1,3-β-d-Glucan Antigenemia for Early Diagnosis of Invasive Fungal Infections in Neutropenic Patients with Acute Leukemia

Background. Invasive fungal infections (IFIs) are life-threatening complications in neutropenic patients with hematological malignancies. Because early diagnosis of IFI is difficult, new noninvasive, culture-independent diagnostic tools are needed to improve clinical management. Recent studies have reported that detection of 1,3-β-d-glucan (BG) antigenemia may be useful for diagnosis of IFI. The aim of the present prospective study was to evaluate the usefulness of monitoring BG in patients undergoing chemotherapy for acute leukemia. Methods. BG antigenemia was measured by a colorimetric assay twice weekly in the absence of fever and daily in the presence of fever. IFIs were classified according to the criteria of the European Organization for Research and Treatment of Cancer/Mycoses Study Group. Results. During 190 consecutive neutropenic episodes (median duration, 22 days; range, 7-113 days) in 95 patients, 30 proven or probable IFIs (13 aspergillosis, 15 candidiasis, and 2 mixed IFIs) were diagnosed. Sensitivity, specificity, positive predictive value, negative predictive value, and efficiency of 2 consecutive BG values ⩾7 pg/mL for diagnosis of proven or probable IFI was 0.63 (95% confidence interval, 0.44-0.79), 0.96 (95% confidence interval, 0.89-0.98), 0.79 (95% confidence interval, 0.57-0.92), 0.91 (95% confidence interval, 0.84-0.95), and 0.89, respectively. The time interval between onset of fever as first sign of IFI and BG antigenemia was significantly shorter than the time to diagnosis of IFI by clinical, microbiological, radiological, and/or histopathological criteria (P50 pg/mL were observed in only 2 patients, both of whom experienced failure of antifungal therapy. Conclusion. Monitoring of BG antigenemia is a useful noninvasive method for early diagnosis of IFI in patients with acute leukemi

Association between High Levels of Blood Macrophage Migration Inhibitory Factor, Inappropriate Adrenal Response, and Early Death in Patients with Severe Sepsis

Background.Identification of new therapeutic targets remains an imperative goal to improve the morbidity and mortality associated with severe sepsis and septic shock. Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine and counterregulator of glucocorticoids, has recently emerged as a critical mediator of innate immunity and experimental sepsis, and it is an attractive new target for the treatment of sepsis. Methods.Circulating concentrations of MIF were measured in 2 clinical trial cohorts of 145 pediatric and adult patients who had severe sepsis or septic shock caused predominantly by infection with Neisseria meningitidis or other gram-negative bacteria, to study the kinetics of MIF during sepsis, to analyze the interplay between MIF and other mediators of sepsis or stress hormones (adrenocorticotropic hormone and cortisol), and to determine whether MIF is associated with patient outcome. Results.Circulating concentrations of MIF were markedly elevated in 96% of children and adults who had severe sepsis or septic shock, and they remained elevated for several days. MIF levels were correlated with sepsis severity scores, presence of shock, disseminated intravascular coagulation, urine output, blood pH, and lactate and cytokine levels. High levels of MIF were associated with a rapidly fatal outcome. Moreover, in meningococcal sepsis, concentrations of MIF were positively correlated with adrenocorticotropic hormone levels and negatively correlated with cortisol levels and the cortisol : adrenocorticotropic hormone ratio, suggesting an inappropriate adrenal response to sepsis. Conclusions.MIF is markedly and persistently up-regulated in children and adults with gram-negative sepsis and is associated with parameters of disease severity, with dysregulated pituitary-adrenal function in meningococcal sepsis, and with early deat

Monitoring Procalcitonin in Febrile Neutropenia: What Is Its Utility for Initial Diagnosis of Infection and Reassessment in Persistent Fever?

Background: Management of febrile neutropenic episodes (FE) is challenged by lacking microbiological and clinical documentation of infection. We aimed at evaluating the utility of monitoring blood procalcitonin (PCT) in FE for initial diagnosis of infection and reassessment in persistent fever.Methods: PCT kinetics was prospectively monitored in 194 consecutive FE (1771 blood samples): 65 microbiologically documented infections (MDI, 33.5%; 49 due to non-coagulase-negative staphylococci, non-CNS), 68 clinically documented infections (CDI, 35%; 39 deep-seated), and 61 fever of unexplained origin (FUO, 31.5%).Results: At fever onset median PCT was 190 pg/mL (range 30-26'800), without significant difference among MDI, CDI and FUO. PCT peak occurred on day 2 after onset of fever: non-CNS-MDI/deep-seated-CDI (656, 80-86350) vs. FUO (205, 33-771; p<0.001). PCT >500 pg/mL distinguished non-CNS-MDI/deep-seated-CDI from FUO with 56% sensitivity and 90% specificity. PCT was >500 pg/ml in only 10% of FUO (688, 570-771). A PCT peak >500 pg/mL (1196, 524-11950) occurred beyond 3 days of persistent fever in 17/21 (81%) invasive fungal diseases (IFD). This late PCT peak identified IFD with 81% sensitivity and 57% specificity and preceded diagnosis according to EORTC-MSG criteria in 41% of cases. In IFD responding to therapy, median days to PCT <500 pg/mL and defervescence were 5 (1-23) vs. 10 (3-22; p = 0.026), respectively.Conclusion: While procalcitonin is not useful for diagnosis of infection at onset of neutropenic fever, it may help to distinguish a minority of potentially severe infections among FUOs on day 2 after onset of fever. In persistent fever monitoring procalcitonin contributes to early diagnosis and follow-up of invasive mycose

Innate Immune Sensing of Modified Vaccinia Virus Ankara (MVA) Is Mediated by TLR2-TLR6, MDA-5 and the NALP3 Inflammasome

Modified vaccinia virus Ankara (MVA) is an attenuated double-stranded DNA poxvirus currently developed as a vaccine vector against HIV/AIDS. Profiling of the innate immune responses induced by MVA is essential for the design of vaccine vectors and for anticipating potential adverse interactions between naturally acquired and vaccine-induced immune responses. Here we report on innate immune sensing of MVA and cytokine responses in human THP-1 cells, primary human macrophages and mouse bone marrow-derived macrophages (BMDMs). The innate immune responses elicited by MVA in human macrophages were characterized by a robust chemokine production and a fairly weak pro-inflammatory cytokine response. Analyses of the cytokine production profile of macrophages isolated from knockout mice deficient in Toll-like receptors (TLRs) or in the adapter molecules MyD88 and TRIF revealed a critical role for TLR2, TLR6 and MyD88 in the production of IFNβ-independent chemokines. MVA induced a marked up-regulation of the expression of RIG-I like receptors (RLR) and the IPS-1 adapter (also known as Cardif, MAVS or VISA). Reduced expression of RIG-I, MDA-5 and IPS-1 by shRNAs indicated that sensing of MVA by RLR and production of IFNβ and IFNβ-dependent chemokines was controlled by the MDA-5 and IPS-1 pathway in the macrophage. Crosstalk between TLR2-MyD88 and the NALP3 inflammasome was essential for expression and processing of IL-1β. Transcription of the Il1b gene was markedly impaired in TLR2−/− and MyD88−/− BMDM, whereas mature and secreted IL-1β was massively reduced in NALP3−/− BMDMs or in human THP-1 macrophages with reduced expression of NALP3, ASC or caspase-1 by shRNAs. Innate immune sensing of MVA and production of chemokines, IFNβ and IL-1β by macrophages is mediated by the TLR2-TLR6-MyD88, MDA-5-IPS-1 and NALP3 inflammasome pathways. Delineation of the host response induced by MVA is critical for improving our understanding of poxvirus antiviral escape mechanisms and for designing new MVA vaccine vectors with improved immunogenicity

Receiver operating characteristic curve of PCT on day 2 after onset of fever for diagnosis of A. documented infections (MDIB, MDInB, CDI) vs. FUO (AUC = 0.695); B. non-CNS MDIB, non-CNS MDInB, and deep-seated CDI vs. FUO (AUC = 0.803); and C. non-CNS MDIB vs. FUO (AUC = 0.860).

<p>MDIB = microbiologically documented infections with bacteremia, MDInB = microbiologically documented infections without bacteremia, CDI = clinically documented infections, FUO = fever of unknown origin, CNS = coagulase-negative staphylococci, AUC = area under the receiver operating characteristic curves.</p

Median PCT values over 7 days after onset of fever according to the etiology of fever and the localization of infection.

<p>1A: documented infections (MDIB, MDInB, and CDI) and FUO. 1B: non-CNS MDIB, non-CNS MDInB, CNS MDIB, CNS MDInB, superficial CDI, deep-seated CDI, and FUO. Day 0 = onset of fever, MDIB = microbiologically documented infections with bacteremia, MDInB = microbiologically documented infections without bacteremia, CDI = clinically documented infections, FUO = fever of unknown origin, CNS = coagulase-negative staphylococci.</p

Percent of patients with PCT >500 pg/ml and fever (temperature >38°C) in follow-up of IFD.

<p>The T0 for PCT and fever is set on the time point at which the first positive PCT value (>500 pg/ml) has been documented.</p

Diagnostic performance of PCT at the 500 pg/mL cut-off on day 2 after onset of fever in i) documented infections (MDIB, MDInB and CDI) vs. FUO, ii) non-CNS MDIB, non-CNS MDInB and deep-seated CDI vs. FUO, and iii) non-CNS MDIB vs. FUO.

<p>PPV = positive predictive value, NPV = negative predictive value, LR = likelihood ratio. 95%CI = 95% confidence interval.</p><p>MDIB = microbiologically documented infections with bacteremia, MDInB = microbiologically documented infections without bacteremia, CDI = clinically documented infections, FUO = fever of unknown origin, CNS = coagulase-negative staphylococci.</p

PCT on day 2 after onset of fever: positivity at different cut-offs in i) all FE, ii) documented infections (MDIB, MDInB and CDI), iii) subset including non-CNS MDIB, non-CNS MDInB, and deep-seated CDI, iv) non-CNS MDIB, and v) FUO.

<p>*In 5 febrile episodes (3 documented infections and 2 FUO), blood sampling on day 2 was missing.</p><p>MDIB = microbiologically documented infections with bacteremia, MDInB = microbiologically documented infections without bacteremia, CDI = clinically documented infections, FUO = fever of unknown origin, CNS = coagulase-negative staphylococci.</p