Transient immune deficiency in patients with acute Epstein-Barr virus infection

Acute Epstein Barr Virus is a risk factor for severe malaria in infants under 24 months

Background

Primary Epstein Barr Virus (EBV) infection occurs during late adolescence and is characterized by the symptomatic manifestation of infectious mononucleosis (IM). Primary EBV infection in malaria-endemic areas often occurs in young children by the age of 2 and is generally asymptomatic. Acute EBV infection in children of this age results in humoral immune suppression to unrelated antigenic challenges for approximately 4 weeks. Whether acute EBV in infants similarly suppresses the development of antibody responses against Plasmodium falciparum (Pf) predisposing infants to severe malaria is unknown.

Methods

We undertook a cross-sectional study of 195 infants aged 6-24 months in Cameroon. Infants were determined to be parasitaemic by microscopy or RDT, and their disease severity classified based on WHO criteria. The EBV infection status of each child was determined using a standard serological classification system, and the magnitude, breadth, and invasion blocking capacity of the anti- Pf antibody response were quantified.

Results

26.7% of children were serologically positive for acute EBV infection, and the highest proportion of severe malaria cases was in children with primary acute EBV. An elevated magnitude and breadth of the antibody response with increased in vitro invasion-blocking capacity was observed in children with acute EBV but circulating parasitaemia in vivo was similar.

Conclusion

Acute EBV infection is a risk factor for developing severe malaria in children 6-24 months. Targeting EBV infection in young children may be beneficial in protecting against the development of severe falciparum malaria in children living in malaria-endemic areas.

Key points

Acute EBV infection in infants increases the risk of severe falciparum malaria. This does not appear to be due to an EBV-induced impairment of the anti- Plasmodium humoral immune response which is elevated in magnitude, breadth and function.

Gammaherpesvirus Co-infection with Malaria Suppresses Anti-parasitic Humoral Immunity

Immunity to non-cerebral severe malaria is estimated to occur within 1-2 infections in areas of endemic transmission for Plasmodium falciparum. Yet, nearly 20% of infected children die annually as a result of severe malaria. Multiple risk factors are postulated to exacerbate malarial disease, one being co-infections with other pathogens. Children living in Sub-Saharan Africa are seropositive for Epstein Barr Virus (EBV) by the age of 6 months. This timing overlaps with the waning of protective maternal antibodies and susceptibility to primary Plasmodium infection. However, the impact of acute EBV infection on the generation of anti-malarial immunity is unknown. Using well established mouse models of infection, we show here that acute, but not latent murine gammaherpesvirus 68 (MHV68) infection suppresses the anti-malarial humoral response to a secondary malaria infection. Importantly, this resulted in the transformation of a non-lethal P. yoelii XNL infection into a lethal one; an outcome that is correlated with a defect in the maintenance of germinal center B cells and T follicular helper (Tfh) cells in the spleen. Furthermore, we have identified the MHV68 M2 protein as an important virus encoded protein that can: (i) suppress anti-MHV68 humoral responses during acute MHV68 infection; and (ii) plays a critical role in the observed suppression of anti-malarial humoral responses in the setting of co-infection. Notably, co-infection with an M2-null mutant MHV68 eliminates lethality of P. yoelii XNL. Collectively, our data demonstrates that an acute gammaherpesvirus infection can negatively impact the development of an anti-malarial immune response. This suggests that acute infection with EBV should be investigated as a risk factor for non-cerebral severe malaria in young children living in areas endemic for Plasmodium transmission.

Secondary antibody deficiency

Secondary antibody deficiencies are defined by a quantitative or qualitative decrease in antibodies that occur most commonly as a consequence of renal or gastrointestinal immunoglobulin loss, hematological malignancies and corticosteroid, immunosuppressive or anticonvulsant medications. Patients with hematological malignancies or requiring immunosuppressive medications are known to be at increased risk of infection, but few studies directly address this relationship in the context of antibody deficiency. Immunoglobulin replacement therapy has been shown to be effective in reducing infections in primary and some secondary antibody deficiencies. The commonly encountered causes of secondary antibody deficiencies and their association with infection-related morbidity and mortality are discussed. Recommendations are made for screening and clinical management of those at risk.

[A 22-year-old patient from Ghana with fever and reduced CD4 T-cell count]

A 22-year-old patient from Ghana without relevant co-morbidities was admitted twice with fever of unknown origin and reduced CD4 T-cell count. During the second hospital stay, after prolonged incubation of blood cultures and detection of vegetations on the mitral valve in a transesophageal echocardiogram, infectious endocarditis with Aggregatibacter aphrophilus was diagnosed. Treatment according to European guidelines resulted in resolution of the fever, dissolution of the mitral valve vegetations and recovery of CD4 T-cell count.

Coinfection with EBV/CMV and other respiratory agents in children with suspected infectious mononucleosis

BACKGROUND

Numerous studies have shown that Epstein-Barr virus (EBV) and cytomegalovirus (CMV) can infect immunocompetent patients simultaneously with other agents. Nonetheless, multiple infections with other agents in EBV/CMV-infected children have received little attention. We conducted a retrospective study of children with suspected infectious mononucleosis. Peripheral blood samples were analyzed by indirect immunofluorescence to detect EBV, CMV and other respiratory agents including respiratory syncytial virus; adenovirus; influenza virus types A and B; parainfluenza virus types 1, 2 and 3; Chlamydia pneumoniae and Mycoplasma pneumoniae. A medical history was collected for each child.

RESULTS

The occurrence of multipathogen infections was 68.9%, 81.3% and 63.6% in the children with primary EBV, CMV or EBV/CMV, respectively, which was significantly higher than that in the past-infected group or the uninfected group (p < 0.001). Of the multipathogen-infected patients, the incidence of C. pneumoniae in children with primary infection was as high as 50%, significantly higher than in the other groups (p < 0.001). In the patients with multipathogen infection and EBV/CMV primary infection, fever, rash, lymphadenopathy, hepatomegaly, splenomegaly, atypical lymphocytes and abnormal liver function were more frequent and the length of hospital stay and duration of fever were longer than in other patients.

CONCLUSION

Our study suggests that there is a high incidence of multipathogen infections in children admitted with EBV/CMV primary infection and that the distribution of these pathogens is not random.

Herpes simplex Virus Esophagitis in an Immunocompetent Patient with Ebstein-Barr Virus Infection

Epstein-Barr virus infectious mononucleosis can cause transient immune deficiency which may predispose to reactivation of latent herpes simplex virus (HSV) infection in the immunocompetent host. We report the case of a 15-year-old male who presented with severe odynophagia and herpes labialis during the course of Epstein-Barr virus infectious mononucleosis that had been diagnosed ten days before. Esophagoscopy revealed extensive ulcerations with distinct borders and whitish exudates at the mid and distal esophagus. Polymerase chain reaction detected HSV-1 DNA in the biopsy specimens. The patient was treated with intravenous acyclovir. The symptoms resolved rapidly within 3 days, in accordance with improved endoscopic findings.

Hemophagocytic lymphohistiocytosis associated with Epstein Barr virus and Leishmania donovani coinfection in a child from Cyprus

We present a case of a 9-month-old girl from Cyprus with hemophagocytic lymphohistiocytosis associated with Epstein Barr virus and Leishmania donovani coinfection. Treatment with liposomal amphotericin B resulted in a dramatic resolution of clinical and laboratory abnormalities. To our knowledge, this is the first reported case of a coinfection-associated hemophagocytic lymphohistiocytosis and the first clinical report of visceral leishmaniasis infection in Europe by L. donovani.

Risk and protective factors for meningococcal disease in adolescents: matched cohort study

OBJECTIVE

To examine biological and social risk factors for meningococcal disease in adolescents.

DESIGN

Prospective, population based, matched cohort study with controls matched for age and sex in 1:1 matching. Controls were sought from the general practitioner.

SETTING

Six contiguous regions of England, which represent some 65% of the country's population.

PARTICIPANTS

15-19 year olds with meningococcal disease recruited at hospital admission in six regions (representing 65% of the population of England) from January 1999 to June 2000, and their matched controls.

METHODS

Blood samples and pernasal and throat swabs were taken from case patients at admission to hospital and from cases and matched controls at interview. Data on potential risk factors were gathered by confidential interview. Data were analysed by using univariate and multivariate conditional logistic regression.

RESULTS

144 case control pairs were recruited (74 male (51%); median age 17.6). 114 cases (79%) were confirmed microbiologically. Significant independent risk factors for meningococcal disease were history of preceding illness (matched odds ratio 2.9, 95% confidence interval 1.4 to 5.9), intimate kissing with multiple partners (3.7, 1.7 to 8.1), being a university student (3.4, 1.2 to 10) and preterm birth (3.7, 1.0 to 13.5). Religious observance (0.09, 0.02 to 0.6) and meningococcal vaccination (0.12, 0.04 to 0.4) were associated with protection.

CONCLUSIONS

Activities and events increasing risk for meningococcal disease in adolescence are different from in childhood. Students are at higher risk. Altering personal behaviours could moderate the risk. However, the development of further effective meningococcal vaccines remains a key public health priority.

Epstein-Barr virus-associated recurrent necrotic papulovesicles with repeated bacterial infections ending in sepsis and death: consideration of the relationship between Epstein-Barr virus infection and immune defect

The disease of Epstein-Barr virus (EBV) -associated recurrent necrotic papulovesicles is a distinct clinicopathologic entity different from classic hydroa vacciniforme (HV). A few patients have been reported as atypical HV with systemic involvement, development of lymphoma, and poor prognosis. We describe a patient with recurrent necrotic papulovesicles and multiple varioliform scars in both sun-exposed and covered areas. In contrast to cases of previously reported atypical HV, our patient suffered from repeated bacterial infections on various sites ending in sepsis and death, but without malignant transformation. EBV was detected in the lymphoid cells from the skin lesions by anti-latent membrane protein (LMP) antibody and in situ hybridization. We suggest that the repeated bacterial infections in this case raise the possibility of an association of EBV infection with increased susceptibility to bacterial infections.

Strong response of T cells in infants with dual infection by Epstein-Barr virus and cytomegalovirus

BACKGROUND

Although a reversed CD4/CD8 ratio and increased proportion of CD8+ HLA-DR+ T cells are well known as the characteristic immune response in infectious mononucleosis (IM), it has not been elucidated whether these immune responses are affected by patient age and pathogenetic viruses.

METHODS

T cell subsets were analyzed by two-color flow cytometry using fluorescein isothiocyanate- and phycoerythrin-conjugated monoclonal antibodies in 115 infants and children aged from 4 months to 10 years with IM due to Epstein-Barr virus (EBV), cytomegalovirus (CMV) and dual infection with both viruses.

RESULTS

A reversed CD4/CD8 ratio and increased proportions of CD4+/HLA-DR+ T cells, CD8+ T cells and CD8+/HLA-DR+ T cells became more prominent as the age of the patients became older. No differences were observed in proportions of T cell subsets between EBV- and CMV-infection among patients aged from 6 to 17 months. Although the responses of these T cells were weak in infants with single virus infection by EBV and CMV, markedly strong T cell responses comparable with those in older children were observed in infants with EBV/CMV dual infection. Clinical symptoms were more severe in patients with EBV/CMV dual infection than those with EBV or CMV alone.

CONCLUSION

The manner of these T cell responses in the acute phase of IM was considered to be age dependent, although strong T cell responses and severe disease were observed in EBV/CMV dual infection irrespective of patient age.

Normal Immunologic Response to a Neoantigen, Bacteriophage ΦX-174, in Baboons With Long-Term Lymphohematopoietic Reconstitution From Highly Purified CD34+ Lin− Allogeneic Marrow Cells

The CD34 antigen is thought to be expressed by hematopoietic stem cells in adult humans and nonhuman primates. We present data that baboons transplanted with highly purified allogeneic CD34+ marrow cells devoid of detectable mature and immature T and B lymphocytes and myeloid cells, isolated from sex-mismatched mixed lymphocyte culture (MLC) nonreactive siblings, have maintained stable lymphohematopoietic engraftment with donor cells for greater than 4.9, greater than 6.0, and 5.0 years. Cytogenetic analysis of unfractionated marrow and peripheral blood cells at multiple time points after transplantation show virtually all donor cells in two animals and stable mixed chimerism in the third. We used polymerase chain reaction to show that colony-forming unit–granulocyte-macrophage, burst-forming unit-erythroid, and high proliferative potential colony-forming cells (HPP-CFC) were virtually all of donor origin in two animals and present at lower levels in the stable mixed chimera. CD20+ B-lymphoblastoid cell lines derived by Herpesvirus Papio transformation of peripheral blood cells were virtually all donor in two animals and 50% donor in the mixed chimera. CD4+ and CD8+ T cells and neutrophils purified from the peripheral blood of the two female animals also were all donor-derived. To assess immunologic function after transplantation, we immunized the three long-term chimeric animals and two normal control animals with bacteriophage ΦX-174, a neoantigen that requires the interaction of antigen-presenting cells, T lymphocytes, and B lymphocytes to mount a normal antibody response. Experimental and control animals, when immunized with bacteriophage, had similar serum Ig levels. The experimental and control animals generated similar titers of antibacteriophage antibodies after primary and secondary immunizations with evidence of amplification and class switching. These findings further support the hypothesis that the CD34+ antigen is expressed on hematopoietic stem cells that can mediate stable long-term lymphohematopoiesis in vivo and, importantly, that normal immunologic function can be reconstituted in vivo after transplantation of the highly purified CD34+ Lin− cells alone.

Normal Immunologic Response to a Neoantigen, Bacteriophage ΦX-174, in Baboons With Long-Term Lymphohematopoietic Reconstitution From Highly Purified CD34+ Lin− Allogeneic Marrow Cells

The CD34 antigen is thought to be expressed by hematopoietic stem cells in adult humans and nonhuman primates. We present data that baboons transplanted with highly purified allogeneic CD34+ marrow cells devoid of detectable mature and immature T and B lymphocytes and myeloid cells, isolated from sex-mismatched mixed lymphocyte culture (MLC) nonreactive siblings, have maintained stable lymphohematopoietic engraftment with donor cells for greater than 4.9, greater than 6.0, and 5.0 years. Cytogenetic analysis of unfractionated marrow and peripheral blood cells at multiple time points after transplantation show virtually all donor cells in two animals and stable mixed chimerism in the third. We used polymerase chain reaction to show that colony-forming unit–granulocyte-macrophage, burst-forming unit-erythroid, and high proliferative potential colony-forming cells (HPP-CFC) were virtually all of donor origin in two animals and present at lower levels in the stable mixed chimera. CD20+ B-lymphoblastoid cell lines derived by Herpesvirus Papio transformation of peripheral blood cells were virtually all donor in two animals and 50% donor in the mixed chimera. CD4+ and CD8+ T cells and neutrophils purified from the peripheral blood of the two female animals also were all donor-derived. To assess immunologic function after transplantation, we immunized the three long-term chimeric animals and two normal control animals with bacteriophage ΦX-174, a neoantigen that requires the interaction of antigen-presenting cells, T lymphocytes, and B lymphocytes to mount a normal antibody response. Experimental and control animals, when immunized with bacteriophage, had similar serum Ig levels. The experimental and control animals generated similar titers of antibacteriophage antibodies after primary and secondary immunizations with evidence of amplification and class switching. These findings further support the hypothesis that the CD34+ antigen is expressed on hematopoietic stem cells that can mediate stable long-term lymphohematopoiesis in vivo and, importantly, that normal immunologic function can be reconstituted in vivo after transplantation of the highly purified CD34+ Lin− cells alone.

Pyomyositis in patients with the human immunodeficiency virus: an unusual form of disseminated bacterial infection

PURPOSE AND PATIENTS

Pyomyositis, a common disease in the tropics, is rare in the continental United States, with approximately 83 cases described in the literature in the past two decades. The occurrence of pyomyositis complicating human immunodeficiency virus (HIV) infection has been reported in 10 patients since 1986. We report six cases of this entity in patients with advanced HIV disease seen in our institution over a 20-month period. A common denominator in all of our patients was muscle injury, induced by either exercise or trauma. Unlike most previous reports of HIV-associated pyomyositis, the clinical picture in our cases was complicated by the development of abscesses in multiple muscle groups, requiring prolonged antimicrobial therapy and repeated drainage procedures for successful management. Interestingly, one patient developed concomitant rhabdomyolysis--an otherwise rare event in classical pyomyositis. Staphylococcus aureus was the predominant infecting organism in this as well as all other series. Of note, we also observed and report the first case, to our knowledge, of gram-negative pyomyositis in an HIV-infected individual. The pathogenic implications of this catalase-producing gram-negative isolate are discussed in the context of neutrophil abnormalities in HIV disease.

CONCLUSION

Like tropical pyomyositis, its HIV-associated counterpart appears to be multifactorial in origin. Its recent recognition suggests that, in addition to underlying abnormalities of host defense, factors relating to the prolonged survival of patients with late-stage disease, including myopathy, might play an important contributory role.

Do infections induce monoclonal immunoglobulin components?

The incidental finding of monoclonal immunoglobulin components (MC) in some infections prompted us to study this phenomenon more systematically. Using isoelectric focusing with immunoblotting (detection limit for MC 0.1 mg/ml), the following infections were studied for the presence of MC: visceral leishmaniasis, cytomegalovirus (CMV) infection, echinococcosis and infectious mononucleosis. MC were found in 16 of 20 leishmania patients and in eight of 18 CMV patients, but in only one of 20 echinococcosis patients and in none of 30 infectious mononucleosis patients. The MC were mostly transient, where tested. A minority of the MC found in the leishmaniasis patients was shown to bind to leishmania antigens. The specificity of the majority of the MC remains unknown. Further study is required to explain the high incidence of MC in CMV infection and visceral leishmaniasis.

Soluble interleukin-2 receptor and soluble CD8 in serum and cerebrospinal fluid during human immunodeficiency virus-associated neurologic disease

We have measured levels of soluble interleukin-2 receptor (sIL-2R) and soluble CD8 (sCD8) in serum and cerebrospinal fluid (CSF) of 127 human immunodeficiency virus (HIV)-seropositive and 51 HIV-seronegative individuals. Serum levels of sIL-2R and sCD8 were higher in HIV+ than in HIV- individuals. HIV+ individuals were grouped by neurological status: asymptomatic, abnormal on neuropsychological screening, HIV-related meningitis, inflammatory demyelinating polyneuropathy, opportunistic central nervous system (CNS) infections and HIV-related dementia, myelopathy or sensory neuropathy. Serum levels of sIL-2R and sCD8 were higher in all HIV+ categories compared to HIV- individuals. Patients with HIV-related meningitis had higher levels of sIL-2R and sCD8 than asymptomatic HIV+ individuals, and inflammatory polyneuropathy patients had higher levels of sCD8. CSF levels of sCD8 were higher in all categories of HIV+ than in HIV- individuals. Patients with HIV-related meningitis, inflammatory neuropathy and opportunistic infections had higher levels than asymptomatic individuals. Examination of the time course showed that serum and CSF levels of sIL-2R and sCD8 increased to very high levels during acute HIV infections. Serum levels then declined over several months to relatively stable elevated levels. By 1-2 years after HIV infection sIL-2R was relatively low in CSF, while sCD8 remained elevated with a gradual decrease over the subsequent years of follow-up.

Detection of X-linked lymphoproliferative disease using molecular and immunovirologic markers

PURPOSE, PATIENTS, AND METHODS

Detection of males affected with the X-linked lymphoproliferative disease (XLP) was sought using immunovirologic and molecular genetic linkage techniques. The study population consisted of 20 males in six families with XLP.

RESULTS

Concordance for detection of affected males was 100% when linkage analysis using DXS42 and DXS37 DNA probes and antibody responses to challenge with bacteriophage phi X174 were both determined. Most affected males showing IgG subclass immune deficiency could not produce antibodies to Epstein-Barr virus nuclear antigen and had deficient responses to challenge with bacteriophage phi X174.

CONCLUSION

Use of only one of the techniques described can fail to lead to the diagnosis of XLP, because problems can prevail with each individual determination.

Human antibody responses to bacteriophage phi X 174: sequential induction of IgM and IgG subclass antibody

We studied the appearance of antigen-specific immunoglobulin classes and IgG subclasses in normal adult human subjects in response to primary, secondary, and tertiary immunization with the T-cell-dependent neo-antigen bacteriophage phi X 174. To complete the study we developed a sensitive, specific, and reproducible ELISA assay which was closely comparable to the widely used neutralization assay for total antibody (r = +0.97) and for IgG antibody (r = +0.93), and reasonably comparable for IgM antibody (r = +0.76). We confirmed that the initial response to primary immunization was predominantly, but not exclusively, IgM antibody. The secondary and tertiary responses demonstrated memory, amplification, and switch from IgM to IgG antibody. There was an orderly appearance of phage-specific IgG subclasses. IgG3 and IgG1 antibodies appeared 2 to 6 weeks after primary immunization. In all subjects there was a marked increase in IgG1 and IgG3 antibody after secondary immunization, and IgG2 antibody followed closely; IgG4 antibody appeared in some subjects. IgM antibody persisted in significant amounts (approx 50%) throughout the secondary response period. Following tertiary immunization, IgG1, IgG2, and IgG3 antibody consistently increased, and IgG4 antibody appeared in all subjects; IgG1 antibody predominated. Low levels of IgM antibody (approx 1% of total) persisted during the tertiary response. The persisting antibody on long-term follow-up (median 4 years after immunization) was virtually all (greater than 90%) IgG1.

Abnormal antibody responses in patients with persistent generalized lymphadenopathy

Persistent, generalized lymphadenopathy (PGL) is a recognized component of human immunodeficiency virus (HIV) infection. We conducted longitudinal studies of B and T cell function in seven homosexual men with HIV infection and PGL. All seven had abnormal antibody-mediated immunity as studied by sequential assessment of in vivo antibody responses after immunization with the T-dependent neoantigens bacteriophage phi X 174 and keyhole limpet hemocyanin (KLH), the T-independent tetradecavalent pneumococcal polysaccharide vaccine, and the recall antigens diphtheria and tetanus toxoid. Compared to HIV-negative heterosexual controls, PGL patients responded with lower antibody titers and, following immunization with phage, failed to develop immunologic memory and to switch from IgM- to IgG-isotype antibody. In vitro antigen-induced antibody production was markedly diminished; and some patients showed depressed mitogen responses. There was a correlation between the degree of compromised immunity and the clinical condition; those with the most severe symptoms showed the most extensive immune deficiency. Yet despite obvious immunologic impairment five of the seven men have remained clinically stable over a 3-year follow-up period.