Comparison of the Cytomegalovirus (CMV) Enzyme-Linked Immunosorbent Spot and CMV QuantiFERON Cell-Mediated Immune Assays in CMV-Seropositive and -Seronegative Pregnant and Nonpregnant Women

Cell-mediated and humoral immune responses to human cytomegalovirus in pregnant women with vertically transmitted infection following primary infection: A case report

Human cytomegalovirus (HCMV) is the major cause of neurological sequelae in infants. Immune control of primary HCMV infection appears to depend on the interaction between humoral and cell-mediated immune responses. We report the case of an HCMV-transmitter mother observed with dissociation between humoral and cell-mediated immune responses. The patient had immunoglobulin (Ig) G and M positivity at 11 weeks of gestation and showed fetal hyperechoic bowel and minimal ascites at 21 weeks of gestation. At 25 weeks of gestation, the polymerase chain reaction result for HCMV using amniotic fluid was positive. The numbers of spots in the enzyme-linked immunosorbent spot (ELISPOT) assay at 25, 36, and 39 weeks of gestation were three, five, and six spots/2 × 105 peripheral blood mononuclear cells, respectively. Furthermore, IgG avidity indexes (AIs) at 21, 25, 36, and 39 weeks of gestation were 37.6, 49.7, 72.5, and 74.3, respectively. At 40+1 weeks of gestation, the patient delivered a symptomatic infected newborn with a weight of 2,384 g (-2.6 SD) and a head circumference of 30 cm (-2.6 SD). The neonate had a petechial rash and bilateral hearing loss although did not show liver dysfunction or thrombocytopenia. Cranial magnetic resonance imaging revealed mild ventriculomegaly, left lateral/parietal polymicrogyria, and a punctate white matter lesion. This case showed that IgG AI increased with increasing gestational age, whereas the numbers of spots in the ELISPOT assay had no change. The dissociation between humoral and cell-mediated immune responses may be characteristic of the immune response of a transmitter mother.

Interferon-gamma FlowSpot assay for the measurement of the T-cell response to cytomegalovirus

Objectives

We describe a new method, FlowSpot, to assess CMV-specific T-cell response by quantification of interferon-gamma (IFN-γ). CMV-specific, T-cell-released IFN-γ was captured by flow beads and measured via flow cytometry. In the present study, we used FlowSpot to assess CMV-specific T-cell response in healthy individuals. The FlowSpot results were compared with those of serological analysis and enzyme-linked immunospot (ELISpot) assay.

Methods

Experimental results and parameter analysis were investigated by using serological, ELISpot, and FlowSpot assays.

Results

The levels of IFN-γ, which is released from CMV-specific T-cells, were measured, and the results and parameter analysis showed a good correlation between FlowSpot and ELISpot. However, FlowSpot was more sensitive and better reflected the strength of IFN-γ secretion than did ELISpot.

Conclusions

Compared to ELISpot, FlowSpot has a high sensitivity and is cost and time effective. Thus, this method can be used in wider clinical and scientific applications.

Four-Year Follow-Up of the Maternal Immunological, Virological and Clinical Settings of a 36-Year-Old Woman Experiencing Primary Cytomegalovirus Infection Leading to Intrauterine Infection

The present study aims to provide the sequential immunological, clinical and virological events occurring in a CMV-infected pregnant woman experiencing intrauterine CMV transmission. In brief, a case of primary CMV infection occurred in a 36-year-old pregnant woman. The patient exhibited early-sustained viremia and viruria, detectable presence of CMV in saliva concomitant with a strong CMV-specific cell-mediated response (427 EliSpots). CMV was detected in the amniotic fluid at 15 weeks of pregnancy (>1 × 106 CMV copies/mL). The pregnancy was deliberately interrupted at 16 weeks of gestation. Fetal histological and pathological examinations revealed placentitis and fetal brain alterations as microcephaly and cortical dysplasia. Interestingly, this clinical report shows: (1) there was a rapid and sustained CMV-specific cell mediated immune response (Th1) in association with low IgG avidity (Th2) correlated with fetal CMV transmission. (2) The levels of CMV-specific cell-mediated immune response persisted at high levels up to 200 weeks after infection despite clinical and viral clearance. (3) The histological and pathological evidence suggests that a potent pro-inflammatory condition at the placental level may lead to cCMV.

A multiple regression model for predicting a high cytomegalovirus immunoglobulin G avidity level in pregnant women with IgM positivity

OBJECTIVE

To establish a model to predict high cytomegalovirus (CMV) immunoglobulin (Ig)G avidity index (AI) using clinical information, to contribute to the mental health of CMV-IgM positive pregnant women.

METHODS

We studied 371 women with IgM positivity at ≤14 w of gestation. Information on the age, parity, occupation, clinical signs, IgM and G values, and IgG AI was collected. The IgG AI cut-off value for diagnosing congenital infection was calculated based on a receiver operating characteristic curve analysis. Between-group differences were assessed using the Mann-Whitney U-test or χ² analysis. The factors predicting a high IgG AI were determined using multiple logistic regression.

RESULTS

The women were divided into high or low IgG AI groups based on an IgG AI cut-off value of 31.75. There were significant differences in the IgG and IgM levels, age, clinical signs, and the number of women with one parity between the two groups. In a multiple logistic regression analysis, IgM and the number of women with one parity were independent predictors. This result helped us establish a mathematical model that correctly classified the IgG AI level for 84.6% of women.

CONCLUSION

We established a highly effective model for predicting a high IgG AI immediately after demonstrating IgM positivity.

Performance of Zika Assays in the Context of Toxoplasma gondii, Parvovirus B19, Rubella Virus, and Cytomegalovirus (TORCH) Diagnostic Assays

Infections during pregnancy that may cause congenital abnormalities have been recognized for decades, but their diagnosis is challenging. This was again illustrated with the emergence of Zika virus (ZIKV), highlighting the inherent difficulties in estimating the extent of pre- and postnatal ZIKV complications because of the difficulties in establishing definitive diagnoses. We reviewed the epidemiology, infection kinetics, and diagnostic methods used for Toxoplasma gondii, parvovirus B19, rubella virus, and cytomegalovirus (TORCH) infections and compared the results with current knowledge of ZIKV diagnostic assays to provide a basis for the inclusion of ZIKV in the TORCH complex evaluations. Similarities between TORCH pathogens and ZIKV support inclusion of ZIKV as an emerging TORCH infection. Our review evaluates the diagnostic performance of various TORCH diagnostic assays for maternal screening, fetal screening, and neonatal screening. We show that the sensitivity, specificity, and positive and negative predictive value of TORCH complex pathogens are widely variable, stressing the importance of confirmatory testing and the need for novel techniques for earlier and accurate diagnosis of maternal and congenital infections. In this context it is also important to acknowledge different needs and access to care for different geographic and resource settings.

The establishment of CMV antigen-specific enzyme-linked immunospot assay among Chinese: A pilot study

BACKGROUND

The prevalence of cytomegalovirus in China is high and the infection could result in disastrous consequences. Cellular immunity is the main mechanism for virus controlling. We explored the performance of cytomegalovirus antigen-specific enzyme-linked immunospot assay in patients with different infection states in endemic area.

METHODS

Twenty-eight patients with reliable results were included in statistical analysis. Peripheral blood mononuclear cells were extracted and were stimulated by cytomegalovirus phosphoprotein 65 or immediate early protein-1 antigen respectively. Spot forming cells (SFCs) were counted to evaluate the cellular immune response elicited by antigens.

RESULTS

Spots could be clearly displayed, and evenly dispersed with a clean background. The numbers of SFCs were 0 [0-0], 426 [210-601] and 230 [57-513] for uninfected individuals (n = 7), latently infected patients (n = 11) and actively infected patients (n = 10) respectively, which were statistically different. The number of SFCs stimulated by phosphoprotein 65 was significantly higher than that by immediate early protein-1.

CONCLUSIONS

The number of SFCs was significantly different among patients with different infection state. The stimulatory effect of phosphoprotein 65 was better than that of immediate early protein-1.

Potential Biomarkers for Predicting Congenital Cytomegalovirus Infection

Early diagnosis and treatment of infants with symptomatic congenital cytomegalovirus (CMV) infection may improve neurological outcomes. For this reason, prenatal detection of newborns at high risk for congenital CMV infection is important. A polymerase chain reaction (PCR) assay for CMV DNA in the amniotic fluid is the gold standard for the diagnosis of intrauterine CMV infection; however, amniocentesis is an invasive procedure. Recently, we have found that the presence of CMV DNA in the maternal uterine cervical secretion is predictive of the occurrence of congenital CMV infection in CMV immunoglobulin M (IgM)-positive pregnant women. In contrast, we have suggested that maternal serological screening for primary CMV infection using CMV-specific immunoglobulin G (IgG), the IgG avidity index, or CMV-specific IgM overlooks a number of newborns with congenital CMV infection. We will review current knowledge of the potential biomarkers for predicting congenital CMV infection.

Cytokine production in whole-blood cultures following immunization with an influenza vaccine

A clinical trial of a quadrivalent split influenza vaccine was performed in the 2014/15 season. Sixty-four subjects aged 6 months to 18 years were enrolled in order to investigate the relationship between cellular and humoral immune responses. Subjects were categorized into two groups by measuring neutralizing antibodies: non-primed naïve/primed or seroconverted/non-seroconverted groups. Whole-blood cultures were stimulated with the H1N1 split antigen before immunization and one month after the first and second immunizations for subjects < 13 years and before and one month after the first dose for those ≥ 13 years in order to investigate cytokine production. Significant amounts of IL-2, IL-12, IL-13, MCP-1, MIP-1β, and TNF-α were detected from one month after the first dose in the naïve group. In addition to these cytokines, the production of IL-1β, IL-4, IL-6, IL-8, IL-10, IL-17, G-CSF, and IFN-γ was enhanced one month after the second dose. No significant increase was noted in the primed group, except in the production of IL-10. In seroconverted subjects, the production of IL-2, IL-4, IL-8, IL-10, G-CSF, MCP-1, TNF-α, and IFN-γ increased one month after the first dose, which was earlier than in the naïve group, whereas no significant cytokine response was noted in subjects without seroconversion. Subjects ≥ 13 years were primed and the production of G-CSF, IL-4, and IL-1β increased in subjects with seroconversion. Whole-blood cultures were also stimulated with the H3N2 split antigen and similar cytokine profiles were obtained. Many cytokines and chemokines, including inflammatory cytokines, were produced in seroconverted, but not non-seroconverted subjects.

Assessment of the T-SPOT.CMV interferon-γ release assay in renal transplant recipients: A single center cohort study

Background

The measurement of CMV specific cellular immunity in organ transplant recipients could contribute additional acuity to serology based, CMV infection risk stratification, facilitating optimisation of immunosuppression and anti-viral prophylaxis.

Methods

A pilot study of renal transplant recipient (RTR’s) responses in the T-SPOT.CMV ELISPOT based assay. 108 RTR’s were recruited 3 months post-transplantation, immediately prior to the cessation of stratified anti-viral prophylaxis, used in recipients from seropositive donors. RTR’s were monitored for CMV viremia and disease. Cellular responses to peptides derived from CMV IE1 and pp65 were measured, using the T-SPOT.CMV assay.

Results

At recruitment, no CMV specific cellular immunity was detected by T-SPOT.CMV in CMV seronegative recipients (IE1 ≤ 1spot / 2.5x10⁵ PBMC’s; pp65 ≤ 3 spots / 2.5x10⁵ PBMC’s). At recruitment, CMV sero-positive recipients who made a robust response to both IE1 (>25 spots / 2.5x10⁵ PBMC’s) and pp65 (>50 spots / 2.5x10⁵ PBMC’s), were less likely to develop high level viremia than those who responded to one or neither antigen (0/28 vs 5/25; p<0.02).

Conclusions

In CMV seronegative RTR’s, CMV specific cellular immunity measured by T-SPOT.CMV was not detected prior to cessation of anti-viral prophylaxis. This differs from recent reports of CMV specific cellular immunity in a proportion of CMV seronegative RTR’s, associated with protection from CMV infection. In seropositive RTR’s, a dual response to IE1 and pp65 at recruitment, was associated with protection from subsequent viremia. This suggests that assessing the diversity of response to CMV antigens, may enhance risk stratification in this group.

Cytomegalovirus (CMV) immune monitoring with ELISPOT and QuantiFERON-CMV assay in seropositive kidney transplant recipients

Although cytomegalovirus (CMV) specific cell-mediated immunity (CMI) has been suggested as a predictive marker for CMV infection, proper CMI monitoring strategy in CMV-seropositive recipients and optimal method are not defined. The aim of this study was to evaluate two interferon gamma release assays during early post-transplant period as a predictor of the development of CMV infection in CMV-seropositive patients. A total of 124 CMV-seropositive recipients who received kidney transplantation from CMV-seropositive donor were prospectively examined. At pre-transplant and post-transplant 1 and 3 months, CMV-CMIs were tested using QuantiFERON-CMV assay (QF-CMV) and CMV specific T cell ELISPOT against CMV pp65 and IE-1 antigens (pp65-ELISPOT, IE-1-ELISPOT). CMV DNAemia occurred in 16 (12.9%) patients within 3 months after transplant. Post-transplant pp65 or IE-1 ELISPOT response, but not QF-CMV, was significantly associated with CMV DNAemia. The pp65 ELISPOT (cut-off; 30 spots/200,000 cells) and IE-1 ELISPOT (10 spots/200,000 cells) at post-transplant 1 month predicted the risk of post-transplant CMV DNAemia (P = 0.019). Negative predictive values (NPV) for protection from CMV DNAemia in case of positive ELISPOT results were 94.5% (95% CI: 86.9–97.8%) and 97.6% (95% CI: 86.3–99.6%) in pp65-ELISPOT and IE-1-ELISPOT assays, respectively. These results suggest that the variability may exist between CMV ELISPOT assays and QF-CMV, and CMV ELISPOT at post-transplant 1 month can identify the risk of CMV DNAemia in seropositive kidney transplant recipients.

Modification of the HCMV-specific IFN-γ release test (QuantiFERON-CMV) and a novel proposal for its application

Human cytomegalovirus (HCMV) is universally distributed among humans without any adverse effects; however, it induces severe diseases in immunocompromised patients such as organ transplant recipients and AIDS patients. To manage these immunocompromised patients, an easy clinical examination for the monitoring of disease risk is required. In this study, we modified the interferon-γ (IFN-γ) release test (QuantiFERON^®-CMV) using HCMV immediate early-1 (IE-1) or pp65 whole proteins, or UV-inactivated HCMV particles as an antigen. The response of heparinized peripheral blood from healthy volunteers to the pp65 protein showed an obvious dose-dependent sigmoid curve, although no correlation was observed between results of this assay and an ELISPOT assay. The addition of pp65 to the blood samples at a final concentration of 1×10³ to 1×10⁵ pg/ml was found to be optimum. Using this assay, we observed a significant enhancement in cellular immunity in volunteers after the daily ingestion of yogurt for 8 weeks, which suggested a novel application of the assay in addition to monitoring HCMV infection risk. IFN-γ secretion from peripheral blood cells on HCMV-antigen stimulation differed significantly between individuals; therefore, the assay could not be normalized. Nevertheless, it was found to be particularly useful for observing fluctuations in cellular immune activity on an individual level.

Impact of age and cytomegalovirus on CD8+ T-cell compartment remodeling after solid organ transplantation: A one-year follow-up study

Cytomegalovirus (CMV), a member of the β-herpesvirus family, is a major complicating infection in transplant patients. CMV latency has a long-term impact on CD8⁺ T-cell differentiation. It is unclear, however, whether this effect can be detected in one-year period. To investigate this, we analyzed the remodeling of the CD8⁺ T-cell compartment during the first year after solid organ transplantation. A total of 55 kidney or lung transplant patients were recruited. CD8⁺ T-cell subsets were prospectively analyzed at pretransplant, at 3 or 6months and 12months after transplantation (mo post-Tx). A significant increase in the frequency of CD27^-CD28^-CD8⁺ T cells (from 32.8% to 42.3%; p=0.014) was observed from pretransplant to 12mo post-Tx. Further analysis, however, showed that the largest expansion was observed from 3/6 to 12mo post-Tx whereas small non-significant variations were observed from pretransplant to 3/6mo post-Tx. The adjusted analysis showed that age and CMV seropositivity were statistically associated with the baseline frequency of CD27^-CD28^-CD8⁺ T cells. Additionally, CMV replication was related to the posttransplant expansion of this subpopulation, since it was not observed in patients without CMV viremia (24% vs. 4.2%). The results indicate that the expanded frequency associated with late CMV replication is additive to the baseline frequency related to aging and CMV seropositivity. If the expanded frequency remains at this high level for a long period it might have clinical consequences related to the control of future reactivations of CMV or of other related viruses.

Validation of T-Track® CMV to assess the functionality of cytomegalovirus-reactive cell-mediated immunity in hemodialysis patients

Background

Uncontrolled cytomegalovirus (CMV) replication in immunocompromised solid-organ transplant recipients is a clinically relevant issue and an indication of impaired CMV-specific cell-mediated immunity (CMI). Primary aim of this study was to assess the suitability of the immune monitoring tool T-Track® CMV to determine CMV-reactive CMI in a cohort of hemodialysis patients representative of patients eligible for renal transplantation. Positive and negative agreement of T-Track® CMV with CMV serology was examined in 124 hemodialysis patients, of whom 67 (54%) revealed a positive CMV serostatus. Secondary aim of the study was to evaluate T-Track® CMV performance against two unrelated CMV-specific CMI monitoring assays, QuantiFERON®-CMV and a cocktail of six class I iTAg™ MHC Tetramers.

Results

Positive T-Track® CMV results were obtained in 90% (60/67) of CMV-seropositive hemodialysis patients. In comparison, 73% (45/62) and 77% (40/52) positive agreement with CMV serology was achieved using QuantiFERON®-CMV and iTAg™ MHC Tetramer. Positive T-Track® CMV responses in CMV-seropositive patients were dominated by pp65-reactive cells (58/67 [87%]), while IE-1-responsive cells contributed to an improved (87% to 90%) positive agreement of T-Track® CMV with CMV serology. Interestingly, T-Track® CMV, QuantiFERON®-CMV and iTAg™ MHC Tetramers showed 79% (45/57), 87% (48/55) and 93% (42/45) negative agreement with serology, respectively, and a strong inter-assay variability. Notably, T-Track® CMV was able to detect IE-1-reactive cells in blood samples of patients with a negative CMV serology, suggesting either a previous exposure to CMV that yielded a cellular but no humoral immune response, or TCR cross-reactivity with foreign antigens, both suggesting a possible protective immunity against CMV in these patients.

Conclusion

T-Track® CMV is a highly sensitive assay, enabling the functional assessment of CMV-responsive cells in hemodialysis patients prior to renal transplantation. T-Track® CMV thus represents a valuable immune monitoring tool to identify candidate transplant recipients potentially at increased risk for CMV-related clinical complications.

Electronic supplementary material

The online version of this article (doi:10.1186/s12865-017-0194-z) contains supplementary material, which is available to authorized users.

An optimized IFN-γ ELISpot assay for the sensitive and standardized monitoring of CMV protein-reactive effector cells of cell-mediated immunity

Background

In healthy individuals, Cytomegalovirus (CMV) infection is efficiently controlled by CMV-specific cell-mediated immunity (CMI). Functional impairment of CMI in immunocompromized individuals however can lead to uncontrolled CMV replication and severe clinical complications. Close monitoring of CMV-specific CMI is therefore clinically relevant and might allow a reliable prognosis of CMV disease as well as assist personalized therapeutic decisions.

Methods

Objective of this work was the optimization and technical validation of an IFN-γ ELISpot assay for a standardized, sensitive and reliable quantification of CMV-reactive effector cells. T-activated® immunodominant CMV IE-1 and pp65 proteins were used as stimulants. All basic assay parameters and reagents were tested and optimized to establish a user-friendly protocol and maximize the signal-to-noise ratio of the ELISpot assay.

Results

Optimized and standardized ELISpot revealed low intra-assay, inter-assay and inter-operator variability (coefficient of variation CV below 22%) and CV inter-site was lower than 40%. Good assay linearity was obtained between 6 × 10⁴ and 2 × 10⁵ PBMC per well upon stimulation with T-activated® IE-1 (R² = 0.97) and pp65 (R² = 0.99) antigens. Remarkably, stimulation of peripheral blood mononuclear cells (PBMC) with T-activated® IE-1 and pp65 proteins resulted in the activation of a broad range of CMV-reactive effector cells, including CD3⁺CD4⁺ (Th), CD3⁺CD8⁺ (CTL), CD3⁻CD56⁺ (NK) and CD3⁺CD56⁺ (NKT-like) cells. Accordingly, the optimized IFN-γ ELISpot assay revealed very high sensitivity (97%) in a cohort of 45 healthy donors, of which 32 were CMV IgG-seropositive.

Conclusion

The combined use of T-activated® IE-1 and pp65 proteins for the stimulation of PBMC with the optimized IFN-γ ELISpot assay represents a highly standardized, valuable tool to monitor the functionality of CMV-specific CMI with great sensitivity and reliability.

Electronic supplementary material

The online version of this article (doi:10.1186/s12865-017-0195-y) contains supplementary material, which is available to authorized users.

QFT-Plus: a plus in variability? - Evaluation of new generation IGRA in serial testing of students with a migration background in Germany

BACKGROUND

Currently available Interferon-gamma release assays (IGRAs) show a considerable variability in serial testing for latent tuberculosis infection (LTBI). This study offers first results for the new generation IGRA QuantiFERON-TB Gold Plus (QFT-Plus) introduced in 2015 in comparison with its predecessor QuantiFERON-TB Gold In-Tube (QFT-GIT) from serial testing of students with a migration background at German universities.

METHODS

Forty-one students were selected from a previous study. All students with a positive IGRA were asked and 11 agreed to participate in this cohort study. Additionally 30 students with negative IGRA results were selected by chance. Weekly testing with QFT-Plus and QFT-GIT was performed in all individuals over a 4-week period. IGRA variability was evaluated by calculating conversion and reversion rates.

RESULTS

From 41 participants a total number of 163 serial measurements were analyzed for each IGRA, leading to 122 possible IGRA changes each. QFT-Plus had four conversions and two reversions leading to a conversion rate of 4.3% (4 of 93 possible conversions, 95% CI 1.4-11.3%) and reversion rate of 6.9% (2 of 29 possible reversions, 95% CI 1.2-24.2%). QFT-GIT had 2 conversions and 1 reversion causing slightly lower rates with 2.2% conversions (2 of 91, 95% CI 0.4-8.5%) and 3.2% reversions (1 of 31, 95% CI 0.2-18.5%). Inconsistent IGRA results occurred in 4 subjects for QFT-Plus (8 stable positives, 29 stable negatives) and in 2 subjects for QFT-GIT (9 stable positives, 30 stable negatives). Agreement between the two IGRAs was 95.1% (κ = 0.89). Variance attributed to the individuals was low (QFT-Plus: ICC = 0.88).

CONCLUSION

This study confirms occurrence of conversions and reversions for the new QFT-Plus in serial testing of a high-risk cohort in a low-incidence setting with improbable new TB contact during the study. QFT-Plus conversion and reversion rates were slightly higher than for the QFT-GIT but overall they were lower for both IGRAs than in other studies that investigated IGRA variability.

Testing for Cytomegalovirus in Pregnancy

Congenital cytomegalovirus (CMV) infection represents a relevant cause of deafness and neurological damage in newborns. Intrauterine CMV transmission might result after primary or nonprimary infections, though at different rates (30% versus 0.2%, respectively). At present, a prenatal diagnosis of CMV infection is based mainly on maternal serology, the detection of CMV-DNA in amniotic fluid and fetal blood, and ultrasound (US) and magnetic resonance imaging (MRI). Recent evidences suggest that congenital CMV infection may be an immune-mediated disease and that evaluation of humoral and especially T-cell immunities may improve the overall prenatal diagnosis. This review summarizes the most recent advancements in the diagnosis of maternal and prenatal CMV infections.

Functional impairment of CMV-reactive cellular immunity during pregnancy

Cytomegalovirus (CMV) is the most common congenital viral infection. Mother-to-child transmission can cause severe child disability. Intact CMV-specific cell-mediated immunity (CMI) was shown to prevent uncontrolled replication in healthy individuals. This study aimed to determine whether CMV-specific CMI is impaired in pregnant women, thus potentially increasing the overall risk for active CMV replication and transmission. CMV-specific CMI in peripheral blood of 60 pregnant women was determined using T-Track® CMV for detection of IE-1 and pp65-reactive effector cells by IFN-γ ELISpot, and compared to the CMV-IgG and -IgM serostatus. CMV-specific CMI was detected in 65% of CMV-seropositive pregnant women. Five percent of CMV-IgG seronegative women showed IE-1- but not pp65-reactive cells. The overall number of CMV-reactive cells in pregnant women was significantly lower compared to a matched non-pregnant control group (P < 0.001). No significant difference in CMV-specific CMI was detected in the course of the three trimesters of pregnancy of CMV-IgG seropositive women. Postpartum (median days postnatal = 123), IE-1- and pp65-specific CMI remained significantly lower than in the non-pregnant control group (P < 0.001 and 0.0032, respectively). Functional analysis of CMV-reactive immune cells using T-Track® CMV therefore suggests a systemic down-regulation of CMV-specific CMI in pregnant women. Further studies are needed to investigate whether this may be indicative of a higher susceptibility to CMV reactivation or transmission. J. Med. Virol. 89:324-331, 2017. © 2016 Wiley Periodicals, Inc.

Cytomegalovirus (CMV) Enzyme-Linked Immunosorbent Spot Assay but Not CMV QuantiFERON Assay Is a Novel Biomarker To Determine Risk of Congenital CMV Infection in Pregnant Women

Cytomegalovirus (CMV) enzyme-linked immunosorbent spot (ELISPOT) and CMV QuantiFERON assays were examined as potential biomarkers predictive of congenital CMV (cCMV) transmission. Fifty-seven pregnant women with primary CMV infection and 23 with nonprimary CMV infection were recruited in the study. Maternal age, CMV IgG avidity, viremia, and viruria were also included among the potential predictors. Spearman's statistical correlation analysis revealed a positive correlation between the CMV ELISPOT and CMV QuantiFERON assay results (P < 0.001), but only the CMV ELISPOT assay correlated with cCMV (P < 0.001). cCMV was positively correlated with maternal viremia and viruria (P < 0.05) and negatively correlated with CMV IgG avidity (P < 0.01). Maternal age and CMV QuantiFERON assay results were not statistically associated with cCMV. CMV-specific cell-mediated immunity detected by the CMV ELISPOT assay plays a critical role in cCMV.