Invasive aspergillosis in patients with AIDS

Quantifying Deaths from Aspergillosis in HIV Positive People

Aspergillus spp. are ubiquitous and cause severe infections in immunocompromised patients. Less is known about its incidence and prognosis in patients with HIV/AIDS. We reviewed the mortality of invasive aspergillosis in HIV/AIDS patients. Pubmed, Embase and Medline databases were used to search for articles. Studies were excluded if they contained other aspergillosis risk factors, no original or patient survival data or were not in English. From 747 articles published, 54 studies and case reports were identified following reading, published between 1985 and 2021, with 54% papers prior to 2000 reporting 853 patients from 16 countries, none from Africa. 707 (83%) patients died with an average time from diagnosis to death of 77.5 days. Postmortem diagnosis was seen in 21% of deaths recorded. A national series from France of 242 cases of invasive aspergillosis diagnosed in life recorded a 3 month mortality of 68% pre-ART, falling to 31% after introduction of ART and voriconazole. CD4 count was recorded in 39 studies and ranged from 2 to >1000 cells/mm3; only 8 patients (1.8%) had a CD4 > 100 cells/mm3. Aspergillosis occurs in patients with HIV/AIDS and associated with high mortality but its slow progression should allow diagnosis and treatment with improved outcome.

Invasive Aspergillus Sinusitis in Human Immunodeficiency Virus Infection: Case Report and Review of the Literature

Invasive Aspergillus (IA) sinusitis is a life-threatening opportunistic infection in immunocompromised individuals, but it is uncommon in human immunodeficiency virus (HIV) infection. To gain a better understanding of the characteristics of IA sinusitis in this population, we present a unique case of chronic IA sinusitis in an HIV-infected patient taking antiretroviral therapy and review the literature summarizing published cases of invasive aspergillosis of the paranasal (n = 41) and mastoid (n = 17) sinuses in HIV-infected individuals. Among these cases, only 4 were reported after 1999, and 98% of patients had acquired immune deficiency syndrome. Orbital invasion occurred in 54% of paranasal sinus cases, whereas intracranial invasion was reported in 53% of mastoid sinus cases. The overall mortality was 79%. We also discuss various clinical and immunologic factors that may play a role in the development of IA and consider the changing epidemiology of aspergillosis in the era of effective antiretroviral therapy.

Allergen Immunotherapy in an HIV+ Patient with Allergic Fungal Rhinosinusitis

Patients with HIV/AIDS can present with multiple types of fungal rhinosinusitis, fungal balls, granulomatous invasive fungal rhinosinusitis, acute or chronic invasive fungal rhinosinusitis, or allergic fungal rhinosinusitis (AFRS). Given the variable spectrum of immune status and susceptibility to severe infection from opportunistic pathogens it is extremely important that clinicians distinguish aggressive fungal invasive fungal disease from the much milder forms such as AFRS. Here we describe a patient with HIV and AFRS to both remind providers of the importance of ruling out invasive fungal disease and outline the other unique features of fungal sinusitis treatment in the HIV-positive population. Additionally we discuss the evidence for and against use of allergen immunotherapy (AIT) for fungal disease in general, as well as the evidence for AIT in the HIV population.

Protein Glycosylation in Aspergillus fumigatus Is Essential for Cell Wall Synthesis and Serves as a Promising Model of Multicellular Eukaryotic Development

Glycosylation is a conserved posttranslational modification that is found in all eukaryotes, which helps generate proteins with multiple functions. Our knowledge of glycosylation mainly comes from the investigation of the yeast Saccharomyces cerevisiae and mammalian cells. However, during the last decade, glycosylation in the human pathogenic mold Aspergillus fumigatus has drawn significant attention. It has been revealed that glycosylation in A. fumigatus is crucial for its growth, cell wall synthesis, and development and that the process is more complicated than that found in the budding yeast S. cerevisiae. The present paper implies that the investigation of glycosylation in A. fumigatus is not only vital for elucidating the mechanism of fungal cell wall synthesis, which will benefit the design of new antifungal therapies, but also helps to understand the role of protein glycosylation in the development of multicellular eukaryotes. This paper describes the advances in functional analysis of protein glycosylation in A. fumigatus.

Elastase Activity in Aspergillus fumigatus Can Arise by Random, Spontaneous Mutations

Aspergillus fumigatus Fresenius has the capacity to degrade elastin (the principal protein of the lungs) and it is considered that elastase activity (EA) is among the most important pathogenicity factors of this mold. In particular, there is a strong correlation between EA in A. fumigatus and invasive aspergillosis. However, EA is not universal in this mold, and it is unknown whether the capacity to degrade elastin is the consequence of physiological mechanisms and/or genetic changes (putative adaptive mutations) induced after the exposure to this substrate or, on the contrary, it is due to random spontaneous mutations that occur under nonselective conditions. In order to discriminate between these possibilities, a Luria-Delbrück fluctuation analysis was carried out on an elastase-negative (EA(-)) A. fumigatus strain, using as selective factor a culture medium containing elastin as the sole source of nitrogen. Here we show that the EA(-) → EA(+) transformation in A. fumigatus appears by rare, random mutations before the exposure of the strain to selective conditions. This work represents the first experimental evidence of pathogenicity factor acquisition in mycelial fungi by preselective mutation.

Long-term suppressive therapy for pulmonary aspergilloma in an immunocompromised man with AIDS. Is it always necessary?

Aspergillus infections are rare opportunistic infections in the course of AIDS and they mostly present as invasive pulmonary disease. Owing to the prolonged survival of profoundly immunocompromised patients with AIDS, invasive pulmonary aspergillosis is being reported with increased frequency. However, although pulmonary aspergilloma has been well described in immunocompetent patients, it has been rarely reported in AIDS patients. The treatment for pulmonary aspergilloma remains challenging and often needs lifelong treatment to minimize fatal haemoptysis, which can occur in up to 25%, and progression to secondary invasive aspergillosis. We report a case of pulmonary aspergilloma in a severely immunocompromised patient with AIDS who stopped taking systemic antifungal treatment in April 1998 and remained well with little progression of invasive aspergillosis up until March 2002 when he died of acute pancreatitis related to a drug interaction of didanosine and tenofovir.

Spinal epidural aspergillosis in a patient with HIV resulting from long-standing (3 years) lung infection

SUMMARY

We present an unusual case of a man with human immunodeficiency virus (HIV) with pulmonary aspergillosis and spinal invasion and compression of the spinal cord occurring during a long period (3 years), as documented by MR imaging and surgical intervention. Invasive pulmonary aspergillosis with cord compression has been reported in the past, but, to the best of our knowledge, none of these have been in a patient with HIV.

Fungal Infections

The incidence of invasive fungal infections has increased dramatically over the past two decades, mostly due to an increase in the number of immunocompromised patients.1–4 Patients who undergo chemotherapy for a variety of diseases, patients with organ transplants, and patients with the acquired immune deficiency syndrome have contributed most to the increase in fungal infections.5 The actual incidence of invasive fungal infections in transplant patients ranges from 15% to 25% in bone marrow transplant recipients to 5% to 42% in solid organ transplant recipients.6,7 The most frequently encountered are Aspergillus species, followed by Cryptococcus and Candida species. Fungal infections are also associated with a higher mortality than either bacterial or viral infections in these patient populations. This is because of the limited number of available therapies, dose-limiting toxicities of the antifungal drugs, fewer symptoms due to lack of inflammatory response, and the lack of sensitive tests to aid in the diagnosis of invasive fungal infections.1 A study of patients with fungal infections admitted to a university-affiliated hospital indicated that community-acquired infections are becoming a serious problem; 67% of the 140 patients had community-acquired fungal pneumonia.8

The use of caspofungin in HIV-infected individuals

Fungal infections are a significant cause of HIV-related morbidity and mortality, particularly in the developing world, but also in countries with access to highly active antiretroviral therapy. New agents are essential to improve present efficacy rates, particularly in cases of drug resistance. Caspofungin is a new antifungal from the echinocandin class and is licensed for the treatment of candidal infections and as a second-line therapy for invasive aspergillosis. In this paper, the pharmacology, interaction and susceptibility data for this agent are reviewed and studies supporting the use of this agent in HIV-infected individuals are examined. Finally, evidence for the use of caspofungin for the treatment of Pneumocystis jiroveci pneumonia, an unlicensed indication, including a case series from our own unit is explored.

A murine model of invasive aspergillosis: variable benefit of interferon-gamma administration under in vitro and in vivo conditions

BACKGROUND

Interferon-gamma modulates host defense in a number of infectious diseases. Previous studies have shown that systemic administration of interferon-gamma (IFN-gamma) can enhance survival in experimental invasive aspergillosis (IA).

METHODS

Using a novel model of murine IA that is characterized by primary pulmonary infection, we investigated the role of IFN-gamma in the phagocytosis and killing of Aspergillus fumigatus by murine neutrophils and pulmonary alveolar macrophages in vitro and the impact of systemic and regional administration of IFN-gamma on the course of IA in glucocorticoid-treated mice.

RESULTS

In vitro, IFN-gamma significantly enhanced phagocytosis and killing function of both neutrophils and alveolar macrophages from normal animals, but not cortisone-treated animals. In vivo, intravenous administration of IFN-gamma did not improve phagocyte recruitment, in vivo killing, or mortality from IA. Regional (intranasal) administration of IFN-gamma to the lungs enhanced recruitment of phagocytic cells to the lungs and improved in vivo killing, but did not alter (and actually worsened) mortality from IA.

CONCLUSIONS

The in vitro and in vivo effects of IFN-gamma in IA are contingent on many variables, including the route of administration and the specific pathogenesis of infection.

Sinusitis in HIV: microbiology and therapy

Rhinosinusitis in the HIV-infected population is an increasingly common finding as HIV infection has transitioned toward becoming a chronic medical condition. In this patient population, rhinosinusitis may be challenging to diagnose and treat effectively. However, adequate diagnostic tools are available, microbial identity can be reasonably anticipated based on the CD4 count, and effective management strategies can be implemented. In this article, we discuss the diagnostic and therapeutic options for HIV-infected patients with rhinosinusitis.

The Aspergillus fumigatus siderophore biosynthetic gene sidA, encoding L-ornithine N5-oxygenase, is required for virulence

Aspergillus fumigatus is the leading cause of invasive mold infection and is a serious problem in immunocompromised populations worldwide. We have previously shown that survival of A. fumigatus in serum may be related to secretion of siderophores. In this study, we identified and characterized the sidA gene of A. fumigatus, which encodes l-ornithine N(5)-oxygenase, the first committed step in hydroxamate siderophore biosynthesis. A. fumigatus sidA codes for a protein of 501 amino acids with significant homology to other fungal l-ornithine N(5)-oxygenases. A stable DeltasidA strain was created by deletion of A. fumigatus sidA. This strain was unable to synthesize the siderophores N',N",N'''-triacetylfusarinine C (TAF) and ferricrocin. Growth of the DeltasidA strain was the same as that of the wild type in rich media; however, the DeltasidA strain was unable to grow in low-iron defined media or media containing 10% human serum unless supplemented with TAF or ferricrocin. No significant differences in ferric reduction activities were observed between the parental strain and the DeltasidA strain, indicating that blocking siderophore secretion did not result in upregulation of this pathway. Unlike the parental strain, the DeltasidA strain was unable to remove iron from human transferrin. A rescued strain (DeltasidA + sidA) was constructed; it produced siderophores and had the same growth as the wild type on iron-limited media. Unlike the wild-type and rescued strains, the DeltasidA strain was avirulent in a mouse model of invasive aspergillosis, indicating that sidA is necessary for A. fumigatus virulence.

Sinusitis in HIV: Microbiology and Therapy

Rhinosinusitis in the HIV-infected population is an increasingly common finding as HIV infection has transitioned toward becoming a chronic medical condition. In this patient population, rhinosinusitis may be challenging to diagnose and effectively treat. However, adequate diagnostic tools are available, microbial identity can be reasonably anticipated based on the CD4 count, and effective management strategies can be implemented. This article discusses the diagnostic and therapeutic options for HIV-infected patients with rhinosinusitis.

Successful treatment of invasive pulmonary aspergillosis in an immunocompetent host

Immunocompromised individuals are susceptible to pulmonary Aspergillus infection, but invasive Aspergillus infection is extremely rare in the presence of normal immunity. A case of invasive pulmonary aspergillosis in an immunocompetent 57-year-old female who was successfully treated with liposomal amphotericin-B is reported here.

Cardiac Aspergillosis in Patients With Acquired Immunodeficiency Syndrome: A Case Report and Review of the Literature

Cardiac aspergillosis is uncommon in patients with acquired immunodeficiency syndrome (AIDS) in the absence of open heart surgery. We report a unique case of a 62-year-old man with AIDS who developed Aspergillus pancarditis with Aspergillus vegetations on mitral valve without evidence of pulmonary aspergillosis. There was extensive embolization to the brain and multiple foci of Aspergillus infection in kidneys and adrenal glands. There are only 10 documented cases of cardiac aspergillosis in the literature (1966–2003) in severely immunocompromised AIDS patients with CD4 T-lymphocyte counts ranging from 10 to 121 cells/μL. The cardiac aspergillosis could result from invasive pulmonary aspergillosis, either by hematogenous dissemination or by direct invasion, and skin Aspergillus infection can be carried through the bloodstream to the right heart in intravenous drug abusers. Most of the reported cases of cardiac aspergillosis were diagnosed at autopsy. Mortality among AIDS patients with cardiac aspergillosis is 100%, despite appropriate therapy.

Site-specific rate constants for iron acquisition from transferrin by the Aspergillus fumigatus siderophores N′,N′′,N′′′-triacetylfusarinine C and ferricrocin

Aspergillus fumigatus is an opportunistic fungal pathogen that causes life-threatening infections in immunocompromised patients. Despite low levels of free iron, A. fumigatus grows in the presence of human serum in part because it produces high concentrations of siderophores. The most abundant siderophores produced by A. fumigatus are N',N'',N'''-triacetylfusarinine C (TAF) and ferricrocin, both of which have thermodynamic iron binding constants that theoretically allow them to remove transferrin (Tf)-bound iron. Urea-polyacrylamide gel electrophoresis was used to measure the change in concentration of Tf species incubated with TAF or ferricrocin. The rate of removal of iron from diferric Tf by both siderophores was measured, as were the individual microscopic rates of iron removal from each Tf species (diferric Tf, N-terminal monoferric Tf and C-terminal monoferric Tf). TAF removed iron from all Tf species at a faster rate than ferricrocin. Both siderophores showed a preference for removing C-terminal iron, evidenced by the fact that k(1C) and k(2C) were much larger than k(1N) and k(2N). Cooperativity in iron binding was observed with TAF, as the C-terminal iron was removed by TAF much faster from monoferric than from diferric Tf. With both siderophores, C-terminal monoferric Tf concentrations remained below measurable levels during incubations. This indicates that k(2C) and k(1C) are much larger than k(1N). TAF and ferricrocin both removed Tf-bound iron with second-order rate constants that were comparable to those of the siderophores of several bacterial pathogens, indicating they may play a role in iron uptake in vivo and thereby contribute to the virulence of A. fumigatus.

Survival of Aspergillus fumigatus in serum involves removal of iron from transferrin: the role of siderophores

Aspergillus fumigatus is a filamentous fungus which can cause invasive disease in immunocompromised individuals. A. fumigatus can grow in medium containing up to 80% human serum, despite very low concentrations of free iron. The purpose of this study was to determine the mechanism by which A. fumigatus obtains iron from the serum iron-binding protein transferrin. In iron-depleted minimal essential medium (MEM), A. fumigatus growth was supported by the addition of holotransferrin (holoTf) or FeCl(3) but not by the addition of apotransferrin (apoTf). Proteolytic degradation of transferrin by A. fumigatus occurred in MEM-serum; however, transferrin degradation did not occur until late logarithmic phase. Moreover, transferrin was not degraded by A. fumigatus incubated in MEM-holoTf. Urea polyacrylamide gel electrophoresis showed that in MEM-holoTf, holoTf was completely converted to apoTf by A. fumigatus. In human serum, all of the monoferric transferrin was converted to apoTf within 8 h. Siderophores were secreted by A. fumigatus after 8 h of growth in MEM-serum and 12 h in MEM-holoTf. The involvement of small molecules in iron acquisition was confirmed by the fact that transferrin was deferrated by A. fumigatus even when physically separated by a 12-kDa-cutoff membrane. Five siderophores were purified from A. fumigatus culture medium, and the two major siderophores were identified as triacetylfusarinine C and ferricrocin. Both triacetylfusarinine C and ferricrocin removed iron from holoTf with an affinity comparable to that of ferrichrome. These data indicate that A. fumigatus survival in human serum in vitro involves siderophore-mediated removal of iron from transferrin. Proteolytic degradation of transferrin may play a secondary role in iron acquisition.

Mucosal and Systemic Fungal Infections in Patients with AIDS

In countries where highly active antiretroviral therapy (HAART) is widely available, a decrease in the incidence of fungal infections has been observed in the last 5 years compared with countries that cannot afford this treatment. Even refractory fungal infections may be controlled when HAART is given to patients, and end-stage AIDS infections, such as aspergillosis, are now only infrequently seen. In contrast, fungal infections in certain regions, such as penicilliosis in Southeast Asia or cryptococcosis in Sub-Saharan Africa, are a growing problem. Antifungal therapy for documented infections has not changed very much during recent years; however, new drugs such as caspofungin and voriconazole may be more effective in the treatment of opportunistic fungal infections, in particular, those involving resistant organisms. Secondary antifungal prophylaxis for many opportunistic pathogens can now be temporarily or even permanently discontinued in many HIV-positive patients who have a marked improvement in immune function parameters, such as CD4(+) cell counts, after initiation of HAART. The link between effective virustatic control of HIV infection and a decreasing incidence of fungal infections has been recognised; and so, despite the availability of very effective new antifungal drugs, the cornerstone of treatment and prevention of opportunistic fungal infections in patients with HIV infection is effective antiretroviral therapy including protease inhibitors.

Outbreak of invasive Aspergillus infection in surgical patients, associated with a contaminated air-handling system

An outbreak of Aspergillus infection at a tertiary care hospital was identified among inpatients who had amputation wounds, peritonitis, allograft nephritis, or mediastinitis. During a 2-year period, 6 patients were identified, all of whom had Aspergillus species recovered from samples from normally sterile sites. All cases clustered in the operating theater during a single 12-day period. To assess operating theater air quality, particle counts were measured as surrogate markers for Aspergillus conidia. A substantial increase in the proportion of airborne particles > or =3 microm in size (range, 3-fold to 1000-fold) was observed in many operating rooms. A confined space video camera identified moisture and contamination of insulating material in ductwork and variable airflow volume units downstream of final filters. No additional invasive Aspergillus wound infections were identified after the operating theater air-handling systems were remediated, suggesting that this unusual outbreak was due to the deterioration of insulating material in variable airflow volume units.

Fungal infections in nontransplant patients with hematologic malignancies

Fungal infections are a major cause of morbidity and mortality in patients with hematologic malignancies. Candida and Aspergillus species are the most important opportunistic fungal pathogens in this patient population. Dimorphic fungi can cause serious infection in immunocompetent persons, but infection is more likely to be disseminated in patients with compromised cell-mediated immunity. Cryptococcus neoformans and Pneumosystis carinii typically cause infections in persons with severe T-cell suppression. The frequency of rare pathogenic fungi commonly resistant to amphotericin B has significantly increased over the past 20 years among patients with hematologic malignancies. Examples of such emerging pathogens include Trichosporon, Fusarium, and Scedosporium species, and dark-walled molds. This article reviews the epidemiology, clinical manifestations, diagnostic evaluation, and treatment of the major fungal pathogens in nontransplant patients with hematologic malignancies.

The clinical spectrum of pulmonary aspergillosis

Aspergillus is a ubiquitous fungus that causes a variety of clinical syndromes in the lung, ranging from aspergilloma in patients with lung cavities, to chronic necrotizing aspergillosis in those who are mildly immunocompromised or have chronic lung disease. Invasive pulmonary aspergillosis (IPA) is a severe and commonly fatal disease that is seen in immunocompromised patients, while allergic bronchopulmonary aspergillosis is a hypersensitivity reaction to Aspergillus antigens that mainly affects patients with asthma. In light of the increasing risk factors leading to IPA, such as organ transplantation and immunosuppressive therapy, and recent advances in the diagnosis and treatment of Aspergillus-related lung diseases, it is essential for clinicians to be familiar with the clinical presentation, diagnostic methods, and approach to management of the spectrum of pulmonary aspergillosis.

Serum stimulates growth of and proteinase secretion by Aspergillus fumigatus

Serum contains iron-binding proteins, which inhibit the growth of most pathogenic microorganisms, including fungi. The purpose of this research was to investigate the effect of serum on growth of the opportunistic fungal pathogen Aspergillus fumigatus. Supplementing minimal essential medium (MEM) with up to 80% human serum or up to 80% fetal bovine serum (FBS) stimulated growth and increased the amount of A. fumigatus dry biomass approximately fourfold. In addition, a 100-fold increase in proteinase secretion, as measured by azocasein hydrolysis, was observed when 10% human serum or 10% FBS was added to MEM. The fungal proteinases secreted in serum-containing media were shown to degrade (3)H-labeled basal lamina proteins. The factor in serum that stimulated proteinase secretion was larger than 10 kDa and was 85% inactivated when the serum was heated for 30 min at 66 degrees C. The proportions of proteinases of each catalytic class secreted by A. fumigatus in the presence of serum were different from the proportions secreted in media containing single proteins. Proteinase secretion did not result from increased protein concentration in the medium per se because bovine serum albumin (BSA) at a concentration equivalent to the concentration of serum produced only 20% of the proteinase activity per milligram (dry weight) that was produced by FBS. Addition of BSA plus 100 microM FeCl(3) to MEM resulted in the same level of growth as addition of serum, indicating that a combination of nutritional factors in serum may stimulate growth. However, the level of proteinase secretion was still only 30% of the level observed with FBS. These data indicate that serum does not inhibit the growth of A. fumigatus and that the nutrients in serum result in high levels of proteinase secretion, potentially increasing the invasiveness of this species.

Central nervous system aspergillosis: a 20-year retrospective series

Over the past 20 years at my institution, 71 patients with invasive necrotizing aspergillosis have been encountered; 42 have shown central nervous system (CNS) involvement by autopsy (40) or surgical biopsy (2). Most non-CNS aspergillosis patients had invasive disease confined to the lung, and only 2 with dissemination to 3 or more organs did not have spread to the CNS. In addition to the expected post-transplantation and hematologic malignancy cases, other risk groups identified included those with chronic asthma and steroid use, acquired immunodeficiency syndrome, thermal burn, hepatic failure, and postoperative infection. Unusual cases manifested with basilar meningitis, myelitis, proptosis caused by sino-orbital disease, or epidural and subdural Aspergillus abscesses. The extent of gross neuropathologic disease ranged from subtle abscesses to massive hemorrhagic necrosis causing herniation and death. In addition to the expected hemorrhagic necrosis, extensive hemorrhage, focal purulent meningitis, and subtle bland infarctions were also seen. Distinctive microscopic findings encountered included 1 case with numerous meningeal granulomas and multinucleated giant cells and 4 cases showing the Splendore-Hoeppli phenomenon. During the same period, single cases of cerebritis caused by morphologically similar fungi (Pseudoallescheria boydii [Scedosporium apiospermum], Scedosporium inflatum, Chaetomium sp) were identified and were indistinguishable from CNS aspergillosis clinically and pathologically.

The epidemiology of invasive pulmonary aspergillosis at a large teaching hospital

OBJECTIVE

To characterize the epidemiology of invasive pulmonary aspergillosis (IPA).

DESIGN

A retrospective case series.

SETTING

An 850-bed, academic, tertiary-care medical center.

PARTICIPANTS

Adult inpatients, between January 1, 1990, and December 31, 1998, with either a histopathology report consistent with IPA or a discharge diagnosis of aspergillosis.

METHODS

We reviewed medical records and categorized case-patients as definitive or probable and acquisition of IPA as nosocomial, indeterminate, or community using standard definitions. To determine the rate of aspergillus respiratory colonization, we identified all inpatients who had a respiratory culture positive for Aspergillus species without a histopathology report consistent with IPA or a discharge diagnosis of aspergillosis. Three study intervals were defined: interval 1, 1990 to 1992; interval 2, 1993 to 1995; and interval 3, 1996 to 1998. Carpeting in rooms for patients following heart-lung and liver transplant was removed and ceiling tiles were replaced during interval 1; a major earthquake occurred during interval 2.

RESULTS

72 case-patients and 433 patients with respiratory colonization were identified. Acquisition was nosocomial for 18 (25.0%), indeterminate for 9 (12.5%), and community-acquired for 45 (62.5%) case-patients. Seventeen (23.6%) of the 72 case-patients had prior transplants, including 15 solid organ and 2 bone marrow. The IPA rate per 100 solid organ transplants (SOTs) decreased from 2.45 during interval 1 to 0.93 during interval 2 and to 0.52 during interval 3 (chi-square for trend, 5.44; P<.05). The hospitalwide IPA rate remained stable at 0.03 per 1,000 patient days.

CONCLUSIONS

The SOT IPA rate decreased after intervals 1 and 2, although the hospitalwide IPA rate remained stable during the study period. Post-earthquake hospital demolition and construction occurring after interval 2 was not associated with an increase in the rate of IPA at our institution.

Differences in sialic acid density in pathogenic and non-pathogenic Aspergillus species

ASPERGILLUS: fumigatus is a ubiquitous soil fungus that causes invasive lung disease in the immunocompromised host. The structure of the conidial wall has not been well characterized although it is thought that adhesins present on the surface are involved in attachment of the conidia to host lung cells and proteins, which is a prerequisite for the establishment of infection. Negatively charged carbohydrates on the conidial surface have been previously identified as the molecules responsible for attachment of conidia to extracellular matrix proteins. The aim of this research was to identify carbohydrates on the conidial surface that contribute to its negative charge. Direct chemical analysis and indirect binding assays have demonstrated that A. fumigatus possesses sialic acids on the conidial surface. Pre-treatment of A. fumigatus conidia with sialidase decreased binding of a sialic acid-specific lectin, Limax flavus agglutinin (LFA), to the conidial surface and decreased adhesion of conidia to the positively charged polymer poly L-lysine. Two other sialic acid-specific lectins, Maackia amurensis agglutinin and Sambucus nigra agglutinin, exhibited negligible binding to A. fumigatus conidia indicating that 2,3-alpha- and 2,6-alpha-linked sialic acids are not the major structures found on the conidial surface. Mild acid hydrolysis and purification of conidial wall carbohydrates yielded a product that had the same R(F) as the Neu5Ac standard when analysed by high-performance thin-layer chromatography. A density of 6.7 x 10(5) sialic acid residues per conidium was estimated using a colorimetric assay. Conidia grown on a minimal medium lacking sialic acid also reacted with LFA, indicating that sialic acid biosynthesis occurs de novo. Sialic acid biosynthesis was shown to be regulated by nutrient composition: the density of sialic acids on the surface of conidia grown in minimal media was lower than that observed when conidia were grown on rich, complex media. It has previously been shown that pathogenic Aspergillus species adhere to basal lamina proteins to a greater extent than non-pathogenic Aspergillus species. To determine whether the expression of sialic acid on the conidial surface was correlated with adhesion to basal lamina, conidia from other non-pathogenic Aspergillus species were tested for their reactivity towards LFA. Flow cytometric analysis demonstrated that A. fumigatus had a significantly greater sialic acid density than three non-pathogenic Aspergillus species. Sialic acids on the conidial wall may be involved in adhesion to fibronectin, a component of the basal lamina, as binding of A. fumigatus conidia to fibronectin was strongly inhibited in the presence of a sialylated glycoprotein.

Pulmonary mycosis in AIDS

We retrospectively reviewed our series of 35 pulmonary mycosis in patients with AIDS, observed from 1987 to 1999, to correlate the imaging and pathologic findings. We further evaluated the frequency of fungal pneumonia before and after the use of a highly active antiretroviral therapy (HAART). Early recognition of pulmonary mycosis is imperative in these patients and improved survival can be achieved with early CT detection and prompt institution of high-dose antifungal therapy.

Aspergillosis among people infected with human immunodeficiency virus: incidence and survival. Adult and Adolescent Spectrum of HIV Disease Project

Aspergillosis is a life-threatening fungal infection in immunocompromised people, including people infected with human immunodeficiency virus (HIV). We determined the incidence of aspergillosis among HIV-infected people and survival after aspergillosis diagnosis by use of a national HIV surveillance database. Among 35,252 HIV-infected patients, the incidence of aspergillosis was 3.5 cases per 1000 person-years (p-y; 95% confidence interval [CI], 3.0-4.0 per 1000 p-y). Incidence was higher among people aged > or =35 years (4.1 per 1000 p-y, 95% CI, 3. 5-4.8), among people with CD4 counts of 50-99 cells/mm(3) (5.1 per 1000 p-y, 95% CI, 2.8-7.3), or CD4 counts of <50 cells/mm(3) (10.2 per 1000 p-y, 95% CI, 8.0-12.2), versus people with CD4 counts of >200 cells/mm(3), people with > or =1 acquired immune deficiency syndrome-defining opportunistic illness (8.6 per 1000 p-y, 95% CI, 7.4-9.9), and people who were prescribed at least one medication associated with neutropenia (27.7 per 1000 p-y, 95% CI, 21.0-34.3). Median survival time after diagnosis of aspergillosis was 3 months, and 26% survived for > or =1 year. These findings suggest that aspergillosis is uncommon, occurs especially among severely immunosuppressed or leukopenic HIV-infected people, and is associated with poor survival.

Central nervous system aspergillosis in patients with human immunodeficiency virus infection. Report of 6 cases and review

Central nervous system (CNS) aspergillosis is a relatively uncommon complication of human immunodeficiency virus (HIV) infection. We describe 6 patients with the acquired immunodeficiency syndrome (AIDS) who developed CNS aspergillosis, and we review a total of 33 cases of CNS aspergillosis among HIV-infected individuals that were diagnosed by histology and/or culture. All patients were diagnosed with advanced HIV infection. Major risk factors for the disease included neutropenia and corticosteroid use. The most common presenting symptoms were nonspecific neurologic manifestations including headache, cranial or somatic nerve weakness or paresthesia, altered mental status, and seizures. The most common sites of additional Aspergillus involvement were the lungs, sinuses, ears, and orbits, while in one-fourth of the cases CNS was the only site of Aspergillus infection. The final diagnosis of CNS aspergillosis was made on autopsy in more than half the cases, and medical treatment of CNS aspergillosis was unsuccessful in all cases. CNS aspergillosis should be included in the differential diagnosis of HIV-infected patients who present with nonspecific neurologic symptoms and signs. If we take into account the much higher prevalence of invasive aspergillosis of the lungs, the findings in the present report suggest that CNS aspergillosis in HIV-infected individuals occurs more often as a result of direct extension from the sinuses, orbits, and ears than through hematogenous spread from the lungs. Physicians should be aware that the CNS might be the only site of Aspergillus involvement and include CNS aspergillosis in the differential diagnosis of HIV-infected patients presenting with focal neurologic signs and symptoms, especially when the head CT reveals hypodense lesions.

Adhesion of Aspergillus species to extracellular matrix proteins: evidence for involvement of negatively charged carbohydrates on the conidial surface

Invasive lung disease caused by Aspergillus species is a potentially fatal infection in immunocompromised patients. The adhesion of Aspergillus fumigatus conidia to proteins in the basal lamina is thought to be an initial step in the development of invasive aspergillosis. The purpose of this study was to determine the mechanism of adhesion of A. fumigatus conidiospores to basal-lamina proteins and to determine whether conidia possess unique adhesins which allow them to colonize the host. We compared conidia from different Aspergillus species for the ability to bind to purified fibronectin and intact basal lamina. Adhesion assays using immobilized fibronectin or type II pneumocyte-derived basal lamina showed that A. fumigatus conidia bound significantly better than those of other Aspergillus species to both fibronectin and intact basal lamina. Neither desialylation nor complete deglycosylation of fibronectin decreased the binding of A. fumigatus conidia to fibronectin, suggesting that oligosaccharides on fibronectin were not involved in conidiospore binding. Further evidence for this hypothesis came from experiments using purified fragments of fibronectin; A. fumigatus conidia preferentially bound to the nonglycosylated 40-kDa fragment which contains the glycosaminoglycan (GAG) binding domain. Negatively charged carbohydrates, including dextran sulfate and heparin, as well as high-ionic-strength buffers, inhibited binding of A. fumigatus conidia to both fibronectin and intact basal lamina, suggesting that negatively charged carbohydrates on the surface of the conidium may bind to the GAG binding domain of fibronectin and other basal-lamina proteins. These data provide evidence for a novel mechanism of conidial attachment whereby adherence to fibronectin and other basal-lamina proteins is mediated via negatively charged carbohydrates on the conidial surface.

Human immunodeficiency virus-related primary cutaneous aspergillosis

A 31-year-old Caucasian man with AIDS developed a crusted violaceous plaque under adhesive tape near a central venous catheter insertion site. Histological examination demonstrated a ruptured hair follicle containing collections of fungal hyphae typical of Aspergillus spp. A culture of the biopsy material grew Aspergillus fumigatus. The patient responded to removal of the catheter and the occlusive dressing, in addition to itraconazole therapy. Aspergillosis must be considered in the differential diagnosis of cutaneous lesions in human immunodeficiency virus-infected patients, in particular when the lesion occurs under adhesive tape or an occlusive dressing.

Invasive fungal sinusitis in the acquired immunodeficiency syndrome

Invasive fungal sinusitis can present as either an indolent or fulminant process that primarily affects immunocompromised individuals. In this article, the clinical characteristics of four cases of invasive fungal sinusitis in patients with AIDS are analyzed and 22 additional previously reported cases in the literature are reviewed. In addition to HIV infection, other variables common to these cases include facial pain or headache out of proportion to clinical or radiographic findings, CD4 lymphocyte count less than 50 cells/mm(3), absolute neutrophil count less than 1,000 cells/mm(3), subtle radiographic evidence suggesting invasion and an indolent clinical course of the invasive infection. The most common pathogen detected was Aspergillus fumigatus. Maintaining a high index of suspicion, critically assessing these clinical findings, and prudently reviewing CT scans may facilitate early diagnosis and prompt intervention in these patients.

Proton translocating ATPase mediated fungicidal activity of a novel complex carbohydrate: CAN-296

CAN-296 is a complex carbohydrate (approximately 4300 Da) isolated from the cell wall of Mucor rouxii. It exhibits excellent in vitro fungicidal activity against a wide spectrum of pathogenic yeasts, including isolates resistant to azoles and polyenes. The rapid irreversible action of CAN-296 on intact fungal cells and protoplasts suggested a membrane-located target for its action. The proton translocating ATPase (H+-ATPase) of fungi is an essential enzyme required for the regulation of intracellular pH and nutrient transport. Inhibition of H+-ATPase leads to intracellular acidification and cell death. We therefore investigated the effect of CAN-296 on H+-ATPase-mediated proton pumping by intact cells of Candida and Saccharomyces species by measuring the glucose-induced acidification of external medium. CAN-296 inhibited proton pumping of Candida albicans, Candida glabrata, Candida krusei, Candida guilliermondii and Saccharomyces cerevisiae at low concentrations (0.078-1.25 mg/l). Other commonly used antifungal agents such as amphotericin B, itraconazole and fluconazole had no effect on H+-ATPase-mediated proton pumping. A clinical isolate of C. glabrata with reduced in vitro susceptibility (MIC = 10 mg/l) to CAN-296 also showed resistance to CAN-296 inhibition of proton pumping. Purified membrane fractions rich in H+-ATPase activity were not inhibited by CAN-296 suggesting that the effect on the H+-ATPase-mediated proton pumping in intact yeast cells is an indirect effect, perhaps mediated by local or global disruption of the plasma membrane. These results suggest that the inhibition of fungal H+-ATPase is at least partly responsible for the antifungal activity of CAN-296.

Proton-pumping-ATPase-targeted antifungal activity of a novel conjugated styryl ketone

NC1175 (3-[3-(4-chlorophenyl)-2-propenoyl]-4-[2-(4-chlorophenyl)vinyle ne]-1- ethyl-4-piperidinol hydrochloride) is a novel thiol-blocking conjugated styryl ketone that exhibits activity against a wide spectrum of pathogenic fungi. Incubation of NC1175 with various concentrations of cysteine and glutathione eliminated its antifungal activity in a concentration-dependent fashion. Since NC1175 is a lipophilic compound that has the potential to interact with cytoplasmic membrane components, we examined its effect on the membrane-located proton-translocating ATPase (H(+)-ATPase) of yeast (Candida albicans, Candida krusei, Candida guilliermondii, Candida glabrata, and Saccharomyces cerevisiae) and Aspergillus (Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus, and Aspergillus nidulans) species. The glucose-induced acidification of external medium due to H(+)-ATPase-mediated expulsion of intracellular protons by these fungi was measured in the presence of several concentrations of the drug. NC1175 (12.5 to 50 microM) inhibited acidification of external medium by Candida, Saccharomyces, and Aspergillus species in a concentration-dependent manner. Vanadate-inhibited hydrolysis of ATP by membrane fractions of C. albicans was completely inhibited by 50 microM NC1175, suggesting that the target of action of NC1175 in these fungi may include H(+)-ATPase.

Acute pancreatitis in human immunodeficiency virus-infected patients: a review

Acute pancreatitis is a clinical condition that develops when active pancreatic inflammation is induced by stimuli noxious to the pancreas. Patients infected with human immunodeficiency virus (HIV) often have histologic abnormalities of the pancreas, and acute pancreatitis is much more common in HIV-infected patients than in the general population. This article reviews the epidemiology and etiology of acute pancreatitis in HIV-infected patients. The clinical presentation and treatment of acute pancreatitis in HIV-infected patients are also reviewed.

AIDS-related visceral aspergillosis: an underdiagnosed disease during life?

Five out of nine consecutive patients with HIV-related visceral aspergillosis observed by us since 1984 were diagnosed only at necropsy examination. The histopathological features of these five patients [two with isolated pneumonia, one with central nervous system (CNS) involvement, one with brain abscess and respiratory disease and one with pulmonary, pleural and kidney infection] have been evaluated according to epidemiological, clinical and radiological features. On the basis of our experience, life-threatening aspergillosis, which is often misdiagnosed or missed in the setting of HIV infection and AIDS, should be suspected in patients with far-advanced underlying disease and unexplained signs and symptoms, even in the absence of some presumed risk factors (i.e. neutropenia and prior steroid treatment). Plain chest radiography and bronchoscopy with broncholaveolar lavage may fail to reveal respiratory disease, CNS aspergillosis is not necessarily associated with suggestive neuroradiological features and disseminated disease may present with multiorgan failure. The unfavorable outcome of this emerging AIDS complication can be improved only by earlier diagnosis based on invasive techniques and appropriate and timely treatment.

Granulocyte colony-stimulating factor and azole antifungal therapy in murine aspergillosis: role of immune suppression

Outbred ICR mice were immune suppressed either with hydrocortisone or with 5-fluorouracil and were infected intranasally with Aspergillus fumigatus. Beginning 3 days before infection some groups of mice were given recombinant human granulocyte colony-stimulating factor (G-CSF), SCH56592 (an antifungal triazole), or both. Corticosteroid-pretreated mice responded to SCH56592 and had reduced counts in lung tissue and prolonged survival. In these mice, G-CSF strongly antagonized the antifungal activity of SCH56592. Animals treated with both agents developed large lung abscesses with polymorphonuclear leukocytes and large amounts of Aspergillus. In contrast, mice made neutropenic with 5-fluorouracil and then infected with A. fumigatus conidia benefited from either G-CSF or triazoles, and the effect of the combination was additive rather than antagonistic. Host predisposing factors contribute in different ways to the outcome of growth factor therapy in aspergillosis.

Changing role of invasive aspergillosis in AIDS--a case control study

OBJECTIVE

From December 1993 until January 1996 we observed 10 cases of invasive aspergillosis in a cohort of 140 patients with AIDS (7%). By contrast, no invasive aspergillosis was diagnosed in a cohort of 278 patients with AIDS between 1986 until 1993.

METHODS

Case controls were assigned randomly to each patient with invasive aspergillosis from the total pool of HIV-infected patients. Patients with invasive aspergillosis were studied retrospectively by matched-pairs analysis with respect to risk factors, radiological, microbiological and autopsy findings.

RESULTS

Patients with aspergillosis had more AIDS-defining events (3.5 [2-5] vs. 2 [2-3], median [range], P < 0.05) and a longer median survival time with full-blown AIDS (31.5 [14-45] months vs. 20.5 [5-32] months, P < 0.005) than their case controls. Patients with invasive aspergillosis tended to have lower white blood cell counts and exhibited significantly decreased median CD4 counts (7 [0-44]/mm3 vs. 27 [8-57]/mm3, P < 0.05).

CONCLUSIONS

Due to better management of opportunistic diseases and improved antiretroviral therapy, the lifespan of patients with full blown AIDS is prolonged. Patients who have survived four or more AIDS-defining events are at risk for invasive aspergillosis. This risk is associated with low white blood cell counts and CD4 cell counts.

Pulmonary aspergillosis and invasive disease in AIDS: review of 342 cases

Aspergillosis is an infrequent but commonly fatal infection among HIV-infected individuals. We review 342 cases of pulmonary Aspergillus infection that have been reported among HIV-infected patients, with a focus on invasive disease. Invasive pulmonary aspergillosis usually occurs among patients with <50 CD4 cells/mm3. Major predisposing conditions include neutropenia and steroid treatment. Fever, cough, and dyspnea are each present in >60% of the cases. BAL is often suggestive, but biopsy specimens are necessary for definite diagnosis. Amphotericin B is the mainstay of treatment and mortality is > 80%. Avoiding neutropenia and judicious use of steroids may be helpful in prevention. Aggressive diagnostic approach, early initiation of treatment, adequate dosing of antifungals, and close follow-up may improve the currently dismal prognosis.

Risk factors and outcomes associated with identification of Aspergillus in respiratory specimens from persons with HIV disease. Pulmonary Complications of HIV Infection Study Group

STUDY OBJECTIVES

To examine the significance of previously suggested risk factors and assess outcomes associated with Aspergillus identification in respiratory specimens from HIV-seropositive individuals.

DESIGN

This was a nested case-control study. Patients who had Aspergillus species identified in respiratory specimens were matched at the time of study entry 1:2 with control subjects according to study center, age, gender, race, HIV transmission category, and CD4 count.

SETTING

The multicenter Pulmonary Complications of HIV Infection Study.

PARTICIPANTS

HIV-seropositive study participants.

MEASUREMENTS AND RESULTS

Between November 1988 and March 1994, Aspergillus species were detected in respiratory specimens from 19 (1.6%) participants. The rate of Aspergillus identification among participants with CD4 counts <200 cells per cubic millimeter during years 2 through 5 after study entry ranged from 1.2 to 1.9%. Neutropenia, a CD4 count <30 cells per cubic millimeter, corticosteroid use, and Pneumocystis carinii infection were associated with subsequent identification of Aspergillus in respiratory specimens. Cigarette and marijuana use, previously suggested risk factors, were not associated with Aspergillus respiratory infection. A substantially greater proportion of patients with Aspergillus compared with control subjects died during the study (90% vs 21%). Excluding four cases first diagnosed at autopsy, 67% died within 60 days after Aspergillus was detected.

CONCLUSIONS

Although Aspergillus is infrequently isolated from HIV-infected persons, the associated high mortality would support serious consideration of its clinical significance in those with advanced disease and risk factors.

Aspergillus species isolated from clinical specimens: suggested clinical and microbiological criteria to determine significance

OBJECTIVE: To test a case-definition score for its usefulness in the diagnosis of pulmonary aspergillosis and to determine microbiological criteria useful in assessing the significance of isolating Aspergillus species from lower respiratory tract specimens (LRTS). METHODS: With the exception of cystic fibrosis patients, all patients with Aspergillus isolated from LRTS were classified according to a clinical case-definition ratio as: (i) colonized patients; (ii) patients with isolates of undetermined significance; (iii) patients with proven or probable pulmonary aspergillosis. Retrospective review of pathology records led to the identification of additional patients with histologically compatible pulmonary aspergillosis. Microbiological variables were compared between aspergillosis and colonization groups. RESULTS: Seventy-six isolates of Aspergillus species were obtained from 73 patients. For patients with proven (n=2) or histologically compatible pulmonary aspergillosis (n=5), the case definition ratio was always higher than 0.3; no patient with proven disease was classified into the colonized group. Compared to patients considered to be colonized (n=26), patients with proven or probable pulmonary aspergillosis showed a significant difference in the total number of Aspergillus colonies cultured per episode. In addition, for bronchoalveolar lavage specimens, the mean number of Aspergillus colonies/agar plate was also significantly higher in the latter group. The sensitivity and specificity of Aspergillus spp. detection by culture of LRTS for proven or probable pulmonary aspergillosis was 35.7% and 70.4%, respectively. CONCLUSION: The case-definition ratio used in this study helps interpret the clinical significance of Aspergillus isolated from LRTS. Data for assessment should include the absolute number of colonies recovered from culture of any LRTS and, for bronchoalveolar lavage, the mean number of Aspergillus colonies per agar plate.