Epidemiological analysis of infectious mononucleosis as primary Epstein-Barr virus infection]

We report the characteristics of 45 Epstein-Barr virus (EBV)-infected patients visiting our hospital from 1989 to 1991 in comparison with 102 patients seen from 1981 to 1988. Cases of infectious mononucleosis (IM) increased especially in patients over 30 years old. They tended to have nonspecific symptoms and signs for IM such as general fatigue. Immunologically showed twice higher positivity for anti-EBV VCA-IgM antibody in the recent 3 years when compared to the previous 8 years. The patients with anti-EBNA antibody decreased in the recent 3 years. This may be due to early diagnosis as IM. EBV also causes atypical diseases. non-IM in this report, including hematological or neurological disorders. We indicated here the increased number and advanced age of patients with IM and early diagnosis as IM in the recent 3 years compared to the previous 8 years.     

Clinical characteristics of primary and reactivated Epstein-Barr virus infection in children

Epstein-Barr virus (EBV) infection occurs commonly in children and presents as a primary or reactivated infection, which are difficult for clinicians to distinguish. This study investigated the clinical characteristics of the two types of infections. Children with detectable plasma EBV-DNA were retrospectively enrolled and divided into primary and reactivated infection group by EBV-specific antibody. We analyzed the patients' characteristics, clinical manifestations, complications, inflammatory biomarkers, and viral load. A total of 9.3% of children with reactivation were immunocompromised over the long-term. The primary infection mostly appeared as infectious mononucleosis (99.8%), while reactivation occurred as an infectious mononucleosis-like disease (65.0%), hemophagocytic syndrome (22.6%), chronic active EBV infection (5.3%) and lymphoma (3.5%). The incidence of fevers, cervical lymphoditis, periorbital edema, pharyngotonsillitis, hepatomegaly and splenomegaly in primary infection were 93.3%, 93.0%, 51.5%, 66.0%, 76.2% and 63.9%, respectively; the incidence of those symptoms in reactivation was 84.0%, 46.9%, 15.4%, 18.5%, 18.5%, and 43.3%, respectively. The incidence of digestive, respiratory, cardiovascular, neurological, hematological, genitourinary complications and multiple serous effusion in primary infection was 68.8%, 18.1%, 8.0%, 0.8%, 2.9%, 0.0% and 2.3%; whereas the incidence of these complications in reactivation was 56.2%, 22.5%, 14.1%, 8.0%, 38.9%, 0.3% and 19.0%. Patients with reactivation were more prone to multi-systemic damage. B-cells were lower, and CD8+ T-cells were higher in primary infection. Viral load was correlated with the level of different cytokines in primary and reactivated infection. EBV primary infection often presents as infectious mononucleosis. The reactivated infection affects more immunocompromised subjects with diverse and complex manifestations. Various complications are more commonly associated with reactivation as a result of different inflammatory responses to different types of infection.     

EB病毒和巨细胞病毒双重感染的传染性单核细胞增多症的临床特征

目的 探讨EB病毒（EBV）和巨细胞病毒（CMV）双重感染的传染性单核细胞增多症（IM）的临床特征.方法 回顾性总结21例由EBV和CMV双重感染导致IM的临床特点,并与单独EBV感染导致的IM病例进行比较.结果 ①两组间临床特点比较：双重感染组的发热持续时间显著长于EBV感染组（P＜0.01）,双重感染组的肝肿大发生率和脾肿大发生率均显著高于EBV感染组（分别P＜0.05,P＜0.01）.IM并发症,如血小板减少症、肺炎和贫血的发生率在双重感染组均显著高于EBV感染组（P＜0.01）.②各组间实验室指标比较：异型淋巴细胞百分比和肝功能异常的发生率在双重感染组均显著高于EBV感染组（P＜0.01）.结论 EBV和CMV双重感染IM常临床症状较重,发热持续时间较长,并发症如血小板减少症、肺炎和贫血的发生率较高.     

Antibody response to Epstein-Barr virus in infectious mononucleosis.

Altogether 171 serum specimens from 58 patients with heterophil antibody-positive infectious monomucleosis were studied for antibody response to Epstein-Barr virus (EBV). The sera were tested for fluorescent immunoglobulin G (IgG) and IgM gel-precipitating (GP) and complement-fixing (CF) antibodies to EBV. All 58 patients had IgG and IgM antibodies to EBV. Both IgG and IgM antibodies developed rapidly; the IgM antibodies disappeared within 8 to 10 weeks, whereas the IgG antibodies remained at an almost constant level. The development of IgG antibodies was so rapid that a fourfold or greater rise in titers was noted only in 22% of the patients. Both GP and CF antibodies to EBV (crude P3HR-1 Burkitt cell antigen) developed slowly; the mean titers kept rising for more than 12 weeks. The micro GP technique seemed to be more sensitive than the CF method, because 86% of the patients with infectious mononucleosis had GP antibodies compared with 72% having CF antibodies. In patients with infectious mononucleosis, a seroconversion or significant rise in GP antibodies was noted in 57%, whereas only 19% had a similar change in CF antibodies. The most promising of these antibody assays in the diagnosis of recent infections was the EBV-specific IgM antibody technique, which enables one to make the diagnosis on the basis of only one serum specimen. In cases where the acute-phase serum specimen is missing, the diagnosis can be made later by using the GP and CF techniques.     

Presence of infective Epstein-Barr virus in the urine of patients with infectious mononucleosis

The presence of Epstein-Barr virus (EBV) in the blood and urine of 20 patients with infectious mononucleosis (IM) was investigated together with the clinical course of the disease, and in 9 patients up to 2–7 months after recovery. EBV DNA, analyzed by the polymerase chain reaction (PCR), was detected in the blood of all 20 patients from the first sample obtained and detected between 3 to 42 days from the beginning of symptoms and up to 2–3 months after recovery. In the urine, EBV DNA was detected in 15 out of 16 (93%) patients in the first sample obtained and detected between 3 to 50 days during the clinical course of the disease. In four patients EBV DNA was detected in the urine up to 3 months after full recovery. Seventeen out of 26 (65%) urine samples including 3 which were obtained 2–7 months after recovery infected B cells as assessed by PCR. Nine out of 12 (75%) urine samples tested induced Epstein-Barr nuclear antigen (EBNA) in the infected B-cell line. In addition to the persistence of EBV in the blood of IM patients, these studies show for the first time the presence of infective EBV in the urine during the clinical course of the disease and up to 7 months after full clinical recovery. © 1994 Wiley-Liss, Inc.     

Acute cerebellar syndrome in infectious mononucleosis: documentation of two cases with Epstein-Barr virus infection

Acute cerebellar ataxia has been described occasionally with infectious mononucleosis. Two additional cases are reported with serologic identification of Epstein-Barr virus (EBV) infection in blood and cerebrospinal fluid. As with previously described cases, the outcome was benign, and examination and laboratory studies did not indicate diffuse neurologic involvement. Visual and brainstem auditory-evoked responses were normal. Electroencephalograms (EEG) demonstrated 14 and 6 per second positive spikes in both patients. This pattern is considered a normal variant and has been recorded from depth electrodes and reported with deep midline lesions. These cases support the prognosis of benign cerebellar involvement in infectious mononucleosis and suggest that evidence of EBV infection be sought in patients with acute ataxia. The significance of 14/sec and 6/sec positive EEG spikes is uncertain.     

Acute kidney injury in symptomatic primary Epstein-Barr virus infectious mononucleosis: Systematic review

Background and objectivesTextbooks and reviews do not mention the association of symptomatic primary Epstein-Barr virus infectious mononucleosis with acute kidney injury in subjects without immunodeficiency or autoimmunity.Study designStimulated by our experience with two cases, we performed a review of the literature.ResultsThe literature documents 38 cases (26 male and 12 female individuals ranging in age from 0.3 to 51, median 18 years) of symptomatic primary Epstein-Barr virus infectious mononucleosis complicated by acute kidney injury: 27 acute interstitial nephritides, 1 jaundice-associated nephropathy, 7 myositides and 3 hemolytic uremic syndromes. Acute kidney injury requiring renal replacement therapy was observed in 18 (47%) cases. Acute kidney injury did not resolve in one patient with acute interstitial nephritis. Two patients died because of systemic complications. The remaining 35 cases fully recovered.ConclusionsIn individuals with acute symptomatic Epstein-Barr virus infectious mononucleosis, a relevant kidney injury is rare but the outcome potentially fatal. It results from interstitial nephritis, myositis-associated acute kidney injury, hemolytic uremic syndrome or jaundice-associated nephropathy.     

Detection of Epstein-Barr virus in lymphoid tissues of patients with infectious mononucleosis by in situ hybridization.

Although the immunological response during infectious mononucleosis (IMN) has been studied in detail, little is known about the spread of Epstein-Barr virus (EBV) in lymphoid organs or the topographical distribution of the infected cells. In this study, EBV was detected in 11 lymph nodes, 4 tonsils, and 1 spleen of 16 patients with IMN. The predominant cell type positive for the EBV genome was identified as small lymphocytes localized chiefly within typical T areas, preferentially in perifollicular and interfollicular regions of the lymph node. A few endothelia of epithelioid venules were also found to be positive. Furthermore, a small number of sinus lining cells of lymph nodes exhibited labelling. Altogether, only a small number of cells, not exceeding 1 per cent of all cells, were infected with EBV. Our results show that only a small number of lymphocytes carry the EBV and that besides B lymphocytes, other cell constituents of lymphatic tissues are infected by EBV during IMN.     

Acute infectious mononucleosis and coincidental measles virus infection.

BACKGROUND: Both Epstein-Barr and measles viruses (MV) cause immune suppression, and the association of the two viruses is evaluated as life threatening. The cell immune impairment caused by simultaneous Epstein-Barr and measles viral infections was responsible for the complicated course of the disease in all described previously reports and for unfavorable outcomes in most of the cases. Timely diagnosis of coincidental viral infections could be a useful predictor for the clinical course and complications. Diagnosis must be based on an accurate assessment of clinical, hematologic, serologic manifestations and supported by appropriate laboratory methods. Recognizing the infectious etiology of concomitant infections is important for both clinicians and epidemiologists. OBJECTIVE: To describe a case report of a 20-year-old woman previously vaccinated against measles infected with acute mononucleosis and coincidental measles virus infection. STUDY DESIGN: The clinical, routine laboratory, as well as serological and virologic findings of this patient were scrutinized. Special emphasis was placed on the use of RT-PCR/PCR for confirming the involvement of both measles virus and Epstein-Barr virus (EBV) in this patient's illness. RESULTS: Infectious mononucleosis was not suspected at admission to the hospital. The final diagnosis of a concomitant measles virus infection and acute infectious mononucleosis was facilitated using viral serology to detect virus-specific IgG and IgM antibodies and by RT-PCR for the detection of measles virus RNA and EBV DNA from peripheral blood monocyte cells (PBMC). CONCLUSION: The present report highlights the difficulty of diagnosing two coincidental virus infections on clinical grounds. Serological and molecular laboratory methods, specifically the PCR (RT-PCR) analysis, are found to be useful for confirming the concomitant viral infections and proper identification of the infecting pathogens.     

Clinical manifestations and quantitative analysis of virus load in Taiwanese children with Epstein-Barr virus-associated infectious mononucleosis.

BACKGROUND AND PURPOSE: To delineate the clinical manifestations in different age groups and to define the viral load in patients with Epstein-Barr virus-associated infectious mononucleosis (EBV-associated IM). METHODS: We reviewed data on 69 children with EBV-associated IM from November 2001 to October 2005. Clinical features were evaluated among four age groups: <3 years, 3 to 5 years, 6 to 9 years and 10 to 18 years. EBV viral load was measured by quantitative real-time polymerase chain reaction (PCR) in 13 patients with 15 specimens. RESULTS: Majority of the children were younger than 7 years of age (76.8%) and the male-to-female ratio was 1.6:1. The symptoms and signs included fever (91.3%), tonsillopharyngitis (88.4%), lymphadenopathy (78.3%) and hepatitis (75.4%). The younger age group had higher monocyte count, lower occurrence of hepatitis, and lower glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) levels than the older age group. The median (range) EBV viral load of peripheral blood mononuclear cells (PBMCs) and plasma in IM patients was 738 (0-7455) copies/mug DNA and 51 (0-957) copies/mL plasma, respectively. The PBMC detection rate was high in the early (within 10 days after onset) and late phase (>10 days after onset) [90-100%]. The plasma detection rate in the early phase (66.7%) was higher than that in the late phase (40%). CONCLUSIONS: The younger age group of EBV-associated IM patients had higher monocyte count, lower occurrence of hepatitis, and lower GOT and GPT levels than the older age group. The PBMC detection rate was almost equally high in both the early and late phases, while the plasma detection rate was higher in the early phase. Quantitative real-time PCR of EBV DNA is useful for diagnosing and monitoring EBV-associated IM, especially in younger children.     

The MLC response of patients with infectious mononucleosis to Epstein-Barr virus-transformed cells

Lymphocytes of 6 patients with infectious mononucleosis were found to be capable of responding in mixed lymphocyte culture (MLC) to Epstein-Barr virus (EBV)--transformed lymphoblastoid cell lines and Raji cells, whereas their response to PWM-induced blasts and non-T cells was significantly depressed. This means that despite the suppression of cellular reactivity, observed in infectious mononucleosis, the specific response to EBV-infected cells remains unaffected.     

Subclass reactivity to Epstein-Barr virus capsid antigen in primary and reactivated EBV infections

A new method for analysis of virus-specific Immunoglobulin G (IgG) subclasses was developed using indirect immunofluorescence. Three hundred thirty-three serum samples from patients with different types of Epstein-Barr virus (EBV)-associated diseases and healthy controls were examined for subclass distribution to the virus capsid antigen (EBV VCA). EBV-VCA-expressing cell preparations were incubated with patient serum followed by monoclonal antibodies to human IgG1 through IgG4 and labelled anti-mouse IgG. Virus-specific IgG1 was found to be the dominant antibody. The titers for IgG1 and total Ig to EBV VCA correlated well. EBV VCA-specific IgG2 was not found. EBV VCA-specific IgG3 in a titer of greater than or equal to 10 was found in 33% of healthy seropositive donors, in 97% of patients with suspected reactivated EBV infection, and in 100% of symptomatic patients with suspected reactivated EBV infection. EBV VCA specific IgG3 occurred in 90% of placebo-treated compared to 30% in long-term acyclovir-treated bone marrow transplant recipients, indicating more frequent reactivations in the former group. IgG4 to VCA was infrequently found in seropositive persons. In serum samples from patients with nasopharyngeal carcinoma and high EBV VCA Ig and IgA titers, IgG4 to VCA was always present. Analysis of EBV VCA specific IgG subclasses seems to be valuable for the diagnosis of reactivated EBV infection.     

Radioimmunoassay for detection of antibodies to Epstein-Barr virus in human infectious mononucleosis serum specimens.

A rapid microradioimmunoassay (RIA) technique was adapted for quantitatively measuring antibody titers to antigens occurring in Epstein-Barr virus (EBV)-infected lymphoid cells. In these experiments two EBV-infected cell lines, HR1K and EB-3, were used as antigen-positive cells and Molt-4 was used as the negative control cells. The antibody titers of sera from suspected infectious mononucleosis patients were compared by RIA and indirect fluorescent antibody (IFA) methods. As determined by each of the methods, 14 of 19 sera had positive antibody titers and the remainder of the sera had negative antibody titers. Thus, the two methods agreed completely in differentiating sera with antibodies to EBV antigens. To further evaluate the antibody specificity of the RIA, the antibody titers of paired sera, pre- or early infection and postinfection, from five confirmed infectious mononucleosis patients were determined by RIA and IFA. Seroconversion was demonstrated by both RIA and IFA for each of the patients. Thus, the sensitivity and specificity of the two procedures are about the same.     

Comparison of four Mycoplasma pneumoniae IgM-, IgG- and IgA-specific enzyme immunoassays in blood donors and patients

Mycoplasma pneumoniae antibodies were studied in 504 blood donors and 102 patients with infections not caused by M. pneumoniae with the use of enzyme immunoassay kits from ThermoLabsystems (L), Savyon (S), Bio-Rad (B) and Novitec (N). Detection frequencies of M. pneumoniae IgM in blood donors were 14.9% (L), 16.0% (S), 2.8% (B) and 3.8% (N), and in patients were 40.2% (L), 42.2% (S), 9.8% (B) and 16.7% (N). Detection frequencies of M. pneumoniae IgA were 68.5% (L) and 22.8% (S), and in 65 respiratory disease patients were 100% (L) and 53.8% (S). Thus, use of some kits may lead to overdiagnosis of M. pneumoniae infections.     

A pathological and immunohistological case report of fatal infectious mononucleosis,Epstein-Barr virus infection,demonstrated by in situ and Southern blot hybridization

We present an autopsy case of 20-month-old boy who had a fulminant course of infectious mononucleosis, with severe hepatic failure. Autopsy revealed marked infiltration of immunoblasts in the lymph nodes, liver, spleen, thymus and kidneys. We identified a large number of Epstein-Barr virus (EBV) genomes in the immunoblasts of the lymph nodes, liver and spleen by in situ hybridization. EBV genomes were also detected in the liver and spleen by Southern blot hybridization. Histology of the liver revealed diffuse feathery degeneration of the hepatocytes. However, EBV genomes were not detected in the hepatocytes by in situ hybridization and monoclonal antibody studies. Immunostaining of the autopsy liver specimen revealed a large number of suppressor/cytotoxic T cells (Leu2a positive) in the portal areas and of natural killer (NK) cells (Leu7 positive) in the portal areas and sinusoids of the liver. We therefore suggest that the hepatocellular damage was not caused by the viral replication in the hepatocytes but was mainly caused by the abnormal killer cell activity of the suppressor/cytotoxic T cells and NK cells.     

Epstein-Barr virus latent membrane protein expression by Hodgkin and Reed-Sternberg-like cells in acute infectious mononucleosis.

In the light of reports of latent membrane protein (LMP) expression by Hodgkin and Reed-Sternberg (HRS) cells, paraffin sections of tonsil (two cases), lymph nodes (eight cases; three cervical, one axillary, and four inguinal) and spleen (four cases) from 14 patients with acute infectious mononucleosis (IM) have been examined for the presence of HRS-like cells and immunostained with an antibody to LMP. Sections of the tonsils and one lymph node were also stained with a panel of antibodies which characterize HRS cells of Hodgkin's disease. The tonsils contained abundant HRS-like cells, mainly adjacent to the crypts, which were highlighted by strong LMP expression. The immunophenotype of these cells closely, but not completely, resembled that of HRS cells of Hodgkin's disease. The lymph nodes and spleens showed the typical changes of acute IM but only few LMP-positive HRS-like cells were present in the cervical lymph nodes and hardly any were present in the inguinal nodes and spleen. These findings suggest that tonsillar crypt squamous epithelium may play a role in the formation of LMP-positive HRS-like cells; these cells could be progenitors of Hodgkin's disease HRS cells and, if so, this might explain the restricted sites of presentation of Hodgkin's disease.     

Serodiagnosis of infectious mononucleosis by using recombinant Epstein-Barr virus antigens and enzyme-linked immunosorbent assay technology.

Four recombinant, diagnostically useful Epstein-Barr virus (EBV) proteins representative of the viral capsid antigen (p150), diffuse early antigen (p54), the major DNA-binding protein (p138), and the EBV nuclear antigen (p72) (W. Hinderer, H. Nebel-Schickel, H.H. Sonneborn, M. Motz, R. Kühbeck, and H. Wolf, J. Exp. Clin. Cancer Res. 7[Suppl.]:132, 1988) were used to set up individual enzyme-linked immunosorbent assays (ELISAs) for the qualitative and quantitative detection of immunoglobulin M (IgM) and IgG antibodies. In direct comparison with results obtained by standard immunofluorescence or immunoperoxidase assays, it was then shown that the recombinant EBV ELISAs provide the means for specific and sensitive serodiagnosis of infectious mononucleosis (IM) caused by EBV. The most useful markers in sera from such patients proved to be IgM antibodies against p54, p138, and p150. Additional positive markers for recent or ongoing IM apparently were IgG antibodies against p54 and p138. In contrast, anti-p72 IgG had a high preference for sera from healthy blood donors and, therefore, can be considered indicative of past exposure to the virus. Altogether, the individual ELISAs proved to be as specific and at least as sensitive for the diagnosis of IM as the currently available standard techniques are. Moreover, our findings suggest that, by combining individual test antigens, a workable ELISA system consisting of three assays (IgM against p54, p138, and p150; IgG against p54 and p138; and IgG against p72) can be established for the standardized rapid diagnosis of acute EBV infections.     

Appearance and some unusual features of Epstein-Barr virus antibody production in infectious mononucleosis and other health disorders.

The indirect immunofluorescence (IF) test and the complement-fixation reaction (CFR) were used in examination of over 1500 sera obtained from patients with infectious mononucleosis (IM) and other health disorders. The evidence obtained supports a direct aetiological relationship between Epstein-Barr virus (EBV) and IM and points on a relationship of EBV to some other lymphadenopathies and health disorders. The incidence of the IgG type antibody against virus capsid antigen (EB-VCA) and soluble antigen (CF-SA) obtained from EBV genome-positive cells among different age groups of patients is described along with results of long-term examinations of serum samples from IM patients. The appearance and dynamics of production of both types of EBV antibody and their persistence in the organism varied. Long-lasting oscillations, in particular of the EB-VCA antibody levels were found in sera of patients with prolonged health disorders following IM. The diagnosis value of the IF test and the CFR is discussed.