Serological Studies in Infectious Mononucleosis

Serological investigations performed on 27 patients with illnesses resembling infectious mononucleosis showed a significant increase in high antibody titres (more than 1:40) to EB virus in 11 of the 12 who developed heterophile antibodies. Two of these patients, however, had a significant increase in antibody titre to cytomegalovirus and rubella virus, respectively. Of 15 patients who failed to develop heterophile antibodies, one had a high antibody titre to EB virus, the others generally having undetectable or low antibody titres. The insidious onset of the illness in many patients together with the fact that EB virus antibodies rose to high titres rapidly reduced the value of this investigation diagnostically.EB virus antibody was still present in the sera of five patients who had had well-authenticated heterophile-antibody-positive infectious mononucleosis some four to seven years previously. Twenty-seven out of 70 (39%) healthy nurses had antibody at a level of more than 1:10 to EB virus. The presence of EB virus antibody in different population groups appears to be related to such factors as age and socioeconomic status.     

EB virus antibody at different ages

In relation to the study of infectious mononucleosis a survey of the prevalence of antibody to EB virus was made on the sera of persons of varying age from several different areas in England by the indirect immunofluorescence technique. About half those tested were found to have acquired antibody by the age of 4 years and there was a further significant increase in the proportion of those positive between the ages of 15 and 24 years. The finding of seroconversion in two patients who developed infectious mononucleosis provides further support for an association between EB virus and this condition.     

Cytomegalovirus in the mononucleosis syndrome in children

In 7 children aged 18 months to 7 years isolated from a group of 128 children with infectious mononucleosis the cytomegalovirus infection was found. Infection was diagnosed by determination of antibodies against immediate early and late CMV antigen by means of the ELISA test. Besides that, antibodies were determined against the capsid antigen and early antigen of EB virus by the method of indirect immunofluorescence. In four children only cytomegalovirus infection was found and three had a mixed infection with both viruses and the diagnosis in these cases was: infectious mononucleosis (due to EBV) with coexistent or following CMV infection. In the sera of two children with cytomegalovirus mononucleosis changes were observed in the antibodies against EBV which is explained as a result of interactions between CMV and EBV in the organism of the host.     

Angioimmunoblastic lymphadenopathy after infectious mononucleosis.

Angioimmunoblastic lymphadenopathy occurred in a 46-year-old man 16 months after an episode of infectious mononucleosis induced by Epstein-Barr (EB) virus. The features of infectious mononucleosis included fever, pharyngitis, lymph gland enlargement, hepatosplenomegaly, hyperbasophilic mononuclear cells, and IgM antibodies to EB virus, although heterophile antibodies were not detected. The illness was severe and prolonged and included an asymptomatic measles virus infection. Over a year later massive enlargement of the lymph nodes led to a biopsy, which showed a diffuse infiltration with lymphoid cells and a proliferation of arborising small vessels typical of angioimmunoblastic lymphadenopathy. In spite of corticosteroids, levamisole, chlorambucil, and radiotherapy, no remission occurred, and serious infections led to death 18 months after the onset. Viral infections with EB virus and measles virus associated with pre-existing or subsequent immunological changes probably resulted in the appearance of angioimmunoblastic lymphadenopathy.     

Infectious mononucleosis at the United States Military Academy. A prospective study of a single class over four years

A prospective study of EB virus infections was initiated in July, 1969 in the entering class of 1401 cadets, at the U.S. Military Academy at West Point, N.Y. and continued over 4 yr. On entry 63.5% possessed EBV antibody and 36.5 lacked EBV antibody. The rate of antibody prevalence varied with the geographic area from which the cadet originated.Except in two cadets already ill on first bleeding no evidence of clinical infectious mononucleosis (I.M.) occurred over the 4 yr period in the 890 cadets entering the Academy with EBV antibody. Among 437 cadets without antibody on entry, 54 or 12.4% were infected (seroconverted) in the freshman year; 15 of these had clinical I.M., 12 had suggestive I.M., and 39 had no known mono-like illness. The annual infection rates in susceptible cadets in the second, third, and fourth years were 24.4, 15.1, and 30.8 per 100, respectively. Of 201 cadets infected with EBV over 4 yr only 26.4% were manifested by heterophile positive clinical infectious mononucleosis. Overall, 46% of the 437 cadets entering without EBV antibody became infected over 40 mo of serologic observation; definite clinical infectious mononucleosis developed in 53 cadets, a clinical attack rate of 12.1 per 100 for 4 yr. The EBV infection rate among exposed and susceptible roommates of known cases was no higher than in roommates not so exposed.Elevations of EBV-specific and total IgM occurred during acute illness and disappeared in late convalescence. Total IgG and IgA levels were less commonly elevated. EBV-specific-IgM antibody was demonstrable during the acute illness but was absent 12 mo later. Analysis of EBV infection rates revealed no difference among persons of different ABO blood groups.     

Serological Response of the EBV Antibodies in Pediatric Cases of Infectious Mononucleosis and in Their Contacts

The EBV antibodies were measured in 378 sera from a group of 129 pediatric and older cases of infectious mononucleosis and from 117 family and social contacts. Cases of infectious mononucleosis with only one exception were EBV seropositive in acute and/or convalescent sera. Fourteen cases, however, from whom no convalescent serum was available were EBV seronegative. A rise in EBV antibodies of two dilutions or more was demonstrated in 15 of the 129 cases. The prevalence of these antibodies in contacts reached 50 to 70% in each of four age groups. A significant antibody rise was encountered in only four cases, one of whom was found to have infectious mononucleosis simultaneously with the index case and one after an interdisease period of 10 months. The infectivity of the EB virus (and of infectious mononucleosis if causally related) and its horizontal transmission seem to be as low in nature as they appear to be experimentally in the laboratory.     

Bone Marrow Colony-stimulating Activity of Sera in Infectious Mononucleosis

From 44 to 100% of sera from patients with infectious mononucleosis exhibited the capacity to stimulate colony formation in vitro by mouse bone marrow cells. The proportion of sera with colony-stimulating activity was highest in patients with a short fever period and developing low Paul-Bunnell titres. Patients with a more severe course of the disease generally displayed no, or only weak, colony-stimulating activity in their sera, and also had higher Paul-Bunnell titres. The level of serum colony-stimulating activity tended to fall in the convalescent stages of the disease.     

Reactivity of Paul-Bunnell type heterophile antibody in sera from infectious mononucleosis patients with the surface of lymphoid cells carrying Epstein-Barr virus genomes.

The possible presence of Paul-Bunnell (PB) antigen on Epstein-Barr virus (EBV)-transformed lymphocytes were investigated. Of 23 EBV genome-positive lymphoblastoid cell lines tested all but one absorbed PB type antibody from the serum of an infectious mononucleosis patient. The one EBV-negative B cell line tested did not absorb the heterophile antibody. PB antibody, purified by an immunoadsorbent procedure using beef cell antigen, reacted with the EBV producer P3HR-1 cell line in an indirect membrane immunofluorescence test and was shown to be IgM antibody. Titers of heterophile agglutinin and reactivity with the cell surface were reduced to the same degree by absorption with beef cell antigen but not with guinea pig kidney antigen. PB antibody was distinct from IgM antibody against the EBV-determined membrane antigen, since the latter was not absorbed by beef cell antigen. PB antibody was also reactive with other EBV-positive B cell lines (QIMR-WIL, NC-37, and Raji) which were free of surface IgM. No reaction occurred with the nonproducer P3HR-1 line, a null cell line, and two T cell lines. The results suggest the presence of PB antigen on most EBV-transformed B lymphocytes, and its appearance in each of the transformed lymphocytes of patients with acute infectious mononucleosis.     

Smooth Muscle Autoantibodies in Infectious Mononucleosis

Smooth muscle antibodies (S.M.A.) were found in the sera of 81% of 126 patients over 10 years old with seropositive infectious mononucleosis tested within one month of onset. In 27 patients presenting clinically with infectious mononucleosis but having negative Paul-Bunnell tests the incidence of S.M.A. was 44%. In children 10 years of age or less in these two categories S.M.A. were present in 75% and 25% respectively, while in children of similar age not suspected of having infectious mononucleosis the incidence of S.M.A. was 10%. Among 45 adults with past histories of seropositive infectious mononucleosis more than one year before the incidence of S.M.A. was 33%, in contrast to 14% in 98 subjects with a negative history for infectious mononucleosis.     

Formation of Paul-Bunnell antibodies by cultures of lymphocytes from infectious mononucleosis.

Short-term cultures of peripheral blood lymphocytes obtained from 20 infectious mononucleosis patients 2–4 weeks after the onset of the disease were studied for formation of heterophile antibodies. In studying pooled supernatant fluids of lymphocytes from three patients cultured for 3–20 days, lytic antibodies for red blood cells of bovine (BRBC) and sheep (SRBC) origin were demonstrated. These hemolysins were shown to be of IgM nature and Paul-Bunnell specificity. Subsequently, plaque-forming cell (PFC) assays were performed with lymphocyte cultures of 15 patients. Significant numbers (60–750/2 × 10⁷ cells) of PFC secreting antibodies against BRBC were demonstrated in lymphocyte cultures of 12 patients. The number of PFC apparently reached its peak after 5 to 10 days of culturing. No or a very few PFC were observed in the lymphocytes that were not cultured or in lymphocytes cultured for 3 weeks or longer. Lymphocyte cultures prepared in a similar fashion from normal individuals or patients suffering from sore throat and submandibular lymphadenopathy of other than infectious mononucleosis origin did not produce PFC. Production of lytic zones by antibodies to BRBC secreted by PFC was inhibited by preincubation of lymphocytes of infectious mononucleosis patients with solubilized Paul-Bunnell antigen but not with other heterophile antigens, indicating that antibodies involved in the PFC formation are of Paul-Bunnell specificity. An increased number of PFC against BRBC were obtained in two of three lymphocyte cultures after cultivation with BRBC or solubilized Paul-Bunnell antigen.     

Serological diagnosis of infection with human herpesvirus type 6.

OBJECTIVE--To identify clinical consequences of acute human herpesvirus type 6 infection by hypothesising that the virus will induce similar clinical syndromes to cytomegalovirus. DESIGN--Examination of consecutive serum samples from patients with illnesses compatible with acute cytomegalovirus infection or exanthem subitum by indirect immunofluorescence for the presence of antibodies to human herpesvirus type 6. An IgG absorption step was included to avoid false positive and negative results for IgM. The criterion standard for diagnosis of human herpesvirus type 6 infection was the presence of IgM human herpesvirus type 6 antibody (titre greater than 20) and a rising titre of IgG human herpesvirus type 6 antibody without serological evidence of alternative infection. SETTING--Routine viral diagnostic and reference laboratory in the largest teaching hospital in Sydney. PATIENTS--341 Consecutive serum samples were analysed from patients with hepatitis (147 samples); infectious mononucleosis-like illness (106); screens for toxoplasma, other viruses, rubella, cytomegalovirus, and herpesvirus (38); fever in an immunocompromised patient (eight); unusual neurological (nine) or haematological syndromes (14); splenomegaly (six); and rash in a child (13). RESULTS--Three cases of acute human herpesvirus type 6 infection were identified: in one patient aged 65 with a previous diagnosis of acute non-A non-B hepatitis, one aged 25 with a glandular fever-like illness, and one aged 6 with a glandular fever-like illness. All three illnesses resolved completely. 15 Further serum samples were positive for human herpesvirus type 6 antibody but were also diagnostic for acute infection with other viruses (cytomegalovirus (nine), Epstein-Barr virus (three), and HIV (one] or had a titre of IgM human herpesvirus type 6 antibody less than 20 (two). CONCLUSIONS--Acute human herpesvirus type 6 infection in immunocompetent patients may result in a mononucleosis-like illness or an acute but self limiting hepatitis.     

Severe Neutropenia in Infectious Mononucleosis

Mild neutropenia is a well-known concomitant of infectious mononucleosis caused by the Epstein-Barr virus (EBV) occurring in the first weeks of illness. However, severe neutropenia (less than 200 polymorphonuclear leukocytes per μl) is not generally regarded as a complication of infectious mononucleosis. Three patients were seen with severe neutropenia and EBV infection, and an additional eight cases were found in the literature. In two of the latter cases the neutropenia was fatal.In the 11 cases the severe neutropenia began 14 to 40 days after illness and usually lasted for three to seven days. At the time of severe neutropenia, studies of marrow specimens showed increased proportions of promyelocytes and myelocytes. Our data suggest that EBV infection is the proximate cause of the severe neutropenia in some patients with infectious mononucleosis and that in such cases close observation and early treatment of suspected superinfections is necessary.     

EBV与HCMV传染性单核细胞增多症患儿的实验室指标比较

目的观察EB病毒（EBV）与人类巨细胞病毒（HCMV）感染所致的传染性单核细胞增多症（IM）患儿超敏C-反应蛋白（hs-CRP）、白细胞（WBC）计数、嗜中性粒细胞比值（N）、异常淋巴细胞（异淋）、嗜异性抗体和血清酶的变化。方法选择70例确诊有EBV病毒感染且具备传染性单核细胞增多症临床特点的患儿（A组）进行实验室检测指标分析及总结;并与37例HCMV相关传染性单核细胞增多症患儿（B组）进行比较。结果与EB组（A组）比较,HCMV组（B组）感染患儿hs-CRP水平、肌酸激酶同功酶（CK-MB）、丙氨酸氨基转移酶（ALT）、外周血WBC计数、异型淋巴细胞增高程度较低（P〈0.05）,嗜异性抗体常为阴性,两组N值差异无统计学意义（P〉0.05）。结论 EBV与HCMV感染所致的传染性单核细胞增多症患儿的实验室指标变化不同,应重视IM患儿的实验室检查以辅助诊断。     

Renal graft dysfunction during infection with cytomegalovirus: association with IgM lymphocytotoxins and HLA-DR3 and DR7.

Of 121 consecutive adult recipients of cadaver renal transplants who were treated with low dose steroids and azathioprine, 23 developed active cytomegalovirus infections. These 23 patients were divided into three groups on the basis of their symptoms related to the infection: five patients had no renal, respiratory, or haematological abnormalities; seven had renal dysfunction; and nine had renal dysfunction plus respiratory or haematological abnormalities. Two patients were regarded as a separate group because their infections occurred two to four weeks after graft nephrectomy. All but three of the patients produced IgM or IgG lymphocytotoxins during their infections. In the patients with mild infections and in control patients without infections, however, these lymphocytotoxins were predominantly IgG antibodies that were not precipitated by 3.5% macrogol (polyethylene glycol). In contrast, 12 of the 16 patients with renal dysfunction during their infections had broadly reactive IgM lymphocytotoxins. These IgM lymphocytotoxins lysed T as well as B lymphocytes at 22 degrees C and were precipitated by 3.5% macrogol, suggesting that they were circulating as immune complexes. Rheumatoid factors were found in sera from nine patients with cytomegalovirus infections, seven of whom developed leukopenia or pneumonia, or both, in addition to renal dysfunction. Some of these immune responses associated with cytomegalovirus infection in transplant recipients may be genetically controlled since 10 of 11 patients positive for HLA-DR3 or DR7 produced IgM lymphocytotoxins.     

IgM Antibodies Specific for Epstein-Barr Virus in Infectious Mononucleosis without Heterophil Antibodies

IgM antibodies specific for Epstein-Barr (E.B.) virus were demonstrable in all but one out of 46 patients diagnosed as having infectious mononucleosis wihout heterophil antibodies; cytomegalovirus aetiology was excluded. In all but two cases the highest titre was found in the first sample. In 21 patients a significant decrease was seen within a few weeks. IgG antibodies to E.B. virus, mostly remaining at a constant level, were demonstrable in all cases. IgM antibodies to E.B. virus were found in only five out of 300 controls.The results suggest that in a disease similar to infectious mononucleosis without heterophil antibodies testing of transient E.B. virus-specific IgM antibodies makes a rapid aetiological diagnosis possible and that in clinically well-defined cases viruses other than E.B. virus and cytomegalovirus are unlikely to be causal agents.     

Heterophilic infectious mononucleosis antigen used in the latex diagnostic test. II. Preliminary evaluation of the usefulness of latex reagents for detection of serum heterophile antibodies in patients with infectious mononucleosis

The aim of this study was to evaluate the usefulness of laboratory made reagent of polystyrene latex coated with three preparations of mononucleosis antigen (reagent MZ-I, MZ-II, and MZ-III) for detection of heterophile antibodies in patients sera with clinical symptoms of infectious mononucleosis. These studies were carried out on 153 serum samples taken from persons suspected of being infected with EB virus and on 100 healthy controls--blood donors. The results of latex tests were compared to the results of Paul-Bunnell-Davidsohn (PBD) and hemolytic tests. Out of three latex reagents evaluated only one (reagent MZ-I) showed sensitivity equal to PBD and haemolytic tests. The sensitivity reached 91.1%. Agglutination reaction when appeared in latex test at serum dilution 1:5, is considered positive and diagnostically significant result.     

Epstein-Barr virus and cytomegalovirus antibodies in infectious mononucleosis.

A method has been evolved for the demonstration of Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infection in 83 cases of infectious mononucleosis. Serum samples were tested for EBV IgM, anti-VCA IgG, anti-EBNA, CMV IgM and CMV IgG antibodies. An acute-phase sample (or samples) and a convalescence sample were examined in each case, and in 44 cases an additional samples was examined 5-12 months after the illness. Since the different antibodies showed characteristic differences in both titre and persistence, a reliable serodiagnosis has become possible. Acute EBV infection is characterized by the presence of EBV-VCA IgG and EBV IgG antibodies and the lack of anti-EBNA. The latter becomes demonstrable as late as the 4th to 5th month after infection. Mean age of the patients was 19 years. EBV infection was demonstrated in 65%, CMV infection in 18% of the cases. In 12% double infection seemed to be probable.     

特发性血小板减少性紫癜与巨细胞病毒、EB病毒感染相关性

目的：探讨小儿特发性血小板减少性紫癜（ITP）与巨细胞病毒、EB病毒感染的关系。方法：实验组：48例确诊断为ITP患儿,对照组：44例同期呼吸道感染患儿,应用酶联免疫吸附法（ELISA）对两组小儿外周血进行巨细胞病毒IgM抗体（HCMV-IgM）、EB病毒感染IgM抗体（EB-IgM）检测。结果：48例ITP患儿中HCMV-IgM抗体阳性者20例,阳性率为41.67%,明显高于对照组,两组之间差异有显著性（P〈0.01）;EBV-IgM抗体阳性者14例,阳性率为29.17%,明显高于正常对照组,两组之间差异有显著性（P〈0.05）。结论：1、巨细胞病毒感染是引起特发性血小板减少性紫癜的重要原因之一,且通过临床观察巨细胞病毒感染引起的ITP患儿病情重,病程长,治疗时间长,转为慢性ITP的可能性大;2、EB病毒感染可能是引起特发性血小板减少性紫癜的原因之一,并且EB病毒感染引起的特发性血小板减少性紫癜病情也偏重。     

Epstein-Barr virus infection in the neonatal period and in childhood

In an attempt to detect and characterize congenital, neonatal and early childhood EBV infections, a prospective sero-epidemiological study was undertaken in 112 newborn infants and their mothers, 25 additional newborns undergoing exchange transfusion, 114 randomly selected hospitalized infants aged 0 to 3 years, and 109 siblings and parents of these infants. Leukocyte culture was attempted in all the newborns and in 25 pre- and post-transfusion.The findings of EBV seroconversion in six patients without clearly apparent illness, infectious mononucleosis in only one case with significant EBV antibody rise, seroreversion in three cases in early childhood, higher newborn than maternal EBV antibody titres in three cases and the establishment of two permanent lymphoblastoid cell lines from newborns following exchange transfusion raise the possibility of abortive primary EBV infection in early life. Congenital or neonatal infections following exchange transfusions, however, could not be substantiated with certainty since the EBV antibodies did not persist at follow-up except possibly in two cases. Parenteral transmission of the EB virus by exchange transfusion at birth is probably prevented by the presence of EBV antibodies in either donor or recipient.     

Failure to demonstrate concomitant antibody changes to viral antigens other than Epstein-Barr virus (EBV) during or after infectious mononucleosis

A search for antibody rises to viral antigens other than to Epstein-Barr virus, the causative agent, has been carried out in serial serum samples from 82 patients with infectious mononucleosis (IM). Fourfold or greater rises in titer rarely occurred and did did not cluster in time. No rises occurred to cytomegalovirus, only 1.2 percent to herpes simplex virus, and 8.5 percent to varicella zoster virus. Rises to measles antibody were found in 7.5 percent of patients and to rubella in 10.4 percent; these may represent natural infections or immunizations. A few patients also showed rises to respiratory viruses but there was no apparent connection to IM.