A revised (earliest Vallesian) age for the hominoid-bearing locality of Can Mata 1 based on new magnetostratigraphic and biostratigraphic data from Abocador de Can Mata (Vallès-Penedès Basin, NE Iberian Peninsula).

The Abocador de Can Mata (ACM) composite stratigraphic sequence (els Hostalets de Pierola, Vallès-Penedès Basin, NE Iberian Peninsula) has yielded a diverse primate assemblage from the late Aragonian (Middle to Late Miocene). Detailed litho-, bio-, and magnetostratigraphic control has enabled an accurate dating of these fossil remains. Comparable data, however, were lacking for the nearby locality of Can Mata 1 (CM1), which yielded a dryopithecine canine of a female individual. Given the lack of hipparionin equids and giraffids, CM1 has been correlated to the latest Aragonian (Mammal Neogene [MN] zone MN7+8). Here we revise the age of CM1 based on fieldwork and associated paleomagnetic samplings undertaken in 2018-2021. Our results extend the ACM composite sequence upward and indicate that CM1 correlates to the earliest Vallesian (MN9). The updated ACM sequence has a thickness of ∼300 m and comprises 12 magnetozones correlated to subchrons C5Ar.1r to C5n.2n (∼12.6-11.1 Ma; latest MN6 to earliest MN9, late Aragonian to earliest Vallesian). CM1 is correlated to C5r.1r (11.146-11.056 Ma), with an interpolated age of 11.11 Ma, thus postdating the dispersal of hipparionin horses into the Vallès-Penedès Basin-which is correlated to the previous subchron C5r.1n, with an interpolated age of 11.18 Ma, and by definition marks the beginning of the Vallesian. CM1 also minimally postdates the earliest record of giraffids at ACM-representing their earliest well-dated occurrence in the basin-being correlated to C5r.1n with an interpolated age of 11.11 Ma. We conclude that CM1 has an earliest Vallesian (MN9) age of ∼11.1 Ma, intermediate between the Aragonian dryopithecins and the Vallesian hispanopithecins. Ongoing paleontological surveillance at ACM thus offers the prospect to yield additional earliest Vallesian ape remains, which are essential to clarify their taxonomic allocation as well as to confirm whether hispanopithecins evolved locally from dryopithecins rather than immigrating from elsewhere during MN9.

Inhibition of LpxC Increases the Activity of Iron Chelators and Gallium Nitrate in Multidrug-Resistant Acinetobacter baumannii.

Infections caused by multidrug-resistant Acinetobacter baumannii would benefit from the development of novel treatment approaches. Compounds that interfere with bacterial iron metabolism, such as iron chelators and gallium nitrate, have previously been shown to have antimicrobial activity against A. baumannii. In this study, we characterize the effect of LpxC inhibitors on the antimicrobial activity of previously characterized iron chelators, 2,2'-bipyridyl (BIP) and deferiprone (DFP), and gallium nitrate (Ga(NO3)3) against A. baumannii reference strains and multidrug-resistant clinical isolates. The LpxC inhibitor LpxC-2 was synergistic with BIP for 30% of strains tested (FICI values: 0.38-1.02), whereas inhibition with LpxC-4 was synergistic with BIP for 60% of strains tested (FICI values: 0.09-0.75). In time-kill assays, combinations of BIP with both LpxC inhibitors demonstrated synergistic activity, with a more than 3 log10 reduction in bacterial counts compared to BIP alone. LpxC-2 was synergistic with Ga(NO3)3 for 50% of strains tested (FICI values: 0.27-1.0), whereas LpxC-4 was synergistic with Ga(NO3)3 for all strains tested (FICI values: 0.08-≤0.50). In time-kill assays, combinations of Ga(NO3)3 with LpxC-2 and LpxC-4 decreased the growth of both strains compared to each compound separately; however, only the combination with LpxC-4 met the defined criteria for synergy. These results identify a novel synergy between two antimicrobial classes against A. baumannii strains.

Recent Advances in Iron Chelation and Gallium-Based Therapies for Antibiotic Resistant Bacterial Infections.

Iron is essential for multiple bacterial processes and is thus required for host colonization and infection. The antimicrobial activity of multiple iron chelators and gallium-based therapies against different bacterial species has been characterized in preclinical studies. In this review, we provide a synthesis of studies characterizing the antimicrobial activity of the major classes of iron chelators (hydroxamates, aminocarboxylates and hydroxypyridinones) and gallium compounds. Special emphasis is placed on recent in-vitro and in-vivo studies with the novel iron chelator DIBI. Limitations associated with iron chelation and gallium-based therapies are presented, with emphasis on limitations of preclinical models, lack of understanding regarding mechanisms of action, and potential host toxicity. Collectively, these studies demonstrate potential for iron chelators and gallium to be used as antimicrobial agents, particularly in combination with existing antibiotics. Additional studies are needed in order to characterize the activity of these compounds under physiologic conditions and address potential limitations associated with their clinical use as antimicrobial agents.

Field performance of the Abbott RealTime MTB assay for the diagnosis of extrapulmonary tuberculosis in a low-prevalence setting / Neumonía en niños: el papel de las pruebas de diagnóstico rápido de virus en la administración de antimicrobianos

INTRODUCTION: The sensitivities of conventional mycobacterial culture in solid or liquid media and acid-fast bacilli (AFB) smear microscopy for Mycobacterium tuberculosis complex (MTBC) detection in extrapulmonary specimens are suboptimal. We evaluated the field performance of the Abbott RealTime MTB assay for the diagnosis of extrapulmonary tuberculosis in a low-prevalence setting. METHODS: The total number of extrapulmonary specimens with mycobacterial culture and PCR results was 566: sterile fluids (n = 278), non-sterile fluids (n = 147), lymph node material (n = 69) tissue biopsies (n = 63), and abscess aspirates (n = 9). A composite standard consisting of mycobacterial culture results, clinical treatment response to anti-TB drugs, when administered, and histopathology, radiological and laboratory findings were used as a reference for sensitivity and specificity calculations. RESULTS: Mycobacterial cultures and PCR were positive in 17 and 28 specimens, respectively. The overall agreement between culture and PCR was moderate (Cohen's kappa coefficient: 0.549; P = 0.0001). Taking as a reference our composite standard, the sensitivity of the Abbott PCR assay was 77.7%, the specificity 99.5%, the PPV 95.4%, and the NPV 98.8%. In turn, the sensitivity of the mycobacterial culture was 62.9%, the specificity and PPV 100%, and the NPV 97.9%. CONCLUSIÓN: The good field performance of the Abbott RealTime MTB assay makes it valuable for the diagnosis of extrapulmonary tuberculosis in a low-prevalence setting. The use of molecular methods along with culture improves the diagnosis of extrapulmonary tuberculosis

INTRODUCCIÓN: La sensibilidad del cultivo convencional de micobacterias en medios sólidos o líquidos y la de la microscopía de bacilos ácido-alcohol resistentes para detectar el complejo Mycobacterium tuberculosis en muestras extrapulmonares es subóptima. Evaluamos el rendimiento del ensayo Abbott RealTime MTB para el diagnóstico de la tuberculosis extrapulmonar en un entorno de baja prevalencia. MÉTODOS: El número total de muestras extrapulmonares con cultivo de micobacterias y resultados de la reacción en cadena de la polimerasa fue de 566: líquidos estériles (n = 278), líquidos no estériles (n = 147), material de los ganglios linfáticos (n = 69), biopsias de tejido (n = 63) y aspiraciones de abscesos (n = 9). Para calcular la sensibilidad y la especificidad del ensayo se utilizó como referencia un parámetro que incluyó: resultados del cultivo, respuesta clínica al tratamiento con antituberculosos y hallazgos de laboratorio, radiológicos e histopatológicos. RESULTADOS: Los cultivos de micobacterias y la PCR fueron positivos en 17 y 28 muestras, respectivamente. La concordancia de los resultados obtenidos por ambos métodos fue moderada (coeficiente kappa de Cohen: 0,549; p = 0,0001). La sensibilidad de la PCR de Abbott fue del 77,7%, especificidad del 99,5 %, valor predictivo positivo del 95,4% y valor predictivo negativo del 98,8%. La sensibilidad del cultivo fue del 62,9%, la especificidad y el valor predictivo positivo del 100% y el valor predictivo negativo del 97,9%. CONCLUSIÓN: El buen rendimiento del ensayo Abbott RealTime MTB lo hace valioso para el diagnóstico de la tuberculosis extrapulmonar en un entorno de baja prevalencia. El uso de métodos moleculares junto al cultivo mejora el diagnóstico de la tuberculosis extrapulmonar

Field performance of the Abbott RealTime MTB assay for the diagnosis of extrapulmonary tuberculosis in a low-prevalence setting.

INTRODUCTION: The sensitivities of conventional mycobacterial culture in solid or liquid media and acid-fast bacilli (AFB) smear microscopy for Mycobacterium tuberculosis complex (MTBC) detection in extrapulmonary specimens are suboptimal. We evaluated the field performance of the Abbott RealTime MTB assay for the diagnosis of extrapulmonary tuberculosis in a low-prevalence setting. METHODS: The total number of extrapulmonary specimens with mycobacterial culture and PCR results was 566: sterile fluids (n=278), non-sterile fluids (n=147), lymph node material (n=69) tissue biopsies (n=63), and abscess aspirates (n=9). A composite standard consisting of mycobacterial culture results, clinical treatment response to anti-TB drugs, when administered, and histopathology, radiological and laboratory findings were used as a reference for sensitivity and specificity calculations. RESULTS: Mycobacterial cultures and PCR were positive in 17 and 28 specimens, respectively. The overall agreement between culture and PCR was moderate (Cohen's kappa coefficient: 0.549; P=0.0001). Taking as a reference our composite standard, the sensitivity of the Abbott PCR assay was 77.7%, the specificity 99.5%, the PPV 95.4%, and the NPV 98.8%. In turn, the sensitivity of the mycobacterial culture was 62.9%, the specificity and PPV 100%, and the NPV 97.9%. CONCLUSION: The good field performance of the Abbott RealTime MTB assay makes it valuable for the diagnosis of extrapulmonary tuberculosis in a low-prevalence setting. The use of molecular methods along with culture improves the diagnosis of extrapulmonary tuberculosis.

Kinetics of inflammatory biomarkers in plasma predict the occurrence and features of cytomegalovirus DNAemia episodes in allogeneic hematopoietic stem cell transplant recipients.

Cytomegalovirus (CMV) DNAemia occurs frequently in CMV-seropositive allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients, and usually results from reactivation of latent infection established in the recipient. Predicting the occurrence of CMV DNAemia may be helpful in managing CMV infection in allo-HSCT recipients. Here, the kinetics of several inflammatory biomarkers in plasma were characterized and assessed for their potential value in anticipating the development and features of active CMV infection in allo-HSCT recipients, as documented using real-time PCR assays. The cohort consisted of 46 non-consecutive adult patients who underwent T-cell replete allo-HSCT at our center. Plasma levels of C-reactive protein (CRP), soluble tumor necrosis factor receptor type 2 (sTNF-R2), transforming growth factor-ß1 (TGF-ß1), and interferon-inducible protein 10 (IP-10/CXCL10) were measured in consecutive specimens obtained from conditioning either by nephelometry (CRP) or by specific immunoassays (the rest). Of the 46 patients, 22 had a first episode of CMV DNAemia at a median of 34 days after allo-HSCT (range, day 19-day 50). We found that both the TGF-ß1 area under a curve (AUC) and peak levels were significantly lower in patients who subsequently developed CMV DNAemia than in patients with no CMV DNAemia. Interestingly, CRP but not TGF-ß1 AUC and peak levels predicted the occurrence of CMV DNAemia episodes requiring preemptive antiviral therapy. The data presented herein suggest that kinetics of inflammatory biomarkers in plasma might be useful to anticipate post-engraftment CMV DNAemia episodes and predict the need for preemptive antiviral therapy in allo-HSCT recipients.

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.

Clinical Effectiveness of Influenza Vaccination After Allogeneic Hematopoietic Stem Cell Transplantation: A Cross-sectional, Prospective, Observational Study.

BACKGROUND: Vaccination is the primary method for preventing influenza respiratory virus infection (RVI). Although the influenza vaccine is able to achieve serological responses in some allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients, its clinical benefits are still uncertain. METHODS: In this prospective, cross-sectional study, we retrospectively analyzed the effect of inactivated trivalent influenza vaccination on the prevalence of influenza RVI in a consecutive cohort of 136 allo-HSCT adult recipients who developed 161 RVI over 5 flu seasons (from 2013 to 2018). Respiratory viruses in upper- and/or lower-respiratory tract specimens were tested using multiplex polymerase chain reaction panel assays. RESULTS: Overall, we diagnosed 74 episodes (46%) of influenza RVI in 70 allo-HSCT recipients. Influenza RVI occurred in 51% of the non-vaccinated compared to 36% of the vaccinated recipients (P = .036). A multivariate analysis showed that influenza vaccination was associated with a lower prevalence of influenza RVI (odds ratio [OR] 0.39, P = .01). A multivariate risk factor analysis of lower-respiratory tract disease (LRTD) identified 2 conditions associated with the probability of influenza RVI progression: influenza vaccination (OR 0.12, 95% confidence interval [CI] 0.014-1, P = .05) and a high-risk immunodeficiency score (OR 36, 95% CI 2.26-575, P = .011). Influenza vaccination was also associated with a lower likelihood of an influenza-related hospital admission (14% vs 2%, P = .04). CONCLUSIONS: This study shows that influenza vaccination may have a clinical benefit in allo-HSCT recipients with virologically-confirmed RVI, in terms of a lower influenza RVI prevalence, slower LRTD progression, and lower likelihood of hospital admission.

Factors influencing cytomegalovirus DNA load measurements in whole blood and plasma specimens from allogeneic hematopoietic stem cell transplant recipients.

We assessed the impact of several parameters, including the nature of the episode of Cytomegalovirus (CMV) DNAemia, the use of preemptive antiviral therapy, and the blood cell content in CMV DNA loads measured in whole blood (WB) and plasma (PL). CMV DNA load was quantified in 245 paired specimens collected within 43 postengraftment episodes of CMV DNAemia by using the CMV RealTime CMV PCR (Abbott Molecular). Concordant categorical results were obtained for 78.4% of paired specimens (Kappa index, 0.385; P = <0.001). Overall, CMV DNA loads in PL were higher than those in WB (mean bias, +0.115 log IU/mL) in both initial and recurrent episodes; this was so in post-antiviral treatment but not in pretreatment paired specimens. Median CMV DNA doubling time values in both compartments were not significantly different. Leukocyte counts had a significant impact on the comparability of CMV DNA loads measured in both matrices.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) proteomic profiling of cerebrospinal fluid in the diagnosis of enteroviral meningitis: a proof-of-principle study.

The use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for diagnosing viral infections by directly testing clinical specimens has not previously been explored. In this proof-of-principle study, we tested the hypothesis that proteomic profiling of cerebrospinal fluid (CSF) by mass spectrometry may be useful in the diagnosis of enteroviral (EV) meningitis. A total of 114 cryopreserved CSF samples were analyzed, of which 47 were positive for EV and 67 were negative. Total CSF proteins were precipitated and subjected to MALDI-TOF-MS analysis in a low (2-20 kDa) molecular weight range using a MicroFlex LT mass spectrometer. The whole data set was randomly split into a training set (n = 76 specimens) and a validation set (n = 38 samples). Backward/forward stepwise logistic regression analyses identified 30 peaks that were differentially present in EV-positive and EV-negative specimens. These were used to build a model which displayed an overall classification accuracy of 93%. The discriminative ability of the model was confirmed by using a validation sample set (overall accuracy 83%). In fact, the model was able to correctly classify 61 out of 67 EV-negative samples and 42 out of 47 EV-positive specimens. EV meningitis is associated with a distinctive protein profile that may be directly detectable in CSF specimens by MALDI-TOF-MS.

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.

Validation of a plasma metabolomics model that allows anticipation of the occurrence of cytomegalovirus DNAaemia in allogeneic stem cell transplant recipients.

A plasma metabolomic model obtained by means of untargeted 1H nuclear magnetic resonance, to which taurine, choline, methylamine, total glutathione, trimethylamine N-oxide, lactate, lysine, isoleucine, total fatty acids and unsaturated fatty acids contributed, was validated for the prediction of first episodes of cytomegalovirus (CMV) DNAaemia in a cohort of 79 allogeneic stem haematopoietic stem cell transplant (allo-HSCT) recipients. The predictive success rate was nearly 65 % for patients at both low and high risk of CMV-related complications according to their baseline characteristics. Plasma metabolomics profiling shortly after engraftment (day 21 after transplantation) allowed the anticipation of the occurrence of CMV DNAaemia in 71 % of patients. Plasma metabolomics analyses may be ancillary for identifying allo-HSCT patients at the highest risk of CMV DNAaemia who may benefit from early targeted antiviral prophylaxis.

Monitoring of oral cytomegalovirus DNA shedding for the prediction of viral DNAemia in allogeneic hematopoietic stem cell transplant recipients.

Preemptive antiviral therapy based on detecting cytomegalovirus (CMV) DNAemia above a preestablished threshold is the mainstay strategy for the prevention of CMV disease in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients; nevertheless, CMV DNAemia, even at low levels, may increase mortality. We investigated whether surveillance of saliva for the presence of CMV DNA may anticipate the occurrence of CMV DNAemia. This was a prospective observational study with 53 consecutively enrolled allo-HSCT recipients. Saliva and plasma specimens were collected on a weekly basis from Day 0 to Day 100 after transplantation. CMV DNA was quantified in both specimen types using the Abbott Real-Time PCR assay (Abbott Molecular, Des Plaines, IL). CMV DNA was quantifiable in 44 (83%) patients: either in saliva (n = 1) or plasma (n = 12) only, or in both specimen types (n = 31). CMV oral shedding preceded the occurrence of CMV DNAemia in eight patients (18.2%), while the opposite pattern was observed in 21 patients (47.7%). The CMV DNA loads quantified in saliva and plasma correlated modestly (P = 0.33; P = 0.013) and did not differ in magnitude (P = 0.527). No transplantation factors, other than recipient CMV seropositivity, were associated with oral CMV DNA shedding; serum CMV IgG levels were comparable, regardless of the timing of the detection of CMV DNA at both sites. In summary, screening of saliva specimens for the presence of CMV DNA appear to be of limited value for anticipating the occurrence of CMV DNAemia in allo-HSCT recipients.

Performance of a Highly Sensitive Mycobacterium tuberculosis Complex Real-Time PCR Assay for Diagnosis of Pulmonary Tuberculosis in a Low-Prevalence Setting: a Prospective Intervention Study.

The potential impact of routine real-time PCR testing of respiratory specimens from patients with presumptive tuberculosis in terms of diagnostic accuracy and time to tuberculosis treatment inception in low-prevalence settings remains largely unexplored. We conducted a prospective intervention cohort study. Respiratory specimens from 1,020 patients were examined by acid-fast bacillus smear microscopy, tested by a real-time Mycobacterium tuberculosis complex PCR assay (Abbott RealTime MTB PCR), and cultured in mycobacterial media. Seventeen patients tested positive by PCR (5 were acid-fast bacillus smear positive and 12 acid-fast bacillus smear negative), and Mycobacterium tuberculosis was recovered from cultures for 12 of them. Patients testing positive by PCR and negative by culture (n = 5) were treated and deemed to have responded to antituberculosis therapy. There were no PCR-negative/culture-positive cases, and none of the patients testing positive for nontuberculous mycobacteria (n = 20) yielded a positive PCR result. The data indicated that routine testing of respiratory specimens from patients with presumptive tuberculosis by the RealTime MTB PCR assay improves the tuberculosis diagnostic yield and may reduce the time to antituberculosis treatment initiation. On the basis of our data, we propose a novel mycobacterial laboratory algorithm for tuberculosis diagnosis.

Epstein-Barr virus DNA load kinetics analysis in allogeneic hematopoietic stem cell transplant recipients: Is it of any clinical usefulness?

BACKGROUND: There is a lack of clinical information regarding the usefulness of plasma Epstein-Barr virus (EBV) DNA load kinetics analyses in the management of EBV infections in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Namely, it remains unknown whether this type of analysis can help physicians to anticipate the development of high-level EBV DNAemia episodes requiring rituximab treatment or predict the risk of recurrent EBV DNAemia or post-transplant lymphoproliferative disorders (PTLDs). STUDY DESIGN: Unicentric, retrospective, observational study including 142 consecutive patients undergoing T-cell replete allo-HSCT. The plasma EBV DNA load was monitored on a weekly basis using the artus® EBV PCR kit. RESULTS: Fifty-five of the 142 patients (38.7%) developed at least one episode of EBV DNAemia; 13 of the 55 initial EBV DNAemia episodes (23.6%) were preemptively treated with rituximab, 7 patients had a recurrent episode of EBV DNAemia, and biopsy-proven PTLDs were diagnosed in 4 patients. The initial plasma EBV DNA load was not significantly different (P=0.269) in episodes of self-resolving EBV DNAemia, those requiring rituximab treatment, or those leading to PTLDs. The plasma EBV DNA load doubling times were similar across all the groups (P=0.799), and the EBV DNA-load half-life was not associated with the occurrence of recurrent EBV DNAemia (P=0.550). CONCLUSION: Plasma EBV DNA-load kinetics analyses are unlikely to be useful in predicting the occurrence of high-level EBV DNAemia, PTLD, or recurrent EBV DNAemia.

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.

Assessing the risk of cytomegalovirus DNAaemia in allogeneic stem cell transplant recipients by monitoring oxidative-stress markers in plasma.

The level of antioxidants, such as thiol-containing tripeptide glutathione (GSH), in cytomegalovirus (CMV)-infected cells is notably increased. We previously showed that GSH levels in plasma, as measured by untargeted 1H nuclear magnetic resonance, are higher in allogeneic stem cell transplant (allo-SCT) recipients who subsequently develop CMV viraemia. We hypothesized that the net level of oxidative-stress markers present in plasma may be reduced in patients who develop CMV DNAaemia compared to those who do not. We serially monitored the levels of malondialdehyde (MDA) and carbonylated proteins (CPs) early after allo-SCT and assessed whether they could predict the occurrence of CMV DNAaemia. MDA levels were measured in 43 patients (28 had CMV DNAaemia) and CPs were quantified in 53 patients (38 patients developed CMV DNAaemia). The area under the curve (AUC) value for MDA, but not for CPs, was significantly lower in patients who subsequently developed CMV DNAaemia compared to those who remained DNAaemia-free (P=0.043). A trend toward lower MDA AUC values was observed in episodes of CMV DNAaemia with faster CMV replicative kinetics and in those who reached higher peak CMV DNA levels. Moreover, receiver operating characteristic curve analyses indicated that the MDA biomarker had the predictive ability to discriminate between patients with or without subsequent CMV DNAaemia (AUC=0.69, 95 % confidence interval 0.51-0.85, P=0.05). In summary, serial quantitation of MDA may be useful for individualizing antiviral prophylaxis therapies (targeted prophylaxis) in the upcoming era of new antiviral drugs with improved safety profiles.

Impact of cytomegalovirus DNAemia on overall and non-relapse mortality in allogeneic stem cell transplant recipients.

BACKGROUND: We conducted a retrospective single-center study to investigate the potential impact of cytomegalovirus (CMV) DNAemia on mortality in allogeneic stem cell transplant (allo-SCT) recipients. METHODS: A total of 151 consecutive patients who underwent T-cell replete allo-SCT were included in the study. Patients with CMV DNAemia were treated preemptively with antivirals upon detection of plasma CMV DNA loads >1500 IU/mL. RESULTS: At least one episode of CMV DNAemia occurred in 109 (72.2%) patients, and 67 of these patients (61.5%) required one or more courses of antiviral therapy. The cumulative incidence of 1-year overall and non-relapse mortality (NRM) was 28.5% (95% confidence interval [CI], 18.4%-39.5%) and 23.2% (95% CI 12.81%-35.4%), respectively. The occurrence of either CMV DNAemia or CMV recurrences had no apparent effect on 1-year overall mortality and NRM; nevertheless, a trend towards an increased risk of death was seen in patients with one or more episodes of CMV DNAemia requiring antiviral therapy (hazard ratio [HR], 2.10; 95% CI, 0.96-4.61; P=.06 for overall mortality, and HR, 2.36; 95% CI, 0.96-5.76; P=.06 for NRM) but not in those displaying one or more self-resolving episodes. CONCLUSION: Therefore, the data suggest that withholding preemptive antiviral therapy until the plasma CMV DNA load reaches 1500 IU/mL has no apparent detrimental effect on patient survival.

Comparison of the artus Epstein-Barr virus (EBV) PCR kit and the Abbott RealTime EBV assay for measuring plasma EBV DNA loads in allogeneic stem cell transplant recipients.

The ability of the artus Epstein-Barr virus (EBV) PCR kit and the Abbott RealTime EBV PCR assay to detect and quantify plasma EBV DNAemia was compared. The agreement between these assays was 95.8%. The EBV DNA loads measured by the two assays significantly correlated (P=< 0.0001).