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Fast diagnosis of invasive pulmonary aspergillosis (IPA) is essential as early adequate therapy improves survival. However, current microbiological methods suffer from a low sensitivity or a long turnaround time, often as a result of batching. Recently, two lateral flow assays for diagnosing IPA have been CE (Conformité Européenne)-marked and commercialized. These assays can be used for fast single sample testing. However, clinical validation and comparative studies are lacking. We therefore sought to evaluate and compare these assays in adult hematology patients. We retrospectively tested 235 bronchoalveolar lavage fluid (BALf) samples of adult hematology patients from four centers using the AspLFD (OLM Diagnostics) and the sōna Aspergillus galactomannan LFA (IMMY). Both tests were read out independently by two researchers and by a digital reader. We included 11 patients with proven IPA, 64 with probable IPA, 43 with possible fungal disease, and 117 controls with no signs of IPA. In cases of proven IPA, the performance of both assays was similar. In cases of proven and probable IPA, we found an identical specificity for both assays, but a higher sensitivity (0.83 vs 0.69, P =.008) and a better negative predictive value (0.89 vs 0.82, P =.009) for the LFA. Digital readout improved the diagnostic performance of both tests. In conclusion, both assays showed a good performance for the diagnosis of IPA in BALf from adult hematology patients. Results were further improved by using a digital reader, especially for weakly positive results. [ABSTRACT FROM AUTHOR]

With the current revived interest in the use of bacteriophages for the treatment of bacterial infections, the study of mycoviruses as novel therapeutic solutions for invasive aspergillosis is the logical next step. Although ssRNA, dsRNA, and ssDNA mycoviruses have been identified, the majority of characterised mycoviruses have dsRNA genomes. Prevalence of dsRNA mycoviruses in Aspergillus spp. varies, and mycoviruses can have different effects on their fungal hosts: hypovirulence, hypervirulence, or a killer phenotype. Therapeutically, extracellular transmission of the mycovirus is essential. DsRNA mycoviruses lack an extracellular phase; however, a single ssDNA mycovirus with homologues in Aspergillus genomes has been described with an extracellular mode of transmission. Mycoviruses can induce hypovirulence or a killer phenotype, and both can be exploited therapeutically. Mycoviruses inducing hypovirulence have been used to control chestnut blight, however for aspergillosis no such mycovirus has been identified yet. Mycovirus encoded killer toxins or anti-idiotypic antibodies and killer peptides derived from these have been demonstrated to control fungal infections including aspergillosis in animals. This indicates that mycoviruses inducing both phenotypes could be exploited therapeutically as long as the right mycovirus has been identified. [ABSTRACT FROM AUTHOR]

Background. Dectin-1 is the major receptor for fungal β-glucans on myeloid cells. We investigated whether defective Dectin-1 receptor function, because of the early stop codon polymorphism Y238X, enhances susceptibility to invasive aspergillosis (IA) in at-risk patients.Methods. Association of Dectin-1 Y238X polymorphism with occurrence and clinical course of IA was evaluated in 71 patients who developed IA post hematopoietic stem cell transplantation (HSCT) and in another 21 non-HSCT patients with IA. The control group consisted of 108 patients who underwent HSCT. Functional studies were performed to investigate consequences of the Y238X Dectin-1 polymorphism.Results. The Y238X allele frequency was higher in non-HSCT patients with IA (19.0% vs 6.9%–7.7%; P < .05). Heterozygosity for Y238X polymorphism in HSCT recipients showed a trend toward IA susceptibility (odds ratio, 1.79; 95% CI, .77–4.19; P = .17) but did not influence clinical course of IA. Functional assays revealed that although peripheral blood mononuclear cells with defective Dectin-1 function due to Y238X responded less efficiently to Aspergillus, corresponding macrophages showed adequate response to Aspergillus.Conclusions. Dectin-1 Y238X heterozygosity has a limited influence on susceptibility to IA and may be important in susceptible non-HSCT patients. This is partly attributable to redundancy inherent in the innate immune system. Larger studies are needed to confirm these findings. [ABSTRACT FROM PUBLISHER]

Background. Monitoring treatment response in invasive aspergillosis is challenging, because an immunocompromised host may not exhibit reliable symptoms and clinical signs. Cytokines play a pivotal role in mediating host immune response to infection; therefore, the profiling of biomarkers may be an appropriate surrogate for disease status. Methods. We studied, in a cohort of 119 patients with invasive aspergillosis who were recruited in a multicenter clinical trial, serum interleukin (IL)-6, IL-8, IL-10, interferon-g, and C-reactive protein (CRP) trends over the first 4 weeks of therapy and correlated these trends to clinical outcome parameters. Results. Circulating IL-6 and CRP levels were high at initiation of therapy and generally showed a downward trend with antifungal treatment. However, subjects with adverse outcomes exhibited a distinct lack of decline in IL-6 and CRP levels at week 1, compared with responders (Pp.02, for both IL-6 and CRP). Nonresponders also had significantly elevated IL-8 levels (P=.001). Conclusions. High initial IL-8 and persistently elevated IL-6, IL-8, and CRP levels after initiation of treatment may be early predictors of adverse outcome in invasive aspergillosis. Cytokine and CRP profiles could be used for early identification of patients with a poor response to antifungal treatment who may benefit from more-aggressive antimicrobial regimens. [ABSTRACT FROM AUTHOR]

A successful pathogen is one that is able to effectively survive and evade detection by the host innate immune defense. Fungal pathogens have adopted strategies which evade host defense and eventually cause disease in at-risk patients. Shielding of stimulatory surface recognition molecules, shedding of decoy components, induction of anti-inflammatory signals, complement evasion and resilient survival capacity are successful evasion mechanisms employed by fungal pathogens. Understanding these complex pathways of immune evasion can potentially contribute to development of novel therapeutic strategies against fungal infections. [ABSTRACT FROM AUTHOR]

Background. Interleukin (IL)-1α and IL-1β are protective proinflammatory cytokines involved in host defense against Candida albicans. It is, however, unknown whether they provide protection through similar mechanisms. We investigated the effect of endogenous IL-1α and IL-1β on disseminated C. albicans infection. Methods. Mice deficient in the genes encoding IL-1α (IL-1α-/-), IL-1β (IL-1β-/-), or both molecules (IL-1α-/-β-/-) were used. Survival and C. albicans outgrowth in the kidneys was assessed after intravenous injection of C. albicans. Results. Both mortality and C. albicans outgrowth in the kidneys were significantly increased in IL-1α-/- and IL-1β-/- mice, compared with those in control mice, with the IL-1α-/-β-/- mice being most susceptible to disseminated candidiasis. The host defense mechanisms triggered by IL-1α and IL-1β differed from one another. IL-1β-/- mice showed decreased recruitment of granulocytes in response to an intraperitoneal C. albicans challenge, and generation of superoxide production was diminished in IL-1β-/- granulocytes. IL-1α-/- mice had a reduced capacity to damage C. albicans pseudohyphae. Protective type 1 responses were deficient in both IL-1α-/- and IL-1β-/- mice, as assessed by production of interferon-γ by splenocytes in response to heat-killed C. albicans. Conclusion. Although IL-1α and IL-1β have differential effects on the various arms of host defense, both cytokines are essential for mounting a protective host response against invasive C. albicans infection. [ABSTRACT FROM AUTHOR]

For quantitative assessment of polymorphonuclear granulocyte (PMN)-mediated pseudohyphal damage, an improved tetrazolium (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide; XTT) dye assay was developed. The modified assay proved to be a reliable indicator of viable pseudohyphal inoculum sizes. In addition, the influence of various endogenous pro-inflammatory cytokines on the capacity of PMN to damage Candida albicans pseudohyphae was investigated. PMN obtained from mice in which the genes encoding for tumor necrosis factor-α /lymphotoxin-α (TNF/LT), interferon-γ (IFNγ), interleukin (IL)-1α, or IL-1β were disrupted, showed a significantly reduced pseudohyphal damage capacity in comparison with control PMN. The reduction amounted 25% for TNF -/ - LT -/ - , 11% for IFNγ -/ - , 21% for IL-1α -/ - , and 34% for IL-1α -/ - β -/ - PMN. In contrast, deficiency of IL-12 or IL-18 did not result in a diminished capacity to damage pseudohyphae and the capacity of PMN to damage Candida pseudohyphae was even slightly increased by 10% in IL-18 -/ - mice. These data suggest that endogenous pro-inflammatory cytokines are able to modulate antihyphal activity of PMN, the main effector cells against disseminated candidiasis by virtue of their capacity to kill both Candida blastoconidia and pseudohyphae. [ABSTRACT FROM AUTHOR]

The effect of hyperlipoproteinemia on systemic candidiasis was investigated by assessing the susceptibility of hyperlipoproteinemic, apolipoprotein E (ApoE)-deficient (ApoE-/-) mice to a systemic Candida albicans infection. The absence of ApoE in these mice resulted in an eightfold increase in plasma lipoprotein concentrations in the very low-density lipoprotein (VLDL) fraction, as compared with levels seen in ApoE+/+ mice. Mortality due to candidemia was significantly higher (86%) in ApoE-/- mice than in ApoE+/+ mice (52%), and in platings of homogenized kidney material on fungal culture medium, ApoE-/- mice yielded significantly higher levels of C. albicans outgrowth than did ApoE+/+ mice. C. albicans grew twofold better in ApoE-/- plasma in 4 h than in ApoE+/+ plasma, and depletion of lipoproteins from plasma resulted in a significant seven- to tenfold increase in C. albicans growth. Recombinant ApoE did not directly inhibit C. albicans growth. Our data indicate that the increased susceptibility of ApoE-/- mice to C. albicans is due both to increased growth of blastoconidia in ApoE-/- mice in response to the availability of lipids as nutrients, and to the neutralization of candidacidal factors by lipoproteins. This study suggests that lipoproteins play a significant role in host defense against candidiasis. [ABSTRACT FROM AUTHOR]

The role of endogenous tumor necrosis factor-α (TNF) and lymphotoxin-α (LT) in a model of intraabdominal Candida sepsis and abscess formation was investigated. Significantly more abscesses were observed in TNF/LT double knockout (TNF[sup -/-]LT[sup -/-]) mice, compared with that in wild-type (TNF[sup +/+]LT[sup +/+]) mice. Outgrowth of Candida in abscesses of TNF[sup -/-]LT[sup -/-] mice was 10-fold increased on day 14 and 60-fold increased on day 21 of infection. The interleukin10:interferon-γ ratio, measured in supernatants of stimulated splenocytes, shifted from 131 for TNF[sup -/-]LT[sup -/-] mice and 13.9 for TNF[sup +/+]LT[sup +/+] mice on day 8 to 0.11 for TNF[sup -/-] LT[sup -/-] mice and 11.66 for TNF[sup +/+]LT[sup +/+] mice on day 14 of infection. The diminished host resistance is explained by an impaired extracellular killing capacity of granulocytes and a delayed development of a T helper 1 response in TNF[sup -/-]LT[sup -/-] mice. In conclusion, TNF and LT are critical to the stimulation of effector cells that leads to elimination of Candida from abscesses. [ABSTRACT FROM AUTHOR]

Examines the role of toll-like receptors in the host defense against disseminated candidiasis. Involvement of sensing pathogenic microorganisms; Production of tumor necrosis factor and interleukin; Importance of Candida albicans in human disease.