Genomic Markers Associated with Cytomegalovirus DNAemia in Kidney Transplant Recipients

Human cytomegalovirus (CMV) is a major pathogen after solid organ transplantation, leading to high morbidity and mortality. Transplantation from a CMV-seropositive donor to a CMV-seronegative recipient (D+/R-) is associated with high risk of CMV disease. However, that risk is not uniform, suggesting a role for host factors in immune control of CMV. To identify host genetic factors that control CMV DNAemia post transplantation, we performed a whole-exome association study in two cohorts of D+/R- kidney transplant recipients. Quantitative CMV DNA was measured for at least one year following transplantation. Several CMV-protective single-nucleotide polymorphisms (SNPs) were identified in the first cohort (72 patients) but were not reproducible in the second cohort (126 patients). A meta-analysis of both cohorts revealed several SNPs that were significantly associated with protection from CMV DNAemia. The copy number variation of several genes was significantly different between recipients with and without CMV DNAemia. Amongst patients with CMV DNAemia in the second cohort, several variants of interest (p < 5 × 10-5), the most common of which was NLRC5, were associated with peak viral load. We provide new predictive genetic markers for protection of CMV DNAemia. These markers should be validated in larger cohorts.

A successfully cured case of cytomegalovirus multiple organ infection after hematopoietic stem cell transplantation: A case report

Cytomegalovirus (CMV) infection is one of the most common infectious complications following hematopoietic stem cell transplantation (HSCT); however, cases involving multiple organs at the same time are rare. The present study describes a case of CMV pneumonia combined with CMV DNAemia and CMV cystitis after HSCT. A 33-year-old male patient with acute myeloid leukemia was treated with HSCT. The first month after HSCT, the patient developed a cough and shortness of breath. At 2 months post-HSCT, the patient developed hematuria. The CMV DNA levels in the blood and urine were elevated; bronchoalveolar lavage fluid (BALF) was also positive for CMV DNA. Heterotypic cells exhibiting a large nuclear morphology were observed in the BALF and bronchial brushes. Recurrent and progressive ground-glass opacities were evident on chest computed tomography. The patient was diagnosed with CMV pneumonia complicated by CMV DNAemia and CMV cystitis, and was treated with a combination of ganciclovir and foscarnet, along with immunoglobulin therapy. The patient was cured and discharged. It was determined that the CMV DNA in the blood was inconsistent with that in the BALF, which delayed the early diagnosis of CMV pneumonia. The association between T-cell immune function and the therapeutic efficacy for CMV multi-organ infection following HSCT is known to be significant. Moreover, the timely administration of ganciclovir and foscarnet in combination with immunoglobulin therapy demonstrated favorable clinical outcomes.

Assessment of the potential value of plasma Torque Teno virus DNA load monitoring to predict cytomegalovirus DNAemia in patients with hematological malignancies treated with small molecule inhibitors: A proof-of-concept study

It is unknown whether Torque Teno virus (TTV) DNA load monitoring could anticipate the development of infectious events in hematological patients undergoing treatment with small molecular targeting agents. We characterized the kinetics of plasma TTV DNA in patients treated with ibrutinib or ruxolitinib and assessed whether TTV DNA load monitoring could predict the occurrence of Cytomegalovirus (CMV) DNAemia or the magnitude of CMV-specific T-cell responses. Multicenter, retrospective, observational study, recruiting 20 patients treated with ibrutinib and 21 with ruxolitinib. Plasma TTV and CMV DNA loads were quantified by real-time PCR at baseline and days +15, +30, +45, +60, +75, +90, +120, +150, and +180 after treatment inception. Enumeration of CMV-specific interferon-γ (IFN-γ)-producing CD8⁺ and CD4⁺ T-cells in whole blood was performed by flow cytometry. Median TTV DNA load in ibrutinib-treated patients increased significantly (p = 0.025) from baseline (median: 5.76 log₁₀ copies/mL) to day +120 (median: 7.83 log₁₀ copies/mL). A moderate inverse correlation (Rho = -0.46; p < 0.001) was found between TTV DNA load and absolute lymphocyte count. In ruxolitinib-treated patients, TTV DNA load quantified at baseline was not significantly different from that measured after treatment inception (p ≥ 0.12). TTV DNA load was not predictive of the subsequent occurrence of CMV DNAemia in either patient group. No correlation was observed between TTV DNA loads and CMV-specific IFN-γ-producing CD8⁺ and CD4⁺ T-cell counts in either patient group. The data did not support the hypothesis that TTV DNA load monitoring in hematological patients treated with ibrutinib or ruxolitinib could be useful to predict either the occurrence of CMV DNAemia or the level of CMV-specific T-cell reconstitution; nevertheless, due to the small sample size, further studies involving larger cohorts are warranted to elucidate this issue.

Impact of cytomegalovirus immunodominant HLA-I donor-recipient matching on the incidence and features of virus DNAemia and virus-specific T-cell immune reconstitution in unmanipulated haploidentical hematopoietic stem cell transplantation

BACKGROUND

We investigated whether donor-recipient mismatch involving one or more cytomegalovirus (CMV) immunodominant (ID) human leukocyte antigen (HLA)-I alleles may impact on the degree of CMV pp65/immediate-early 1 (IE-1) T-cell reconstitution and the incidence of CMV DNAemia in patients undergoing unmanipulated haploidentical hematopoietic stem cell transplantation with high-dose posttransplant cyclophosphamide (PT/Cy-haplo).

METHODS

Multicenter observational study including 106 consecutive adult PT/Cy-haplo patients (34 CMV ID HLA-I matched and 72 mismatched). A real-time PCR was used for plasma CMV DNA load monitoring. Enumeration of CMV-specific (pp65/IE-1) interferon (IFN)-γ-producing T cells from several patients was performed by flow cytometry by days +30, +60, +90 and +180 after transplantation.

RESULTS

The cumulative incidence of CMV DNAemia, clinically significant CMV DNAemia episodes (cs-CMVi), and recurrent CMV DNAemia was comparable across CMV ID HLA-I matched and mismatched patients (71.8% vs. 80.9%, p = .95; 40.7% vs. 44.2%, p = .85; 16.4% vs. 28.1%; p = .43, respectively). The percentage of patients exhibiting detectable CMV-specific IFN-γ-producing T-cell responses (either CD8⁺ or CD4⁺ ) was similar across groups; nevertheless, significantly higher CMV-specific CD8⁺ T-cell counts were enumerated in the CMV ID HLA-I matched compared to mismatched patients by day +60 (p = .04) and +180 (p = .016) after transplantation.

CONCLUSION

CMV ID HLA-I matching may impact on the magnitude of CMV-pp65/IE-1-specific CD8⁺ T-cell reconstitution; yet, this effect seemed not to have an impact on the incidence of initial, recurrent CMV DNAemia, or cs-CMVi.

Features of cytomegalovirus DNAemia and virus-specific T-cell responses in allogeneic hematopoietic stem-cell transplant recipients during prophylaxis with letermovir

BACKGROUND

There is scarce information on the natural kinetics of cytomegalovirus (CMV) DNAemia and dynamics of CMV-specific T-cell reconstitution in allogeneic hematopoietic transplant recipients (allo-HSCT) undergoing letermovir (LMV) prophylaxis.

METHODS

Twelve adult CMV-seropositive high-risk recipients (median age, 53 years; 9 males/3 females) undergoing LMV prophylaxis and 13 non-LMV allo-HSCT controls (median age, 58 years; 7 males/6 females) were included. CMV DNAemia in plasma was monitored by real-time polymerase chain reaction. Preemptive antiviral therapy (PET) was administered upon detection of ≥1500 IU/ml. CMV-specific interferon-gamma (IFN-γ)-producing CD8⁺ and CD4⁺ T cells were enumerated by flow cytometry around days +30, +60, and +90 after allo-HSCT. Ex vivo experiments assessing of the potential effect of LMV on CMV-specific T-cell expansion in a single CMV-seropositive donor were also conducted.

RESULTS

Five LMV patients (41.6%) developed CMV DNAemia that cleared spontaneously. Four patients (33.3%) developed CMV DNAemia after LMV cessation, of which two required PET. Nine non-LMV patients (69.2%) developed CMV DNAemia (five required PET). The percentage of LMV and non-LMV patients exhibiting detectable CMV-specific T-cell responses was comparable (7/10 vs. 10/13; p = .71). Nevertheless, median CMV-specific CD4⁺ and CD8⁺ T-cell counts were lower in LMV patients by days +60 (p = .006 and .02, respectively) and +90 (p = .08 and .02). Ex vivo, CMV-specific CD8⁺ T cells expanded to the same level either in the presence (19.8%) or in the absence of LMV (20.6%).

CONCLUSIONS

In our series, episodes of CMV DNAemia in LMV patients cleared spontaneously. A diminished degree of CMV-specific T-cell reconstitution in LMV patients compared to non-LMV patients was observed.

Whole Blood versus Plasma Samples-How Does the Type of Specimen Collected for Testing Affect the Monitoring of Cytomegalovirus Viremia?

Viral infections, or their reactivations, are one of the most important groups of transplantation complications that can occur among recipients of both hematopoietic cells and solid organ transplants. They are the most commonly caused by cytomegalovirus (CMV). Currently, the use of whole blood or plasma samples is recommended for CMV viral load monitoring. The aim of the study was to assess and compare the level of CMV DNA, depending on the type of clinical material—whole blood or plasma fraction derived from the same patient. The studies were carried out on 156 whole blood samples in which the presence of CMV genetic material was confirmed and the corresponding plasma samples from the same rounds of sampling. CMV DNA was not present in 59 (37.8%) of plasma samples compared to whole blood-positive counterparts. Of the samples positive in both types of clinical specimen, 77 (79.4%) had higher viral DNA levels in the whole blood samples. There were statistically significant differences in the detected CMV DNA load in the whole blood compared to plasma fraction counterparts (p < 0.001). The detected CMV DNA value is usually higher in whole blood compared to plasma samples of the same patient. Due to the variability in CMV viral load depending on the clinical material used for a particular patient, one type of specimen should be always used consequently for CMV viremia monitoring.

Cytomegalovirus DNA detection in pregnant women with a high IgG avidity index: a valuable tool for diagnosing non-primary infections?

BACKGROUND/AIM

Congenital human cytomegalovirus infection (cCMV) is the commonest congenital infection, and it can result in hearing loss and neurodevelopmental delay. Even if primary infections are more frequent and cause more severe congenital cCMV manifestations compared to NPIs, and despite partial protection from maternal immunity, the highest birth prevalence of cCMV is observed in seropositive women with non-primary CMV infection (NPI). Given that NPI contribute significantly to the overall burden of cCMV, their accurate diagnosis of NPI remains clinically important. Considering that the serological testing for CMV infection is not always reliable, we sought to determine whether detection of CMV DNA in pregnant women with a high IgG avidity index (AI) can help diagnose NPI.

MATERIALS AND METHODS

Human CMV serology screening (IgG, IgM, and IgG AI) was performed for confirmation of CMV infection in serum samples from mainly pregnant women with indications of CMV infection due to IgG⁺ and IgM⁺-positive samples in other laboratories. Pregnant women (or those with termination of pregnancy during the last period) with adequate IgG levels to perform IgG AI were included. Demographic data and mean gestation week at the time of screening were recorded. Serological testing was performed using CE-IVD commercial kits. CMV DNAemia detection by real time PCR (RT-PCR) was applied to confirm suspected CMV infection.

RESULTS

Nine-hundred and thirty-four pregnant women CMV IgG positive with adequate IgG titers for AI testing were included in the study. The percentage of women with a high AI was 71.8% (671/934); among them, nearly 2.4% (16/671) had presence of CMV DNA. Also, 12.4% of women (116/934) had intermediate IgG AI and 15.7% of women (147/934) had low IgG AI. The presence of CMV DNA was observed in 13.8% (16/116) and 39.5% (58/147) of the groups with intermediate and low IgG AI, respectively. A high CMV IgG AI was associated with a negative CMV PCR status (p-value <.00001).

CONCLUSIONS

CMV DNA was present in 2.4% of seropositive women with high IgG AI, indicating active NPI and thus, harboring the risk of cCMV sequelae to the fetus. Moreover, the incidence of NPI may have been underestimated due to single timepoint testing. In order to detect CMV NPI in a seropositive woman, regular and frequent serology testing as well as detection of CMV DNAemia are required which render the whole diagnostic process impractical and not cost-effective.

Evaluation of cytomegalovirus "Blips" in high risk kidney/kidney-pancreas transplant recipients

BACKGROUND

Cytomegalovirus (CMV) is a significant cause of morbidity and mortality after solid organ transplantation. While guidelines suggest using highly sensitive QNAT assays for CMV detection, there is no defined viral load to guide initiation of preemptive therapy.^1,2 This study evaluates the progression to quantifiable CMV (DNAemia) following a CMV "blip" in high risk (D+/R) kidney/kidney-pancreas (KP) transplant recipients.

METHODS

This is a single center, retrospective study. A CMV "blip" was defined as the first positive QNAT assay below the level of quantification (< 1.37×10² IU/mL or < 200 viral copies). Subsequent CMV QNAT assays were followed to assess the progression from blip to CMV DNAemia for 1 year following transplant.

RESULTS

134 patients were included in the study. Fifty-three (39.6%) patients had their first positive CMV QNAT value below the level of quantification, a "CMV blip". Of these 53 patients, 69.8% (n = 37) progressed to DNAemia while 30.2% (n = 16) did not. The median time from transplant to the first CMV blip was 68 (46-97) days and most patients with viral blips (71.1%) were on prophylaxis. No differences in patient characteristics were found among those who progressed from blip to DNAemia and those who only had a blip.

CONCLUSIONS

In CMV high risk kidney/KP transplant recipients, CMV blips progressed to CMV DNAemia in the majority of cases. This progression typically occurred 2-3 weeks following the initial blip. CMV blips are common early post-transplant despite prophylaxis and likely represent an early marker of CMV infection. This article is protected by copyright. All rights reserved.

Acute and Chronic Changes in Gene Expression After CMV DNAemia in Kidney Transplant Recipients

Cytomegalovirus (CMV) viremia continues to cause significant morbidity and mortality in kidney transplant patients with clinical complications including organ rejection and death. Whole blood gene expression dynamics in CMV viremic patients from onset of DNAemia through convalescence has not been well studied to date in humans. To evaluate how CMV infection impacts whole blood leukocyte gene expression over time, we evaluated a matched cohort of 62 kidney transplant recipients with and without CMV DNAemia using blood samples collected at multiple time points during the 12-month period after transplant. While transcriptomic differences were minimal at baseline between DNAemic and non-DNAemic patients, hundreds of genes were differentially expressed at the long-term timepoint, including genes enriching for pathways important for macrophages, interferon, and IL-8 signaling. Amongst patients with CMV DNAemia, the greatest amount of transcriptomic change occurred between baseline and 1-week post-DNAemia, with increase in pathways for interferon signaling and cytotoxic T cell function. Time-course gene set analysis of these differentially expressed genes revealed that most of the enriched pathways had a significant time-trend. While many pathways that were significantly down- or upregulated at 1 week returned to baseline-like levels, we noted that several pathways important in adaptive and innate cell function remained upregulated at the long-term timepoint after resolution of CMV DNAemia. Differential expression analysis and time-course gene set analysis revealed the dynamics of genes and pathways involved in the immune response to CMV DNAemia in kidney transplant patients. Understanding transcriptional changes caused by CMV DNAemia may identify the mechanism behind patient vulnerability to CMV reactivation and increased risk of rejection in transplant recipients and suggest protective strategies to counter the negative immunologic impact of CMV. These findings provide a framework to identify immune correlates for risk assessment and guiding need for extending antiviral prophylaxis.

Immune Monitoring Using QuantiFERON®-CMV Assay in Congenital Cytomegalovirus Infection: Correlation With Clinical Presentation and CMV DNA Load

BACKGROUND

Cytomegalovirus (CMV)-specific CD8 + T-cell responses can be detected early in fetal life, but their role in the manifestations of congenital CMV (cCMV) infection remains largely unknown.

METHODS

CMV-specific CD8 + T-cell responses were assessed in neonates with cCMV using QuantiFERON®-CMV assay, within day 14 of life (T0) and during the second month of life (T1). Detection and quantification of CMV DNA in whole blood and urine samples were performed at both time points. QuantiFERON®-CMV results were evaluated in relation to timing of maternal infection, clinical manifestations of cCMV and CMV DNA levels.

RESULTS

Thirty neonates were enrolled (10/30 [33%] symptomatic; 20/30 [67%] asymptomatic). At T0 16/30 (53%) subjects had a reactive QuantiFERON®-CMV result and 16/16 (100%) were asymptomatic, whereas 14/30 (47%) had a nonreactive or indeterminate QuantiFERON®-CMV result and 4/14 (29%) were asymptomatic. At T1, 17/29 (59%) subjects had a reactive QuantiFERON®-CMV result, and 17/17 (100%) were asymptomatic, whereas 12/29 (41%) had a nonreactive or indeterminate result and 3/12 (25%) were asymptomatic. At both T0 and T1 reactive QuantiFERON®-CMV results correlated with lack of symptoms (P = .0001). At T1 median CMV DNAemia was lower in subjects with reactive QuantiFERON®-CMV results as compared with subjects with nonreactive or indeterminate results (1.82 log IU/mL [1.82-2.89] vs 2.55 log IU/mL [1.82-4.42], P = .009). No correlation was found between QuantiFERON®-CMV results and gestational age at maternal infection nor with urine CMV DNA levels.

CONCLUSIONS

A detectable CMV-specific CD8 + T-cell response, evaluated using the QuantiFERON®-CMV assay, correlates with the lack of CMV-related symptoms and the control of CMV DNAemia.

Assessment of the association between cytomegalovirus DNAemia and subsequent acute graft-versus-host disease in allogeneic peripheral blood stem cell transplantation: A multicenter study from the Spanish hematopoietic transplantation and cell therapy group

The potential role of active CMV infection in promoting acute Graft-versus-Host Disease (aGvHD) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a matter of debate. We further addressed this issue conducting a retrospective, observational, multicenter study of 632 patients subjected to allogeneic peripheral blood HSCT at 20 Spanish centers. Monitoring of CMV DNA load in plasma or whole blood was performed by real-time PCR assays. Cumulative incidence of CMV DNAemia was 48.9% (95% CI, 45%-52.9%), of any grade aGvHD, 45.6; 95% (CI, 41.3%-50.1%), and of grade II-IV aGvHD, 30.7 (95% CI, 24.9%-36.4%). Overall, development of CMV DNAemia at any level resulted in an increased risk of subsequent all grade (HR, 1.38; 95% CI, 1.08 - 1.76; P = .009) or grade II-IV (HR, 1.58; 95% CI, 1.22 - 2.06; P = .001) aGvHD. The increased risk of aGvHD linked to prior occurrence of CMV DNAemia was similar to the above when only clinically significant episodes were considered for the analyses (HR for all grade aGvHD, 1.48; 95% CI, 1.13 - 1.91; P = .041, and HR for grade II-IV aGvHD, 1.53; 95% CI. 1.13-1.81; P = .04). The CMV DNA doubling time in blood was comparable overall in episodes of CMV DNAemia whether followed by aGvHD or not. Whether CMV replication is a surrogate risk marker of aGvHD or it is causally involved is an important question to be addressed in future experimental research.

Features of Cytomegalovirus DNAemia Blips in Allogeneic Hematopoietic Stem Cell Transplant Recipients: Implications for Optimization of Preemptive Antiviral Therapy Strategies

Cytomegalovirus (CMV) DNAemia occurs frequently in allogeneic hematopoietic stem cell transplant recipients (allo-HSCT). There is limited information about the incidence, features, and clinical impact of CMV DNAemia blips (episodes defined by an isolated positive PCR result) in this setting. In this retrospective study, 225 consecutive adult patients undergoing any modality of allo-HSCT at our center between May 2012 and July 2019 were included. Plasma CMV DNA load was monitored using a highly sensitive real-time PCR assay. In all, 187 of 225 patients had CMV DNAemia through day 365 after allo-HSCT (total number of episodes, n = 379). Eighty-three of the 187 patients had 1 or more blips (n = 104). Blips occurred as a first episode of CMV DNAemia as opposed to prolonged CMV DNAemia (≥2 consecutive positive PCR results) in 47 patients; in 20 of these patients, blips represented the only documented episode throughout the study period, and in 27 patients, blips preceded a prolonged CMV DNAemia episode. In the remaining 36 patients, blips developed as recurrences. Blips presenting as initial episodes occurred more frequently (P < .001) in patients receiving an allograft from a CMV-seropositive donor. The cumulative incidence of recurrent CMV DNAemia following initial blips, self-resolving prolonged CMV DNAemia episodes, or CMV DNAemia episodes treated preemptively with antivirals was not significantly different (P = .34). Receiver operating characteristic curve analysis indicated that a CMV DNA load cutoff of 48 IU/mL yielded the highest combined sensitivity (66%) and specificity (70.2%) for predicting a prolonged CMV DNAemia episode. The practical implications of our data in the optimization of preemptive antiviral therapy strategies are discussed.

Incidence, features, and outcomes of cytomegalovirus DNAemia in unmanipulated haploidentical allogeneic hematopoietic stem cell transplantation with post-transplantation cyclophosphamide

BACKGROUND

Conflicting data have been published as to the risk of cytomegalovirus (CMV) DNAemia and CMV disease in patients undergoing haploidentical hematopoietic stem cell transplantation (haplo-HSCT) with post-transplantation cyclophosphamide.

METHODS

We conducted a multicenter retrospective study including 118 patients subjected to unmanipulated haplo-HSCT to further clarify this issue. An historic cohort comprising 165 patients undergoing other transplant modalities (HLA-matched related, matched unrelated or mismatched) was built for comparison purposes. Plasma CMV DNA monitoring was performed using two highly sensitive real-time PCR assays.

RESULTS

Overall, the cumulative incidence of CMV DNAemia, recurrent CMV DNAemia, and CMV DNAemia requiring preemptive antiviral therapy in patients undergoing haplo-HSCT was 63.9%, 34.9%, and 50.1%, respectively. These figures were rather comparable for other transplant modalities (P = .22, P = .13 and P = .72, respectively). A trend toward longer duration of episodes and shorter CMV DNA doubling times was observed in haplo-HSCT patients in comparison with other transplant modalities. Furthermore, median CMV DNA peak load was significantly higher in haplo-HSCTs (P = .008), yet overall mortality by day 180 and 365 was the same across comparison groups. There were five cases of CMV disease, and all occurred in haplo-HSCT patients. This latter observation is worrying and merits further investigation.

CONCLUSIONS

The incidence of initial and recurrent episodes of CMV DNAemia either requiring or not antiviral therapy in unmanipulated haplo-HSCT was comparable to other transplant modalities in our cohort.

Impact of standardized protocols for cytomegalovirus disease prevention in pediatric solid organ transplant recipients

End-organ disease caused by CMV is a significant cause of morbidity and mortality in pediatric SOT recipients. Pediatric transplant centers have adopted various approaches for CMV disease prevention in this patient population. We observed significant practice variation in CMV testing, prophylaxis, and surveillance across SOT groups in our center. To address this, we implemented evidence-based standardized protocols and measured outcomes pre- and post-implementation of these protocols. We performed retrospective chart review for SOT recipients from 2009 to 2014 at Boston Children's Hospital. Using descriptive statistics, we measured practice improvement in provision of appropriate prophylaxis, occurrence of neutropenia and associated complications, and occurrence of CMV DNAemia and CMV disease pre- and post-intervention. The pre- and post-intervention periods included 141 and 109 patients, respectively. With the exception of kidney transplant recipients, provision of appropriate valganciclovir prophylaxis improved across SOT groups post-intervention (P < .01). Occurrence of >1 episode of neutropenia was greater in the preintervention period (30% vs 10%, P < .001). In both periods, neutropenia was associated with few episodes of invasive infections. The occurrence of CMV disease did not differ and was overall low. However, due to routine surveillance a significantly greater number of asymptomatic CMV DNAemia episodes were identified and treated in the post-intervention period. Implementation of standardized prevention protocols helped to improve the provision of appropriate prophylaxis to patients at risk for CMV acquisition, increased the diagnosis and treatment of asymptomatic CMV DNAemia, and decreased episodes of recurrent neutropenia in patients receiving prophylaxis.

Pulmonary cytomegalovirus (CMV) DNA shedding in allogeneic hematopoietic stem cell transplant recipients: Implications for the diagnosis of CMV pneumonia

OBJECTIVES

To date no definitive cut-off value for cytomegalovirus (CMV) DNA load in bronchoalveolar lavage (BAL) fluid specimens has been established to discriminate between CMV pneumonia and pulmonary CMV DNA shedding in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients.

METHODS

The current retrospective study is aimed at assessing the range of CMV DNA loads quantified in BAL fluid specimens from allo-HSCT patients with pneumonia in which different microorganisms were causally involved.

RESULTS

A total of 144 BAL specimens from 123 patients were included. CMV DNA was detected in 56 out of 144 BAL fluid specimens and the median CMV DNA load from patients in whom CMV pneumonia was unlikely or could be tentatively ruled out was 1210 (31-68, 920) IU/ml. The frequency of CMV DNA detection and median CMV DNA loads were comparable, irrespective of the attributable cause of pneumonia. Detection of CMV DNA loads in BAL fluid specimens >500 IU/ml was independently associated with pneumonia-attributable mortality.

CONCLUSIONS

The current study highlights the difficulty in establishing universal CMV DNA load thresholds in BAL fluid specimens for distinguishing between CMV pneumonia and pulmonary CMV DNA shedding, and suggests that the presence of CMV DNA in BAL fluid specimens beyond a certain level may have a deleterious impact on patient outcome.

Community-acquired respiratory virus lower respiratory tract disease in allogeneic stem cell transplantation recipient: Risk factors and mortality from pulmonary virus-bacterial mixed infections

Risk factors (RFs) and mortality data of community‐acquired respiratory virus (CARVs) lower respiratory tract disease (LRTD) with concurrent pulmonary co‐infections in the setting of allogeneic hematopoietic stem cell transplantation (allo‐HSCT) is scarce. From January 2011 to December 2017, we retrospectively compared the outcome of allo‐HSCT recipients diagnosed of CARVs LRTD mono‐infection (n = 52, group 1), to those with viral, bacterial, or fungal pulmonary CARVs LRTD co‐infections (n = 15, group 2; n = 20, group 3, and n = 11, group 4, respectively), and with those having bacterial pneumonia mono‐infection (n = 19, group 5). Overall survival (OS) at day 60 after bronchoalveolar lavage (BAL) was significantly higher in group 1, 2, and 4 compared to group 3 (77%, 67%, and 73% vs 35%, respectively, P = .012). Recipients of group 5 showed a trend to better OS compared to those of group 3 (62% vs 35%, P = .1). Multivariate analyses showed bacterial co‐infection as a RF for mortality (hazard ratio[HR] 2.65, 95% C.I. 1.2‐6.9, P = .017). We identified other 3 RFs for mortality: lymphocyte count <0.5 × 10⁹/L (HR 2.6, 95% 1.1‐6.2, P = .026), the occurrence of and CMV DNAemia requiring antiviral therapy (CMV‐DNAemia‐RAT) at the time of BAL (HR 2.32, 95% C.I. 1.1‐4.9, P = .03), and the need of oxygen support (HR 8.3, 95% C.I. 2.9‐35.3, P = .004). CARV LRTD co‐infections are frequent and may have a negative effect in the outcome, in particular in the context of bacterial co‐infections.

Cytomegalovirus (CMV) Disease Despite Weekly Preemptive CMV Strategy for Recipients of Solid Organ and Hematopoietic Stem Cell Transplantation

Background

Transplant recipients presenting with cytomegalovirus (CMV) disease at the time of diagnosis of CMV DNAemia pose a challenge to a preemptive CMV management strategy. However, the rate and risk factors of such failure remain uncertain.

Methods

Solid organ transplantation (SOT) and hematopoietic stem cell transplantation (HSCT) recipients with a first episode of CMV polymerase chain reaction (PCR) DNAemia within the first year posttransplantation were evaluated (n = 335). Patient records were reviewed for presence of CMV disease at the time of CMV DNAemia diagnosis. The distribution and prevalence of CMV disease were estimated, and the odds ratio (OR) of CMV disease was modeled using logistic regression.

Results

The prevalence of CMV disease increased for both SOT and HSCT with increasing diagnostic CMV PCR load and with screening intervals >14 days. The only independent risk factor in multivariate analysis was increasing CMV DNAemia load of the diagnostic CMV PCR (OR = 6.16; 95% confidence interval, 2.09–18.11). Among recipients receiving weekly screening (n = 147), 16 (10.8%) had CMV disease at the time of diagnosis of CMV DNAemia (median DNAemia load 628 IU/mL; interquartile range, 432–1274); 93.8% of these cases were HSCT and lung transplant recipients.

Conclusions

Despite application of weekly screening intervals, HSCT and lung transplant recipients in particular presented with CMV disease at the time of diagnosis of CMV DNAemia. Additional research to improve the management of patients at risk of presenting with CMV disease at low levels of CMV DNAemia and despite weekly screening is warranted.

Monitoring of Cytomegalovirus (CMV)-Specific Cell-Mediated Immunity in Heart Transplant Recipients: Clinical Utility of the QuantiFERON-CMV Assay for Management of Posttransplant CMV Infection

The clinical utility of the QuantiFERON-CMV (QFN-CMV) assay in heart transplant recipients was assessed. Forty-four cytomegalovirus (CMV)-seropositive patients were enrolled: 17 received antiviral prophylaxis, and 27 were managed preemptively. CMV-DNAemia monitoring was performed by the use of a quantitative real-time PCR assay. The QFN-CMV assay was retrospectively performed on blood samples collected at five posttransplant time points. A higher proportion of patients with an indeterminate QFN-CMV result after the suspension of prophylaxis than of patients who showed a global T-cell responsiveness developed CMV infection (P = 0.036). Patients who reconstituted a CMV-specific response following the first CMV-DNAemia-positive result (42.9%) showed a median CMV-DNAemia peak 1 log of magnitude lower than that seen with patients with indeterminate results, and all controlled viral replication spontaneously. The 25% of patients with an indeterminate result developed CMV disease. In the preemptive strategy group, no differences in the development of subsequent infection, magnitude of viral load, and viral control were observed on the basis of QFN-CMV measurements performed before and after the first CMV-DNAemia-positive result. Considering both CMV prevention strategies, viral relapse was associated with the failure to reconstitute CMV-specific cell-mediated immunity (CMI) after the resolution of the first episode of CMV infection (P = 0.032). QFN-CMV measurements can be a useful tool for identifying patients (i) at higher risk of developing infection after discontinuing antiviral prophylaxis, (ii) with late CMV infection who would benefit from appropriate antiviral interventions, and (iii) at higher risk of viral relapses. QFN-CMV measurements taken within 1 month posttransplantation (early period) are not revealing.

The impact of virus population diversity on the dynamics of cytomegalovirus DNAemia in allogeneic stem cell transplant recipients

Mixed cytomegalovirus (CMV) infections are associated with delayed viral clearance in solid organ transplant recipients. We investigated whether this could be extrapolated to allogeneic stem cell transplant (allo-SCT) recipients. A total of 48 plasma specimens, obtained during 29 episodes of active CMV infection in 25 non-consecutive allo-SCT patients, were analysed. Baseline blood specimens, drawn shortly prior to the inception of pre-emptive antiviral therapy (pre-treatment specimen; n=29), as well as follow-up samples obtained either after the initiation of antiviral therapy (post-treatment specimen; n=15) or during recurrent episodes (n=4) were analysed. Plasma CMV DNA loads were quantified by real-time PCR and the CMV genotyping was performed by ultra-deep sequencing of hypervariable regions in the genes coding for glycoproteins N (gN) and O (gO). A trend towards higher CMV DNA peak loads, longer CMV DNAemia episode durations and slower CMV DNAemia decay rates was observed for episodes with mixed CMV genotype populations compared to those caused by single CMV variants, although the differences did not reach statistical significance. The length of the treatment course required to clear DNAemia was significantly longer in these mixed episodes (P=0.002). Significant changes in the number or frequency of CMV gN or gO genetic variants were documented following the initiation of antiviral therapy or in recurrent episodes. CMV diversity may have a major impact on the kinetics of CMV DNAemia clearance during the treatment of active CMV infection episodes in allo-SCT recipients.

IL28B genetic variation and cytomegalovirus-specific T-cell immunity in allogeneic stem cell transplant recipients

A single nucleotide polymorphism (SNP), 3 kbp upstream of the IL28B gene (rs12979860; C/T), has been shown to influence the dynamics of cytomegalovirus (CMV) replication in allogeneic stem cell transplant recipients (Allo-SCT). We investigated whether this SNP had any effect on the dynamics of CMV-specific T-cell immunity in these patients. CMV pp65/IE-1 IFN-γ CD8+ and CD4+ T cells were enumerated by flow cytometry in 85 patients with no prior CMV DNAemia (group A) and in 57 after the onset of CMV DNAemia (group B). Donor IL28B genotype was determined by real-time PCR and plasma levels of IL-28B were quantitated by ELISA. CMV-specific T-cell counts and plasma IL-28B levels in patients in group A were not significantly different among the IL28B genotype groups. Patients harboring the donor IL28B T/T genotype appeared to expand CMV-specific IFN-γ CD8+ cells to a higher level in response to viral replication than their C/T and C/C counterparts. Fewer patients in the T/T group received pre-emptive antiviral therapy (P = 0.05). Overall, a significant inverse correlation was observed between median IL-28B levels measured prior to the CMV DNAemia onset and the level of CMV-specific CD8+ T cells enumerated after detection of CMV DNAemia (σ = -0.471; P = 0.013). In summary, the data suggested that the protective effect attributed to the rs12979860 SNP minor T allele could be mediated, at least in part, by eliciting robust CMV-specific T-cell responses. J. Med. Virol. 89:685-695, 2017. © 2016 Wiley Periodicals, Inc.

Functional patterns of cytomegalovirus (CMV) pp65 and immediate early-1-specific CD8(+) T cells that are associated with protection from and control of CMV DNAemia after allogeneic stem cell transplantation

BACKGROUND

The functional profile of cytomegalovirus (CMV)-specific CD8(+) T cells that associate with protection from and control of CMV DNAemia in allogeneic stem cell transplant (allo-SCT) recipients remains incompletely characterized.

METHODS

We enumerated pp65 and immediate early (IE)-1-specific CD8(+) T cells expressing interferon-gamma, tumor necrosis factor-alpha, and CD107a, by flow cytometry in 94 patients at days +30 and +60 after allo-SCT.

RESULTS

Fifty of 94 patients had CMV DNAemia within the first 100 days after transplant. CMV-specific CD8(+) T-cell responses (of any functional type) were more likely to be detected in patients who did not display CMV DNAemia than in those who did (P = 0.04). Qualitatively, no major differences in the functional signature of CMV-specific CD8(+) T cells were noted between patients who had or did not have CMV DNAemia. Patients displaying levels of polyfunctional CD8(+) T cells at day +30 >0.30 cell/μL had a lower risk of CMV DNAemia (positive predictive value 76%, and negative predictive value 43%).

CONCLUSION

The presence of polyfunctional CD8(+) T cells (either expressing CD107a or not) was associated with lower levels of CMV replication, and higher frequency of self-resolved episodes. The data reported further clarify the role of polyfunctional CD8(+) T cells in control of CMV DNAemia in allo-SCT recipients.

Incidence and dynamics of active cytomegalovirus infection in allogeneic stem cell transplant patients according to single nucleotide polymorphisms in donor and recipient CCR5, MCP-1, IL-10, and TLR9 genes

Single nucleotide polymorphisms (SNPs) in genes involved in the activation or regulation of innate and adaptive immune responses may modulate the susceptibility to and the natural history of certain chronic viral infections. The current study aimed to investigate whether donor and recipient SNPs in the chemokine receptor 5 (rs1800023), monocyte chemoattractant protein 1 (rs13900), interleukin-10 (rs1878672), and Toll-like receptor 9 (rs352140) genes would exert any influence on the rate of incidence and features of CMV DNAemia in the allogeneic stem cell transplantation setting. This was a retrospective observational multicenter study. The cohort consisted of 102 non-consecutive allogeneic stem cell transplant recipients. SNP genotyping was performed by allele-specific real-time PCR. CMV surveillance was performed by the pp65 antigenemia assay/and or by real-time PCR. Seventy-three patients developed CMV DNAemia within the first 100 days after transplantation (71.5%). Neither donor nor recipient SNPs were associated significantly with the rate of incidence of active CMV infection, nor with the need for pre-emptive antiviral therapy. Both the duration of CMV DNAemia and the plasma CMV DNA peak load during episodes were significantly higher in patients harboring the donor (but not the recipient) chemokine receptor 5 A/A genotype, than in their A/G and G/G counterparts (P = 0.022 and P = 0.045, respectively). The data reported suggest that SNPs in chemokine receptor 5 may influence the dynamics of CMV infection in the Allo-SCT setting.

Effect of the IL28B Rs12979860 C/T polymorphism on the incidence and features of active cytomegalovirus infection in allogeneic stem cell transplant patients

The current study was aimed at investigating whether the single nucleotide polymorphism (SNP) (rs12979860), upstream of the IL28B gene, had any effect on the incidence rate and the features of active CMV infection in the Allogeneic stem cell transplantation setting. This was a retrospective observational study including 151 patients undergoing T cell-replete Allo-SCT. Donor and recipient IL28 SNP genotype was determined by allele-specific real-time PCR. The incidence rate of active CMV infection was not significantly associated with either the donor or the recipient IL28B SNP genotype. Nevertheless, a trend towards a lower incidence of active CMV infection was noted in the donor T/T population with respect to the donor C/T and C/C population. The duration of first episodes of CMV DNAemia was significantly shorter in patients carrying the donor T/T genotype with respect to their C/C or C/T counterparts (P = 0.038). Peak CMV DNAmeia levels tended to be lower in patients carrying the T/T genotype (donor or recipient) than in C/C or C/T patients, although statistical significance was not reached. In conclusion the data presented pointed to a protective effect of the T allele (recessive genetic model) against CMV infection in the Allo-SCT setting.

An evaluation of the role of NKG2C+ natural killer cells in protection from cytomegalovirus DNAemia early following allogeneic stem cell transplantation

The role of natural killer (NK) cells in affording protection against human cytomegalovirus (CMV) in allogeneic stem cell transplant recipients is largely unknown. The current study was aimed at determining whether NKG2C+ NK cells confer protection from CMV DNAemia early following transplantation in patients lacking mono and polyfunctional CMV pp65 and IE-1-specific CD4+ and CD8+ T-cell responses, as measured by flow cytometry for intracellular cytokine staining. Fourteen out of the 36 patients included in this study developed CMV DNAemia between days +30 and +60 after transplant. Three patients did so after day +60. Peripheral blood levels of CD56(bright) CD16(-/low) and CD56(dim) CD16+ NKG2C+ NK cells measured at day +30 and at day +60 in patients who had or had not subsequent CMV DNAemia did not differ significantly. In addition, no significant correlation was found between CD56(bright) CD16(-/low) (σ = -0.229; P = 0.39) and CD56(dim) CD16+ (σ = -0.285; P = 0.28) NKG2C+ NK-cell levels and initial plasma CMV DNA loads. In summary, the data presented do not support a direct implication of NKG2C+ NK cells in preventing the development of CMV DNAemia or modulating the magnitude of CMV replication at early stages during episodes of CMV DNAemia in allogeneic stem cell transplant patients with unreconstituted CMV-specific T-cell responses.