Effect of cytomegalovirus (CMV) serostatus on the incidence and virological features of active CMV infection in allogeneic stem cell transplant recipients.

Surveillance for adenovirus DNAemia early after transplantation in adult recipients of unrelated-donor allogeneic stem cell transplants in the absence of clinically suspected infection

Surveillance for adenovirus DNAemia early after transplantation in adult recipients of unrelated-donor allogeneic stem cell transplants in the absence of clinically suspected infection

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 …

Reconstitution of CMV pp65 and IE-1-specific IFN-γ CD8+ and CD4+ T-cell responses affording protection from CMV DNAemia following allogeneic hematopoietic SCT

Threshold levels of CMV-specific T-cell populations presumably affording protection from active CMV infection in allo-SCT recipients have been proposed, but lack extensive validation. We quantified CMV pp65 and immediate-early 1-specific IFN-γ CD8(+) and CD4(+) T cell responses at days +30, +60 and +90 after transplantation in 133 patients, and established cutoff cell levels protecting from CMV DNAemia within the first 120 days after transplantation. No patients showing IFN-γ CD8(+) or IFN-γ CD4(+) T-cell counts1.0 and1.2 cells/μL, respectively, developed a subsequent episode of CMV DNAemia. Initial or recurrent episodes of CMV DNAemia occurred in the face of IFN-γ T-cell levels below defin…

Kinetics of cytomegalovirus (CMV) pp65 and IE-1-specific IFNgamma CD8+ and CD4+ T cells during episodes of viral DNAemia in allogeneic stem cell transplant recipients: potential implications for the management of active CMV infection.

The dynamics of CMV pp65 and IE-1-specific IFNgamma-producing CD8(+) (IFNgamma CD8(+)) and CD4(+) (IFNgamma CD4(+)) T cells and CMV DNAemia were assessed in 19 pre-emptively treated episodes of active CMV infection. Peripheral counts of IFNgamma CD8(+) and IFNgamma CD4(+) T cells inversely correlated with CMV DNAemia levels (P = <0.001 and P = 0.003, respectively). A threshold value of 1.3 cells/microl predicting CMV DNAemia clearance was established for IFNgamma CD8(+) T cells (PPV, 100%; NPV, 93%) and for IFNgamma CD4(+) T cells (PPV, 100%; NPV, 75%). Undetectable T-cell responses were usually observed at the time of initiation of pre-emptive therapy. Either a rapid (within 7 days) or a d…

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+ NK…

Lack of prompt expansion of cytomegalovirus pp65 and IE-1-specific IFNγ CD8+ and CD4+ T cells is associated with rising levels of pp65 antigenemia and DNAemia during pre-emptive therapy in allogeneic hematopoietic stem cell transplant recipients

Rising levels of cytomegalovirus (CMV) DNAemia and/or pp65 antigenemia have been observed during pre-emptive ganciclovir therapy in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-SCT). We assessed the incidence of this event in our series, and investigated whether its occurrence was associated with an impairment in the CMV-specific T-cell response. A total of 36 allo-SCT recipients experienced one or more episodes of active CMV infection (n=68) that were pre-emptively treated with val(ganciclovir). Rising levels of antigenemia and DNAemia, and an isolated increase in antigenemia, were observed in 39.7 and 2.9% of all episodes, respectively. Receipt of corticost…

A polymorphism in the TYMP gene is associated with the outcome of HLA-identical sibling allogeneic stem cell transplantation.

Thymidine phosphorylase (TYMP), an enzyme involved in nucleotide synthesis, has been implicated in critical biological processes such as DNA replication, protection against mutations, and tissue repair. In this work, we retrospectively evaluated the influence of a polymorphism in the TYMP gene (rs112723255; G/A) upon the outcome of 448 patients subjected to allogeneic stem cell transplantation (allo-SCT) from an human leukocyte antigen (HLA)-identical sibling donor. The TYMP genotype of patients correlated with overall survival—carriers of the minor allele (A) being at an increased risk of dying after transplantation (hazard ratio, HR = 1.9; P = 0.004). This effect was mostly due to differe…

Enumeration of NKG2C+natural killer cells early following allogeneic stem cell transplant recipients does not allow prediction of the occurrence of cytomegalovirus DNAemia

The role of Natural killer (NK) cells in the control of cytomegalovirus (CMV) infection in allogeneic stem cell transplant recipients has not been precisely characterized. The current study is aimed at investigating the potential role of NK cells expressing the activating receptor NKG2C in affording protection against the development of CMV DNAemia in patients exhibiting detectable CMV-specific CD8+ T-cell responses early following transplantation. A total of 61 nonconsecutive patients were included in the study. Peripheral levels of CD56brightCD16−/low and CD56dimCD16+ NKG2C+ NK cells and CMV pp65/IE-1-specific IFN-γ-producing CD8+ T-cells were enumerated by flow cytometry at days +30 and …

An Assessment of the Effect of Human Herpesvirus-6 Replication on Active Cytomegalovirus Infection after Allogeneic Stem Cell Transplantation

Human herpesvirus-6 (HHV-6) may enhance cytomegalovirus (CMV) replication in allogeneic stem cell transplant (allo-SCT) recipients either through direct or indirect mechanisms. Definitive evidence supporting this hypothesis are lacking. We investigated the effect of HHV-6 replication on active CMV infection in 68 allo-SCT recipients. Analysis of plasma HHV-6 and CMV DNAemia was performed by real-time PCR. Enumeration of pp65 and IE-1 CMV-specific IFNgamma CD8(+) and CD4(+)T cells was performed by intracellular cytokine staining. HHV-6 DNAemia occurred in 39.8% of patients, and was significantly associated with subsequent CMV DNAemia in univariate (P=.01), but not in multivariate analysis (P…

Functional profile of cytomegalovirus (CMV)-specific CD8+ T cells and kinetics of NKG2C+ NK Cells associated with the resolution of CMV DNAemia in allogeneic stem cell transplant recipients

Immune mechanisms involved in control of cytomegalovirus (CMV) infection in the allogeneic stem cell transplantation setting have not been fully disclosed. CMV pp65 and IE-1-specific CD8(+) T cells expressing IFN-γ, TNF-α, and CD107a, alone or in combination, and NKG2C(+) NK cells were prospectively enumerated during 13 episodes of CMV DNAemia. The expansion of monofunctional and polyfunctional CD8(+) T cells was associated with CMV DNAemia clearance. The size and functional diversity of the expanding CD8(+) T-cell population was greater in self-resolved episodes than in episodes treated with antivirals. These differences were related to the magnitude of expansion of cognate antigen IFN-γ C…

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 …