Kinetics of specific immunoglobulins M, E, A, and G in congenital, primary, and secondary cytomegalovirus infection studied by antibody-capture enzyme-linked immunosorbent assay

The Association of Cytomegalovirus and Allostatic Load by Country of Birth and Length of Time in the United States

BACKGROUND

Cytomegalovirus (CMV) is a highly prevalent virus with a worldwide distribution. It typically remains dormant in most individuals until reactivation. Immunocompromised states are known to be potential causes for CMV reactivation. Current research has shown a link in the decline of immigrant health among those living in the US for an extended period, though the impact of CMV on this is not clear.

METHODS

This study investigated the association between country of birth, duration of US residency, allostatic load, and latent cytomegalovirus infection (CMV IgG) in a sample of US adults aged 20-49. The data utilized for our analysis was obtained from the National Health and Nutrition Examination Survey (NHANES) conducted between 2001 and 2004. Allostatic load, an index measuring the cumulative physiological strain on the body as it strives to regain stability in the presence of chronic stress, provided a valuable approach to assess stress within the context of CMV exposure. Logistic regression modeling was employed to estimate odds ratios and confidence intervals for the analysis. The chi-square test of association and Cramer's V statistic were used to assess the correlation among categorical variables, while Pearson's correlation coefficient was applied to evaluate the relationship between continuous variables. The results revealed that individuals born outside the US and those with less than 20 years of residency in the US exhibited significantly higher proportions of positive CMV IgG compared to individuals born in the US. Specifically, individuals born outside the US had more than triple the odds of CMV IgG when adjusting for the AL index (OR = 3.69, p-value = 0.0063). A similar trend was observed when examining AL risk based on the duration of US residency. Furthermore, age and sex were identified as significant predictors (p-value < 0.05) of AL risk, considering the individual's country of birth. In summary, the findings of this study significantly enhance our comprehension of the intricate interplay between cytomegalovirus (CMV) and allostatic load (AL). The investigation sheds light on how CMV and AL interact within specific demographic contexts, providing valuable insights into the underlying risk factors for CMV infection.

Venous thromboembolism in viral diseases: A comprehensive literature review

Venous thromboembolism (VTE) is known to be a common respiratory and/or cardiovascular complication in hospitalized patients with viral infections. Numerous studies have proven human immunodeficiency virus infection to be a prothrombotic condition. An elevated VTE risk has been observed in critically ill H1N1 influenza patients. VTE risk is remarkably higher in patients infected with the Hepatitis C virus in contrast to uninfected subjects. The elevation of D-dimer levels supported the association between Chikungunya and the Zika virus and the rise of clinical VTE risk. Varicella-zoster virus is a risk factor for both cellulitis and the consequent invasive bacterial disease which may take part in thrombotic initiation. Eventually, hospitalized patients infected with the coronavirus disease of 2019 (COVID-19), the cause of the ongoing worldwide pandemic, could mainly suffer from an anomalous risk of coagulation activation with enhanced venous thrombosis events and poor quality clinical course. Although the risk of VTE in nonhospitalized COVID-19 patients is not known yet, there are a large number of guidelines and studies on thromboprophylaxis administration for COVID-19 cases. This study aims to take a detailed look at the effect of viral diseases on VTE, the epidemiology of VTE in viral diseases, and the diagnosis and treatment of VTE.

CMV proctitis: a rare disease presentation in a young and immunocompetent man

A young adult man presented to an outlying emergency department with a sore throat, fever and chills. Upon failure of symptomatic management and a course of amoxicillin, he developed rectal pain and loose stools. Despite outpatient doxycycline treatment for presumed chlamydial proctitis, he developed worsening rectal pain and bloody stools. Results on abdominal and pelvic CT were consistent with proctitis. His symptoms worsened despite added metronidazole for bacterial proctitis. Workup revealed an elevated erythrocyte sedimentation rate, C reactive protein and calprotectin, suggestive of a diagnosis of inflammatory bowel disease (IBD). A colonoscopy revealed proximal tightness of the rectum, and pathology reported features suggestive of IBD. He was treated with prednisone and mesalamine. However, immunostaining positive for cytomegalovirus (CMV) confirmed a diagnosis of tissue-invasive CMV proctitis. This was further supported by serological testing for CMV consistent with a diagnosis of CMV proctitis preceded by a primary CMV infection of the pharynx.

The Association of Cytomegalovirus IgM and Allostatic Load

Background: Cytomegalovirus (CMV) is a deoxyribonucleic acid virus that affects a significant proportion of the worldwide population; after primary infection, it goes into a latent state and can be reactivated, primarily after a reduction in host immune defenses. Methods: This study evaluated the association of acute cytomegalovirus infection (CMV IgM) and Allostatic Load (AL) by sociodemographic factors using data from the National Health and Nutrition Examination Survey (NHANES) 2001–2004 among participants (aged 20–49 years). CMV infection was determined by the level of CMV IgM antibody in serum samples. AL was assessed as a combination of 10 biomarkers from the cardiovascular, inflammatory, and metabolic systems. The evaluation of the association between CMV infection and AL included descriptive statistics and logistic regression models, which were adjusted for demographic and behavioral covariates. Results: AL was more elevated among those who were older, male, those with lower education, those performing limited physical activity, and smokers. CMV was more elevated in females than males among those who consumed alcohol and cigarette smokers. In Pearson’s correlation analysis, there was a slight positive correlation between CMV IgM and AL, with triglycerides and Body Mass Index (BMI) the most strongly correlated with AL. Binary logistic regression showed no significant relationship between high AL and positive CMV IgM but did show a significant relationship between high AL and age (OR = 1.0592, 95% CI 1.0215–1.0983, p = 0.00715). The findings of this study provide insight into the relationship between CMV and AL and provide awareness of factors that affect their relationship.

Cytomegalovirus in Haematological Tumours

The exquisite coupling between herpesvirus and human beings is the result of millions of years of relationship, coexistence, adaptation, and divergence. It is probably based on the ability to generate a latency that keeps viral activity at a very low level, thereby apparently minimising harm to its host. However, this evolutionary success disappears in immunosuppressed patients, especially in haematological patients. The relevance of infection and reactivation in haematological patients has been a matter of interest, although one fundamentally focused on reactivation in the post-allogeneic stem cell transplant (SCT) patient cohort. Newer transplant modalities have been progressively introduced in clinical settings, with successively more drugs being used to manipulate graft composition and functionality. In addition, new antiviral drugs are available to treat CMV infection. We review the immunological architecture that is key to a favourable outcome in this subset of patients. Less is known about the effects of herpesvirus in terms of mortality or disease progression in patients with other malignant haematological diseases who are treated with immuno-chemotherapy or new molecules, or in patients who receive autologous SCT. The absence of serious consequences in these groups has probably limited the motivation to deepen our knowledge of this aspect. However, the introduction of new therapeutic agents for haematological malignancies has led to a better understanding of how natural killer (NK) cells, CD4+ and CD8+ T lymphocytes, and B lymphocytes interact, and of the role of CMV infection in the context of recently introduced drugs such as Bruton tyrosine kinase (BTK) inhibitors, phosphoinosytol-3-kinase inhibitors, anti-BCL2 drugs, and even CAR-T cells. We analyse the immunological basis and recommendations regarding these scenarios.

Acute superior mesenteric vein thrombosis in the setting of cytomegalovirus mononucleosis: a case report and review of the literature

Cytomegalovirus is a viral genus of the overarching family Herpesviridae, and is of particular importance because of its relevance to human disease. This association is predominantly due to human cytomegalovirus, a well-studied pathogen. In addition to the mononucleosis syndrome that can occur during acute cytomegalovirus viraemia, this virion has been recurrently implicated as a provoking factor for thromboembolic disease in the published scientific literature. As physicians increasingly forgo extensive laboratory investigation in the setting of clinical hypercoagulability, it has also become evident that in some circumstances whether or not a particular investigation alters clinical management is not necessarily the only important question. Viraemia as a provoking factor for thrombosis stands as such an example. The aim of this Grand Round is to further explore the role of cytomegalovirus as it pertains to thromboembolic disease, especially in the present era of viral-associated thromboembolism.

Positive predictive values of CMV-IgM and importance of CMV-IgG avidity testing in detecting primary infection in three different clinical settings. A French retrospective cohort study

BACKGROUND

Diagnosis of Cytomegalovirus (CMV) primary infection during pregnancy or in immunocompetent patients relies on serology with detection of specific CMV-IgG and IgM. In case of positive CMV-IgM in pregnant women, CMV-IgG avidity is now widely recommended, but in general population it is not currently performed.

OBJECTIVE

In this study, we aimed to determine CMV-IgM positive predictive values (PPV) in different clinical settings.

MATERIAL AND METHODS

We conducted a retrospective study on positive CMV-IgM in our virology laboratory from 2013 to 2019, in three clinical groups: screening in non-symptomatic pregnant women (group 1), pregnant women with ultrasound (US) abnormalities (group 2) and patients (general population) with clinical signs suggestive of CMV primary infection (group 3). CMV-IgG avidity had been performed in all cases allowing to evaluate PPV of positive CMV-IgM to diagnose CMV primary-infection in each group.

RESULTS

Between 2013 and 2019, 6859 serum samples were found positive for CMV-IgM and had been tested for CMV-IgG avidity, with 6560 sera for group 1, 30 for group 2 and 269 for group 3. Overall, low avidity confirming primary infection was observed respectively in 16.4 % for group 1, 36.7 % for group 2, and 35.3 % for group 3. CMV-IgM PPV was significantly lower in group 1 compared to groups 2 (p = 0.01) and 3 (p < 0.001).

DISCUSSION

Our observations highlight the major importance of including CMV-IgG avidity in the diagnostic algorithm, whatever the clinical situation (for immunocompetent patients), to confirm or exclude a recent CMV primary infection in case of positive CMV-IgM.

Seroprevalence of Cytomegalovirus Infection Among a Rural Population of Côte d'Ivoire

Human cytomegalovirus (HCMV) is a betaherpesvirus that can be pathogenic to humans. In particular, immunocompromised patients can develop life-threatening symptoms. In the present study, HCMV seroprevalence was investigated in a rural population of Western Côte d'Ivoire. Plasma samples collected from 166 apparently healthy subjects living in 8 villages surrounding the Taï Forest National Park were tested for anti-HCMV immunoglobulin G and M antibody with two commercial enzyme-linked immunosorbent assays. Prevalence of anti-HCMV IgG and IgM antibody was 100% and 5.4%, respectively. Anti-HCMV IgM positive was 10.2% (5/49) of the children and adolescents and 3.4% (4/117) of the adults. This observed decrease of IgM seropositivity and the seroprevalence difference between males and females (3.8% vs. 6.1%) was not statistically significant. In plasma of one IgM-positive participant, a low CMV load was detected indicating low-level replication. A second IgM-positive participant showed signs of local CMV replication. The other seven IgM-positive plasma samples likely reacted nonspecifically or due to polyclonal stimulation. Taken together, the results indicate that HCMV infection is hyperendemic in Côte d'Ivoire.

Elevated humoral response to cytomegalovirus in HIV-infected individuals with poor CD4+ T-cell immune recovery

Some HIV-infected c-ART-suppressed individuals show incomplete CD4⁺ T-cell recovery, abnormal T-cell activation and higher mortality. One potential source of immune activation could be coinfection with cytomegalovirus (CMV). IgG and IgM levels, immune activation, inflammation and T-cell death in c-ART-suppressed individuals with CD4⁺ T-cell counts >350 cells/μL (immunoconcordant, n = 133) or <350 cells/μL (immunodiscordant, n = 95) were analyzed to evaluate the effect of CMV humoral response on immune recovery. In total, 27 HIV-uninfected individuals were included as controls. In addition, the presence of CMV IgM antibodies was retrospectively analyzed in 58 immunoconcordant individuals and 66 immunodiscordant individuals. Increased CMV IgG levels were observed in individuals with poor immune reconstitution (p = 0.0002). Increased CMV IgG responses were significantly correlated with lower nadir and absolute CD4⁺ T-cell counts. In contrast, CMV IgG responses were positively correlated with activation (HLA-DR⁺) and death markers in CD4⁺ T-cells and activated memory CD8⁺ T-cells (CD45RA^-CD38⁺). Longitudinal subanalysis revealed an increased frequency of IgM⁺ samples in individuals with poor CD4⁺ T-cell recovery, and an association was observed between retrospective IgM positivity and the current level of IgG. The magnitude of the humoral immune response to CMV is associated with nadir CD4⁺ T-cell counts, inflammation, immune activation and CD4⁺ T-cell death, thus suggesting that CMV infection may be a relevant driving force in the increased morbidity/mortality observed in HIV⁺ individuals with poor CD4⁺ T-cell recovery.

Analysis of cellular and humoral immune responses against cytomegalovirus in patients with autoimmune Addison's disease

Background

Autoimmune Addison’s disease (AAD) is caused by multiple genetic and environmental factors. Variants of genes encoding immunologically important proteins such as the HLA molecules are strongly associated with AAD, but any environmental risk factors have yet to be defined. We hypothesized that primary or reactivating infections with cytomegalovirus (CMV) could represent an environmental risk factor in AAD, and that CMV specific CD8⁺ T cell responses may be dysregulated, possibly leading to a suboptimal control of CMV. In particular, the objective was to assess the HLA-B8 restricted CD8⁺ T cell response to CMV since this HLA class I variant is a genetic risk factor for AAD.

Methods

To examine the CD8⁺ T cell response in detail, we analyzed the HLA-A2 and HLA-B8 restricted responses in AAD patients and healthy controls seropositive for CMV antibodies using HLA multimer technology, IFN-γ ELISpot and a CD107a based degranulation assay.

Results

No differences between patients and controls were found in functions or frequencies of CMV-specific T cells, regardless if the analyses were performed ex vivo or after in vitro stimulation and expansion. However, individual patients showed signs of reactivating CMV infection correlating with poor CD8⁺ T cell responses to the virus, and a concomitant upregulation of interferon regulated genes in peripheral blood cells. Several recently diagnosed AAD patients also showed serological signs of ongoing primary CMV infection.

Conclusions

CMV infection does not appear to be a major environmental risk factor in AAD, but may represent a precipitating factor in individual patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-0822-z) contains supplementary material, which is available to authorized users.

Cytomegalovirus seroprevalence in women with bad obstetric history in Kirkuk, Iraq

The human cytomegalovirus (CMV) is a major cause of congenital infections. A case-control descriptive study was conducted in Kirkuk, Iraq to determine the seroprevalence of CMV in women with bad obstetric history (BOH) compared to women with a normal previous pregnancy. The CMV IgG and IgM seroprevalence was higher in women with BOH. The CMV IgG seroprevalence was significantly influenced by pregnancy, age, residence and level of education. In addition, the current CMV infection was significantly associated with pregnancy, age, residence and education. Large families (crowding index >3) exhibited higher seroprevalence for CMV IgM (8.3%) and IgG (98.3%), but odd ratio (OR) showed no significant association between family size and seropositivity. The CMV IgG seropositivity was higher in working women (100%) compared to housewives (95.4%). However, the CMV IgM (current infection) was 6.8% in housewives and was not detected in any working women (0%). The OR exhibited no significant association between occupation and both IgM and IgG levels.

Pattern of the epitope-specific IgG/IgM response against human cytomegalovirus in patients with multiple myeloma

Human cytomegalovirus (HCMV) is a member of the herpesvirus family and represents a major human pathogen causing severe disease in newborns and immunocompromised patients, e.g., organ transplant recipients and patients with AIDS. One characteristic of herpesviruses is their ability to establish lifelong latency in their hosts; thus, reactivation during immunosuppression leads to recurrent episodes of disease. In several recent reports, it has been shown that HCMV infection may occur in patients with malignancy. This study focused on HCMV infection in patients with multiple myeloma (MM). In order to determine the IgM and IgG humoral immune response, sera from MM patients and healthy donors were analyzed with an accredited immunoblot test, and the IgM response was analyzed with an accredited enzyme-linked immunosorbent assay. A response against HCMV was detected in 80% of the MM patients. While the IgG pattern varied in each patient, the most prominent IgM response was against the tegument protein pp150 and two nonstructural proteins, the processivity factor (pUL44) and the single-stranded DNA binding protein (pUL57). An IgG avidity test revealed that 4 out of 20 MM patients had a fresh infection and 2 MM patients had a recent infection. The combination of IgG avidity and the IgM pattern will be a useful tool for reliable clinical diagnostics concerning HCMV and for application of early therapy for those MM patients suffering from a high viral load.

Maternal and neonatal anti-cytomegalovirus IgG level and risk of postnatal cytomegalovirus transmission in preterm infants

Immunological mechanisms influencing the risk of mother-to-child cytomegalovirus (CMV) transmission in preterm infants have not been studied sufficiently. In this study, the correlation between maternal and neonatal serum anti-CMV IgG levels and risk of postnatal CMV transmission in preterm infants was assessed. Anti-CMV IgG levels of 79 CMV seropositive mothers and their 94 infants were determined in peripheral blood samples collected within 3 days after delivery. Postnatal CMV infection was detected in 39/94 (41%) infants by PCR on urine at term-equivalent age (gestational age 40 weeks) after congenital infection was excluded. Maternal or infant anti-CMV IgG levels were not significantly different between infants with and without postnatal CMV infection. The anti-CMV IgG infant-mother ratio showed a significant positive correlation with gestational age (range 25-32 weeks, R(2)  = 0.218, P < 0.001), reaching 1.0 at 32 weeks of gestation. Anti-CMV IgG infant-mother ratio was significantly lower in infants with postnatal CMV infection (P = 0.015). In conclusion, the risk of postnatal CMV transmission is related to low gestational age and low anti-CMV IgG infant-mother ratio.

Clinical evaluation of new automated cytomegalovirus IgM and IgG assays for the Elecsys(®) analyser platform

Cytomegalovirus (CMV) is a leading cause of physical and neurological abnormalities in newborns. Hence, the diagnosis of CMV infection in pregnant women is necessary in order to allow appropriate management of their pregnancy. New assays have been developed for the Roche Elecsys® immunoassay platform that detect CMV-specific immunoglobulin (Ig)M and IgG, with the IgM assay designed to target IgM produced at the start of infection rather than IgM persisting later in infection. This study aimed to evaluate the performance of the new assays compared with other commercial kits widely distributed in laboratories. The performance of the Elecsys and comparator CMV IgM and IgG assays was assessed using 967 preselected patient samples characterised by CMV infection status, as well as being compared using 1,668 unselected clinical samples. The Elecsys CMV IgM and IgG assays performed consistently with comparator assays using the preselected samples. The Elecsys CMV IgM assay showed improved sensitivity compared with the Enzygnost® assay in primary infection (91.2 % vs. 79.4 %) and improved specificity over the Architect® assay in potentially cross-reacting samples (94.1 % vs. 82.4 %). The Elecsys IgM assay reported fewer positive results in the later stages of CMV infection compared with ETI-CYTOK-M ELISA, while the Elecsys IgG assay reported slightly fewer negative results in the early stages of infection compared with ETI-CYTOK-G ELISA. There was good agreement between Elecsys and comparator assays using unselected clinical samples (range 90.4-99.4 %). The Elecsys CMV IgM and IgG assays compare well with routinely used assays and are suitable for clinical use.

Kinetics of CMV seroconversion in a Swiss pregnant women population

Retrospective evaluation of the kinetics of cytomegalovirus (CMV) seroconversion with CMV IgM, IgG, and IgG avidity assays, in a Swiss pregnant women population, has shown that the current published CMV serologic diagnostic algorithms were valid and fit for use. In 19% of the cases analyzed, CMV-specific IgM was detected before IgG.

National prevalence estimates for cytomegalovirus IgM and IgG avidity and association between high IgM antibody titer and low IgG avidity

Primary cytomegalovirus (CMV) infection of the mother during pregnancy presents risk of CMV infection of the fetus with resulting permanent disability. CMV IgM antibody is generated following primary CMV infection but also can appear during nonprimary CMV infection and is thus of limited diagnostic use by itself. In contrast, the presence of low CMV IgG avidity has been shown to be a unique and reliable serologic indicator of primary CMV infection. We measured CMV IgG and IgM antibody levels and IgG avidity in sera from a population sample of 6,067 U.S. women aged 12 to 49 years from NHANES (National Health and Nutrition Examination Survey). The CMV IgG prevalence was 58% overall and increased strongly with age. The CMV IgM prevalence was 3.0% overall and remained relatively flat across age groups. The prevalence of low IgG avidity was 2.0% overall, decreased sharply with age, and was seen mainly among IgM-positive sera. Fourteen to 18% of the CMV IgM-positive sera were low IgG avidity, presumably representing primary CMV infection. High CMV IgM antibody titer was a strong predictor of low IgG avidity. The ability to reliably identify primary CMV infection during pregnancy is important for management of the pregnancy, including possible treatment options for the fetus. Both IgM and IgG avidity measurements provide useful clinical information for evaluating primary CMV infection, although commercial tests for CMV IgG avidity are not yet widely available in the United States.

Association of an overlap syndrome of autoimmune hepatitis and primary biliary cirrhosis with cytomegalovirus infection

A 63-year-old woman, who presented with severe jaundice and elevated serum conjugated bilirubin level, denied alcohol and drug use and showed no evidence of viral hepatitis. Based on clinical and laboratory features, she was diagnosed with autoimmune hepatitis with primary biliary cirrhosis. Hematological and immunochemical assays, radiographic imaging, clinical examination, and liver biopsy were conducted. Laboratory results were the following: negative for fluorescence antinuclear antibody, negative for antismooth muscle antibodies but positive for antinuclear antibody (enzyme-linked immunosorbent assay) and antimitochondrial M2 antibody, high titers of serum globulin, and positive for cytomegalovirus IgM. Liver biopsy showed submassive lobular necrosis, inflammation with broad areas of parenchymal collapse, and chronic nonsuppurative destructive cholangitis. The patient responded well to corticosteroid therapy. This case might illustrate an association between cytomegalovirus infection and the occurrence of autoimmune hepatitis.

Periconceptional cytomegalovirus infection: pregnancy outcome and rate of vertical transmission

OBJECTIVE

To evaluate pregnancy outcome and rate of vertical transmission in primary maternal periconceptional cytomegalovirus (CMV) infection.

METHODS

All women serologically diagnosed with primary periconceptional CMV infection between 1999 and 2008 were included. Periconceptional infection was defined as primary maternal CMV infection occurring within 4 weeks prior to the last reported menstrual period and up to 3 weeks following the expected date of the missed menstrual period. Intrauterine infection was verified by PCR and shell vial culture of amniotic fluid at 22-24 weeks or neonatal urine culture within 48 h of birth.

RESULTS

Of the 59 patients studied, 43 (73%) underwent diagnostic amniocentesis. Eleven of the 43 patients (25.5%) were positive for CMV contamination. Ten of the 11 patients (90%) elected to terminate pregnancy. Twelve women (20.3%) declined amniocentesis: of these 2 elected to undergo a first-trimester termination of pregnancy and 10 gave birth to a live-born infant. Six of the ten neonates were negative for CMV and two tested positive for urinary CMV; all eight were healthy on long-term follow-up, and two were lost to follow-up. The remaining four women had a spontaneous first-trimester abortion.

CONCLUSION

The risk of transmission of periconceptional CMV infection is lower than previously reported. These data should be borne in mind when counseling affected couples.

Measurement of the sensitivity of different commercial assays in the diagnosis of CMV infection in pregnancy

To evaluate the performance of different commercial assays for the detection of recent cytomegalovirus (CMV) in pregnancy, the sensitivity and specificity of assays for CMV-specific IgM antibodies were compared. Routine specimens from pregnant women were screened for CMV IgM using the Abbott AxSYM assay. Sera that were reactive according to AxSYM were further tested for IgM by other commercial assays. In selected IgM positive samples a CMV IgG avidity assay (Radim) and virus isolation from urine (shell vial) were also performed. The positivity rate for IgM anti-CMV by AxSYM was relatively high (140 out of 492, combining reactive and grayzone results). Only 26 of the 140 samples were positive for IgM according to Radim. The IgG avidity was low in 16 of the 43 samples tested, and the Radim and DiaSorin IgM assays were negative in 5 of them; 2 of the latter cases were also positive for viral isolation according to a shell vial method. There are differences in the sensitivity of the commercially available tests for CMV antibodies. CMV screening in pregnancy is performed as a first step by immunoassays and the choice of highly sensitive IgM test associated with further serological and virological methods could help to identify early primary infections.

Primary cytomegalovirus infection in patients with Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is frequently associated with the presence of CMV-specific IgM-antibodies or CMV-DNA in serum. Detection of IgM-antibodies or viremia may indicate primary infection, but also reactivation or reinfection. We identified 46 GBS patients with detectable CMV-specific IgM- or IgG-antibodies, or both. Sera from these patients were tested for the presence of CMV-specific, low-avidity IgG-antibodies, which indicate primary infection that occurred <6 months before sample collection, and for the presence of CMV-DNA by polymerase chain reaction (PCR). Primary infection was identified by the presence of low-avidity IgG-antibodies in 9/46 (20%) or by detection of IgM-antibodies in the absence of IgG-antibodies in 1/46 (2%) patients. CMV-DNA was detectable in 17/46 (37%) sera. In contrast, CMV-DNA was detected in only 2% of sera from 46 age-matched patients with neuroborreliosis. The likelihood of viremia decreased in GBS patients significantly with increasing antibody-avidity (P=0.041). Detection of IgM-antibodies correlated with that of CMV-DNA in patients with low-avidity IgG-antibodies (P=0.048) but not in those with high-avidity IgG-antibodies (P=0.543). In 45 age-matched healthy controls, low-avidity IgG-antibodies and CMV-DNA were detected in only 2% and 0% of sera, respectively. Our findings further strengthen evidence for an association between CMV infection and GBS. Primary CMV infection was identified in almost one-fourth of patients with detectable CMV-specific antibodies. Nevertheless, endogenous reactivation and reinfection have to be considered also as relevant events associated with GBS.

Diagnosis of and screening for cytomegalovirus infection in pregnant women

No single diagnostic test for cytomegalovirus (CMV) infection is currently available for pregnant women at all stages of gestation. Improved accuracy in estimating the timing of primary infections can be used to identify women at higher risk of giving birth to congenitally infected infants. A diagnostic algorithm utilizing immunoglobulin G (IgG), IgM, and IgG avidity was used to prospectively screen serum from 600 pregnant women enrolled from two groups: < or =20 weeks gestation (n = 396) or >20 weeks gestation (n = 204). PCR testing of urine and/or blood was performed on all seropositive women (n = 341). The majority (56.8%) of women were CMV IgG seropositive, with 5.5% being also CMV IgM positive. In the IgM-positive women, 1.2% had a low-avidity IgG, indicating a primary CMV infection and a high risk of intrauterine transmission. Two infants with asymptomatic CMV infection were born of mothers who had seroconverted in the second trimester of pregnancy. Baseline, age-stratified CMV serostatus was established from 1,018 blood donors. Baseline seropositivity from a blood donor population increased with age from 34.9% seroprevalence at less than 20 years of age to 72% seroprevalence at 50 years of age. Women at high risk of intrauterine transmission of CMV were identified at all stages of gestation. Women infected with CMV during late gestation may be more likely to transmit the virus, so failure to detect seroconversions in late gestation may result in failure to detect infected neonates.

An unusual case of thrombocytosis associated with concurrent cytomegalovirus and respiratory syncytial virus infection in an immunocompetent infant: possible roles of thrombopoietin and interleukin-6

This is the case study of concurrent cytomegalovirus and respiratory syncytial virus infection in an infant who showed thrombocytosis, liver dysfunction and bronchiolitis. The combination of thrombocytosis with this co-infection is causally related to elevated levels of thrombopoietin and interleukin-6. This study represents the first such case ever recorded.

Different profiles of cytomegalovirus RNA transcripts and anti-cytomegalovirus IgM antibodies in renal transplant recipients

BACKGROUND

A difference in anti-cytomegalovirus IgM antibody profile has been found between sera from acutely cytomegalovirus (CMV)-infected patients and sera from CMV-infected patients with subclinical infection.

OBJECTIVES

The aim of this study is to investigate whether such different IgM antibody responses are correlated with differences in the expression of CMV immediate early and late mRNAs.

STUDY DESIGN

We have investigated the anti-CMV IgM response in 46 renal transplant recipients by employing two commercially available IgM kits (AxSYM and IMX) as well as two novel enzyme-linked immunosorbent assays (ELISAs), which were developed using recombinant ppUL32 (pp150) and pUL80a (p38), respectively. The results were compared with four direct CMV diagnostic tests: pp65 antigenemia, viral culture and nucleic acid sequence-based amplification (NASBA), detecting either CMV immediate early 1 (IE1) mRNA (IE1-NASBA), or CMV pp67 (late) mRNA (pp67-NASBA).

RESULTS

Analysis of all CMV-infected recipients (n=28) showed that in 16 recipients (group I) more than one direct test became positive after transplantation, while in the other 12 recipients (group II), IE1-NASBA was the only direct test to become positive. In group I, 100, 81, 100 and 50% of the recipients were IgM-positive with AxSYM, IMX, p38 and pp150, respectively. In group II, 100, 83, 17 and 83% of the recipients were IgM-positive with AxSYM, IMX, p38 and pp150, respectively.

CONCLUSIONS

Our data indicate that the IgM-response against p38 and pp150 differs significantly (P<0.01) between group I recipients with productive CMV infection, and group II recipients with a non-productive CMV infection which may be of diagnostic and prognostic relevance.

Evaluation of five commercial enzyme immunoassays for the detection of human cytomegalovirus-specific IgM antibodies in the absence of a commercially available gold standard

In the recent years the number of commercially available immunoassays for the detection of human cytomegalovirus (HCMV)-specific immunoglobulin M (IgM) antibodies has rapidly increased. The aim of the present study was to evaluate five commercial immunoassays for the serological diagnosis of HCMV-infection. These methods, namely the IMx CMV IgM assay, the AxSYM CMV IgM assay (both Abbott), the Gull CMV IgM, the CMV-IgM-ELA test PCS Medac and the Biotest Anti-HCMV recombinant IgM ELISA, were compared for their diagnostic effectiveness and interference with substances eventually producing cross-reactions with HCMV-IgM (Epstein-Barr-virus (EBV)-IgM, rheumatoid factor (RF)). In addition, repeated measurements on samples from kidney and heart transplant recipients with active HCMV infection were examined to compare the temporal development of the HCMV-IgM measured with the five assay systems. Since there is no commercially available gold standard, it was assumed that the true classification, of whether the patient sample is HCMV-IgM positive or negative, was unknown. Hence sensitivity and specificity were assessed based on a maximum likelihood approach using a "latent class" model. The cross-reactions were quantified by a Bayesian statistical model using prior information for the expected prevalences in the EBV-IgM and rheumatoid factor sample groups. The results of the study demonstrated that there are great differences in sensitivity and specificity as well as in cross-reactions with EBV-IgM and RF between the tested ELISAs.

Evaluation of the Abbott AxSYM cytomegalovirus (CMV) immunoglobulin M (IgM) assay in conjunction with other CMV IgM tests and a CMV IgG avidity assay

The measurement of the avidity of cytomegalovirus (CMV) immunoglobulin G (IgG) antibodies has been shown by several investigators to be useful in identifying and excluding primary CMV infections in pregnant women. In this work, we examined the diagnostic utility of reflex testing of CMV IgM-positive specimens from pregnant women by using a CMV IgG avidity assay. The utility of this approach was directly dependent on the sensitivity of the CMV IgM assay employed during the initial screen. The higher initial reactivity rate of the AxSYM CMV IgM assay was necessary in order to detect CMV IgM in specimens containing low-avidity CMV IgG antibodies, indicative of a primary CMV infection, which other CMV IgM assays (Behring, Vidas, Captia, and Eurogenetics) fail to detect in some cases. The use of the AxSYM CMV IgM assay, followed by an avidity test, should result in more accurate diagnosis of CMV infection in pregnant women.

Reactivity to p52 and CM2 recombinant proteins in primary human cytomegalovirus infection with a microparticle agglutination assay

We evaluated the reactivities of sera against p52 and CM2 recombinant antigens of human cytomegalovirus (HCMV), coated on microparticles, for the differentiation of primary HCMV infection from an established infection. Two different test formats of the CMV Multiplex Copalis assay were evaluated. The 214 serum samples tested were immunoglobulin M (IgM) positive or equivocal by our reference assay. Reactivities against p52 and CM2 antigens were tested for sera from 37 patients with a well-documented seroconversion within the preceding 3 months (119 serum specimens), 31 patients known to have had a seroconversion at least 8 months earlier (31 serum specimens), and 57 patients without a documented seroconversion (64 serum specimens). The assay had a sensitivity for the detection of a primary infection of 70 or 86% by the first test format and a sensitivity of 88 or 94% by the second test format, according to the criteria used to indicate a primary infection by this test. A good correlation of the results of the assay with our in-house avidity index was found. The specificity of the assay warrants further evaluation. With IgM-positive sera, the assay was not sufficiently specific to make a distinction between a primary infection and an established infection.

Diagnosis of human immunodeficiency virus infection using an immunoglobulin E-based assay

Immunoglobulin assays that are sensitive and specific for detecting human immunodeficiency virus type 1 (HIV-1) infection are especially important in developing countries where PCR and viral culture may not be readily available. Immunoglobulin E (IgE), which is elevated in HIV-1 infection, is the only antibody that does not cross the placenta, making it potentially valuable for viral detection in both children and adults. This study developed an assay for detection of HIV specific IgE antibodies in adults. A total of 170 serum samples from 170 adults (116 HIV positive and 54 HIV negative) were analyzed. Serum or plasma samples were treated by using the protein G affinity method. The HIV status was determined by using two IgG enzyme-linked immunosorbent assays (ELISAs) and one Western blot evaluation. The IgE enzyme immunoassay test for HIV-1 correctly identified the HIV status in 98.8% of the samples (168 of 170). One false-positive and one false-negative test occurred with the IgE ELISA, as well as with the IgG ELISA test but were correctly identified by the IgE test. Analysis of the data demonstrated a high specificity (99%) and sensitivity (99%) of the IgE test, with 95% confidence intervals. The IgE assay appears to be sensitive and specific, suggesting that IgE-specific antibodies offer an effective method to detect HIV-1 infection in adults.

Immunological characterization of anti-endothelial cell antibodies induced by cytomegalovirus infection

BACKGROUND

We have previously shown that the levels of anti-endothelial cell antibodies (AECA) determined by an enzyme immunoassay are elevated during cytomegalovirus (CMV) infection in cardiac and renal transplant recipients. In a separate study, high levels of AECA are associated with higher frequency of humoral allograft rejection (AR), chronic AR and lower 2 year allograft survival in cardiac transplant recipients. These results suggests that high levels of AECA produced during CMV infection may have a pathogenic role or be a risk factor for humoral AR, chronic AR and decreased allograft survival. Here we examined the reactivity of AECA against endothelial cells and other tissues to further characterize AECA induced by CMV infection.

METHODS

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis/Western blot analysis was performed.

RESULTS

The number and intensity of bands reactive with human umbilical vein ECs (HUVECs) increased during and after CMV infection. AECA(+) plasma reacted with multiple antigens expressed not only on endothelial cells but also on human fibroblasts, keratinocytes, platelets (PLs), peripheral blood mononuclear cells (PBMCs), Raji cells and THP-1 cells. Each individual's AECA(+) plasma showed different patterns of reactivity against these cells, whereas each plasma showed similar patterns of reactivity against ECs, PLs or peripheral blood mononuclear cells obtained from different individuals. AECA(+) plasma also showed a similar pattern of reactivity against HUVECs pretreated with/without interferon-gamma/tumor necrosis factor-alpha. The reactivity of preabsorbed sera with PLs significantly decreased against most reactive antigens expressed on PLs and other cell types.

CONCLUSIONS

(1) Antibodies induced by CMV infection are not specific to endothelial cells and appear to react with multiple cell types, (2) AECA (+) plasma react with multiple antigens expressed on various cell types that are primarily constitutively expressed on these cells and are not individual specific, (3) CMV-induced antibodies in AECA (+) plasma are primarily autoantibodies. These results suggest that the elevated AECA levels seen in CMV-infected transplant recipients may represent a polyclonal activation of humoral immune responses induced by CMV, which is of uncertain pathogenic significance.

Long-term persistence of immunoglobulin A (IgA) and IgM antibodies against human cytomegalovirus in solid-organ transplant recipients

The retrospective analysis of 494 solid-organ transplant recipients revealed that during the follow-up period (mean duration, 3.2 years) 184 (88%) of 209 anti-human cytomegalovirus (HCMV) immunoglobulin A (IgA)-positive patients remained IgA positive, as did 128 (74.85%) of 171 anti-HCMV IgM-positive patients. We conclude that anti-HCMV IgA and IgM testing for management of clinically relevant HCMV infections in solid-organ transplant recipients is dispensable.

Total immunoglobulin E levels and dengue infection on San Andrés Island, Colombia

An evaluation of total immunoglobulin E (IgE) and dengue serostatus in 168 subjects from San Andrés Island, Colombia, revealed altered levels of IgE in 89% of the population. IgE levels were higher in patients with a history of dengue or with a current secondary or current primary infection than in subjects with no exposure (P = 0. 01). Dengue infection accounted for 23% of the variation in IgE levels.

Development of a new cytomegalovirus (CMV) immunoglobulin M (IgM) immunoblot for detection of CMV-specific IgM

We developed a new cytomegalovirus (CMV) immunoglobulin M (IgM) immunoblot to detect CMV-specific IgM in human sera. The new test contains four viral proteins (vp150, vp82, vp65, and vp28) purified from viral particles and four recombinant proteins (rp150, rp130, rp52, and rp38) purified from Escherichia coli. These antigens were individually loaded onto nitrocellulose strips, and the strips were then used to detect CMV-specific IgM by using a mu-specific conjugate. The new assay was evaluated in parallel with one or two IgM enzyme-linked immunosorbent assays (ELISAs) to test 592 serum samples from different groups of latently or acutely infected individuals. The sensitivity of the new assay with respect to the consensus of two ELISAs was 100%, the specificity was 98.6%, the positive predictive value was 96.9%, and the negative predictive value was 100%. We also evaluated the new test by testing sera from pregnant women and transplant recipients with a known clinical history. Our results suggest that the new test combines high sensitivity with high specificity, characteristics that are mutually exclusive with the other commercially available tests. Furthermore, a statistically significant correlation was observed between the number of IgM-reactive bands and the elevated risk of transmission from CMV-infected pregnant women to their offspring.

Prophylaxis against herpes infections in kidney transplant patients with special emphasis on CMV

METHOD

Since 1990, we have treated all kidney transplanted patients with cyclosporin (CsA)+ an initial 10 d antilymphocyte globulin (ALG) course, from September 1995 supplemented with mycophenolate mofetil (MMF). In 170 consecutive transplantations from June 1992 to the end of 1996, aciclovir 3200 mg/d (adjusted for kidney function and in children to age) was given prophylactically for 3 months post-transplantation (Tx), monitored with systematic and frequent tests for HSV and CMV. In case of CMV infection, we gave ganciclovir intravenously (oral ganciclovir from 1996) in doses according to kidney function for 3 months, followed by a further 3 months observation and monitoring period. In case of acute cellular rejection, ganciclovir was given during the 10-d OKT3 course and 1 week further. In case of delayed graft function combined with aciclovir side effects, ganciclovir was given until aciclovir could be reintroduced.

RESULTS

39% were HSV seronegative at Tx. There were no seroconversions or reactivations within the observation period. No mucocutaneous HSV infections was observed. No resistant strains developed. 26% were both HSV and CMV negative at Tx. 52% were CMV negative at Tx. 30% experienced a CMV infection post-transplant. The patients were grouped according to CMV status in the donor (D) and recipient (R) before Tx. We found approximately the same number of patients in the 4 CMV groups D-/R-, D+/R-, D-/R+ and D+/R+. Most infections occurred in the D+/R- group compared to D-/R- (p = 0.009). A significant increase in the number of CMV infections occurred in this subgroup when we gave reduced doses in case of delayed graft function (p = 0.015), from 1994. We observed only 1 CMV disease (in 1992). Serological EBV testing were performed concomitantly. No correlation was seen between CMV and EBV infections. From September 1995 we have treated all transplanted patients (n = 40) with CsA/ALG/MMF. We found no significant increase in CMV infections in this group.

CONCLUSIONS

Prophylaxis with aciclovir (combined with ganciclovir during acute rejections and in case of delayed graft function with aciclovir side effects) gives a good protection against HSV and CMV infections and prevents CMV disease effectively. High-dose aciclovir post-transplantation (or shift to ganciclovir) seems to be important to obtain effective prophylaxis. Better immunosuppression with MMF does not result in more CMV infections.

Evaluation of a novel immunoglobulin A capture enzyme immunoassay for diagnosis of cytomegalovirus infection in renal and heart transplant recipients

In a retrospective cohort study of 68 organ transplant patients, the usefulness of a new commercial immunoglobulin A (IgA) antibody capture enzyme immunoassay (EIA) specific to human cytomegalovirus (CMV) for the early diagnosis of CMV disease was investigated. The results were compared with those obtained with the CMV pp65 antigen assay in peripheral blood leukocytes, an IgM immunoblot assay, and six other commercial EIAs. In 21 of 28 patients with CMV disease, the pp65 antigen assay and the immunoblot assay identified patients before the onset of disease more frequently than any other serological test method (17 and 13 patients, respectively; p = 0.0029). In patients at risk for primary CMV infection, the pp65 antigen assay was the only method that identified all patients prior to the onset of CMV disease (p = 0.008). For the other patients who were at risk for CMV infection, the pp65 antigen assay and the immunoblot assay detected infection before CMV disease more frequently than any other test system (p = 0.026). With respect to CMV disease, both immunoblotting and the pp65 antigen assay showed excellent sensitivity (100% and 89%, respectively). However, the specificity of the immunoblot was poor (41%), while the specificity of the pp65 antigen assay was reasonably good (68%). The IgA capture EIA showed moderate sensitivity (61%) and reasonable specificity (76%). In conclusion, the pp65 antigen assay, which detects pp65 antigen in leukocytes, is the method of choice for diagnosis of either primary or recurrent CMV infection. The specificity of the pp65 antigen assay was improved by additional testing for specific IgA and IgM antibodies (95% vs. 68%). The IgA assay is of limited value in renal and heart transplant patients, since it detected IgA antibodies only sporadically, and even then, too late for a timely therapy.

Avidity of immunoglobulin G directed against human cytomegalovirus during primary and secondary infections in immunocompetent and immunocompromised subjects

Diagnosis of primary human cytomegalovirus (HCMV) infection is accomplished exclusively by serologic testing. Among the possible methods, the determination of immunoglobulin G (IgG) avidity is one of the least explored. In this work, we used a commercially available kit to test anti-HCMV IgG avidity in 336 serum samples from pregnant women and transplant recipients undergoing virologically proven HCMV primary or nonprimary infections and from latently infected blood donors. Our results demonstrate that the anti-HCMV IgG avidity test differentiates primary from nonprimary HCMV infections in both pregnant women and solid organ transplant recipients. In fact, 88.6% of primary infections and no secondary infections showed low-avidity IgG to HCMV. In particular, low IgG avidity is a marker of primary infection for 18 to 20 weeks after onset of symptoms in both immunocompromised and immunocompetent subjects.

Correlation of cytomegalovirus DNA levels with response to antiviral therapy in cardiac and renal allograft recipients

BACKGROUND

Cytomegalovirus (CMV) infection represents a significant morbidity factor for transplant recipients. A rapid, sensitive, specific, and reliable test is desirable for early detection of CMV infection and for monitoring the efficacy of antiviral therapy.

METHODS

We examined the incidence of CMV infection in 95 cardiac and 25 renal allograft recipients followed for up to 3 years using qualitative and quantitative polymerase chain reaction (PCR) techniques. Results were subsequently correlated with clinical findings. Of the 236 samples analyzed by the CMV PCR, 84 and 20 were also analyzed by blood buffy coat culture and anti-CMV antibody IgM assays, respectively.

RESULTS

The sensitivity of the CMV PCR was found to be superior to that of the other assays, although the specificity of the blood buffy coat culture is as good as that of the CMV PCR, which is higher than that of the anti-CMV antibody IgM assay. CMV infection was detected by the CMV PCR in 17 of 95 cardiac and 9 of 25 renal transplant recipients. Clinical symptoms were observed when > or =500 copies of CMV DNA/1 microg of total DNA were detected by a quantitative CMV PCR assay using an external control CMV plasmid; however, some patients had symptoms when 50-100 copies were present. The levels of CMV DNA detected varied (50-1000 copies) in patients who developed asymptomatic CMV infection. The CMV DNA levels decreased to 50-100 copies 1-2 weeks after antiviral therapy was initiated and correlated well with disappearance of clinical symptoms. CMV DNA levels decreased to < or =5 copies at 4-7 weeks after treatment. This contrasts with patients who were unresponsive to anti-CMV therapy, in whom high levels of CMV DNA (> or =500 copies) persisted for at least 5 weeks and significant levels of CMV DNA (50-100 copies) were detected for several months afterward, despite multiple courses of anti-CMV therapy. Clinical symptoms also did not disappear during this period of observation.

CONCLUSIONS

(1) The CMV PCR represents a rapid, sensitive, specific, reliable test for detection of CMV infection, especially for detection of virus replication in an incipient phase. (2) The quantitative CMV PCR is useful for monitoring the efficacy of antiviral therapy to distinguish patients who respond to therapy from those who do not. (3) CMV DNA levels > or =500 copies/1 microg of total DNA analyzed by the quantitative CMV PCR can be used to differentiate CMV infection from other infections and rejection.

A novel Western blot test containing both viral and recombinant proteins for anticytomegalovirus immunoglobulin M detection

We devised a novel Western blot (WB) test for anti-human cytomegalovirus (HCMV) immunoglobulin M (IgM) detection which contains viral structural polypeptides, significant portions of recombinant p150 (ppUL32), and a significant portion of the most immunogenic nonstructural protein p52 (ppUL44). This new test was evaluated in latently infected blood donors, pregnant women, and transplant recipients with ongoing HCMV infection and shown to be more sensitive and specific than traditional WB and conventional enzyme immunoassay for the detection of HCMV-specific IgM.

Recent advances in the diagnosis of cytomegalovirus infection

Herpesviruses are highly disseminated in nature, and nearly 100 Herpesviruses have been at least partially characterized. Seven Herpesviruses have been isolated so far from humans and one has recently been detected by sequence analysis. Consequently, the diagnosis of human Herpesvirus infection is based on eight different viruses. The diagnosis of a Herpesvirus infection can be achieved through the direct demonstration of the presence of the virus or its components (mainly nucleic acids and antigens) in pathological materials or indirectly through serology. In recent years much progress has been made in both directions and thanks to the detailed study of the viral genomes and their antigenic gene products and by the determination of the immune reactivity against individual antigenic polypeptides in different clinical settings. Progress in the direct detection of the viruses in pathological materials mainly regards the production of specific probes and their use with or without DNA amplification for the detection of viral genomes. Serological advances are mainly linked to the production, characterization and use of specific viral antigens by DNA recombinant procedures and by the production and use of synthetic peptides acting as good antigenic epitopes.

Detection of serum immunoglobulin M to human cytomegalovirus by western blotting correlates better with virological data than detection by conventional enzyme immunoassay

Western blotting (immunoblotting) with proteins separated from purified human cytomegalovirus (HCMV) particles (viral WB) has repeatedly been shown to be a reliable and sensitive method for detecting HCMV-specific immunoglobulin M (IgM). The aim of the present work was to determine whether IgM detected by viral WB correlates with virological diagnosis better than conventional enzyme immunoassay (conv-EIA). The presence of an active HCMV infection was documented on the basis of isolation of virus from urine and/or saliva and on the basis of antigenemia and/or PCR with polymorphonuclear leukocytes for immunocompetent and immunocompromised subjects, respectively. The agreement observed between IgM detected by viral WB and the results obtained by virological detection of HCMV was significantly higher (88.7%) than the agreement of IgM detected by conv-EIA and virological results (67.5%).

Specific IgE detected by ELISA and immunoblot after human cytomegalovirus infection (HCMV) in renal transplant (RT) recipients

BACKGROUND

Specific HCMV IgE response has been reported by some authors, and was proposed as a valuable virologic marker of CMV infection.

OBJECTIVES

we evaluated specific HCMV IgE in renal transplant patients with active (primary and secondary) HCMV infection with special interest to symptomatic infections.

STUDY DESIGN

Specific IgE was tested retrospectively by ELISA and immunoblot (IB) on sera of 55 RT patients who were followed before and after transplantation with virologic markers of CMV infection.

RESULTS

Total serum IgE levels were similar in control group and in patients with primary and secondary HCMV infections. Anti-CMV specific IgE response by ELISA was more frequently found in patients with primary infection (76.9%) than in patients with secondary infection (47.1%). These specific IgE reacted on immunoblot with a 150 kDa protein in 84.6% of patients with primary infection and 94.1% with secondary infections; and reacted with rp52 (pUL44) in 76.9% of primary infection and 47.1% of secondary infection.

CONCLUSIONS

Anti-CMV specific IgE tested by immunoblot and ELISA is a marker of CMV infection. It was clearly detected in cases of active infection (primary and secondary) and was present in cases with severe CMV clinical manifestations. In contrast, anti-CMV specific IgE, was consistently negative among healthy blood donors. This is the first report of CMV proteins detected by IgE immunoblot.

Immunoglobulin A-specific serodiagnosis of acute human cytomegalovirus infection by using recombinant viral antigens

The immunoglobulin A-specific reactivities of recombinant viral proteins from nine different reading frames of human cytomegalovirus were evaluated in enzyme-linked immunosorbent assay experiments. Antigen fragments of reading frames pUL32, pUL44, and pUL57 were identified as preferable antigens for immunoglobulin A serodiagnosis. Application of autologous fusion proteins which combine these polypeptides may be useful especially for the early detection of acute secondary human cytomegalovirus infection.

Recombinant mono- and polyantigens to detect cytomegalovirus-specific immunoglobulin M in human sera by enzyme immunoassay

Serological detection of human cytomegalovirus (HCMV)-specific antibody varies greatly because of antigen composition and the lack of antigen standardization. Antigenic materials composed of single well-characterized viral proteins or portions of them, produced via molecular biology, have proven to be promising tools in improving serodiagnosis. We constructed a recombinant protein containing two regions of ppUL32 (p150) and half of ppUL44 (p52) and compared the immunoglobulin M (IgM) reactivity of this triple-antigen fusion protein with that of a double-antigen fusion protein containing the two ppUL32 fragments and that of a monoantigen fusion protein containing half of ppUL44. We also constructed and tested two other monoantigen fusion proteins containing a large fraction of ppUL80a and a fraction of ppUL83. More than 700 serum samples from different groups of immunocompetent and immunosuppressed subjects were tested for the presence of HCMV IgM by recombinant enzyme immunoassay (rec-EIA) and by a commercially available EIA. Western blotting (immunoblotting) and (in the case of immunosuppressed individuals) antigenemia tests by immunofluorescence and PCR of polymorphonuclear leukocytes were also carried out. The results obtained demonstrate that (i) the triple-antigen fusion protein can replace the individual proteins; (ii) the triple-antigen fusion protein cannot be used alone to replace the virus or infected cells in the serological detection of anti-CMV IgM; (iii) the addition of the fusion proteins containing portions of ppUL83 and ppUL80a is essential for the formation of an antigenic mixture that can replace the virus for the search of HCMV-specific IgM; (iv) rec-EIA is very specific and is more sensitive than the commercially available EIA, and the results obtained are consistent with those obtained by Western blotting; and (v) rec-EIA can reliably be used to detect HCMV-specific IgM in different groups of patients with active HCMV infection.

Elevated IgE level in relationship to nutritional status and immune parameters in early human immunodeficiency virus-1 disease

Elevation of IgE has been associated with T-cell dysregulation and with the occurrence of opportunistic infections in patients with acquired immunodeficiency syndrome. The precise cause of IgE overproduction during the early stages of human immunodeficiency virus (HIV)-1 disease, however, has not been established. In light of reports demonstrating that IgE production may be affected by vitamin E levels in an animal model, we evaluated nutritional status in relationship to plasma IgE levels and immune parameters in 100 asymptomatic HIV-1-seropositive and 42 HIV-1-seronegative homosexual men. Approximately 18% of the HIV-1-seropositive population demonstrated biochemical evidence of plasma vitamin E deficiency (< 5 micrograms/ml). Subsequent analysis of available samples indicated a dramatic elevation of IgE levels (308 +/- 112 IU/ml) in vitamin E-deficient seropositive subjects (n = 9) as compared with age and CD4-matched HIV-1-seropositive persons with adequate vitamin E levels (n = 16, 118.1 +/- 41.1 IU/ml) and significantly lower levels (59.5 +/- 15.7 IU/ml) in HIV-1-seronegative men (n = 20, p = 0.01). This effect, which was independent of CD4 cell count, did not appear to be influenced by atopic or gastrointestinal parasitic disease. The low plasma vitamin E levels were related at least in part to dietary intake (r = 0.552, p = 0.01), suggesting that supplementation may be warranted in HIV-1-infected persons in whom vitamin E deficiency develops. Analysis of covariance revealed a strong relationship between IgE levels and CD8 cell counts (p < 0.006), and between IgE level and vitamin E deficiency (p < 0.039).(ABSTRACT TRUNCATED AT 250 WORDS)

Serological diagnosis of cytomegalovirus infection: comparison of 8 enzyme immunoassays for the detection of HCMV-specific IgM antibody

BACKGROUND

Recently, numerous commercial ELISA kits for the detection of HCMV-specific IgM antibodies have been developed and are available on the international market.

OBJECTIVE

The aim of the present study was to compare eight different ELISAs for the early serological diagnosis of HCMV infection.

STUDY DESIGN

A panel of paired sera obtained from patients suffering from primary or secondary infection and potential cross-reactive serum samples positive for IgM antibodies against other herpesviruses, antinuclear antibody and rheumatoid factor were investigated with 5 indirect ELISAs (1-5) and 3 mu-capture assays (ELISAs 6-8).

RESULTS

The highest sensitivity for IgM detection was achieved by a mu-capture assay (ELISA 8) and a traditional indirect ELISA (4). Their respective sensitivities were 78.0 and 76.0%. Overall, mu-capture immunoassays (ELISAs 6-8) detected HCMV infection earlier than indirect ELISAs (1-5) and showed a higher sensitivity for antibody detection in dilution series of IgM positive serum samples. Whereas ELISAs 1, 2, 5 and 6 showed a specificity of 100%, the alternative assays were affected by a variable number of false positive results obtained by testing potential cross-reactive serum samples. Their specificities ranged from 72.0% (ELISA 8) to 96.0% (ELISA 3).

CONCLUSION

The results of the present study show that recent mu-capture and indirect ELISAs permit a relatively sensitive and reliable diagnosis of HCMV infection. Cross-reactive antigens and interference from antinuclear antibody may limit the specificity of commercial kits.

Improvement of serological diagnosis of human cytomegalovirus infection in renal transplant recipients by testing for specific immunoglobulin E by ELISA

The kinetics of human cytomegalovirus (HCMV)-specific immunoglobulin E (IgE), M (IgM), A (IgA) and G (IgG) were studied in 421 sera obtained from 19 renal allograft recipients by enzyme-linked immunosorbent assay (ELISA). Cytomegalic inclusion disease (CID) occurred in 11 (57.9%) patients. HCMV infection was diagnosed in all (100%) of these patients by testing for specific IgE. In contrast, increased levels of IgM and IgA class antibody against HCMV were detected in only 45.5% and 18.2% patients suffering from primary or recurrent HCMV infection, respectively. Concerning the time interval between the onset of clinical symptoms and the first positive test, no significant differences in the kinetics of HCMV-specific immunoglobulins E, M, A and G were observed. Elevated specific IgE levels persisted for longer time intervals than the other immunoglobulin classes. As shown by the present study, specific IgE proved to be a more reliable serologic marker than IgM and IgA for the serologic detection of HCMV infection in renal allograft recipients.

Comparison of the Vitek Immunodiagnostic Assay System with three immunoassay systems for detection of cytomegalovirus-specific immunoglobulin G

The Vitek Immunodiagnostic Assay System (VIDAS; bioMerieux Vitek Inc., Hazelwood, Mo.) was evaluated for its ability to detect anticytomegalovirus immunoglobulin G (IgG) and was compared with the following assay systems: Abbott IMx Cytomegalovirus IgG antibody assay (Abbott Laboratories, Abbott Park, Ill.), Whittaker Cytomegelisa II IgG assay (Whittaker Bioproducts, Walkersville, Md.), and Whittaker FIAX Cytomegalovirus IgG assay (Whittaker Bioproducts). Samples were considered positive if at least two of three (IMx, Cytomegelisa II, and FIAX) comparative assays gave positive results; a sample was considered negative if at least two of the three assays were negative. Of the 199 clinical serum samples tested, 194 gave concordant results among the three comparative assays (145 were positive and 49 were negative). The VIDAS results with two samples were persistently equivocal and were therefore excluded from the comparison study. The overall agreement between VIDAS and the established standard was 98.5%. The VIDAS assay yielded one false-positive and two false-negative results. The intra- and interassay precision studies indicate that the VIDAS assay is suitable for clinical use. The VIDAS system is rapid, self-contained, and fully automated and would be useful for screening of cytomegalovirus immune status.

Human cytomegalovirus (HCMV)-specific immunoglobulin E as a serologic marker for HCMV infection in immunocompromised patients

An antibody capture assay using an enzyme-linked human cytomegalovirus (HCMV) antigen for the detection of specific immunoglobulin E (IgE) was established. IgG, M, and E responses to HCMV were studied in 497 sera obtained from 44 renal transplant recipients and 51 acquired immunodeficiency syndrome (AIDS) patients. The results were compared with those obtained from 58 HCMV-seropositive healthy individuals. HCMV-specific IgE was detected in 11 (91.7%) renal transplant recipients with primary HCMV infection. In contrast, antibodies of the IgG and IgM classes were detected in only 6 (50.0%) of these patients. Specific IgE was detected in 10 (90.9%) out of 11 renal allograft recipients suffering from secondary HCMV infection. Significant IgG titer rises and IgM were detected in 2 (18.2%) and 6 (54.6%) of these patients, respectively. IgG titer rises and IgM and IgE antibodies were seen in 5 (12.2%), 1 (2.4%) and 18 (43.9%) AIDS patients respectively. All healthy immunocompetent HCMV-seropositive individuals were tested IgE negative. The results obtained in our study indicate that IgE against HCMV is a more reliable serologic marker for primary and secondary HCMV infection than IgM in immunocompromised individuals, especially in organ transplant recipients, since it is not affected by the prophylactic application of HCMV hyperimmune globulin preparations.

Antibodies to Epstein-Barr virus and cytomegalovirus in relation to CD4 cell number in human immunodeficiency virus 1 infection

Interaction between herpesviruses and human immunodeficiency virus (HIV)1 is postulated in the progression of HIV disease. In order to evaluate the specific antibody responses directed to Epstein-Barr virus (EBV) and cytomegalovirus (CMV) and to provide serological evidence suggesting reactivation of these viruses able to accelerate the immunodeficiency, we studied IgA and IgG titres to EBV and CMV in the serum of HIV positive patients in relation to the CD4 cell number. The titres of IgG antibodies to EBV and the prevalence of IgG to CMV were significantly higher in HIV positive patients compared to control high risk HIV negative subjects. In HIV infected patients, anti-VCA IgG antibodies increased and anti-EBNA IgG antibodies decreased progressively in relation to the decline of CD4 cell number whereas anti-CMV IgG antibodies did not varied significantly at the same time. Anti-VCA IgA and anti-EA IgG antibodies were found uncommonly and with low titres. IgA antibodies to EA and CMV were not detected in any patient. The variations in EBV antibody response that we describe in HIV infection were previously reported in other immunodeficiency states and could be distinctive of these diseases.