Invasive aspergillosis in mice immunosuppressed with cyclosporin A, tacrolimus (FK506), or sirolimus (rapamycin)

Cyclosporin A, tacrolimus, and sirolimus are immunosuppressive agents initially described as antifungal compounds with different activities for Aspergillus species. The outcome of invasive aspergillosis in mice treated with each agent was investigated in outbred CD-1 mice. Immunosuppressant or vehicle alone was administered from days -1 to +14. Mice were infected on day 0 with resting Aspergillus conidia via lateral tail vein injection. Survival was significantly greater with most regimens than for mice treated with cyclosporin A (100 mg/kg/day; median survival, 3 days): tacrolimus, 1 mg/kg/day (6.5 days, P = .003); sirolimus, 1 or 10 mg/kg/day (7.5 and 9.5 days, respectively; P = .002 and .0001); and vehicle alone (6.5 days, P = .001). However, mice treated with 10 mg/kg/day of tacrolimus survived a median of 4.5 days (P = .25). Survival in the 10-mg sirolimus group did not differ from that of mice given vehicle alone (P = .55). Histologic evaluation suggested the improved survival with tacrolimus and sirolimus may be due in part to direct anti-Aspergillus activity.

Retroviral-mediated gene transfer of gp91phox into bone marrow cells rescues defect in host defense against Aspergillus fumigatus in murine X-linked chronic granulomatous disease

The X-linked form of chronic granulomatous disease (X-CGD), an inherited deficiency of the respiratory burst oxidase, results from mutations in the X-linked gene for gp91phox, the larger subunit of the oxidase cytochrome b. The goal of this study was to evaluate the impact of retroviral-mediated gene transfer of gp91phox on host defense against Aspergillus fumigatus in a murine model of X-CGD. Retrovirus vectors constructed using the murine stem cell virus (MSCV) backbone were used for gene transfer of the gp91phox cDNA into murine X-CGD bone marrow cells. Transduced cells were transplanted into lethally irradiated syngeneic X-CGD mice. After hematologic recovery, superoxide production, as monitored by the nitroblue tetrazolium (NBT) test, was detected in up to approximately 80% of peripheral blood neutrophils for at least 28 to 35 weeks after transplantation. Neutrophil expression of recombinant gp91phox and superoxide production were significantly less than wild-type neutrophils. However, 9 of 9 mice with approximately 50% to 80% NBT+ neutrophils after gene transfer did not develop lung disease after respiratory challenge with 150 to 500 A fumigatus spores, doses that produced disease in 16 of 16 control X-CGD mice. In X-CGD mice transplanted with mixtures of wild-type and X-CGD bone marrow, > or = 5% wild-type neutrophils were required for protection against A fumigatus challenge. These data suggest that expression of even low levels of recombinant gp91phox can substantially improve phagocyte function in X-CGD, although correction of very small percentage of phagocytes may not be sufficient for protection against A fumigatus.

Detection of galactomannan and complement activation in the pregnant mouse during experimental systemic aspergillosis

Foeto-placental infections are obtained when pregnant mice are challenged intravenously with conidial suspensions of Aspergillus fumigatus. This experimental model, which is used without any immuno-suppressive pretreatment, can be employed to screen for differences in foeto-placental infectivity of A. fumigatus strains when the number of colony-forming units (CFUs) in conidial suspensions used for infection is from 1 x 10(5) to 1 x 10(6). In the foeto-placental unit, hyphal growth was initiated at the periphery of the placental disc from which infection spread to the central parts of the placenta, the extrafoetal membranes and the foetus. Complement activation was noticed as a consequence of pregnancy and conidial inoculation, but was neither dose-dependent nor related to the extent of infection. Galactomannan was present in the plasma of infected mice and, in contrast to the situation in bovine placental aspergillosis, can be used as a good marker of foeto-placental aspergillosis.

Alloimmunization after granulocyte transfusions

BACKGROUND

Although granulocyte transfusions are recommended for neutropenic patients with bacterial infections that are unresponsive to antibiotic therapy, the presence of white cell (WBC) antibodies in the recipient can render these transfusions ineffective.

STUDY DESIGN AND METHODS

A 25-year-old man with chronic granulomatous disease experienced a pulmonary transfusion reaction while receiving granulocyte transfusions, and he was found to be immunized to neutrophil antigen NA2. A retrospective study of alloimmunization to HLA and neutrophil antigens in 18 patients with chronic granulomatous disease who had also received repeated granulocyte transfusions was then performed. Sera were tested in lymphocytotoxicity, granulocyte agglutination, granulocyte immunofluorescence, monoclonal antibody immonobilization of granulocyte antigen, and immunoprecipitation assays.

RESULTS

After the granulocyte transfusions, sera from 14 of the 18 patients contained WBC antibodies. Seven sera samples reacted in the lymphocytotoxicity, granulocyte immunofluorescence, and granulocyte agglutination assays; seven reacted in the lymphocytotoxicity and granulocyte immunofluorescence assays but not the granulocyte agglutination assay, and four did not react. When the monoclonal antibody immobilization of granulocyte antigen assay was used, three sera samples reacted with Fc gamma receptor III, three with the 58- to 64-kDa protein carrying the neutrophil antigen NB1, one with CD11a, and one with CD18. Antibodies from three patients immunoprecipitated a neutrophil protein of 60 kDa. Overall, antibodies to neutrophil antigens other than HLA could be detected in sera from eight patients. Transfusion reactions occurred in 11 of the 14 individuals with WBC antibodies and in none of the 4 without antibodies. Seven pulmonary reactions occurred in patients with WBC antibodies. The patients with WBC antibodies were given significantly more granulocyte concentrates (78 +/- 65 vs. 29 +/- 15 units, p < 0.05).

CONCLUSION

Recipients of granulocyte transfusions often become alloimmunized. Screening for WBC antibodies periodically during transfusions, after adverse reactions, or before subsequent transfusions is indicated. If WBC antibodies are present, no further granulocyte transfusions should be given unless the granulocytes are collected from HLA- and/or neutrophil antigen-compatible donors.

Specific antibody detection in human aspergillosis: a GEMO* multicentre evaluation of a rapid immunoelectrophoresis method (Paragon). Group d'Etude des Mycoses Opportunistes

A new immunoelectrophoresis system, the Paragon system, was evaluated in three different hospital centres with the aim of improving standardization of the serodiagnosis of human aspergillosis. To select the most efficient antigen, various commercial and home-made antigens were first tested on 19 sera from 19 patients with highly probable aspergillosis. The value measured using the Paragon anti-Aspergillus antibody detection system was then compared with the results obtained by conventional serological diagnostic methods (conventional immunoelectrophoresis, enzyme linked-immunosorbent assay, indirect immunofluorescence): this step was performed using the first 19 sera as well as 16 other sera from 13 patients with suspected aspergillosis. Concordant results were obtained in 28 cases. The discrepancies observed with seven sera were probably related to differences in the nature of the antigens. Paragon immunoelectrophoresis proved to be a practicable technique requiring only a small amount of serum and giving results within a shorter time than competitive methods (24-48 h). Its major drawbacks compared with conventional immunoelectrophoresis are some difficulties in reading, fewer precipitin lines and the relatively high cost of routine analysis.

Disseminated aspergillosis in a dog: an immunohistochemical study

An immunohistopathological study of a case of disseminated aspergillosis in a 4-year-old female German shepherd dog was carried out to characterize the cellular infiltrate within the granulomatous lesions of various organs. Polyclonal antibodies specific for canine immunoglobulins IgG, IgM, IgA, complement C3c, human CD3 antigen (pan T-lymphocyte marker), human lysozyme and alpha-1-antitrypsin and a monoclonal antibody for myeloid/ histocyte antigen (MAC 387) (macrophage marker) were used. In the mycotic granulomata of the heart, liver, spleen and kidneys a correlation was found between the numbers of CD3+ T lymphocytes and lysozyme+ macrophages (r = 0.9944, P = 0.0056), and between the numbers of CD3+ T lymphocytes and MAC 387+ macrophages (r = 0.9943, P = 0.0057).

Specific IgG4 responses during chronic and transient antigen exposure in aspergillosis

The factors that lead to increased production of specific IgG subclasses are still largely unknown. Recent studies suggest that increased IgG4 responses may be related to prolonged antigen exposure. We present data showing that increased IgG4 responses are found under conditions of chronic exposure to Aspergillus fumigatus (Af) antigen. IgG(total), IgG subclass, and IgE responses were studied using ELISA, CAP-FEIA, and immunoblotting techniques in patients with pulmonary aspergilloma (PA), which is a model for chronic antigen exposure, and allergic bronchopulmonary aspergillosis (ABPA), characterized by transient antigen exposure. Af-IgG1 was increased in patients with PA compared with those with ABPA. Patients with PA and IgE responses to Af and/or other inhalant allergens showed significantly higher Af-IgG4 responses than did patients with PA and negative IgE responses or patients with ABPA. Surveillance studies over time in individual patients showed concordance in Af-IgG1 and Af-IgG4 responses. Both Af-IgG1 and Af-IgG4 levels followed the course of disease progression and treatment. Immunoblotting revealed correlations between Af-IgG1 and Af-IgG4 binding to most, but not all, antigenic Af components. This study documents for the first time increased IgG4 levels under conditions of chronic exposure to fungal antigen in PA. Furthermore, a significantly higher IgG4 response was found in those patients with PA who produced IgE. The transient exposure to Af antigen during exacerbation of ABPA gives rise to transient elevations in IgG4 levels.

Aspergillus fumigatus specific antibodies in multitransfused children with human immunodeficiency virus (HIV) infection in relation to serum levels of Interleukin-2, gamma Interferon and tumour necrosis factor

Anti-Aspergillus fumigatus antibodies (IgG and IgE class) and serum levels of cytokines (gamma Interferon, Interleukin-2 and tumour necrosis factor-alpha) were studied in multitransfused (MT) children in relation to human immunodeficiency virus (HIV) infection. The specific antibodies to Aspergillus fumigatus were present in 25 per cent of MT children seropositive for HIV as compared to only 2 per cent among HIV-negative MT children (X2 = 14, P < 0.001). Estimation of serum cytokines level in MT children showed that the asymptomatic HIV-infected children had elevated levels of gamma interferon (Y-IFN) and tumor necrosis factor-alpha (TNF-alpha) without any alteration of Interleukin-2 (IL-2) level, compared to HIV-negative group. However, clinically diagnosed cases of AIDS in the HIV-infected group showed elevation of all the three cytokines levels as compared to HIV negative group, as well as asymptomatic HIV infected group. Presence or absence of concomitant A. fumigatus infection did not lead to alteration of Y-IFN and IL-2 level in the HIV infected group, while TNF-alpha levels were markedly raised in the cases with evidences of presence of A. fumigatus specific antibodies irrespective of whether the group belonged to asymptomatic HIV infection or clinically proven cases of AIDS. The significance of these altered cytokines profile with respect to occurence of A. fumigatus infection in HIV-positive MT children has been discussed.

[Extralobar sequestration presenting increased serum CA19-9 and associated with lung aspergillosis--an unusual case]

In a thirty-four-year old man, an asymptomatic abnormal mass shadow was detected in S10 of the left lower lobe on chest X-ray film. The serum CA19-9 was abnormally elevated 395 U/ml). The definitive histological diagnosis was not obtained by both transbronchial and percutaneous lung biopsy preoperatively. Surgery demonstrated that an abnormal mass was separated from S10 of the left lower lobe by a fibrous tissue, and it contained severe inflammatory changes and abscess. Extralobar pulmonary sequestration was diagnosed, but aberrant arteries were not conformed. Sequestered lung and a part of the lower lobe were resected en bloc. The serum CA19-9 level returned to normal postoperatively. Aspergillus was only detected in the sequestered lung by postoperative cultre. Moreover, CA19-9 level in the fluid of this sequestered lung was markedly high, 50,000 U/ml. Production of CA19-9 was demonstrated in bronchial epithelium of the sequestered lung immunohistochemically. Extralobar pulmonary sequestration associated with aspergillosis and high serum CA19-9 is very rare. To our knowledge, this is the first reported case in the literatures.

Prospective sandwich enzyme-linked immunosorbent assay for serum galactomannan: early predictive value and clinical use in invasive aspergillosis

BACKGROUND

The delay between the onset of invasive aspergillosis and the start of antifungal therapy is crucial for the patient's recovery. Early diagnosis is difficult in cancer patients through lack of precocious specific signs. We have investigated the clinical usefulness of circulating Aspergillus antigen monitoring in pediatric hematology patients with a new sensitive sandwich enzyme-linked immunosorbent assay.

METHODS

A prospective study was conducted by assessing circulating galactomannan levels in high risk patients. Thirty-seven patients studied during an 18-month period were evaluated twice weekly during neutropenic phases with the sandwich enzyme-linked immunosorbent assay for serum Aspergillus galactomannan.

RESULTS

Twelve patients had one or more episodes of positive circulating galactomannan detection, 10 of whom developed presumptive invasive aspergillosis. The clinical and radiologic signs occurred at a mean of 13.4 days (range, 0 to 48) after circulating galactomannan detection and reversed in 6 patients treated with amphotericin B at the same time circulating galactomannan detection became negative. Reappearance of circulating galactomannan was observed during subsequent neutropenic periods in 3 patients.

CONCLUSIONS

The detection of galactomannan at concentrations as low as 1 ng/ml can be useful for the early initiation of antifungal therapy and monitoring treatment in clinically documented lung aspergillosis. This technique coupled with chest computed tomography could help to restrict the need of invasive diagnostic procedures in fragile patients.

Immunoblotting patterns in the serodiagnosis of aspergilloma: antibody response to the 90kDa Aspergillus fumigatus antigen

At present there are no accepted criteria to assess the usefulness of Western blot assays for the serodiagnosis of aspergilloma. An Aspergillus fumigatus cytosolic fraction complex (CFC) composed of four proteins (p90, p60, p40, and p37) has been identified. The usefulness of Western blotting with CFC antigens for the serodiagnosis of aspergilloma was evaluated in 25 patients with well-established diagnoses and in 94 controls. The most consistently reactive antigen was p90 (92% of patients with aspergilloma), followed by p40 (76%) and the entire CFC taken together (76%). With these data, interpretive criteria for positive and negative immunoblots were established, with p90 indicated as a helpful marker of aspergilloma.

The use of respiratory-tract cultures in the diagnosis of invasive pulmonary aspergillosis

PURPOSE

To define the role of lower-respiratory-tract cultures in the diagnosis of invasive pulmonary aspergillosis (IPA) in immunocompromised hosts.

METHODS

Immunocompromised patients with a positive, nonbiopsy, lower-respiratory-tract culture for Aspergillus species were classified as having definite, probable, indeterminate, or no IPA. Culture data, positive predictive values (PPVs), correlation with clinical and radiographic findings, and the relationship between the number of specimens submitted and the likelihood of recovering Aspergillus were assessed.

RESULTS

Definite or probable IPA was diagnosed in 72% of episodes from patients with hematologic malignancy, granulocytopenia, or bone-marrow transplant; in 58% of those with solid-organ transplant or using corticosteroids; and in 14% of those with human immunodeficiency virus infection. The PPV of cultures ranged from 14% in the latter group to 72% in the first group (bone-marrow-transplantation subgroup, 82%). Fungal cultures were more often positive than were routine cultures (P < 0.001). Clinical and radiographic findings suggestive of IPA were present more frequently in infected than uninfected patients (59% versus 24%, P < 0.025); and 73% versus 6%, (P < 0.0001, respectively). Infected patients with > or = 1 positive node had more cultures submitted than a control group of patients with no positive cultures (5.8 +/- 4.7 versus 2.1 +/- 2.2 cultures, P < 0.001).

CONCLUSION

Recovery of Aspergillus species from high-risk patients is associated with invasive infection. Clinical and radiographic correlations help to separate true- from false-positive cultures. At least 3 sputum specimens should be submitted for fungal culture whenever fungal infection is suspected.

Comparison of an enzyme immunoassay and latex agglutination test for detection of galactomannan in the diagnosis of invasive aspergillosis

Aspergillus antigenemia was followed up in 215 consecutively observed bone marrow transplant (BMT) patients over a period of two years, using both a latex agglutination test and a sandwich immunocapture enzyme immunoassay (EIA) with a rat antigalactomannan monoclonal antibody as capture and detector antibody. For each patient, sequential sera (3 to 20) were obtained before and after BMT. No positivity was observed before BMT. After BMT, the EIA and latex agglutination test were positive in 19 and 4 patients respectively of 25 patients with confirmed aspergillosis and 14 and 7 of 15 patients with probable aspergillosis. In 19 of 25 patients with confirmed aspergillosis and 9 of 15 patients with probable aspergillosis, the EIA was more sensitive and detected infection earlier than the latex test. In all positive cases, antigenemia rapidly increased in sequential samples and remained strongly positive. In 31 of 169 (19%) BMT patients without clinical signs of aspergillosis, the EIA was occasionally positive in samples taken within the first month after BMT, giving a specificity of 81% in these patients. In non-BMT patients suffering from other diseases (n = 77), the specificity was 98.7%. The overall positive and negative predictive values for the EIA were 54% and 95% respectively. These results favour the use of EIA for early diagnosis and monitoring of aspergillosis in BMT patients, although the predictive value of transient positivity remains to be ascertained.

Primary lymph node invasive aspergillosis

A case of apparently primary lymph node granulomatous aspergillosis is described. A review of the so-called primary aspergillosis cases since 1977 shows that granulomatous instead of exudative inflammation patterns have been observed in histological sections only when neither major nor minor predisposing factors have been detected in the clinical history of the patients. A possible pathogenetic role of selectively impaired cell-mediated immune response in these cases is hypothesized. Flucytosine treatment is indicated in a few selected cases of deep aspergillosis.

Evaluation of eight antibody tests and one antigen test for the diagnosis of invasive aspergillosis

Eight Aspergillus antibody detection assays--three indirect haemagglutination assays (IHA-LD, IHA-Roche, IHA-Fumouze), three enzyme immunoassays (EIA-IgG, EIA-IgM, EIA-IgA, DDV) and two complement fixation tests (CF-metabolic and CF-somatic, Virion--and one latex agglutination test (LAT) for Aspergillus galactomannan antigen detection (Sanofi Pasteur) were evaluated in 14 patients with proven invasive aspergillosis (a total of 47 serum samples and one cerebrospinal fluid sample) and in 68 selected control individuals (one selected serum sample each). For the antibody tests, sensitivity ranged from 14% to 36% and specificity from 72% to 99%. The antigen detection test had a sensitivity of 36% and a specificity of 100%. Currently commercially available antibody detection assays for the serodiagnosis of invasive aspergillosis are inadequate. The antigen detection test appears to be highly specific, but lacks sufficient sensitivity.

Activation of the complement system by pathogenic fungi

Fungi have been studied as prototype activators of the complement cascade since the early 1900s. More recently, attention has focused on the role of the complement system in the pathogenesis of fungal infections. The interactions of Cryptococcus neoformans and Candida albicans with the complement system are the most widely characterized; however, all pathogenic fungi examined to date have the ability to initiate the complement cascade. The molecular mechanisms for initiation and regulation of the complement cascade differ from one fungus to another, most likely reflecting differences in the structure of the outer layers of the cell wall. The molecular bases for such differences remain to be identified. Studies of mycoses in experimental animals with induced or congenital deficiencies in the complement system demonstrate that complement is an important innate system for control of fungal infection. Contributions to host resistance include opsonization and generation of inflammatory mediators. Inflammation induced by chemotactic products of the complement system may contribute to the pathogenesis of some fungal infections.

[Chronic necrotizing pulmonary aspergillosis in a patient with chronic pulmonary emphysema]

A 67-year-old man with pulmonary emphysema was admitted to the hospital because of left back pain. Chest roentgenography revealed an infiltrate in the left upper lobe, with cavitation, Mycetoma-like shadows were seen in the cavities about 3 weeks later, and a test for the precipitating antibody to Aspergillus fumigatus was positive. Chronic necrotizing pulmonary aspergillosis (CNPA) was diagnosed, and fluconazole was given. A chest roentgenogram taken 4 weeks later showed resolution of both the mycetoma-like shadows and much of the infiltrate. Systemic immunosuppression was highly unlikely: the patient had not been undergoing corticosteroid therapy, and had no predisposing conditions, such as a chronic debilitating illness or diabetes mellitus. In that sense, this case is similar to another reported recently, in which CNPA was associated with chronic obstructive pulmonary disease in an immunocompentent patient.

[Morphofunctional description of protective cell reactions in aspergillosis]

Pathomorphosis of aspergillosis was studied in 160 male guinea pigs which were given intraperitoneally a small dose (50000 conidia per 1 ml of isotonic sodium chloride solution) of Aspergillus fumigatus. Protective cell reactions under condition of a normal immune resistance are described. Immunological and mycological methods allowed one to reveal a variability of morphological changes at early stages of aspergillosis and to follow the development of secondary immunodeficiency on the disease day 14.

Arthropathy, leucopenia and recurrent infection associated with a TcR gamma delta population

This report documents the presence of clonal gamma delta T-cell receptor (TcR) population in the blood of a patient who presented with an arthropathy of undetermined cause, leucopenia and splenomegaly. There was no evidence for lymphoid malignancy clinically or at post-mortem. The phenotype and genotype of the clonal T-cell population were not associated with the predominant TcR delta rearrangement found in peripheral blood gamma delta cells, but were similar to those found in gamma delta TcR cells infiltrating rheumatoid synovium. The data indicate the presence of a monoclonal population of gamma delta cells TcR cells which in the face of continued immunosuppression behaved benignly. The case may represent a cytomorphologically atypical example of the large granular lymphocytes, neutropenia and arthropathy syndrome/lymphoproliferative disease of granular lymphocytes and, although the patient's clinical features were not 'classical', rheumatoid arthritis (RA) may have been the underlying primary disorder.

Aspergillus fumigatus antigens

Cytosolic fractions of mycelial extracts from Aspergillus nidulans, A. flavus, and three different isolates of A. fumigatus, grown to stationary phase in Czapek-Dox-AOAC medium, were tested by immunoblotting for the presence of antigens reactive to 80 serum samples from aspergilloma patients. Fifty control serum samples were used to determine the specificity of the reactions. In the A. fumigatus cytosolic fraction a group of four main antigenic bands (p90, p60, p40 and p37) was consistently recognized (in total or partial form) by 90% of the serum samples from the aspergilloma patients. This group of antigens was designated as the 'cytosolic fraction complex' (CFC). As confirmed by two-dimensional electrophoresis followed by immunoblotting with aspergilloma serum samples, each of the four antigenic bands is formed of several isoforms of acidic glycopeptides with slightly different pls. All the isoforms are at least N-glycosylated, as demonstrated by endoglycosidase H removal of a considerable amount of sugar residues. The relationship of these antigens with certain other A. fumigatus antigens previously reported in the literature, and their potential use in the immunodiagnosis of aspergilloma, are discussed.