Pneumopericardium due to invasive pulmonary aspergillosis

We describe a 59-year-old female patient with leukemia who developed pneumopericardium as a complication of invasive pulmonary aspergillosis. Spiral computed tomography (CT) was very helpful for the detection of such complications.

[LTR retrotransposons from genomes of Aspergillus fumigatus and A. nidulans]

Fungi Aspergillus spp. are able to infect all tissues and organs and often cause invasive mycosis (aspergillosis), which is usually a fatal disease, especially in the patients with compromised immune system. Microbiological monitoring of these infectious agents is necessary in modem medical facilities. Mobile elements can be used as markers for identification of species and strains of Aspergillus found indoors as well as in aspergillosis diagnostics. Genomic sequences of two representative Aspergillus species, A. fumigatus and A. nidulans, were analysed in silico in order to detect LTR retrotransposons. We found considerable differences in the composition of retrotransposon families between two studied species. One of the detected families, which is present in both studied Aspergillus species, is phylogenetically quite different from all other known fungal retrotransposons. The majority of elements are represented by damaged copies. Nevertheless, we describe for the first time allegedly non-damaged LTR copies that contain intact ORFs and could be active.

Role of Toll-like receptors in lung innate defense against invasive aspergillosis. Distinct impact in immunocompetent and immunocompromized hosts

Toll-like receptors are key to pathogen recognition by a host and to the subsequent triggering of an innate immune response. Experimental and clinical evidence shows that defects in Toll-like receptors or in signaling pathways downstream from these receptors render hosts susceptible to various types of infection, including aspergillosis. Patients receiving an immunosuppressive regimen, including corticosteroid therapy or cytotoxic chemotherapy, are also susceptible to infections. Aspergillus fumigatus is an opportunistic pathogen that infects the lungs of immunosuppressed hosts. Here, we review the evidence that experimental inactivation of various Toll-like receptors and of their signaling pathways may worsen cases of invasive pulmonary aspergillosis. Moreover, the literature clearly indicates that the type of immunosuppression is very important, as it influences whether or not Toll-like receptors contribute to infection. The involvement of Toll-like receptors, based on the immunological status of the patient, should be considered if an immunosuppressive treatment must be administered.

Effectsof Aspergillus fumigatusgliotoxin and methylprednisolone on human neutrophils: implications for the pathogenesis of invasive aspergillosis

Aspergillus fumigatus (AF) is a ubiquitous mold and the most common cause of invasive aspergillosis (IA) in immunocompromised patients. In stem cell transplant recipients, IA now occurs most frequently in the setting of therapy with corticosteroids, including methylprednisolone (MP). We showed previously that gliotoxin (GT), an AF-derived mycotoxin, induces apoptosis in monocytes and dendritic cells, resulting in the suppression of AF-specific T cell responses. We examined the ability of GT to induce apoptosis in polymorphonuclear leukocytes (PMN) and assessed GT effects on important neutrophil functions, including phagocytic function, degranulation, myeloperoxidase activity, and the production of reactive oxygen species (ROS). In contrast to its effects on monocytes, PMN remained resistant to GT-mediated apoptosis. Although many essential neutrophil functions were unaffected, GT inhibited phagocytosis and also induced a decrease in ROS generation by PMN. In contrast, MP therapy potentiated ROS production, suggesting a mechanism that may facilitate tissue injury in IA. Distinct from its effects on untreated PMN, GT augmented ROS production in MP-treated PMN. Our results suggest that although GT may suppress the adaptive immune response, GT may also serve to increase PMN-mediated inflammation, which is likely to play an important role in tissue destruction in the setting of IA.

Successful early voriconazole treatment of Aspergillus infection in two non immunocompromised patients in Intensive Care Unit

We report two cases of respiratory Aspergillus infection that occurred in patients admitted to the Intensive Care Unit of a teaching hospital during renovation works and treated with new triazole voriconazole (Vfend). The first patient was affected with cerebral hemorrhage, the second with polytrauma and both developed Aspergillus Pneumonia during their ICU stay. Bronchoalveolar lavage, dosage with anti-Aspergillus antibodies, antigen measurements and galactomannan research with Sanofi Platelia were performed. Therapy was carried out with voriconazole for 12 days. Chest X-ray and laboratory tests showed complete resolution after 12 days of therapy; clinical symptoms were negative after 4 days. Aspergillus infection can be observed frequently in non-immunocompromised patients during ward renovation or in hospitals near building areas. Since treatment is often unsuccessful, we preferred to immediately employ new agents to reduce the impact of this disease.

[Bronchopulmonary aspergillosis infections in the non-immunocompromised patient]

The definition of broncho-pulmonary aspergillosis infections in non-immunocompromised patients remains vague and a wide range of clinical, radiological and pathological entities have been described with a variety of names, i.e. simple aspergilloma, complex aspergilloma, semi-invasive aspergillosis, chronic necrotizing pulmonary aspergillosis, chronic cavitary and fibrosing pulmonary and pleural aspergillosis, pseudomembranous tracheobronchitis caused by Aspergillus, and invasive aspergillosis. However, these disease entities share common characteristics suggesting that they belong to the same group of pulmonary aspergillosis infectious disorders: 1- a specific diathesis responsible for the deterioration in local or systemic defenses against infection (alcohol, tobacco abuse, or diabetes); 2- an underlying bronchopulmonary disease responsible or not for the presence of a residual pleural or bronchopulmonary cavity (active tuberculosis or tuberculosis sequelae, bronchial dilatation, sarcoidosis, COPD); 3- generally, the prolonged use of low-dose oral or inhaled corticosteroids and 4- little or no vascular invasion, a granulomatous reaction and a low tendency for metastasis. There are no established treatment guidelines for broncho-pulmonary aspergillosis infection in non-immunocompromised patients, except for invasive aspergillosis. Bronchial artery embolization may stop hemoptysis in certain cases. Surgery is generally impossible because of impaired respiratory function or the severity of the comorbidity and when it is possible morbidity and mortality are very high. Numerous clinical cases and short retrospective series have reported the effect over time of the various antifungal agents available. Oral triazoles, i.e. itraconazole, and in particular voriconazole, appear to provide suitable treatment for broncho-pulmonary aspergillosis infections in non-immunocompromised patients.

Common variable immune deficiency and lung transplantation

We report on a male patient with bronchiectasis secondary to common variable immune deficiency (CVID) receiving lung transplantation. The patient had been diagnosed with CVID many y prior to right-sided single lung transplantation and was receiving appropriate immunoglobulin substitution therapy. He received antithymocyte globulin induction and maintenance triple therapy with cyclosporine, azathioprine and prednisolone. The early post-operative course was complicated by the development of severe acute cellular rejection and organizing pneumonia. Despite immunoglobulin replacement and antifungal prophylaxis and treatment, Aspergillus fumigatus was repeatedly cultured from bronchoalveolar lavage fluid, 18 months after transplantation. The patient died following a protracted period of repeated hospital admissions, 46 months after transplantation. A review of the literature suggests that many CVID patients appear to have had a complicated post-operative course after lung- and other solid-organ transplantation, and highlights the need for the establishment of international registries for transplanted patients with uncommon conditions.

Invasive fungal infections in allogeneic and autologous stem cell transplant recipients: a single-center study of 166 transplanted patients

OBJECTIVES

Invasive fungal infections (IFIs) remain a major cause of infection-related morbidity and mortality following hematopoietic stem cell transplantation (HSCT).

PATIENTS AND METHODS

We retrospectively analyzed the incidence of IFIs in 166 patients undergoing either allogeneic or autologous HSCT at our institution between January 2000 and December 2003.

RESULTS

Incidence of invasive aspergillosis (IA) and invasive candidiasis among allogeneic HSCT recipients was 23% (16-32%, 95% confidence interval [CI]) and 3% (1-9%, 95% CI), respectively. Duration of neutropenia and reduced-intensity conditioning were the only risk factors for IA in the multivariate model. Patients with IA had significantly reduced overall survival (8% versus 56%, P=0.01) due to higher transplant-related mortality (63% versus 31%, P=0.03). Following autologous HSCT, incidence of IA and invasive candidiasis was 8% (4-19%, 95% CI) and 2% (0.2-11%, 95% CI), respectively. Duration of neutropenia was the only risk factor for the development of IA following autologous HSCT. Overall survival of autologous HSCT recipients with IA was similar to that of patients without IA. Seventeen percent of autologous HSCT recipients were colonized with Candida species. Compared with non-colonized patients these patients had significantly reduced overall survival (72% versus 23%, P=0.004), due to increased treatment-related mortality (23% versus 9%, P=0.02).

CONCLUSION

Diagnosis of IA following allogeneic HSCT and Candida colonization in the setting of autologous HSCT defines patient populations with poor outcome but primarily not as a result of the fungal pathogen. Regarding the incidence of IA, duration of neutropenia is the main risk factor, and dose-reduced conditioning is an additional risk factor for the development of IA following allogeneic HSCT, probably owing to increased recipient age in this patient cohort, requiring further studies in this transplantation setting.

Thymosin alpha1: an endogenous regulator of inflammation, immunity, and tolerance

Thymosin alpha1 (Talpha1), first described and characterized by Allan Goldstein in 1972, is used worldwide for the treatment of some immunodeficiencies, malignancies, and infections. Although Talpha1 has shown a variety of effects on cells and pathways of the immune system, its central role in modulating dendritic cell (DC) function has only recently been appreciated. As DCs have the ability to sense infection and tissue stress and to translate collectively this information into an appropriate immune response, an action on DCs would predict a central role for Talpha1 in inducing different forms of immunity and tolerance. Recent results have shown that Talpha1: (a) primed DCs for antifungal Th1 resistance through Toll-like receptor (TLR)/MyD88-dependent signaling and this translated in vivo in protection against aspergillosis; (b) activated plasmacytoid DCs (pDC) via the TLR9/MyD88-dependent viral recognition, thus leading to the activation of interferon regulatory factor 7 and the promotion of the IFN-alpha/IFN-gamma-dependent effector pathway, which resulted in vivo in protection against primary murine cytomegalovirus infection; (c) induced indoleamine 2,3-dioxygenase activity in DCs, thus affecting tolerization toward self as well as microbial non-self-antigens, and this resulted in vivo in transplantation tolerance and protection from inflammatory allergy. Talpha1 is produced in vivo by cleavage of prothymosin alpha in diverse mammalian tissues. Our data qualify Talpha1 as an endogenous regulator of immune homeostasis and suggest that instructive immunotherapy with Talpha1, via DCs and tryptophan catabolism, could be at work to control inflammation, immunity, and tolerance in a variety of clinical settings.

Two children with invasive gastrointestinal aspergillosis

We report two immunocompromised infants aged six and four months with invasive gastrointestinal aspergillosis. Both patients presented with weight loss and diarrhea. The underlying disorders were combined immunodeficiency and transient hypogammaglobulinemia of infancy. The diagnosis of gastrointestinal aspergillosis was established by gastrointestinal endoscopy and histopathological examination of the tissue specimens. Both children responded well to Amphotericin B.

Susceptibility to opportunistic infections in HIV-infected patients with increased CD4 T-cell counts on antiretroviral therapy may be predicted by markers of dysfunctional effector memory CD4 T cells and B cells

OBJECTIVES

HIV-infected patients responding to combination antiretroviral therapy (ART) after experiencing severe immunodeficiency may exhibit persistent immune defects and occasionally experience opportunistic infections (OIs) despite increased CD4 T-cell counts. The investigation of immune defects in such patients was examined in this study.

METHODS

CD4 effector memory T-cell (T(em)-cell) function [assessed by blood cytomegalovirus (CMV) interferon-gamma (IFN-gamma) enzyme-linked immunosorbent spot-forming cell assay (ELISPOT) counts] and B-cell dysregulation [assessed by serum immunoglobulin A (IgA) and IgE levels] were examined in 27 patients with increased CD4 T-cell counts after receiving ART for over 2 years. Two of these patients and one other had developed OIs on ART and are described in detail.

RESULTS

Serum levels of IgA and IgE were higher than reference intervals (P<0.001) and CMV IFN-gamma ELISPOT counts were lower than those in non-HIV-infected controls (P<0.001) in the HIV-infected patients. Low CMV IFN-gamma ELISPOT counts were associated with high IgA levels (r=-0.5, P=0.01, Spearman's correlation test) and segregated with high IgE levels (P=0.06, Fisher's test). CMV IFN-gamma ELISPOT counts and serum IgA and IgE levels did not change significantly over a median time of 35 (range 8-60) months after the first measurement, whereas CD4 T-cell counts increased. All three patients who experienced OIs had repeatedly low CMV IFN-gamma ELISPOT counts and increased serum levels of IgA and/or IgE.

CONCLUSION

Low CD4 T(em)-cell function and B-cell dysregulation are immune defects that may persist independently of changes in the CD4 T-cell count in HIV-1-infected patients responding to ART and are associated with an increased risk of developing an OI.

In vitro infection of human dendritic cells by Aspergillus fumigatus conidia triggers the secretion of chemokines for neutrophil and Th1 lymphocyte recruitment

Given the role played by chemokines in the selective homing of immune cells, we sought to characterize the profile of chemokines produced by human dendritic cells (DC) following in vitro Aspergillus fumigatus infection and their ability to recruit cells involved in the antifungal defense. At the onset of A. fumigatus infection, DC released elevated amounts of CXCL8 that promote the migration of polymorphonuclear cells (PMN). Moreover, soluble factors released from A. fumigatus-infected DC increased also the surface expression of two activation markers, CD11b and CD18, on PMN. A. fumigatus infection resulted also in CCL3, CCL4, CXCL10 and CCL20 productions that induce the migration of effector memory Th1 cells. Moreover, the late expression of CCL19 suggests that A. fumigatus-infected DC could be implicated in the migration of CCR7+ naïve T cells and mature DC in lymph nodes. Together these results suggested the involvement of human DC in the regulation of innate and adaptive immunity against A. fumigatus through the recruitment of cells active in the fungal destruction.

Protective role of mannan-binding lectin in a murine model of invasive pulmonary aspergillosis

Innate immune molecules such as lung collectins and serum pentraxins have evolved as important host defence proteins against Aspergillus fumigatus, a medically important opportunistic fungal pathogen. Mannan-binding lectin (MBL), an opsonin and lectin complement pathway activator, constitutes another vital player of innate immunity against several pathogenic organisms in the serum. Studies have reported significant binding of MBL to A. fumigatus; however, the protective role of MBL against A. fumigatus-mediated invasive disease remains elusive. Henceforth, we investigated the contribution of externally administered recombinant human (rh) MBL towards anti-fungal defence in invasive pulmonary aspergillosis (IPA) by in vivo and in vitro studies. In murine models of IPA with corticosteroid-induced immunosuppression, rhMBL-treated mice showed 80% survival compared to untreated IPA mice with no survivors. Treated IPA mice also showed a marked increase in tumour necrosis factor (TNF)-alpha and interleukin (IL)-1alpha and a significant decrease in pulmonary fungal hyphae and IL-10. In vitro, rhMBL-bound A. fumigatus conidia showed a dose-dependent increase in the deposition of C4b, the first product of the lectin pathway. There was an enhanced uptake of A. fumigatus conidia by the polymorphonuclear cells (PMNs) in the presence of rhMBL that increased further in the presence of MBL supplemented with MBL-deficient serum. However, an increase in the oxidative burst of PMNs and A. fumigatus killing were observed only when MBL was supplemented with MBL-deficient serum. The study suggests a therapeutic role of ex vivo-administered MBL in host defence against aspergillosis, possibly through MBL-mediated complement activation and other protective mechanisms aimed both directly at the pathogen, and indirectly through modulation of the host inflammatory responses.

Interleukin-10 promoter polymorphism as risk factor to develop invasive pulmonary aspergillosis

This present study was undertaken to examine the role of the host response to Aspergillus fumigatus in the development of clinical symptoms of invasive pulmonary aspergillosis (IPA). The natural outcome and response to IPA infection varies between individuals. Whereas some variation may be attributable to fungi and environmental variables, it is probable that host genetic background also plays a significant role. Interleukin (IL)-10 has a key function in the regulation of cellular immune responses and is involved in various inflammatory diseases. IL-10 promoter carries a polymorphism that has been associated to production levels. Our aim was to investigate the role of this polymorphism in susceptibility to develop IPA infection. The study included 120 haematological patients and 124 age and sex-matched controls and bi-allelic IL-10 -1082(G/A) polymorphism was examined. Genotypic (p=0.385) and allelic frequencies (p=0.527, OR=0.89, 95% CI=0.78-1.60) were similar between patients and healthy controls. IPA was diagnosed in 59 of the 120 patients according to consensus criteria published by the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group (EORTC/IFICG). Our results provide evidence that IL-10 -1082(AA) genotype is associated with resistance to develop IPA (p=0.001). Allele frequency of IL-10 -1082A allele was weakly associated with susceptibility to develop IPA infection (p=0.052). In conclusion, these results suggest that differential production of IL-10 may alter the risk for IPA in haematological patients.

Rapidly progressive invasive pulmonary aspergillosis in a diabetic man

A 45-year-old man was admitted to our hospital with high fever and a large amount of gray sputum. His initial chest X-ray showed broncho-bronchiolitis and thickening of the large bronchus, and he was subsequently diagnosed with pulmonary aspergillosis based on his sputum culture, polymerase chain reaction for Aspergillus fumigatus, and mannan antigen for Aspergillus. His immune responses, including neutrophil phagocytosis function and neutrophil sterilizing function, were normal as far as we could determine. He was treated with itraconazole, amphotericin B, and meropenem trihydrate, but died of respiratory failure on the twenty-fifth hospital day. Chest X-ray showed rapidly progressive invasive shadows in both lung fields, resulting in multiple cavity formation. This was a rare case of invasive pulmonary aspergillosis in a diabetic man with normal neutrophil phagocytosis function and neutrophil sterilizing function.

Galactomannan antigen enzyme-linked immunosorbent assay for diagnosis of invasive aspergillosis after hematopoietic stem cell transplantation

Invasive aspergillosis is difficult to diagnose in patients undergoing hematopoietic stem cell transplantation (HSCT). In 2003, a serum enzyme-linked immunosorbent assay (ELISA) test for the detection of galactomannan (a glycoprotein found on the Aspergillus cell wall) became available in the United States. In 2004, patients undergoing HSCT were screened biweekly with the galactomannan ELISA at our institution. We performed a retrospective chart review of 121 SCT patients who underwent galactomannan testing. Thirteen of the patients (10.7%) had at least 1 positive galactomannan ELISA, and 4 had multiple positive tests. When calculated in reference to a proved or probable diagnosis of aspergillosis, the galactomannan ELISA had a sensitivity of 0.50 and a specificity of 0.94. The positive predictive value was 0.46, and the negative predictive value was 0.94. Galactomannan ELISA had fewer false-positive and false-negative results in pediatric patients than in adult patients. In 4 of the 12 cases of invasive aspergillosis, the galactomannan ELISA was positive before other microbiologic evidence of aspergillosis was available. In these cases, a positive ELISA predated culture and cytologic evidence of invasive aspergillosis by a mean of 5 days (range, 1-8 days). Our findings indicate that a biweekly serum galactomannan ELISA is a highly specific diagnostic tool for detecting invasive aspergillosis in patients undergoing HSCT. When used regularly, the ELISA may allow for earlier diagnosis of invasive aspergillosis in some patients. The test is troubled by a low sensitivity and high frequency of false-negative tests.

Efficacy of intravenous itraconazole against invasive pulmonary aspergillosis in neutropenic mice

The efficacy of itraconazole (ITZ) solubilized in hydroxypropyl-beta-cyclodextrin (ITZ-IV) was examined in a murine model of invasive pulmonary aspergillosis (IPA). Immunosuppressed mice were infected by the intratracheal inoculation of Aspergillus fumigatus conidia (2 x 10(6) conidia/mouse). Their body weight rapidly decreased and they died within 6 days after infection. Intravenous administration of various doses of ITZ-IV was started 24 h after infection and was continued once a day for 4 days. ITZ-IV at daily doses of 10, 20, or 40 mg/kg was as effective as the intraperitoneal administration of amphotericin B (AMPH) at a dosage of 1 mg/kg daily in improving survival. ITZ-IV (20 mg/kg per day), as well as AMPH (1 mg/kg per day) significantly lowered the fungal burden in the pulmonary tissues. Histological improvement was seen within 2 days after the beginning of administration of ITZ-IV (20 mg/kg per day). In mice intravenously given a single dose of ITZ-IV (20 mg/kg), the blood level and pulmonary tissue level of ITZ plus its active metabolites, mainly hydroxyitraconazole (OH-ITZ), decreased gradually after the injection, but after 4 h their concentration was still between 1.4 microg/ml (ITZ) and 1.9 microg/ml (OH-ITZ), concentrations that were approximately 10 to 20 times greater than the minimum inhibitory concentration (MIC) of ITZ for challenging the strain of A. fumigatus (0.16 microg/ml). These results support the clinical usefulness of ITZ-IV for the treatment of IPA in immunocompromised patients.

Aspergillusiris granuloma in a young male: A case report with review of literature

Endogenous aspergillosis is a rare occurrence. Endogenous Aspergillus endophthalmitis is a rare but devastating infection usually associated with disseminated aspergillosis or with intravenous drug abuse. We report a case of an isolated Aspergillus iris granuloma in a young immunocompetent male patient with review of the literature.

Gliotoxin from Aspergillus fumigatus affects phagocytosis and the organization of the actin cytoskeleton by distinct signalling pathways in human neutrophils

Gliotoxin is a mycotoxin having a considerable number of immuno-suppressive actions and is produced by several moulds such as Aspergillus fumigatus. In this study, we investigated its toxic effects on human neutrophils at concentrations corresponding to those found in the blood of patients with invasive aspergillosis. Incubation of the cells for 10min with 30-100ng/ml of gliotoxin inhibited phagocytosis of either zymosan or serum-opsonized zymosan without affecting superoxide production or the exocytosis of specific and azurophil granules. Gliotoxin also induced a significant re-organization of the actin cytoskeleton which collapsed around the nucleus leading to cell shrinkage and the disappearance of filopodia. This gliotoxin-induced actin phenotype was reversed by the cAMP antagonist Rp-cAMP and mimicked by pCPT-cAMP indicating that it probably resulted from the deregulation of intracellular cAMP homeostasis as previously described for gliotoxin-induced apoptosis. By contrast, gliotoxin-induced inhibition of phagocytosis was not reversed by Rp-cAMP but by arachidonic acid, another member of a known signalling pathway affected by the toxin. This suggests that gliotoxin can affect circulating neutrophils and favour the dissemination of A. fumigatus by inhibiting phagocytosis and the consequent killing of conidia.

Case of pseudomembranous necrotizing tracheobronchial aspergillosis in an immunocompetent host

A 44-year-old Korean male died of rapidly progressive respiratory failure and refractory hypoxemia in 8 days after being admitted with a fever and dyspnea. The patient was diagnosed with pseudomembranous necrotizing tracheobronchial aspergillosis by fibroptic bronchoscopy and it was not related to an invasion of the pulmonary parenchyma. To the best of our knowledge, this case represents a patient with pseudomembranous necrotizing tracheobronchial aspergillosis that developed in an immunocompetent host, rapidly resulting in airway obstruction with acute respiratory failure and refractory hypoxemia without an invasion of the pulmonary parenchyma.

The bug in MyD88 dependency

The contribution of MyD88 adaptor-mediated signaling in immune responses to fungi is largely unexplored. In this issue of Immunity, show that MyD88 is dispensable in several aspects of dendritic-cell trafficking and T cell differentiation in response to a respiratory fungus.

Interferon-gamma therapy in two patients with progressive chronic pulmonary aspergillosis

Infection by Aspergillus species causes a wide spectrum of pulmonary disease in humans. In two patients with semi-invasive Aspergillus-induced lung disease, significantly reduced levels of interferon-gamma secretion by peripheral blood mononuclear cells were found after in vitro stimulation with the T-cell mitogen phytohaemagglutinin. Despite anti-fungal therapy, both patients exhibited progressive disease, and adjunctive interferon-gamma therapy was associated with significant clinical improvement. The data suggest that impaired production of interferon-gamma can be seen in patients with chronic pulmonary aspergillosis. Adjunctive cytokine therapy with interferon-gamma may be useful in patients with progressive disease despite adequate anti-fungal therapy.

Intrathecal aspergillosis and fusiform arterial aneurysms in an immunocompromised child: a clinico-pathological case report

CASE REPORT

We describe a 12-year-old boy with subarachnoid hemorrhage. Cerebral angiography revealed multiple fusiform intracranial arterial aneurysms. Surgical therapy other than ventricular drainage was not feasible due to the extent and pattern of pathological changes. Aspergillus antigen was found in the cerebrospinal fluid (CSF). However, cultures of urine, CSF, and samples from the upper airways were negative for Aspergillus and other fungi. The boy was immunocompromised due to prophylactic antibiotic therapy for recurrent pneumonia and continuous steroid therapy for his hemolytic anemia. There were Aspergillus antigens but no evidence of ongoing infection with the fungus was found. The patient suffered recurrent intraventricular hemorrhage and died on the 31st day after admission.

PATHOLOGICAL EXAMINATION

Pathological examination showed multiple fusiform aneurysms, hypertrophy of the intima, and destruction of the internal elastic membrane of the cerebral arteries. No fungus infiltration was detected. We speculate that the patient had previously had an Aspergillus infection, causing segmental destruction of the internal elastic membrane. However, we cannot rule out noninfectious vasculitis as possible etiology.

CONCLUSIONS

In the immunocompromised child, fusiform segmental intracranial arterial aneurysms may be secondary to the destruction of the internal elastic membrane by fungus infection. The condition may present with aneurysm rupture and subarachnoid hemorrhage. In this patient group, surgical therapy is rarely an option and the prognosis is poor.

Vaccinations with recombinant variants of Aspergillus fumigatus allergen Asp f 3 protect mice against invasive aspergillosis

A vaccine that effectively protects immunocompromised patients against invasive aspergillosis is a novel approach to a universally fatal disease. Here we present a rationale for selection and in vivo testing of potential protein vaccine candidates, based on the modification of an immunodominant fungal allergen for which we demonstrate immunoprotective properties. Pulmonary exposure to viable Aspergillus fumigatus conidia as well as vaccination with crude hyphal extracts protects corticosteroid-immunosuppressed mice against invasive aspergillosis (J. I. Ito and J. M. Lyons, J. Infect. Dis. 186:869-871, 2002). Sera from the latter animals contain antibodies with numerous and diverse antigen specificities, whereas sera from conidium-exposed mice contain antibodies predominantly against allergen Asp f 3 (and some against Asp f 1), as identified by mass spectrometry. Subcutaneous immunization with recombinant Asp f 3 (rAsp f 3) but not with Asp f 1 was protective. The lungs of Asp f 3-vaccinated survivors were free of hyphae and showed only a patchy low-density infiltrate of mononuclear cells. In contrast, the nonimmunized animals died with invasive hyphal elements and a compact peribronchial infiltrate of predominantly polymorphonuclear leukocytes. Three truncated versions of rAsp f 3, spanning amino acid residues 15 to 168 [rAsp f 3(15-168)], 1 to 142, and 15 to 142 and lacking the known bipartite sequence required for IgE binding, were also shown to be protective. Remarkably, vaccination with either rAsp f 3(1-142) or rAsp f 3(15-168) drastically diminished the production of antigen-specific antibodies compared to vaccination with the full-length rAsp f 3(1-168) or the double-truncated rAsp f 3(15-142) version. Our findings point to a possible mechanism in which Asp f 3 vaccination induces a cellular immune response that upon infection results in the activation of lymphocytes that in turn enhances and/or restores the function of corticosteroid-suppressed macrophages to clear fungal elements in the lungs.

Aspergillus infection limited to renal allograft: case report and review of literature

We report a case of a 28-year-old recipient of a cadaveric renal transplant who developed Aspergillus infection in the allograft without having disseminated disease. We review the previously reported cases of isolated Aspergillus in kidney transplant recipients and discuss the possible route of transmission in our patient. We also discuss the alternate but successful treatment that our patient received.

Innate Immune Activation and CD4+ T Cell Priming during Respiratory Fungal Infection

Aspergillus fumigatus is a mold that causes a spectrum of diseases, including lethal lung infections in immunocompromised humans and allergic asthma in atopic individuals. T helper 1 (Th1) CD4(+) T cells protect against invasive A. fumigatus infections whereas Th2 CD4(+) T cells exacerbate asthma upon inhalation of A. fumigatus spores. Herein, we demonstrate that A. fumigatus-specific T cells were rapidly primed in lymph nodes draining the lung and fully differentiated into interferon-gamma (IFN-gamma)-producing Th1 CD4(+) T cells upon arrival in the airways. T-bet induction in A. fumigatus-specific CD4(+) T cells was enhanced by MyD88-mediated signals in draining lymph nodes, but T cell proliferation, trafficking, and Th1 differentiation in the airways were Toll-like receptor (TLR) and MyD88 independent. Our studies demonstrate that CD4(+) T cell differentiation during respiratory fungal infection occurs incrementally, with TLR-mediated signals in the lymph node enhancing the potential for IFN-gamma production whereas MyD88-independent signals promote Th1 differentiation in the lung.

Cytokine profiling of pulmonary aspergillosis

Aspergillus fumigatus is ubiquitous and yet causes invasive, chronic and allergic disease of the lung. Chronic cavitary pulmonary aspergillosis (CCPA) is a slowly destructive form of pulmonary aspergillosis, without immunocompromise. We hypothesized that CCPA cytokine gene polymorphisms would differ from patients with allergic bronchopulmonary aspergillosis (ABPA) and uninfected controls. We have profiled functional cytokine gene polymorphisms for interleukin (IL)-10, IL-15, transforming growth factors (TGF)-beta1, tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma in patients with CCPA (n = 24) who were compared with other forms of aspergillosis (mostly ABPA) (n = 15) and with ethnically matched controls (n = 65-330). Results are described with reference to the high-producing genotype in each case. Susceptibility to aspergillosis (all patients compared with normal controls) was associated with higher frequency of the IL-15 +13689*A allele (OR = 2.37, P = 0.0028) and A/A genotype (chi(2) = 10.31, P < 0.001), with a lower frequency of the TNF-alpha-308*A/A genotype (chi(2) = 11.05, P < 0.01). Within the aspergillosis patients, CCPA is associated with lower frequency of the IL-10 -1082*G allele (OR = 0.38, P = 0.0006) and G/G genotype (chi(2) = 22.45, P < 0.001) and with a lower frequency of the TGF-beta1 +869 *T allele (OR +0.42, P < 0.0029) and T/T genotype (chi(2) = 17.82, P < 0.001) compared with non-CCPA patients and normal controls. Patients infected with Aspergillus appear to be higher producers of IL-15, a Th2-promoting cytokine, and lower producers of TNF-alpha, a cytokine central in protective responses. CCPA occurs in patients who are genetically lower producers of both IL-10 and TGF-beta1. As these cytokines are regulatory and anti-inflammatory, CCPA may be a consequence of poor inflammatory response control in the lung.

Phagocytosis of Aspergillus fumigatus conidia by murine macrophages involves recognition by the dectin-1 beta-glucan receptor and Toll-like receptor 2

Aspergillus fumigatus is a fungal pathogen causing severe infections in immunocompromised patients. For clearance of inhaled conidia, an efficient response of the innate immune system is required. Macrophages represent the first line of defence and ingest and kill conidia. C-type lectins represent a family of receptors, which recognize pathogen-specific carbohydrates. One of them is beta1-3 glucan, a major component of the fungal cell wall. Here we provide evidence that beta1-3 glucan plays an important role for the elimination of A. fumigatus conidia. Laminarin, a soluble beta1-3 glucan and antibodies to dectin-1, a well known beta1-3 glucan receptor, significantly inhibited conidial phagocytosis. On resting conidia low amounts of surface accessible beta1-3 glucan were detected, whereas high amounts were found on small spores that appear early during germination and infection as well as on resting conidia of a pksP mutant strain. Swollen conidia also display larger quantities of beta1-3 glucan, although in an irregular spotted pattern. Resting pksP mutant conidia and swollen wild-type conidia are phagocytosed with high efficiency thereby confirming the relevance of beta1-3 glucans for conidial phagocytosis. Additionally we found that TLR2 and the adaptor protein MyD88 are required for efficient conidial phagocytosis, suggesting a link between the TLR2-mediated recognition of A. fumigatus and the phagocytic response.

Early neutrophil recruitment and aggregation in the murine lung inhibit germination of Aspergillus fumigatus Conidia

Several types of polymorphonuclear neutrophil (PMN) deficiency are a predisposing condition for fatal Aspergillus fumigatus infection. In order to study the defensive role of PMNs in the lungs, with particular reference to PMN recruitment and antimicrobial oxidant activity, responses to pulmonary instillation of A. fumigatus conidia were examined. Responses in BALB/c and C57BL/6 mice were compared with those in CXCR2(-/-) and gp91(phox-/-) mice, which are known to have delayed recruitment of PMN to the lungs in response to inflammatory stimuli and inactive NADPH oxidase, respectively. In BALB/c mice, PMNs were recruited to the lungs and formed oxidase-active aggregates with conidia, which inhibited germination. In C57BL/6, gp91(phox-/-), and CXCR2(-/-) mice, PMN recruitment was slower and there was increased germination compared to that in BALB/c mice at 6 and 12 h. In gp91(phox-/-) mice, germination was extensive in PMN aggregates but negligible in alveolar macrophages (AM). Lung sections taken at 6 and 48 h from BALB/c mice showed PMN accumulation at peribronchiolar sites but no germinating conidia. Those from C57BL/6 and CXCR2(-/-) mice showed germinating conidia at 6 h but not at 48 h and few inflammatory cells. In contrast, those from gp91(phox-/-) mice showed germination at 6 h with more-extensive hyphal proliferation and tissue invasion at 48 h. These results indicate that when the lungs are exposed to large numbers of conidia, in addition to the phagocytic activity of AM, early PMN recruitment and formation of oxidative-active aggregates are essential in preventing germination of A. fumigatus conidia.

Long-term CT follow-up in 40 non-HIV immunocompromised patients with invasive pulmonary aspergillosis: kinetics of CT morphology and correlation with clinical findings and outcome

OBJECTIVE

The aim of this study was to assess CT signs of invasive pulmonary aspergillosis (IPA) and their long-term kinetics in correlation with clinical findings and outcome.

MATERIALS AND METHODS

Three hundred ten serial CT scans (mean, 7.7) in 40 consecutive patients were reviewed retrospectively over a median follow-up of 112 days (range, 5-841 days). Along with underlying disease, hematopoietic stem cell transplantation, neutropenia, graft-versus-host disease or antifungal treatment, signs of IPA, and number or size of lesions were evaluated regarding outcome and radiologic dynamics.

RESULTS

On the day of IPA diagnosis, median lesion number and size were 3 or 3.1 cm(2), respectively. Irrespective of antifungal therapy, 90% of patients showed an increase in lesion size and number until day 9 (median and mean). Lesion size subsequently showed a median plateau phase of 3.5 days (mean, 7), during which median lesion numbers dropped by 17%. Consequently, 42.5% of patients showed a complete radiologic remission within a median 80 days. Of all parameters, formation of cavitation most strongly predicted time until radiologic remission, which was 2.5 times as long in patients with cavitary lesions. Likewise, cavitations were strong precursors of beneficial outcome (odds ratio, 8.4; confidence interval [CI], 1.07-176).

CONCLUSION

The kinetics of radiologic signs of IPA adheres to a distinctive pattern with initial rise in number and size, followed by a plateau phase of size and gradual reduction. Both time until complete radiologic remission and outcome are independent of initial or maximum lesion size and number yet strongly influenced by cavitation.

The mitochondrial protein Bak is pivotal for gliotoxin-induced apoptosis and a critical host factor of Aspergillus fumigatus virulence in mice

Aspergillus fumigatus infections cause high levels of morbidity and mortality in immunocompromised patients. Gliotoxin (GT), a secondary metabolite, is cytotoxic for mammalian cells, but the molecular basis and biological relevance of this toxicity remain speculative. We show that GT induces apoptotic cell death by activating the proapoptotic Bcl-2 family member Bak, but not Bax, to elicit the generation of reactive oxygen species, the mitochondrial release of apoptogenic factors, and caspase-3 activation. Activation of Bak by GT is direct, as GT triggers in vitro a dose-dependent release of cytochrome c from purified mitochondria isolated from wild-type and Bax- but not Bak-deficient cells. Resistance to A. fumigatus of mice lacking Bak compared to wild-type mice demonstrates the in vivo relevance of this GT-induced apoptotic pathway involving Bak and suggests a correlation between GT production and virulence. The elucidation of the molecular basis opens new strategies for the development of therapeutic regimens to combat A. fumigatus and related fungal infections.

The rationale of combination antifungal therapy in severely immunocompromised patients: empiricism versus evidence-based medicine

PURPOSE OF REVIEW

Despite expansion of the antifungal armamentarium over the past decade, the mortality rate for invasive fungal infections remains high in severely immunocompromised patients. Furthermore, in recent years, difficult-to-treat invasive infections caused by rare molds and yeasts have emerged in high-risk patients receiving antifungal prophylaxis or empirical treatment. Antifungal combinations are increasingly used in clinical practice to improve outcomes for refractory mycoses because of the suboptimal efficacy of current antifungal agents. Herein we review recent advances in the area of antifungal combinations in high-risk patients to separate empiricism from evidence-based medicine.

RECENT FINDINGS

Thus far, the benefits of combination antifungal therapy have been difficult to prove for invasive fungal infections other than cryptococcal meningitis. The recent introduction of a new class of antifungal agents (the echinocandins) and extended-spectrum triazoles has rejuvenated interest in studying those combinations for difficult-to-treat aspergillosis, as recent observational studies show promise.

SUMMARY

In view of the evolving epidemiology of invasive fungal infections, combination antifungal therapy could be most valuable in preemptive management of carefully selected high-risk patients; however, this should be studied in appropriate trials.

Paradoxical Increase in CirculatingAspergillusAntigen during Treatment with Caspofungin in a Patient with Pulmonary Aspergillosis

A paradoxical increase in circulating Aspergillus antigen was observed during treatment with caspofungin in a patient with proven invasive aspergillosis. With the exception of treatment with the echinocandin, no other factors were found that might explain this clinical observation, which was supported by experiments done in vitro.

Quantification of IgG antibodies to Aspergillus fumigatus and pigeon antigens by ImmunoCAP technology: an alternative to the precipitation technique?

BACKGROUND

We evaluated the ImmunoCAP technique for measurement of IgG specific to Aspergillus fumigatus and pigeon antigens.

METHODS

We used ImmunoCAP and precipitation technique to measure concentrations of IgG to A. fumigatus or pigeon antigens in sera from 265 patients and 42 controls. We also evaluated linearity, interference, imprecision, concordance, and diagnostic accuracy of the measuring techniques.

RESULTS

The precipitation and ImmunoCAP technique showed moderate concordance (kappa, 0.46 for both A. fumigatus and pigeon antibodies). Specific IgG results for A. fumigatus and pigeon were linear (r = 0.98 and 0.97, respectively), with interrun reproducibility rates of 23% and 14% and maximal interference of 36.5% and 8% by lipid and 24% and 21% by hemolysis, respectively. A. fumigatus antibody concentrations were higher in patients with aspergillosis and allergic bronchopulmonary aspergillosis (ABPA) (median, 103 and 70.1 mgA/L, respectively) than in patients with other pulmonary diseases (median, 18.15-33.40 mgA/L). Antibodies to pigeon antigens were high in patients with hypersensitivity pneumonitis (median, 1024 mgA/L) but also in patients with other pulmonary diseases (median, 445 mgA/L). Antibody titers were substantially higher in patients with other pulmonary diseases and contact with pigeons (median, 1060 mgA/L) than in patients without antigen contact (median, 27.35 mgA/L) (P <0.004).

CONCLUSIONS

Agreement between the precipitation and ImmunoCAP technique was 86% for A. fumigatus and 70% for pigeon antigens. Highest concentrations of specific IgG to A. fumigatus were found in patients with aspergillosis and ABPA. Our results suggest that antigen contact was the most important variable affecting the presence of antibodies to pigeon antigen.

Quantification of phagocytosis of Aspergillus conidia by macrophages using a novel antibody-independent assay

The pathogenic mould Aspergillus fumigatus can cause severe infections in immunocompromised patients. Phagocytosis of inhaled conidia is an early and crucial event in the defense of A. fumigatus infections. Here we describe a novel antibody-independent assay for quantification of phagocytosis, that in this study has been applied to different Aspergillus species, but that is in principle suitable for many fungi.

Interaction of airway epithelial cells (A549) with spores and mycelium of Aspergillus fumigatus

OBJECTIVE

To study the interaction of airway epithelial cell line A549 with fragments of mycelium, spores of Aspergillus fumigatus in vitro and to determine if toll-like receptors (TLRs) are involved in the process.

METHODS

A549 cells were exposed to fragments of A. fumigatus mycelium, zymosan and inactivated A. fumigatus spores. Interleukin 6 (IL-6) and IL-8 released by A549 cells to the culture supernatant were measured by ELISA. Presence of TLR2 and TLR4 on A549 cells were studied by immuno-histochemistry.

RESULTS

Mycelium fragments of A. fumigatus showed strong binding to epithelial cells but had limited effects on the release of IL-6 and IL-8 by A549 cells. Irradiated A. fumigatus spores were partly internalised by A549 cells and inhibited A549 cells to produce IL-6. TNF-alpha pre-incubated A549 cells produced increased IL-6 after exposure to zymosan and WIAF. Immuno-histochemistry showed a negative staining for TLR2 and TLR4.

CONCLUSIONS

The low levels of cytokines produced by A549 cells after the firm binding of either mycelium or spores of A. fumigatus may lead to insufficient recruitment of inflammatory cells to the infected site, which may result in the escape of detection by the immune defence system. TLR2 and TLR4 are probably not or only in part involved in the above process, although very low expression cannot be excluded.

Signalling and oxidant adaptation in Candida albicans and Aspergillus fumigatus

Candida species and Aspergillus fumigatus were once thought to be relatively benign organisms. However, it is now known that this is not the case - Candida species rank among the top four causes of nosocomial infectious diseases in humans and A. fumigatus is the most deadly mould, often having a 90% mortality rate in immunocompromised transplant recipients. Adaptation to stress, including oxidative stress, is a necessary requisite for survival of these organisms during infection. Here, we describe the latest information on the signalling pathways and target proteins that contribute to oxidant adaptation in C. albicans and A. fumigatus, which has been obtained primarily through the analysis of mutants or inference from genome annotation.

Human dendritic cells following Aspergillus fumigatus infection express the CCR7 receptor and a differential pattern of interleukin-12 (IL-12), IL-23, and IL-27 cytokines, which lead to a Th1 response

Aspergillus fumigatus is the most prevalent airborne fungal pathogen and causes fatal invasive aspergillosis in immunocompromised patients. Given the essential role of dendritic cells (DC) in initiating and regulating immune responses, we investigated the impact of A. fumigatus conidial infection on human DC. A. fumigatus conidia were rapidly internalized and induced the release of tumor necrosis factor alpha within the first 8 h. After A. fumigatus infection, the majority of DC underwent full maturation, although CCR7 expression was observed only in DC that had internalized the conidia. Additionally, the analysis of regulatory cytokines showed that infected DC simultaneously produced interleukin-12p70 (IL-12p70) and significant amounts of IL-10. IL-10 neutralization was not able to further increase IL-12p70 production from infected DC. Whereas the central role of IL-12 in the generation of Th1 cells has long been appreciated, recently two other members of the IL-12 family, IL-23 and IL-27, were reported to play important roles in the regulation of gamma interferon (IFN-gamma) production from naïve and memory T cells. A. fumigatus-infected DC were also able to express high levels of IL-23p19 and low levels of IL-27p28 at later stages of infection. According to this expression pattern, A. fumigatus-infected DC were able to prime IFN-gamma production of naïve T cells. Thus, this study on the expression of the new IL-12 family members controlling the Th1 response sheds light on a novel aspect of the contribution of DC to anti-Aspergillus immunity.

Invasive Aspergillosis with Central Nervous System Dissemination in a Presumably Immunocompetent, Non-neutropenic Patient: Case Report and Review

We present a case of a 45-year-old gentlemen with invasive Aspergillosis who has no apparent immune deficiencies. Follow up imaging shows improvement after the initiation of therapy. The case is accompanied by a brief discussion over invasive aspergillosis.