiveness, dyskinesias, autonomic instability and central hypoventilation during treatment. Her conventional blood work on admission showed high titers of IgG antibodies to thyroglobulin, thyroid peroxidase and IgM antibodies to Epstein-Barr virus viral capsid antigen. An immature ovarian teratoma was found and removal of the tumor resulted in a full recovery. The final diagnosis of anti-N-methyl-D-aspartate receptor encephalitis was made by the identification of anti-N-methyl-D-aspartate receptor antibodies in her cerebral spinal fluid. Pathology studies of the teratoma revealed N-methyl-D-aspartate receptor subunit 1 positive ectopic immature nervous tissue and Epstein-Barr virus latent infection. She was discharged with symptoms free, but titers of anti-thyroid peroxidase and anti-thyroglobulin antibodies remained elevated. One year after discharge, her serum remained positive for anti-thyroid peroxidase and anti-N-methyl-D-aspartate receptor antibodies, but negative for anti-thyroglobulin antibodies and IgM against Epstein-Barr virus viral capsid antigen.

Conclusions

Persistent high titers of anti-thyroid peroxidase antibodies from admission to discharge and until one year later in this patient may suggest a propensity to autoimmunity in anti- N-methyl-D-aspartate receptor encephalitis and support the idea that neuronal and thyroid autoimmunities represent a pathogenic spectrum. Enduring anti-N-methyl-D-aspartate receptor antibodies from admission to one year follow-up but seroreversion of Epstein-Barr virus viral capsid antigen IgM may raise the important issue of elucidating the triggers and boosters of anti- N-methyl-D-aspartate receptor encephalitis.