Postmortem analysis of invasive aspergillosis in a tertiary care hospital

Functional expression of an echinocandin B deacylase from Actinoplanes utahensis in Escherichia coli

Echinocandin B deacylase (ECBD) from Actinoplanes utahensis can be applied to produce echinocandin B nucleus (ECBN), an essential intermediate of the echinocandins antifungal drugs such as anidulafungin. To date, the expression of ECBD has been limited to Streptomyces. To achieve the active expression of ECBD in Escherichia coli (E. coli), we constructed a plasmid carrying two subunits of ECBD for T7 RNA polymerase driven transcription of dicistron messenger after codon optimization. Subsequently, the introduction of peptide tags in the recombinant ECBD was adopted to reduce the formation of inclusion bodies and enhance the ECBD solubility. The peptide tags with the opposite electrostatic charge, hexa-lysine (6K) and GEGEG (GE), exhibited the best positive effect, which was verified by activity assay and structural simulation. After that, optimization of culture conditions and characterization of ECBD were conducted, the optimal pH and temperature were 7.0 and 60 °C. It is the first report concerning the functional expression of ECBD in the host E. coli. Our results reported here can provide a reference for the high-level expression of other deacylases with respect to a possible industrial application.

Mucormycosis of the Thyroid Gland: A Cataclysmic Event in Renal Allograft Recipient

Invasive fungal infection is a complication seen in immunocompromised patients. A disseminated fungal infection has a high rate of mortality. Although disseminated infection is known to be seen in most organs, thyroid involvement is rarely reported. Hence, we report a fatal case of thyroid mucormycosis which resulted into laryngeal nerve paralysis and death of a renal allograft recipient.

Endomyocardial and pericardial aspergillosis in critically ill patients

Invasive aspergillosis(IA) is a potentially lethal complication of Aspergillus infection affecting mainly immunocompromised hosts; however, during the last two decades its incidence was increasingly observed in critically ill immunocompetent patients. The objective of this study is to describe the clinical characteristics of histologically proven endomyocardial and pericardial invasion, in the context of IA, in critically ill patients. Eight critically ill patients with histopathological confirmation of endomyocardial/pericardial aspergillosis were evaluated. Risk factors, clinical and laboratory characteristics, treatment, histopathological characteristics and mortality were recorded. Signs and symptoms of cardiac dysfunction were not observed in any of the patients. Therapy was administered to six of them shortly after the first positive culture. The observed histopathological lesions included haemorrhagic lesions, small vessels with central thrombosis and surrounding consolidated tissue with necrosis. Voriconazole, caspofungin, lipid amphotericin B and itraconazole were the used antifungals. The mortality rate was high (87.5%). Endomyocardial and pericardial aspergillosis are devastating complications of invasive aspergillosis. Clinical suspicion is low making the diagnosis difficult, therefore histopathological examination of tissues are required. The mortality is high.

Aspergillus thyroiditis: first antemortem case diagnosed by fine-needle aspiration culture in a pediatric stem cell transplant patient

Aspergillus thyroiditis (AT) has historically been considered a postmortem diagnosis in immunocompromised patients; most have disseminated disease. This report summarizes the clinical challenge of diagnosing AT. It also highlights the value of the early use of thyroid fine-needle aspiration culture and the need for a high index of suspicion to reach the final diagnosis before disease dissemination.

Aspergillus thyroiditis: a complication of respiratory tract infection in an immunocompromised patient

A 59-year-old male with past medical history significant for non-Hodgkin's lymphoma status after chemotherapy presented with acute onset of neck pain, odynophagia, and dysphagia associated with subjective fever, chills, and dyspnea. Physical findings included a temperature of 38.4°C, hypertension, and tachycardia. Patient was found to have anterior neck tenderness. Laboratory evaluation revealed neutropenia. The patient was started on empiric antibacterial and antiviral therapy and continued on home prophylactic antifungal treatment. Thyroid function tests revealed overt hyperthyroidism. A thyroid ultrasound showed heterogeneous echotexture without discrete nodules. Subacute thyroiditis was treated with methylprednisolone, metoprolol, and opiate analgesics. Patient's antibacterial, antifungal, and antiviral treatments were broadened. A fine needle aspiration was not conducted. The patient's condition deteriorated rapidly over his brief hospital course and he expired. Autopsy showed fungal thyroiditis secondary to disseminated invasive Aspergillus. This report describes the presentation of fungal thyroiditis secondary to disseminated invasive Aspergillus originating from the respiratory tract. The authors review the diagnostic challenges, pathophysiology, and treatment of this condition.

Rapidly growing thyroid mass in an immunocompromised young male adult

We describe a 20-year-old man diagnosed with a myelodysplastic syndrome (MDS), admitted to our hospital due to pancytopenia and fever of undetermined origin after myelosuppression with chemotherapy. Disseminated aspergillosis (DIA) was suspected when he developed skin and lung involvement. A rapidly growing mass was detected on the left neck area, during hospitalization. A thyroid ultrasound reported a 3.7 × 2.5 × 2.9 cm oval heterogeneous structure, suggestive of an abscess versus a hematoma. Fine needle aspiration of the thyroid revealed invasion of aspergillosis. Fungal thyroiditis is a rare occurrence. Thyroid fungal infection is difficult to diagnose; for this reason it is rarely diagnosed antemortem. To our knowledge, this is the 10th case reported in the literature in an adult where the diagnosis of fungal invasion to the thyroid was able to be corroborated antemortem by fine needle aspiration biopsy.

A retrospective series of gut aspergillosis in haematology patients

Gut invasive aspergillosis is an extremely rare infection in immunocompromised patients. The goal of this retrospective multicentre study is to report on cases of gut aspergillosis in haematology patients, including clinical presentation, risk factors, and outcome. Twenty-one patients from nine centres were identified. Eight had isolated gut aspergillosis, with no evidence of other infected sites, and 13 had disseminated aspergillosis. Thirteen patients had acute leukaemia. Nine were allogeneic stem cell transplant recipients. Clinical symptoms and imaging were poorly specific. The galactomannan antigenaemia test result was positive in 16/25 (64%) patients, including in four of the eight cases of isolated gut aspergillosis. Five of 21 patients had a dietary regimen rich in spices, suggesting that, in these cases, food could have been the source of gut colonization, and then of a primary gut Aspergillus lesion. The diagnosis was made post-mortem in six patients. The mortality rate in the remaining patients at 12 weeks was 7/15 (47%). Gut aspergillosis is probably misdiagnosed and underestimated in haematology patients, owing to the poor specificity of symptoms and imaging. Patients with a persistently positive galactomannan antigenaemia finding that is unexplained by respiratory lesions should be suspected of having gut aspergillosis in the presence of abdominal symptoms, and be quickly investigated. In the absence of severe abdominal complications leading to surgery and resection of the lesions, the optimal treatment is not yet defined.

Progressive increase in cavitation with the evolution of fungus ball: A clue to the diagnosis of chronic necrotizing pulmonary aspergillosis

Chronic necrotizing pulmonary aspergillosis (CNPA) is an uncommon pulmonary infection seen in the patients with chronic obstructive pulmonary disease, bronchiectasis, pneumoconiosis, diabetes mellitus, alcoholism, poor nutrition or low dose corticosteroid therapy. Here, we are presenting a case of CNPA with diabetes mellitus that was misdiagnosed as pulmonary tuberculosis.

Invasive aspergillosis: epidemiology, diagnosis and management in immunocompromised patients

Morbidity and mortality caused by invasive Aspergillus infections are increasing. This is because of the higher number of patients with malignancies treated with intensive immunosuppressive therapy regimens as well as their improved survival from formerly fatal bacterial infections, and the rising number of patients undergoing allogeneic haematopoietic stem cell or organ transplantation. Early initiation of effective systemic antifungal treatment is essential for a successful clinical outcome in these patients; however, clinical clues for diagnosis are sparse and early microbiological proof of invasive aspergillosis (IA) is rare. Clinical diagnosis is based on pulmonary CT scan findings and non-culture based diagnostic techniques such as galactomannan or DNA detection in blood or bronchoalveolar lavage samples. Most promising outcomes can be expected in patients at high risk for aspergillosis in whom antifungal treatment has been started pre-emptively, backed up by laboratory and imaging findings. The gold standard of systemic antifungal treatment is voriconazole, which has been proven to be significantly superior to conventional amphotericin B and has led to a profound improvement of survival rates in patients with cerebral aspergillosis. Liposomal amphotericin B at standard dosages appears to be a suitable alternative for primary treatment, while caspofungin, amphotericin B lipid complex or posaconazole have shown partial or complete response in patients who had been refractory to or intolerant of primary antifungal therapy. Combination therapy with two antifungal compounds may be a promising future strategy for first-line treatment. Lung resection helps to prevent fatal haemorrhage in single patients with pulmonary lesions located in close proximity to larger blood vessels, but is primarily considered for reducing the risk of relapse during subsequent periods of severe immunosuppression. Strict reverse isolation appears to reduce the incidence of aspergillosis in allogeneic stem cell transplant recipients and patients with acute myeloid leukaemia undergoing aggressive anticancer therapy. Well designed, prospective randomised studies on infection control measures effective to prevent aspergillosis are lacking. Prophylactic systemic antifungal treatment with posaconazole significantly improves survival and reduces IA in acute myeloid leukaemia patients and reduces aspergillosis incidence rates in patients with intermediate-to-severe graft-versus-host reaction emerging after allogeneic haematopoietic stem cell transplantation. Voriconazole prophylaxis may be suitable for prevention of IA as well; however, the results of large clinical trials are still awaited.

Primary invasive aspergillosis of the digestive tract: report of two cases and review of the literature

Background:

Disseminated aspergillosis is thought to occur as a result of vascular invasion from the lungs with subsequent bloodstream dissemination, and portals of entry other than sinuses and/or the respiratory tract remain speculative.

Methods:

We report two cases of primary aspergillosis in the digestive tract and present a detailed review of eight of the 23 previously-published cases for which detailed data are available.

Results and Conclusion:

These ten cases presented with symptoms suggestive of typhlitis, with further peritonitis requiring laparotomy and small bowel segmental resection. All cases were characterized by the absence of pulmonary disease at the time of histologically-confirmed gastrointestinal involvement with vascular invasion by branched Aspergillus hyphae. These cases suggest that the digestive tract may represent a portal of entry for Aspergillus species in immunocompromised patients.

Fungal Thyroiditis: An Overview

The authors review the epidemiology, clinical manifestations, diagnosis, and treatment of fungal thyroiditis cases previously reported in the medical literature. Aspergillus was by far the most common cause of fungal thyroiditis. Immunocompromised patients, such as those with leukemia, lymphoma, autoimmune diseases, and organ-transplant patients on pharmacological immunosuppression were particularly at risk. Fungal thyroiditis was diagnosed at autopsy as part of disseminated infection in a substantial number of patients without clinical manifestations and laboratory evidence of thyroid dysfunction. Local signs and symptoms of infection were indistinguishable from other infectious thyroiditis and included fever, anterior cervical pain, thyroid enlargement sometimes associated with dysphagia and dysphonia, and clinical and laboratory features of transient hyperthyroidism due to the release of thyroid hormone from follicular cell damage, followed by residual hypothyroidism. Antemortem diagnosis of fungal thyroiditis was made by direct microscopy and culture of a fine-needle aspirate, or/and biopsy in most cases. Since most patients with fungal thyroiditis had disseminated fungal infection with delay in diagnosis and treatment, the overall mortality was high.

Characterisation and expression of phospholipases B from the opportunistic fungusAspergillus fumigatus

The phospholipase B family (PLB) are enzymes sharing phospholipase (PL), lysophospholipase (LPL) and lysophospholipase-transacylase (LPTA) activities. They have been shown to be important virulence factors in several human fungal pathogens including Candida albicans and Cryptococcus neoformans. Aspergillus fumigatus, a human opportunistic fungal pathogen leading to a high rate of mortality in immunosuppressed patients is known to possess an extracellular phospholipase B activity. In this paper, we report the molecular characterisation of three PLB genes from A. fumigatus (afplb) using degenerate primers in PCR amplification and data from the A. fumigatus genome project. They are expressed at 37 degrees C, and two of them (afplb1 and afplb3) are induced by lecithin. They encode proteins of 633, 588 and 630 amino acids, respectively, presenting together a T-Coffee score of 81. They also possess the amino acid triad responsible for enzymatic activity in the mammalian cytosolic PLA2 and other fungal PLBs. AfPLB1 and afPLB3 are secreted with a cleaved signal peptide. The complete cDNA sequences were obtained by RACE-PCR for the two secreted afPLBs and probably account for the extracellular phospholipase activity previously reported in the culture media of A. fumigatus.

Oxidative and amphotericin B-mediated cell death in the opportunistic pathogen Aspergillus fumigatus is associated with an apoptotic-like phenotype

When protoplasts of the opportunistic fungal pathogen Aspergillus fumigatus were treated with low but toxic levels of hydrogen peroxide (0.1 mM) or amphotericin B (0.5 microg ml(-1)), loss of cell viability and death were associated with a number of phenotypic changes characteristic of apoptosis. The percentage of protoplasts staining positive with annexin V-FITC, an indicator of the externalization of phosphatidylserine and an early marker of apoptosis, rose to approximately 55 % within 1 h. This was followed by a similar increase in apoptotic DNA fragmentation detected by the TUNEL assay, and led to a loss of cell permeability and death in approximately 90 % of protoplasts, as indicated by the uptake of propidium iodide. The development of an apoptotic phenotype was blocked when protoplasts were pre-treated with the protein synthesis inhibitor cycloheximide, indicating active participation of the cell in the process. However, no significant activity against synthetic caspase substrates was detected, and the inclusion of the cell-permeant broad-spectrum caspase inhibitor Z-VAD-fmk did not block the development of the apoptotic-like phenotype. Higher concentrations of H(2)O(2) (1.8 mM) and amphotericin B (1 microg ml(-1)) caused protoplasts to die without inducing an apoptotic phenotype. As predicted, the fungistatic antifungal agent itraconazole, which inhibits growth without causing immediate cell death, did not induce an apoptotic-like phenotype.

Insight into the genome of Aspergillus fumigatus: analysis of a 922 kb region encompassing the nitrate assimilation gene cluster

Aspergillus fumigatus is the most ubiquitous opportunistic filamentous fungal pathogen of human. As an initial step toward sequencing the entire genome of A. fumigatus, which is estimated to be approximately 30 Mb in size, we have sequenced a 922 kb region, contained within 16 overlapping bacterial artificial chromosome (BAC) clones. Fifty-four percent of the DNA is predicted to be coding with 341 putative protein coding genes. Functional classification of the proteins showed the presence of a higher proportion of enzymes and membrane transporters when compared to those of Saccharomyces cerevisiae. In addition to the nitrate assimilation gene cluster, the quinate utilisation gene cluster is also present on this 922 kb genomic sequence. We observed large scale synteny between A. fumigatus and Aspergillus nidulans by comparing this sequence to the A. nidulans genetic map of linkage group VIII.

Echinocandin antifungal drugs

The echinocandins are large lipopeptide molecules that are inhibitors of beta-(1,3)-glucan synthesis, an action that damages fungal cell walls. In vitro and in vivo, the echinocandins are rapidly fungicidal against most Candida spp and fungistatic against Aspergillus spp. They are not active at clinically relevant concentrations against Zygomycetes, Cryptococcus neoformans, or Fusarium spp. No drug target is present in mammalian cells. The first of the class to be licensed was caspofungin, for refractory invasive aspergillosis (about 40% response rate) and the second was micafungin. Adverse events are generally mild, including (for caspofungin) local phlebitis, fever, abnormal liver function tests, and mild haemolysis. Poor absorption after oral administration limits use to the intravenous route. Dosing is once daily and drug interactions are few. The echinocandins are widely distributed in the body, and are metabolised by the liver. Results of studies of caspofungin in candidaemia and invasive candidiasis suggest equivalent efficacy to amphotericin B, with substantially fewer toxic effects. Absence of antagonism in combination with other antifungal drugs suggests that combination antifungal therapy could become a general feature of the echinocandins, particularly for invasive aspergillosis.

Entry into the stationary phase is associated with a rapid loss of viability and an apoptotic-like phenotype in the opportunistic pathogen Aspergillus fumigatus

When the opportunistic pathogen Aspergillus fumigatus entered the stationary phase, there was a rapid loss in cell viability which was associated with the appearance of markers characteristic of apoptosis, namely annexin V-FITC binding to the cytoplasmic membrane, demonstrating exposure of phosphatidylserine to the outer leaflet of the membrane; and TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) staining of the nuclei, indicating DNA fragmentation. This was followed later by a loss of membrane integrity as revealed by propidium iodide staining. The development of the apoptotic phenotype was blocked when the protein synthesis inhibitor cycloheximide was added to the culture 1h prior to the onset of the stationary phase, demonstrating active participation of the cell. In addition, intracellular activity against substrates specific for caspase-1 and -8 also increased on stationary phase entry and the development of the apoptotic phenotype was blocked when the cell permeant caspase inhibitor Z-FAD-fmk was present in the medium. Cell death in A. fumigatus during the stationary phase therefore appears to share similarities to apoptotic cell death in higher eukaryotes and to be dependent on a caspase-like activity.

[Invasive aspergillosis: results of an 8-year study]

We analysed retrospectively 90 cases of invasive aspergillosis (IA) which occurred at the University Hospital and the Thoraxklinik gGmbH Heidelberg between 1991 and 1998. 71 cases were histologically proven, 19 were probable diseases. There were 49 male and 41 female patients, with a mean age of 51.5 years (range 16 days to 80 years). Underlying diseases were: hematological malignancies in 52% (n = 47; 24 with acute leukemia), solid organ transplantation (n = 11; 9 liver, 1 kidney, 1 heart), solid cancer (n = 10), others (n = 21), and in one case no underlying disease was diagnosed. Only 54 cases (60%) were correctly diagnosed as IA during lifetime of the patients. In 59 cases (65%) only the lung was affected, 25 patients suffered from disseminated IA, in 6 patients only extrapulmonary lesions were present. 11 patients underwent lung surgery, 63 patients received antimycotic drugs (44 amphotericin B, 15 fluconazole, 4 itraconazole), 21 were not treated antimycotically. 68 patients (71%) died, from these 30 (36%) due to IA during remission of the underlying disease. The laboratory methods showed the following sensitivities, respectively: microscopy by calcofluor white staining 17%, culture 69%, Aspergillus-PCR from respiratory tract samples and biopsies 95%, galactomannan antigen detection by latex agglutination 28%, by enzyme immunoassay 59%, Aspergillus antibody detection 23%.

Invasive aspergillosis in cancer

Ten confirmed cases of invasive aspergillosis (IA) in cancer patients were analysed retrospectively. Eight were pulmonary, one was sinonasal and one was cutaneous. The majority of patients had haematological malignancies (7), the remaining three were cases of solid tumours. Fever was present in all 10 cases. Cough and lung signs were present in all eight cases of invasive pulmonary aspergillosis. Haemoptysis was encountered in three of nine cases of pulmonary and sinonasal aspergillosis. Mortality was low (2%). While corticosteroids, antibiotics and anticancer chemotherapy/radiotherapy were factors predisposing the patients to IA, neutropenia was perhaps responsible for their mortality. Seven of the patients had other associated pathogens isolated in culture in addition to Aspergillus spp. Aspergillus fumigatus was the predominant species, followed by A. flavus, A. glaucus, A. nidulans and A. niger. Direct microscopic examination (in six of seven cases) and culture (six of seven cases) correlated well with radiographic and clinical findings in cases with lung involvement. Serology for anti-Aspergillus antibodies performed by gel diffusion precipitin test was positive in one case of sinonasal aspergillosis, wherein only one precipitin band was observed. Correlation of clinical symptoms, consistent radiographic findings and microbiological work-up (the latter including a triad of direct microscopy, culture and serology) are required to arrive at a diagnosis of IA, especially where histology cannot form the mainstay of diagnosis.

Sequencing the Aspergillus fumigatus genome

Aspergillus fumigatus is the most common mould pathogen of human beings and unusually causes both invasive disease in immunocompromised patients and allergic disease in patients with atopic immune systems. 4% of patients dying in modern European teaching hospitals have invasive aspergillosis and it is the leading infectious cause of death in leukaemia and bone marrow transplant patients. Until 2001, only two licensed antifungal drugs were available to treat aspergillosis-amphotericin B and itraconazole. Its 28-30Mb genome is being sequenced in an international collaboration, with the Wellcome Trust Sanger Institute (UK) and The Institute for Genomic Research (TIGR, USA) as the two main centres. A whole-genome shotgun approach was adopted and initiated in 2001 with an expected completion date in 2003. The complete sequence will permit identification of pathways specific to pathogenic Aspergillus species, help identify new targets for antifungal drugs, and enable investigations into the basic biology of fungi. Numerous secondary metabolic pathways with biotechnological applications and pharmacological properties are found in the Aspergilli and the genome sequence will facilitate research in this area.

Detection of early phase specific surface appendages during germination of Aspergillus fumigatus conidia

During the past 15 years the saprophytic fungus Aspergillus fumigatus has become the most prevalent airborne fungal pathogen, causing severe and often fatal infections especially in immuno-compromised patients. Germination of inhaled conidia is an early and crucial event in the infection process of A. fumigatus. In this study we have analyzed morphological changes that take place during this differentiation process using scanning electron microscopy. Our data show that (i) the hydrophobic surface layer of resting conidia seems to be shed before the cells start to swell and (ii) that filamentous surface appendages are expressed at a very early phase of the germtube formation. These surface structures were only found on the first few microm of the germtube, but were absent from the surface of mycelial hyphae and resting or swollen conidia. The highly regulated expression of these novel surface organelles suggests that they may play an important role during early germination and represent a potential target for future anti-A. fumigatus therapies.

Pulmonary aspergillosis in an unselected autopsy series

The present study was performed to analyze the relationship between underlying diseases and the morphologic form of aspergillosis. This retrospective analysis of 3284 autopsies yielded 18 cases of aspergillosis. The specific diagnosis of aspergillosis was rendered by a monoclonal antibody versus Aspergillus spp. Patients with hematological disorders, such as acute leukemia and aplastic anemia, made up about 35% of all patients dying of invasive aspergillosis. Diseases of the airways and the pulmonary parenchyma constituted the second most pathogenetic factor for the development of aspergillosis. The morphologic form of aspergillosis was closely related to the underlying diseases. Non- and semi-invasive forms of aspergillosis--saprophytic infection and chronic necrotizing aspergillosis--were observed only in patients with an isolated underlying pulmonary disease devoid of any other precipitating factor. In contrast, seven patients, five of whom suffered from hematological diseases, had no underlying lung disease and developed aspergillus pneumonia. The remaining 5 patients with aspergillus pneumonia showed a combination of underlying extrapulmonary disease and pulmonary alterations that preceded aspergillosis. The local distribution of fungal infection showed a characteristic distribution pattern with a predominance of the upper lung lobes. Hematogeneous spread beyond the lungs occurred exclusively in cases with aspergillus pneumonia. We conclude that the different forms of aspergillosis are closely related to the nature of the underlying disease.

Case reports. Invasive pulmonary aspergillosis in non-neutropenic patients treated with liposomal amphotericin B

We report two cases of invasive pulmonary aspergillosis due to Aspergillus flavus in one patient who with chronic nephritis and to A. fumigatus in another with malignant lymphoma. After receiving intravenous liposomal amphotericin B therapy for 31 and 35 days, respectively, the patients were cured and did not experience any severe adverse effects.

Diagnosis of invasive aspergillosis in bone marrow transplant recipients by polymerase chain reaction

A nested polymerase chain reaction (PCR) test targeting Aspergillus spp. large ribosomal subunit genes was evaluated retrospectively on 175 serum samples from 37 bone marrow transplant recipients, 70% of whom received grafts from unrelated donors. Six patients had proven infection, seven had probable infection, and three had possible infection, using the revised EORTC case definitions. These 16 patients were all PCR positive (57 out of 93 samples tested). Two additional patients who did not fulfil current diagnostic criteria, but in whom invasive aspergillosis (IA) was thought clinically probable, were also PCR positive (five out of nine samples). Invasive aspergillosis was unlikely in the remaining 19 patients, four of whom were PCR positive on a single occasion (four out of 70 samples). Three samples were inhibitory to PCR. Sensitivity of PCR in diagnosing patients with IA was 100%, specificity was 79% and positive predictive value was 80%, using the criterion of a single positive result. If two positive results were required, these values were 81%, 100% and 100% respectively. The median duration of infection documented by PCR was 36 days (range 3-248 days) in 17 out of 18 patients (94%) who did not survive. Positive PCR results predated the institution of antifungal therapy in two-thirds of patients. Four patients became PCR positive during pretransplant conditioning therapy.

Invasive aspergillosis diagnosed by fine-needle aspiration of the thyroid gland

Invasive aspergillosis has been increasingly recognized as causing significant morbidity and mortality in immunocompromised patients but has never been diagnosed by fine-needle thyroid aspiration. A 24-year-old female with systemic lupus erythematosus presented with cough, shortness of breath, and fever of unknown origin unresponsive to broad-spectrum antibiotics. History and physical examination failed to indicate a source of infection. An 111In white blood cell scan showed thyroid localization. Physical examination revealed a multinodular goiter with a left dominant nodule. Fine-needle aspiration biopsy of a thyroid nodule revealed branching hyphae suggestive of Aspergillus sp. Despite immediate and aggressive treatment with amphotericin B and fluconazole, the patient died of overwhelming infection.

Aspergillus fumigatus and aspergillosis

Aspergillus fumigatus is one of the most ubiquitous of the airborne saprophytic fungi. Humans and animals constantly inhale numerous conidia of this fungus. The conidia are normally eliminated in the immunocompetent host by innate immune mechanisms, and aspergilloma and allergic bronchopulmonary aspergillosis, uncommon clinical syndromes, are the only infections observed in such hosts. Thus, A. fumigatus was considered for years to be a weak pathogen. With increases in the number of immunosuppressed patients, however, there has been a dramatic increase in severe and usually fatal invasive aspergillosis, now the most common mold infection worldwide. In this review, the focus is on the biology of A. fumigatus and the diseases it causes. Included are discussions of (i) genomic and molecular characterization of the organism, (ii) clinical and laboratory methods available for the diagnosis of aspergillosis in immunocompetent and immunocompromised hosts, (iii) identification of host and fungal factors that play a role in the establishment of the fungus in vivo, and (iv) problems associated with antifungal therapy.

Disseminated aspergillosis caused by Aspergillus ustus in a patient following allogeneic peripheral stem cell transplantation

The first case of disseminated aspergillosis caused by Aspergillus ustus in an allogeneic peripheral stem cell transplant patient is described. The patient, a 46-year-old female with a history of myelodysplastic syndrome, underwent high-dose chemotherapy and total body irradiation prior to transplantation. She was released from the hospital 49 days posttransplant (p.t.) in a stable condition with an absolute neutrophil count (ANC) of 2,700 cells per microl. Multiple antimicrobial agents, including itraconazole (ITR), were prescribed during hospitalization and at the time of discharge. Three days after discharge, the patient was readmitted with hemorrhagic cystitis, persistent thrombocytopenia, and bilateral pulmonary consolidation, although no fever was present. The ANC at the time of readmission was 3,500. Upon detection of a pulmonary nodule (day 67 p.t.), a bronchoalveolar lavage was performed; the lavage fluid was positive for both cytomegalovirus and parainfluenza virus and negative for fungus. The patient was placed on ganciclovir. A biopsy specimen from a leg lesion also noted on day 67 p.t. revealed septate hyphae consistent with Aspergillus species, and a culture subsequently yielded Aspergillus ustus. Confirmation detection of A. ustus was made by demonstration of characteristic reproductive structures with the presence of Hülle cells. On day 67 p.t., ITR was discontinued and liposomal amphotericin B (AMB) was initiated. The patient's condition worsened, and she died 79 days p.t. At the time of autopsy, septate hyphae were present in heart, thyroid, and lung tissues, with lung tissue culture positive for A. ustus. In vitro susceptibility testing indicated probable resistance to AMB but not to ITR. This case supports the need for the development of rapid methods to determine antifungal susceptibility.

Invasive aspergillosis. Clinical features of 35 proven cases at a single institution

Thirty-five patients with clinical features and histologically or microbiologically proven infection met predetermined stringent criteria for invasive aspergillosis over a 5-year period at our institution. Underlying conditions included hematologic malignancy, solid tumor, bone marrow and solid organ transplantation, and immunosuppressive therapy. The majority of patients (94%) presented with respiratory symptoms and abnormal pulmonary chest radiography; only 40% had neutropenia at time of infection. Invasive aspergillosis was suspected in only 21 cases (60%). Concomitant infections were present in 83% of patients. Half of patients had pathogenic or potentially pathogenic microorganisms other than Aspergillus spp. isolated from pulmonary specimens at time of aspergillosis. Aspergillus spp. were recovered from sputum in 75% of patients and from bronchoalveolar lavage in only 52%. Invasive aspergillosis is an unexpectedly unrecognized disease with poor outcome; overall mortality was 94% in our series. The lack of sensitivity of diagnostic procedures, together with the high frequency of concomitant infections, delays the time of diagnosis. Early diagnostic tests are needed, and presumptive antifungal therapy among high-risk patients is mandatory.