Risk Of Cytomegalovirus Reactivation Research Articles

S1640 POLYMORPHISMS IN CYTOKINES, CHEMOKINES AND THEIR RECEPTORS GENES CONTRIBUTED TO CYTOMEGALOVIRUS REACTIVATION AFTER ALLOGENEIC STEM CELL TRANSPLANTATION

Background: Cytomegalovirus (CMV) is the most common viral infection after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Without prophylaxis, 80% of CMV-seropositive patients experience CMV infection after allo-HSCT. Cytokines and chemokines are the first line of defence against viral infections and recent studies have shown that gene polymorphisms result in inter-individual differences in cytokine production. Aims: To determine the genotype of Cytokines and chemokines in the donor (D) and recipient (R) and their association with the CMV reactivation of patients receiving an allo-HSCT. Methods: Eighty-five patients who received allo-HSCT from an HLA-identical sibling donor from 2000 to 2015 were included. CMV DNAemia was evaluated until approximately day 100 after allo-HSCT. CMV reactivation was defined as the detection of CMV DNAemia ≥100 copies/ml in plasma. All of patients were classified according to epidemiological risk factors of clinical interest. Fifty genes were selected for their potential role in the pathogenesis of CMV: C-C Motif Chemokine Ligand (CCL) and Receptor (CCR), C-X-C Motif Chemokine Ligand (CXCL) and Receptor (CXCR), Forkhead Box P3 (FOXP3), CD48 Molecule (CD48), Interferon (IFN), Interleukin (IL), Killer Cell Immunoglobulin Like Receptor (KIR), Transforming Growth Factor Beta (TGFB), tumor necrosis factor alpha (TNF) and Lymphotoxin Alpha (LTA). Genomic DNA was purified from 170 PB (D and R) using Maxwell® RSC Blood DNA Kit (Promega, USA). Libraries were performed using an enrichment-capture gene panels according to the manufacturer's protocol. Paired-end 2x101 bp was performed using the Illumina HiSeq platform (Illumina, USA). Variants located in coding region, splicing sites and intronic polymorphisms were analyzed. Synonymous variants were excluded. During the variant calling process, the values of Depth, variant allele frequency (VAF) and the minor allele frequency (MAF) in European population are obtained and used to variants filtration (Depth ≥ 30, VAF ≥ 0.4 and MAF≥ 10%). Differences among groups were evaluated by Chi-Squared and Fischer Exact Test. Results: CMV reactivation was observed in 51/85 (60%) patients. Initial episodes of CMV DNAemia occurred at a median of 48 days (2–151) after transplant. Clinical variables are not associated with CMV reactivation: age, gender, stem cells, hematological disease, conditioning regimen, serology status and prior autologous transplant. Twenty-four patients (47.1%) had only one episode of CMV reactivation, 12 (23.5%) had two episodes and 15 (29.3%) had more than two episodes after allo-HSCT. Using filters discussing previously, 221 polymorphisms were detected in D and R. Although 209 variants studied had no apparent impact on the features of CMV reactivation, but we found that 12 variants in 7 different genes were associated significantly with the development or protection of CMV reactivation (Table 1). Our data showed that determined polymorphism in TNF-α, IL12A, TGBF2, IL1RN and CD48 play an important role to protection against CMV. On other hand, KIR3DL1 and CXCL12 represent examples of how receptor polymorphism can influence CMV development.Summary/Conclusion: The data presented suggest that screening of patients and donor pre-transplantation could help to predict the individual risk of the development of CMV infection. These results might also enable the identification of patients at high risk of CMV reactivation, enabling pre-emptive therapy or attempts to cure the infection by administrating antiviral therapy or CMV-specific T lymphocytes.

Effects of Rituximab on Atherosclerotic Biomarkers in Kidney Transplant Recipients

IntroductionCardiovascular disease is the leading cause of mortality in kidney transplant recipients. Rituximab is widely used in kidney transplantation for a variety of situations, and rituximab may inhibit some cytokines and antibodies that may play an active role in the atherosclerotic process. The aim of the study was to evaluate the efficacy of rituximab on atherosclerosis biomarkers in kidney transplant recipients. MethodsAll patients, 18 years of age and older, who underwent kidney transplantation and received at least 1 dose of 375 mg/m2 rituximab were considered for participation in this study. The primary study endpoint was the development of cardiovascular diseases after rituximab therapy. The secondary endpoint was the onset of cytomegalovirus (CMV) disease or biopsy-confirmed BK virus nephropathy. In addition, comparison of atherosclerosis biomarkers was performed between study and control groups. ResultsThere were no cardiovascular events observed during follow up. Only 8 patients in the study group suffered from CMV disease during follow up. Serum interleukin 10 levels were significantly higher in the rituximab group compared with the control group, although anti–oxidized low-density lipoprotein levels were lower in the rituximab group compared with the control group, though this did not achieve statistical significance. DiscussionRituximab treatment may increase the risk of CMV reactivation and decrease lymphocyte counts and interleukin 10 levels; however, significant decreases in all atherosclerotic-related biomarkers have not been shown in our study.

PTX3 Polymorphisms Influence Cytomegalovirus Reactivation After Stem-Cell Transplantation.

Background: Reactivation of latent human cytomegalovirus (CMV) in patients undergoing allogeneic stem-cell transplantation (HSCT) predisposes to several clinical complications and is therefore a major cause of morbidity and mortality. Although pentraxin-3 (PTX3) has been previously described to bind both human and murine CMV and mediate several host antiviral mechanisms, whether genetic variation in the PTX3 locus influences the risk of CMV infection is currently unknown.Methods: To dissect the contribution of genetic variation within PTX3 to the development of CMV infection, we analyzed described loss-of-function variants at the PTX3 locus in 394 recipients of HSCT and their corresponding donors and assessed the associated risk of CMV reactivation.Results: We report that the donor, but not recipient, h2/h2 haplotype in PTX3 increased the risk of CMV reactivation after 24 months following transplantation, with a significant effect on survival. Among recipients with h2/h2 donors, CMV seropositive patients as well as those receiving grafts from unrelated donors, regardless of the CMV serostatus, were more prone to develop viral reactivation after transplantation. Most importantly, the h2/h2 haplotype was demonstrated to display an influence toward risk of CMV reactivation comparable to that conferred by the unrelated status of the donor alone.Conclusions: Our findings demonstrate the important contribution of genetic variation in donor PTX3 to the risk of CMV reactivation in patients undergoing HSCT, highlighting a promising prognostic value of donor PTX3 to predict risk of CMV reactivation in this clinical setting.

Impact of Post-Transplant High-Dose Cyclophosphamide and Donor Sources on CMV Reactivation.

Introduction Cytomegalovirus (CMV) reactivation remains a common cause of morbidity and mortality following allogeneic hematopoietic cell transplant (HCT) despite attempts at prophylaxis. Following transplantation, surveillance of the peripheral blood CMV viral load with early aggressive treatment is commonly employed and has been an effective strategy at preventing overt infection. While a matched related donor (MRD) is often the preferred transplant type, the use of alternative donors including matched unrelated donors (MUD), mismatched unrelated donors (MMUD) and haploidentical (HI) transplants, has greatly increased over the past several years. The data regarding CMV infection among these alternative donor types is scarce. Objectives To better characterize the extent and risk factors for CMV reactivation among patients who received an allogeneic HCT for hematologic malignancies, particularly among HI transplant recipients and those who received post-transplant high-dose cyclophosphamide (PTCy) for graft-versus-host disease (GVHD) prophylaxis. Methods A retrospective analysis was performed on 88 adults with hematologic malignancies who received an allogeneic HCT at our institution from 2012-2017. Only cases with CMV seropositive donors and/or recipients were included. We compared donor types/sources, conditioning regimens, GVHD prophylaxis regimens, and assessed for CMV reactivation utilizing the peripheral blood polymerase chain reaction (PCR) values that are monitored in post-transplant clinic visits. Results Nineteen (22%) patients received MRD transplants, while the remainder received alternative donor sources, including 17 (19%) HI transplants. Overall, the rate of CMV reactivation was 27% with a significant difference noted between donor sources (p= Conclusion HI HCT transplant recipients are at high risk for CMV reactivation. The use of myeloablative conditioning regimens or PTCy did not affect the rate of CMV reactivation.

Letermovir in Allogeneic Hematopoietic Cell Transplantation: Beyond the Label

Background Cytomegalovirus (CMV) is associated with significant morbidity and mortality in allogeneic hematopoietic cell transplantation (allo-HCT) patients (pts). Cumulative incidence of CMV infection in high-risk patients such as CD34-selected or haploidentical HCT have been reported as high as 61.8-84.5% and 53-81%, respectively. Letermovir (LTV) was approved in 11/2017 for prophylaxis (ppx) in CMV-seropositive recipients (R+) of allo-HCT. Since 12/2017, LTV ppx was implemented at our center for both primary and secondary ppx. We report our real-world experience. Methods Adult CMV R+ allo-HCT pts who initiated LTV as primary or secondary prophylaxis were identified between 1/1/2018 and 6/30/18. Cord blood transplants were excluded. The primary outcome was the incidence of clinically significant CMV infection (CMV viremia requiring preemptive treatment or CMV disease). Pts were followed through 9/2018. Results 53 pts initiated LTV. 69.8% pts were at high risk for CMV reactivation and disease (primarily ex vivo T-cell depleted HCT [n = 18; 34%] or haploidentical T-replete HCT [n = 12; 22.6%]). Baseline characteristics are summarized in Table 1. 39 pts (73.5%) received LTV as primary ppx after HCT, with a median day of LTV initiation of D+7 (range D+7D+40). At LTV initiation, 34 pts had an undetectable CMV DNA, and 4 had CMV Conclusion Primary LTV ppx significantly reduced CMV reactivation, and high-risk patients may benefit from extended prophylaxis. In patients who received preemptive therapy for CMV, use of secondary ppx showed no recurrent CMV reactivation. LTV is well tolerated. Additional studies are needed to determine optimal ppx duration and to clarify role of secondary CMV ppx in high-risk allo-HCT. The future standard of care will likely include extended primary ppx and secondary ppx and result in decreased morbidity and mortality associated with CMV.

Quantifying Cytomegalovirus-Specific T Cell Responses Prior to Hospital Discharge Allows Risk Stratification for Late Viral Reactivation after Allogenic Hematopoietic Cell Transplantation

Background Cytomegalovirus (CMV) infection remains a significant complication after allogenic hematopoietic cell transplantation (HCT). In the first three months after HCT, close monitoring of patients associated with prophylactic or preemptive administration of ganciclovir effectively prevents CMV-related complications. However, once patients are discharged from cancer centers around day 100 after HCT their risk of late CMV reactivation remains high. Since virus-specific T cells are capable of controlling CMV replication, we assessed whether their quantification shortly before hospital discharge allows risk-stratification for late CMV reactivation. Methods Allogeneic HCT recipients of all ages at the Fred Hutchinson Cancer Research Center who were CMV-seropositive or had a CMV-seropositive donor and participated in a prospective immune monitoring study were analyzed if they received at least 50% of weekly scheduled viral load (VL) PCR tests between days 100 and 180 after transplantation. CMV-specific cellular immunity was quantified via interferon-gamma ELISpot assay from cryopreserved peripheral blood mononuclear cells (PBMC) that were collected around day 90 after HCT. Cells were stimulated with peptide pools spanning the entire IE-1 and pp65 proteins (15mers with 11 amino acid overlap). Univariate Cox regression analysis was performed to determine hazard ratios (HR) for developing CMV reactivation at ≥50 IU, ≥500, ≥1000 IU/mL using different threshold levels (10, 50, or 100 spot-forming units (SFU) per 200,000 PBMC) for IE-1 and pp65. Results 13 out of 69 patients (18.8%) in this cohort showed clinically significant viral reactivation between days 100 and 180 after HCT, defined as having a viral load ≥1000 IU/ml at least once during the observational period (this level is commonly used to start preemptive treatment in the late setting). The best separation of risk was achieved by using a threshold of 10 SFU for both antigens: Individuals with less than 10 SFU for IE-1 or pp65 had an increased risk for CMV reactivation (HR 8.49, 95% CI, p=0.04) compared to patients with at least 10 SFU for both antigens. Correspondingly, the cumulative incidence of CMV reactivation was significantly higher in the group of patients with Conclusions Quantification of CMV-specific cellular immune responses around day 100 can help identify patients that are at risk for developing clinically significant late CMV reactivation. Both IE-1 and pp65 are useful for predicting CMV reactivation. Further studies with larger cohorts should be performed to confirm the suggested threshold levels of immune protection.

Rapid Acquisition of Cytomegalovirus-Specific T Cells with a Differentiated Phenotype, in Nonviremic Hematopoietic Stem Transplant Recipients Vaccinated with CMVPepVax

Early cytomegalovirus (CMV) reactivation remains a significant cause of morbidity and mortality in allogeneic hematopoietic cell transplant (HCT) recipients. CMVPepVax is an investigational peptide vaccine designed to control CMV infection in HCT recipients seropositive for CMV by stimulating the expansion of T cell subsets that target the CMV tegument protein pp65. In a randomized Phase Ib pilot trial (ClinicalTrials.gov NCT01588015), two injections of CMVPepVax (at days 28 and 56 post-HCT) demonstrated safety, immunogenicity, increased relapse-free survival, and reduced CMV reactivation and use of antivirals. In the present study, we assessed the phenotypes and time courses of the pp65-specific CD8 T cell subsets that expanded in response to CMVPepVax vaccination. The functionality and antiviral role of CMV-specific T cells have been linked to immune reconstitution profiles characterized predominantly by differentiated effector memory T (TEM) subsets that have lost membrane expression of the costimulatory molecule CD28 and often reexpress the RA isoform of CD45 (TEMRA). Major histocompatibility complex class I pp65495-503 multimers, as well as CD28 and CD45 memory markers, were used to detect immune reconstitution in blood specimens from HCT recipients enrolled in the Phase Ib clinical trial. Specimens from the 10 (out of 18) vaccinated patients who had adequate (≥.2%) multimer binding to allow for memory analysis showed highly differentiated TEM and TEMRA phenotypes for pp65495-503-specific CD8 T cells during the first 100days post-transplantation. In particular, by day 70, during the period of highest risk for CMV reactivation, combined TEM and TEMRA phenotypes constituted a median of 90% of pp65495-503-specific CD8 T cells in these vaccinated patients. CMV viremia was not detectable in the patients who received CMVPepVax, although their pp65495-503-specific CD8 T cell profiles were strikingly similar to those observed in viremic patients who did not receive the vaccine. Collectively, our findings indicate that in the absence of clinically relevant viremia, CMVPepVax reconstituted significant levels of differentiated pp65495-503-specific CD8 TEMs early post-HCT. Our data indicate that the rapid reconstitution of CMV-specific T cells with marked levels of effector phenotypes may have been key to the favorable outcomes of the CMVPepVax clinical trial.

Donor NKG2C Copy Number: An Independent Predictor for CMV Reactivation after Double Cord Blood Transplantation

Cytomegalovirus (CMV) is a member of the herpesviridae family and remains latent in the host cells after primary infection. The virus reactivates in the immunosuppressed host and is a leading cause of morbidity following allogeneic hematopoietic stem cell transplant (allo-HSCT). Natural killer (NK) cells provide the first-line defence against viruses and a subset of NK cells expressing NKG2C have been shown to play a role in the immune surveillance of human CMV. Deletion of the NKG2C gene has been reported as a risk factor for viral infections including CMV and HIV, but current data on the influence of NKG2C gene-copy number variations in the donor graft on the risk of CMV reactivation after allo-HSCT is limited. Following cord blood transplantation (CBT), where the T-cell compartment is functionally naïve, the NKG2C genotype may have an even more pronounced impact on the risk of CMV reactivation. Therefore, we studied NKG2C copy number in the donor graft and the risk of CMV reactivation after double umbilical cord blood transplantation (DUCBT) in 100 CMV seropositive DUCBT recipients and their corresponding cord blood grafts (n=200). The gene encoding NKG2C is present at different copy numbers in the genomes of different individuals, with possible genotypes including 2 copies (wt/wt), 1 copy due to heterozygous deletion (wt/del) or 0 copies due to homozygous deletion (del/del). Among the donor CB units, approximately 2/3 had both copies of the gene (wt/wt), 1/3 had only one copy (wt/del) and only a minority of units had 0 copies with both alleles deleted (del/del). In the setting of DUCBT, the combined graft may contain 0 to 4 functional copies of NKG2C gene. In our cohort, patients whose combined grafts contained only 1 or 2 NKG2C gene copies had a significantly higher probability of CMV reactivation than patients whose combined grafts had 3 or 4 NKG2C copies. The 6-month cumulative incidence of CMV reactivation for the 4 groups was 100%, 92.9%, 60.5% and 55.9% respectively (p=0.005). No patient received a graft with zero gene copies. For the rest of the analysis we divided the patients into two groups, namely the 84 patients who received a combined graft with 3 or 4 NKG2C copies and the 16 patients who received two units with 1 or 2 NKG2C copies. The 6-month cumulative incidence of CMV reactivation for the two groups was 58.4% and 93.7% respectively (p=0.0003). In a multivariate analysis, receiving a combined graft with low NKG2C copy number (1 or 2 copies) (HR=2.72, CI=1.59-4.64; p<0.0001) and reduced intensity conditioning (RIC) (HR=0.59, CI=0.35-0.99, p=0.046) were the only independent predictors for CMV reactivation. Interestingly, the NKG2C copy number of the dominant cord was not predictive for CMV reactivation, suggesting that both cord blood units contribute to the antiviral response early post-DUCBT. Our study points to an important role for donor NKG2C in protection against CMV reactivation after DUCBT. If confirmed in larger numbers of CBT recipients, NKG2C genotyping of the CB graft may be a useful biomarker for predicting the risk of CMV infection after CBT, thus guiding the intensity of CMV prophylaxis for individual patients. Moreover these novel findings may provide a compelling rationale for considering NKG2C genotype as a criterion in the algorithm of CB selection for DUCBT. DisclosuresOran:ASTEX: Research Funding; AROG pharmaceuticals: Research Funding; Celgene: Consultancy, Research Funding. Champlin:Sanofi: Research Funding; Otsuka: Research Funding. Shpall:Affirmed GmbH: Research Funding.

Donor NKG2C Copy Number: An Independent Predictor for CMV Reactivation After Double Cord Blood Transplantation.

Cytomegalovirus (CMV) remains a major cause of morbidity following allogeneic hematopoietic stem cell transplant. Natural killer cells expressing NKG2C have been shown to play a role in the immune surveillance of human CMV. We studied NKG2C copy number in the donor graft and the risk of CMV reactivation after double umbilical cord blood transplantation (DUCBT) in 100 CMV seropositive DUCBT recipients and their corresponding cord blood (CB) grafts (n = 200). In the setting of DUCBT, the combined graft may contain 0–4 functional copies of NKG2C gene. Sixteen patients received a combined graft with 1 or 2 NKG2C copies and 84 patients were recipients of a combined graft with 3 or 4 NKG2C copies. The 6-month cumulative incidence of CMV reactivation for the two groups was 93.7 and 58.4%, respectively (p = 0.0003). In multivariate analysis, low NKG2C copies in the graft was an independent predictor of CMV reactivation (HR = 2.72, CI = 1.59–4.64; p < 0.0001). Our study points to an important role for donor NKG2C for protection against CMV reactivation after DUCBT. These novel findings may help identify patients at a higher risk of CMV reactivation after DUCBT. Donor NKG2C genotype may be used as a potential criterion in the algorithm for graft selection for DUCBT.

Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms severity score: A useful tool for assessing disease severity and predicting fatal cytomegalovirus disease

The prognosis of drug-induced hypersensitivity syndrome (DiHS)/drug reaction with eosinophilia and systemic symptoms (DRESS) is highly unpredictable. Severe complications, either related or unrelated to cytomegalovirus (CMV) reactivation, are a highly probable cause of death. The aim was to establish a scoring system for DiHS/DRESS that can be used to monitor severity, predict prognosis, and stratify the risk of developing CMV disease and complications. A retrospective analysis of 55 patients with DiHS/DRESS was performed. A composite score was created using clinical data. DiHS/DRESS patients were also stratified into 3 groups based on the scores to predict the risk of CMV reactivation and complications. This scoring system made it possible to predict CMV disease and complications. Scores ≥4 were associated with the later development of CMV disease and complications, while no patients with scores <4 developed complications. This was a single-institution study with a relatively small patient cohort that lacked a validation cohort. Our scoring system may be useful for predicting CMV-related complications, and early intervention with anti-CMV agents should be considered in patients with scores ≥4 or with evidence of CMV reactivation.

New Developments in the Management of Cytomegalovirus Infection After Transplantation.

Cytomegalovirus (CMV) continues to be one of the most important pathogens that universally affect solid organ and allogeneic hematopoietic stem cell transplant recipients. Lack of effective CMV-specific immunity is the common factor that predisposes to the risk of CMV reactivation and clinical disease after transplantation. Antiviral drugs are the cornerstone for prevention and treatment of CMV infection and disease. Over the years, the CMV DNA polymerase inhibitor, ganciclovir (and valganciclovir), have served as the backbone for management, while foscarnet and cidofovir are reserved for the management of CMV infection that is refractory or resistant to ganciclovir treatment. In this review, we highlight the role of the newly approved drug, letermovir, a viral terminase inhibitor, for CMV prevention after allogeneic hematopoietic stem cell transplantation. Advances in immunologic monitoring may allow for an individualized approach to management of CMV after transplantation. Specifically, the potential role of CMV-specific T-cell measurements in guiding the need for the treatment of asymptomatic CMV infection and the duration of treatment of CMV disease is discussed. The role of adoptive immunotherapy, using ex vivo-generated CMV-specific T cells, is highlighted. This article provides a review of novel drugs, tests, and strategies in optimizing our current approaches to prevention and treatment of CMV in transplant recipients.

A Modified Intensive Strategy to Prevent Cytomegalovirus Disease in Seropositive Umbilical Cord Blood Transplantation Recipients

We previously demonstrated a lower rate of cytomegalovirus (CMV) reactivation and disease among seropositive umbilical cord blood transplantation (CBT) recipients receiving an intensive prophylaxis strategy consisting of ganciclovir on days −8 to −2 pretransplantation, high-dose valacyclovir post-transplantation, and twice-weekly serum CMV polymerase chain reaction testing. We hypothesized that a modified intensive strategy excluding pretransplantation ganciclovir would be similarly effective. We compared the risk of CMV reactivation, occurrence of CMV disease, and duration of anti-CMV therapy by day 100 post-CBT in patients receiving the modified intensive and intensive strategies. Forty patients received the modified intensive strategy, and 43 received the intensive strategy. There was no difference in the hazard for CMV reactivation (hazard ratio, 1.1; P = .77). No patients in the modified intensive cohort, but 2 patients in the intensive cohort, developed CMV disease (P = .53). There was no difference in the hazard for early (≤30 days post-CBT; P = .76) or high-level (>1000 IU/mL; P = .37) CMV reactivation. Patients in the modified intensive cohort had marginally higher CMV viral loads and percentage of days of CMV detection and treatment, although the contribution of pretransplantation ganciclovir to these differences is unclear. The overall percentage of treatment days was 32% in both cohorts after accounting for pretransplantation ganciclovir. In conclusion, exclusion of prophylactic ganciclovir before CBT did not impact the risk of CMV reactivation or disease, although CMV kinetics appeared to differ by prevention strategy. Best practices for CMV prevention will need further study as new prophylactic strategies become available.

The potential association of CMV-specific CD8+ T lymphocyte reconstitution with the risk of CMV reactivation and persistency in post allogeneic stem cell transplant patients

ABSTRACTObjectives: development of cytomegalovirus (CMV)-specific CD8+ T cell response is crucial in preventing symptomatic CMV infection specially, in stem cell transplant (SCT) patients. The aim of this study was to evaluate CMV-specific CD8+ T cell reconstitution in allogeneic SCT recipients and to study the possible association between CMV-specific CD8+ T cell recovery with protection from CMV reactivation and persistency.Methods: Human leuKocyte antigen (HLA)-tetramers were used for CMV-specific CD8+ cell quantitation by Flow cytometry in twenty post-allogeneic SCT patients.Results: Nine patients (45%) developed rapid recovery of CMV-specific CD8+ cells, among them; 7 patients (78%) had no CMV reactivation in the first 95 days post-transplant.Five patients had developed persistent CMV viremia; all of them had not developed CMV-specific CD8+ recovery till day 95 post-transplant.Patients with persistent CMV viremia had a statistically significant lower means of CMV-specific CD8+ percent and absolute count compared to those without persistent viremia (p = .001, .015), respectively.Discussion: The incidence of CMV reactivation and persistency was higher among patients with delayed CMV-specific CD8+ reconstitution in the first 95 days post-transplant.Conclusion: CMV-specific CD8+ cells can help in categorizing patients into risk groups: (early recovery/low risk) and (delayed recovery/increased risk), this tool may guide clinicians in the selection of patients who may profit from prophylactic antiviral therapy and frequent viral monitoring.

Reconstitution of T and NK cells after haploidentical hematopoietic cell transplantation using αβ T cell-depleted grafts and the clinical implication of γδ T cells.

To investigate reconstitution of T and NK cells after αβ T lymphocyte-depleted haploidentical hematopoietic cell transplantation (HHCT) and the clinical implications of γδ T cells, we analyzed 50 pediatric patients who received 55 HHCTs using αβ T cell-depleted grafts. The number of CD3+ T cells and CD8+ T cells recovered rapidly and reached donor levels at days 180 and 60, respectively. Recovery of NK cells was rapid, and the median of NK cells at day 14 was comparable to the donor level. At day 14, median percentage of γδ T lymphocytes was 70.5%. After day 14, the percentage of γδ T cells gradually decreased, while the percentage of αβ T cells gradually increased. Patients with a low percentage (≤21%) of γδ T cells at day 30 had significantly higher incidence of cytomegalovirus (CMV) reactivation compared to patients with a high percentage (>70%) of γδ T cells (P<.01). In patients with acute leukemia, patients with high percentage of γδ T cells at day 30 showed significantly higher relapse-free survival compared to those with low percentage of γδ T cells (P=.02). Data suggest that early recovery of γδ T cells decreases the risk of CMV reactivation and leukemia relapse.

Corticosteroids and Thiopurines, But Not Tumor Necrosis Factor Antagonists, are Associated With Cytomegalovirus Reactivation in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis.

The association between cytomegalovirus (CMV) reactivation and individual immunosuppressive agents in inflammatory bowel disease (IBD) has not been clearly defined. Therefore, we performed a systematic review and meta-analysis to assess this association. Multiple electronic databases were searched systematically through July 2015 for observational studies reporting CMV reactivation (based on serum-based or tissue-based tests) in IBD patients stratified by medication exposure. We estimated summary odds ratios (ORs) and 95% confidence intervals (CI) using random-effects model. Study quality was assessed using the Newcastle-Ottawa scale. Sixteen observational studies were identified. As compared with nonexposed patients, exposure to corticosteroids (CS) (12 studies, 1180 patients, 52.3% exposed; OR, 2.05; 95% CI, 1.40-2.99) and thiopurines (14 studies, 1273 patients, 24.1% exposed; OR, 1.56; 95% CI, 1.01-2.39) was associated with increased risk of CMV reactivation. In contrast, as compared with patients not exposed to tumor necrosis factor (TNF) antagonists, exposure to TNF antagonists was not associated with an increased risk of CMV reactivation (7 studies, 818 patients, 18.5% exposed; OR, 1.44; 95% CI, 0.93-2.24). The results remained stable for CS and thiopurines when the analysis was limited to hospitalized patients, and by a tissue-based diagnosis. Studies were limited in the ability to assess the impact of concomitant immunosuppressive therapy, duration of medication exposure, and disease severity. On the basis of 16 observational studies, exposure to CS or thiopurines, but not TNF antagonists, was associated with an increased risk of CMV reactivation in IBD patients.

Peptide vaccination in the presence of adjuvants in patients after hematopoietic stem cell transplantation with CD4+ T cell reconstitution elicits consistent CD8+ T cell responses.

Rationale: Patients receiving an allogeneic stem cell graft from cytomegalovirus (CMV) seronegative donors are particularly prone to CMV reactivation with a high risk of disease and mortality. Therefore we developed and manufactured a novel vaccine and initiated a clinical phase I trial with a CMV phosphoprotein 65 (CMVpp65)-derived peptide.Methods: Ten patients after allogeneic stem cell transplantation received four vaccinations at a biweekly interval. All patients were monitored for CMVpp65 antigenemia. Flow cytometry for CMV-specific CD8+ and γδ T cells as well as neutralizing anti-CMV antibodies were correlated to clinical parameters.Results: The vaccination was well tolerated. Seven of nine patients cleared CMVpp65 antigenemia after four vaccinations and are still free from antigenemia to this day. Two patients with CMV reactivation showed persisting CMV antigenemia. One patient received prophylactic vaccination and did not develop antigenemia. An increase of up to six-fold in frequency of both CMV-specific CD8+ T cells and/or Vδ2negative γδ T cells was detected. Titers of neutralizing antibodies increased up to the tenfold. Humoral and cellular immune responses correlated with clearance of CMV.Conclusion: In summary, CMVpp65 peptide vaccination for patients after allogeneic stem cell transplantation at high risk for CMV reactivation was safe, well tolerated and clinically encouraging. A study in solid-organ transplant patients is ongoing.

Alemtuzumab as graft-versus-host disease (GVHD) prophylaxis strategy in a developing country: lower rate of acute GVHD, increased risk of cytomegalovirus reactivation.

Acute graft-versus-host disease (aGVHD) and cytomegalovirus reactivation are important complications after allogeneic stem cell transplantation (alloHSCT). Here, we evaluated the impact of treatment with alemtuzumab on the occurrence of aGVHD, cytomegalovirus reactivation and survival after alloHSCT. This was a prospective cohort study conducted at the allo-HSCT unit of Hospital das Clínicas, Universidade Federal de Minas Gerais, Brazil, from January 2009 to December 2011. Fifty-seven patients who underwent alloHSCT were included. Forty-five (79%) patients had a malignant disease. Alemtuzumab was administered before the conditioning regimen at a dose of 1 mg/kg in children and 30 mg/day for 2 days in adults or children weighing more than 40 kg (a total dose of 60 mg) with a non-malignant disease or patients with a malignant disease and high-risk for GVHD mortality. Alemtuzumab was used in 23 (40%) patients, of whom 17 received a reduced-intensity conditioning. Eleven patients presented aGVHD (grade 2–4) and only 1 of them received alemtuzumab. Cumulative incidence of aGVHD (grade 2–4) at day 100 after transplantation (D+100) was 4 for patients receiving alemtuzumab and 29% for patients not receiving alemtuzumab. Cumulative incidence of cytomegalovirus reactivation for patients receiving or not alemtuzumab was 62 and 38%, respectively. Sixteen patients died in the first 100 days after alloHSCT, most of them due to bacterial sepsis. Only 2 patients died of aGVHD until D+100. Overall survival was 50% without any impact of alemtuzumab. Alemtuzumab effectively controlled aGVHD but increased the risk of cytomegalovirus reactivation without improving survival.

Risk of cytomegalovirus reactivation in patients with immune-mediated inflammatory diseases undergoing biologic treatment: a real matter?

The use of biological agents has grown exponentially in immune-mediated inflammatory diseases (IMID), often achieving a good control of disease progression and improving patients' quality of life. However, their use resulted in an increased risk of adverse events, including reactivation of chronic/latent infectious diseases. As for the risk of Cytomegalovirus (CMV) reactivation, very few data are available. We reviewed the literature reporting cases of CMV infection in IMID patients during biological therapy. Although the risk of CMV reactivation cannot be excluded, we concluded that there is no evidence to warrant CMV screening before starting a biological agent.

Peptide Vaccination Against Cytomegalovirus (CMV) Elicits Immunological and Clinical Responses after Allogeneic Stem Cell Transplantation Even from a CMV Seronegative Donor

Introduction: Patients receiving an allogeneic stem cell graft from a cytomegalovirus (CMV) seronegative donor are prone to CMV reactivation with high risk of disease and mortality. Therefore we initiated a clinical phase I trial with a novel vaccine designed by our group: a CMV phosphoprotein 65 (CMVpp65)-derived peptide in water-in-oil emulsion (Montanide™) plus administration of granulocyte-macrophage colony stimulating factor.Material and Methods: 10 patients after allogeneic stem cell transplantation received four vaccines s.c. at a biweekly interval. Patients were monitored for clinical course and CMVpp65 antigenemia. CMV-specific CD8+ and gamma/delta T cells were analyzed by multi-color flow cytometry. Neutralizing anti-CMV antibody assays were established and correlated to clinical parameters.Results: Peptide vaccination was well tolerated, no drug-related serious adverse events were detected. 7 of 9 patients with CMVpp65 antigenemia cleared the CMV with enduring response > 1.5 years after 4 vaccinations and are still free from antigenemia until present. 2 patients with CMV reactivation showed persisting CMV antigenemia. One patient received prophylactic vaccination and did not develop antigenemia. An up to 6-fold increase in frequency of both CMV-specific CD8+ T cells or Vdelta2- gamma/delta T cells with a maximum of 1.32% CMV-specific CD8+ T cells ex vivo without priming and 13.7% Vdelta2- gamma/delta T cells of all CD8+ T cells was detected in five patients. Also titers of neutralizing antibodies increased in four patients up to 10-fold over the time of vaccination. Humoral and cellular immune responses correlated with clearance of the CMV load.Conclusion: Administration of CMVpp65 peptide vaccination for patients after allogeneic stem cell transplantation at high risk for CMV reactivation was safe, well tolerated and clinically encouraging. A study in solid-organ transplant patients is ongoing. DisclosuresKuball:Gadeta B.V.: Membership on an entity's Board of Directors or advisory committees. Wuchter:Sanofi-Aventis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Hexal: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Dreger:Gilead: Consultancy; Janssen: Consultancy; Novartis: Consultancy; Gilead: Speakers Bureau; Novartis: Speakers Bureau; Roche: Consultancy. Greiner:BMS: Research Funding.

The Knife's Edge of Tolerance: Inducing Stable Multilineage Mixed Chimerism but With a Significant Risk of CMV Reactivation and Disease in Rhesus Macaques.

Although stable mixed-hematopoietic chimerism induces robust immune tolerance to solid organ allografts in mice, the translation of this strategy to large animal models and to patients has been challenging. We have previously shown that in MHC-matched nonhuman primates (NHPs), a busulfan plus combined belatacept and anti-CD154-based regimen could induce long-lived myeloid chimerism, but without T cell chimerism. In that setting, donor chimerism was eventually rejected, and tolerance to skin allografts was not achieved. Here, we describe an adaptation of this strategy, with the addition of low-dose total body irradiation to our conditioning regimen. This strategy has successfully induced multilineage hematopoietic chimerism in MHC-matched transplants that was stable for as long as 24 months posttransplant, the entire length of analysis. High-level T cell chimerism was achieved and associated with significant donor-specific prolongation of skin graft acceptance. However, we also observed significant infectious toxicities, prominently including cytomegalovirus (CMV) reactivation and end-organ disease in the setting of functional defects in anti-CMV T cell immunity. These results underscore the significant benefits that multilineage chimerism-induction approaches may represent to transplant patients as well as the inherent risks, and they emphasize the precision with which a clinically successful regimen will need to be formulated and then validated in NHP models.