Imaging findings in acute invasive pulmonary aspergillosis: clinical significance of the halo sign

Volume dependency for culture of fungi from respiratory secretions and increased sensitivity of Aspergillus quantitative PCR

Diagnosis of aspergillosis is often difficult. We compared fungal yields from respiratory specimens using the Health Protection Agency standard culture method (BSOP57), a higher volume undiluted culture method Mycology Reference Centre Manchester (MRCM) and Aspergillus quantitative real time polymerase chain reaction (qPCR). Sputum, bronchial aspirate and bronchoalveolar lavage (BAL) samples (total 23) were collected from aspergillosis patients. One fraction of all samples was cultured using the MRCM method, one BSOP57 and one was used for qPCR. The recovery rate for fungi was significantly higher by MRCM (87%) than by BSOP57 (8.7%) from all 23 specimens. Sputum samples were 44% positive by MRCM compared to no fungi isolated (0%) by BSOP57. Bronchial aspirates were 75% positive by MRCM and 0% by BSOP57. BAL samples were positive in 20% by MRCM and 10% by BSOP57. qPCR was always more sensitive than culture (95.6%) from all samples. In general, over 100 mould colonies (81 Aspergillus fumigatus) were grown using the MRCM method compared with only one colony from BSOP57. This study provides a reference point for standardisation of respiratory sample processing in diagnostic laboratories. Culture from higher volume undiluted respiratory specimens has a much higher yield for Aspergillus than BSOP57. qPCR is much more sensitive than culture and the current UK method requires revision.

Establishment and application of real-time quantitative PCR for diagnosing invasive aspergillosis via the blood in hematological patients: targeting a specific sequence of Aspergillus 28S-ITS2

BACKGROUND

Invasive aspergillosis (IA) is an important cause of morbidity and mortality in immunocompromised individuals. This study was conducted to identify a desirable target DNA sequence for the diagnosis of aspergillosis using real-time quantitative polymerase chain reaction (qPCR).

METHODS

Genomic DNA was extracted from Aspergillus, Candida, and bacteria species, and qPCR was applied to validate a partial ribosomal DNA 28S-ITS2 sequence. Ethylenediaminetetraacetic acid-anticoagulated blood samples were collected from 72 febrile hematological patients, while total DNA was isolated from plasma and whole blood for the Aspergillus qPCR. The results were analyzed using a receiver operating characteristic curve. All cases were evaluated using the revised European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) diagnostic criteria.

RESULTS

Use of qPCR yielded positive results for 15 Aspergillus species but negative results for Candida species, bacterial strains, and human DNA. The limit of detection was one copy per microliter of DNA. Analytical sensitivity and specificity were six copies of DNA and 100%, respectively. The standard curve showed that qPCR was reliable for Aspergillus detection and that significantly more DNA copies were obtained from whole blood than from plasma (P < 0.001). At a cut-off value ≥ 25 copies/μL, the diagnostic sensitivity and specificity for IA using 28S-ITS2 qPCR were 90.9% and 73.4%, respectively.

CONCLUSIONS

The use of qPCR with whole blood to detect and verify the 28S-ITS2 sequence is a specific and useful way to diagnose IA.

Diagnostic methods for invasive fungal diseases in patients with hematologic malignancies

Invasive fungal disease is associated with increased morbidity and mortality in hematologic malignancy patients and hematopoietic stem cell transplant recipients. Timely recognition and treatment of invasive fungal diseases in these patients are essential and decrease mortality. However, conventional definitive diagnostic methods are difficult and time consuming. While conventional microbiological and histopathological methods are still needed for a definitive diagnosis of invasive fungal disease, new noninvasive diagnostic methods including serologic and molecular biomarkers are now available. These new diagnostic methods facilitate an early diagnosis of invasive fungal disease and allow for utilization of a pre-emptive treatment approach, which may ultimately lead to improved treatment outcomes and reduced toxicity.

Invasive fungal infections in acute leukemia

Invasive fungal infection (IFI) is among the leading causes for morbidity, mortality, and economic burden for patients with acute leukemia. In the past few decades, the incidence of IFI has increased dramatically. The certainty of diagnosis of IFI is based on host factors, clinical evidence, and microbiological examination. Advancement in molecular diagnostic modalities (e.g. non-culture-based serum biomarkers such as β-glucan or galactomannan assays) and high-resolution radiological imaging has improved our diagnostic approach. The early use of these diagnostic tests assists in the early initiation of preemptive therapy. Nonetheless, the complexity of IFI in patients with leukemia and the limitations of these diagnostic tools still mandate astute clinical acumen. Its management has been further complicated by the increasing frequency of infection by non-Aspergillus molds (e.g. zygomycosis) and the emergence of drug-resistant fungal pathogens. In addition, even though the antifungal armamentarium has expanded rapidly in the past few decades, the associated mortality remains high. The decision to initiate antifungal treatment and the choice of anti-fungal therapy requires careful consideration of several factors (e.g. risk stratification, local fungal epidemiologic patterns, concomitant comorbidities, drug-drug interactions, prior history of antifungal use, overall cost, and the pharmacologic profile of the antifungal agents). In order to optimize our diagnostic and therapeutic management of IFI in patients with acute leukemia, further basic research and clinical trials are desperately needed.

Fungal diagnosis: how do we do it and can we do better?

BACKGROUND

Morbidity and mortality remain high for patients with invasive fungal infections (IFIs) despite an increasing number of antifungals and other treatments. Many studies indicate that delayed or inaccurate diagnosis and treatment are major causes of poor outcomes in patients with IFIs.

OBJECTIVE

The aim of the current paper is to provide a review of traditional and newer approaches to the diagnosis of IFIs, with a particular focus on invasive candidiasis (IC) and aspergillosis (IA). Recent studies from the author's institution are highlighted, along with an advancement in cryptococcal meningitis diagnosis that should improve the care of AIDS and its opportunistic infection in many developing countries.

FINDINGS

Currently available tools for the diagnosis of IFIs include traditional methods like histopathology, culture, and radiology, and newer antigen- and PCR-based diagnostic assays. Attempts have also been made to predict IFIs based on colonization or other factors, including genetic polymorphisms impacting IFI susceptibility in high-risk patients. Biopsy with histopathologic analysis is often not possible in patients suspected of pulmonary aspergillosis due to increased bleeding risk, and blood cultures for IC, IA, or other IFIs are hindered by poor sensitivity and slow turnaround time which delays diagnosis. Radiology is often used to predict IFI but suffers from inability to differentiate certain pathogens and does not generally provide certainty of IFI diagnosis. Newer antigen-based diagnostics for early diagnosis include the β-glucan assay for IFIs, galactomannan assay for IA, and a recent variation on the traditional cryptococcal antigen (CRAG) test with a Lateral Flow Assay for invasive cryptococcosis. PCR-based diagnostics represent additional tools with high sensitivity for the rapid diagnosis of IFIs, although better standardization of these methods is still required for their routine clinical use.

CONCLUSION

Better understanding of the strengths and weaknesses of currently available diagnostic tools, and further devising linked strategies to best implement them either alone or in combination, would greatly improve early and accurate diagnosis of IFIs and improve their successful management.

Utility of galactomannan antigen detection in bronchoalveolar lavage fluid in immunocompromised patients

Diagnosis of invasive pulmonary aspergillosis (IPA) is a challenging process in immunocompromised patients. Galactomannan (GM) antigen detection in bronchoalveolar lavage (BAL) fluid is a method to detect IPA with improved sensitivity over conventional studies. We sought to determine the diagnostic yield of BAL GM assay in a diverse population of immunocompromised patients. A retrospective review of 150 fiberoptic bronchoscopy (FOB) with BAL for newly diagnosed pulmonary infiltrate in immunocompromised patients was performed. Patient information, procedural details and laboratory studies were collected. BAL and serum samples were evaluated for GM using enzyme-linked immunoassay. Of 150 separate FOB with BAL, BAL GM was obtained in 143 samples. There were 31 positive BAL GM assays. In those 31 positive tests, 13 were confirmed as IPA, giving a positive predictive value of 41.9%. There was one false negative BAL GM. Of the 18 false positive BAL GM, 4 were receiving piperacillin-tazobactam and 11 were receiving an alternative beta-lactam antibiotic. BAL GM assay shows excellent sensitivity for diagnosing IPA. There was a significant number of false positive BAL GM assays and several of those patients were receiving beta-lactam antibiotics at the time of bronchoscopy.

The pulmonologist's point of view on lung infiltrates in haematological malignancies

In haematological malignancies, the development of lung disease is a common source of significant morbidity and mortality for this population of patients. There is a wide range of infectious and non-infectious aetiologies that can be responsible for such complications. It is a major challenge to make an early diagnosis of aetiology in order to choose the most suitable treatment. Computed tomography (CT) of the chest has undeniably become a crucial tool in diagnosing these cases of lung disease. Although it is not possible to make a definitive diagnosis of aetiology based solely on analysing CT scan findings in these complex patients, there are some abnormalities that are highly suspicious for particular diagnoses. CT, therefore, allows the clinician to put forward and prioritise possible diagnoses that may then be considered in view of clinical information and laboratory study results. There must be multidisciplinary involvement in the management of lung disease patients and there must be an ongoing dialogue between the radiologist and the clinician.

Evaluation and Management of Bacterial and Fungal Infections Occurring in Patients with a Hematological Malignancy: A 2011 Update

Patients with a hematological malignancy are a heterogeneous patient population who are afflicted with diseases that range from rapidly fatal acute leukemia to indolent lymphoma or chronic leukemia. Treatment options for these patients range from observation to hematopoietic stem cell transplantation (HSCT), but all patients are more susceptible to infection. The problem of infection is dynamic with continued shifts in pathogenic organisms and microbial susceptibilities, new treatment regimens that further diminish immune function, and patients receiving treatment who are now older and frailer. The classic patterns of immunodeficiency for patients with a hematological malignancy include: periods of profound neutropenia, increased iatrogenic risks (i.e., central vascular catheters), and cellular immune suppression that affects HSCT recipients, patients with lymphoid malignancies, and those receiving treatment with corticosteroids or agents like alemtuzumab [1–4]. Recent advances in antimicrobial drug development, new technology, clinical trial results, and further clinical experience have enhanced the database on which to make infection prophylaxis and treatment decisions. However, the practicing clinician must remember that the majority of basic infection management principles for patients who are neutropenic remain unchanged.

Immediate versus deferred empirical antifungal (IDEA) therapy in high-risk patients with febrile neutropenia: a randomized, double-blind, placebo-controlled, multicenter study

Empirical antifungal therapy is widely used in high-risk neutropenic hematology patients with fever persisting for more than 4 days. This clinical trial assessed whether immediate empirical therapy with voriconazole could lower the rates of invasive fungal infections (IFIs) compared with this approach. In a double-blind, placebo-controlled, multicenter study, patients with acute leukemia undergoing chemotherapy or allogeneic hematopoietic stem cell transplantation (HSCT) recipients were randomized to broad-spectrum antibacterial therapy plus voriconazole (immediate) or placebo (deferred) after the onset of neutropenic fever. If fever persisted for 96 h, patients were switched to open-label intravenous voriconazole; oral treatment was permitted after 96 h. The primary endpoint was the rate of proven/probable IFIs between Days 2 and 28 after fever onset in the modified intent-to-treat (mITT) complete-case population. One hundred and forty-seven patients were randomized to immediate (n = 81) or deferred (n = 66) voriconazole. In the mITT population, six patients in the immediate group and nine in the deferred group developed proven/probable IFI between Days 2 and 28 (p = 0.258). The safety profiles were similar in both groups. While immediate empirical therapy with voriconazole appears to be safe in febrile neutropenic high-risk patients, it was not associated with a significant reduction in IFIs compared with therapy deferred for 96 h after fever onset.

Interlaboratory and interstudy reproducibility of a novel lateral-flow device and influence of antifungal therapy on detection of invasive pulmonary aspergillosis

Interest in lateral-flow devices (LFDs) as potential point-of-care assays for the diagnosis of infectious diseases has increased. Our objective was to evaluate the interlaboratory and interstudy reproducibility and the effects of antifungal therapy on an LFD developed for invasive pulmonary aspergillosis (IPA) detection. An established neutropenic guinea pig model of IPA caused by Aspergillus fumigatus was used. At predetermined time points (1 h and 3, 5, and 7 days postinoculation), blood and bronchoalveolar lavage (BAL) fluid were collected from infected and uninfected animals. In a separate experiment, guinea pigs were treated with posaconazole (10 mg/kg of body weight orally [p.o.] twice a day [BID]), voriconazole (10 mg/kg p.o. BID), liposomal amphotericin B (10 mg/kg intraperitoneally [i.p.] once a day [QD]), or caspofungin (2 mg/kg i.p. QD), and samples were collected on days 7 and 11. Each laboratory independently evaluated the IgG monoclonal antibody-based LFD. Galactomannan and (1 → 3)-β-D-glucan were also measured using commercially available kits. Good interlaboratory agreement was observed with the LFD, as the results for 97% (32/33) of the serum and 78.8% (26/33) of the BAL fluid samples from infected animals were in agreement. Good interstudy agreement was also observed. The serum sensitivity of each surrogate-marker assay was reduced in animals treated with antifungals. In contrast, these markers remained elevated within the BAL fluids of treated animals, which was consistent with the fungal burden and histopathology results. These results demonstrate that the LFD assay is reproducible between different laboratories and studies. However, the sensitivity of this assay and other markers of IPA may be reduced with serum in the presence of antifungal therapy.

Have novel serum markers supplanted tissue diagnosis for invasive fungal infections in acute leukemia and transplantation?

Invasive fungal infections (IFIs) are difficult to diagnose, especially early in the course of infection when antifungal therapy is most effective. There are two commercially available biomarker assays useful for detection of the IFIs most commonly seen in patients with hematologic malignancies, the galactomannan and beta glucan assays. The former is specific for aspergillosis, the latter positive for not only Aspergillus and Candida species, but several other clinically relevant fungal pathogens as well. Both have good assay performance characteristics, provide rapid test results, are widely available, can be assayed non-invasively, and are positive early in the course of infection, often before onset of signs and symptoms of infection. Adoption of these assays into clinical practice has led to reduced need to perform invasive procedures to obtain deep tissue to establish the diagnosis of invasive fungal infections. Improved survival rates from aspergillosis are, in part, due to earlier detection of infection and earlier therapy.

Invasive Pulmonary Aspergillosis in Patients with Acute-on-chronic Liver Failure

Objective:

Patients with acute-on-chronic liver failure (AoCLF) are prone to various infections, including invasive pulmonary aspergillosis (IPA). This retrospective study investigated the relationship between AoCLF and IPA in a large patient cohort.

Methods:

Twenty-nine out of 470 patients with AoCLF, who were diagnosed with definite or probable IPA by clinical and laboratory parameters and were treated with voriconazole, were analysed for predisposing factors for IPA and clinical outcome.

Results:

Imaging findings, such as the halo sign and increased white blood cell count, contributed to the early diagnosis of IPA. Patients with AoCLF and IPA experienced fever, cough and chest pain and, despite treatment with antifungal therapy, most (25/29 patients) died within 7 days. Possible risk factors for IPA included prolonged antibiotic therapy and dexamethasone exposure.

Conclusions:

AoCLF with prolonged antibiotic therapy and dexamethasone exposure carries a high risk for IPA. AoCLF patients with IPA involved in this study exhibited fever, cough, chest pain and increased white blood cell count, and their imaging findings were useful for the early diagnosis of IPA.

Invasive aspergillosis in a renal transplant recipient successfully treated with interferon-gamma

Invasive aspergillosis is a serious complication of solid organ transplantation. An early diagnosis is hampered by the lack of reliable serum markers and, even if appropriately diagnosed and treated with current antifungal agents, has a high mortality rate. We report a case of invasive pulmonary and cerebral aspergillosis in a renal transplant patient treated with IFN-γ in conjunction with combination anti-fungal therapy for six weeks in whom complete resolution of the fungal infection was achieved. Renal function remained intact throughout the treatment period. Surveillance CT scans of the chest and head showed resolution of prior disease but revealed a new left upper lobe mass four months after completion of treatment with IFN-γ. Biopsy of the lesion was positive for primary lung adenocarcinoma, for which she underwent left upper lobe resection. The pathology report confirmed clear surgical margins and lymph nodes and no evidence of fungal hyphae. IFN-γ should be considered early in the management of invasive aspergillosis in renal transplant patients. To date, allograft rejection has not been encountered.

Co-infection with invasive pulmonary aspergillosis and Pneumocystis jirovecii pneumonia after corticosteroid therapy

A 95-year-old man with chronic obstructive pulmonary disease and chronic hepatitis C virus infection was treated for acute lung injury caused by Chlamydophila pneumoniae with antibiotics and high-dose corticosteroids. In total, 7,500 mg methylprednisolone and 680 mg prednisolone were administered over 21 days. However, respiratory failure progressed, and chest computed tomography (CT) scan showed bilateral ground-glass opacity and cavity-forming consolidation in the right upper lobe. Despite intensive therapy, the patient died of multiple organ failure on day 7. CT-guided necropsy was performed, and pathological examination revealed invasive pulmonary aspergillosis and Pneumocystis jirovecii pneumonia. Invasive pulmonary aspergillosis and P. jirovecii pneumonia are both life-threatening opportunistic fungal infections. Co-infection of these organisms is rare but possible if the patient is in an extremely immunocompromised state. Short-term but high-dose systemic corticosteroid therapy was considered to be the risk factor in this case. We should pay more attention to immunocompromised hosts who might be suffering from co-infection of opportunistic infections. Moreover, we need to consider preventive measures in such high-risk cases.

How I manage pulmonary nodular lesions and nodular infiltrates in patients with hematologic malignancies or undergoing hematopoietic cell transplantation

Pulmonary nodules and nodular infiltrates occur frequently during treatment of hematologic malignancies and after hematopoietic cell transplantation. In patients not receiving active immunosuppressive therapy, the most likely culprits are primary lung cancer, chronic infectious or inactive granulomata, or even the underlying hematologic disease itself (especially in patients with lymphoma). In patients receiving active therapy or who are otherwise highly immunosuppressed, there is a wider spectrum of etiologies with infection being most likely, especially by bacteria and fungi. Characterization of the pulmonary lesion by high-resolution CT imaging is a crucial first diagnostic step. Other noninvasive tests can often be useful, but invasive testing by bronchoscopic evaluation or acquisition of tissue by one of several biopsy techniques should be performed for those at risk for malignancy or invasive infection unless contraindicated. The choice of the optimal biopsy technique should be individualized, guided by location of the lesion, suspected etiology, skill and experience of the diagnostic team, procedural risk of complications, and patient status. Although presumptive therapy targeting the most likely etiology is justified in patients suspected of serious infection while evaluation proceeds, a structured evaluation to determine the specific etiology is recommended. Interdisciplinary teamwork is highly desirable to optimize diagnosis and therapy.

(1-3)-β-D-Glucan vs Galactomannan Antigen in Diagnosing Invasive Fungal Infections (IFIs)

Invasive fungal infections (IFIs) are serious and often life-threatening complications in patients with haematological malignancies. Early diagnosis and the initiation of efficacious antifungal treatments could affect the prognosis of these patients. The detection of (1-3)-β-D-Glucan (BDG) could be a promising non-culture-based, noninvasive tool for IFI analyses in haemato-oncological patients, allowing the diagnosis of the two major IFIs, invasive aspergillosis (IA) and invasive candidiasis (IC), with a single test. The aim of this work was to evaluate and compare the use of the BDG in combination with the galactomannan antigen (GAL) assay in order to exclude or confirm suspected IFIs. Sera from 46 haemato-oncological patients (24 with proven/probable IFI and 22 without IFI symptoms) were evaluated retrospectively for the detection of GAL and BDG. In 24 patients, the serum BDG levels facilitated IFI diagnosis: 18 probable IA, 3 proven IA and 3 IC. In the remaining 22 patients, the BDG level helped exclude IFIs. The BDG was positive earlier than GAL in 5/24 cases [three of probable invasive aspergillosis (IA), one of proven IA and one case of proven invasive candidiasis (IC)] and was positive at the same time as GAL in 19/24 cases; in no case was GAL positive before BDG was. The BDG detection is useful, however, the test has a great limitation because it is a completely manual procedure.

Invasive Mold Infections in Pediatric Cancer Patients Reflect Heterogeneity in Etiology, Presentation, and Outcome: A 10-Year, Single-Institution, Retrospective Study

BACKGROUND

There is scarcity of data regarding invasive mold infections (IMIs) in children with cancer.

METHODS

We retrospectively identified patients (18 years old or younger) with malignant disease who developed proven or probable IMIs (European Organization for Research on the Treatment of Cancer/Mycoses Study Group criteria) during a 10-year period (1998-2008). We reviewed their risk factors and clinical characteristics and assessed their crude mortality rates and treatment outcomes 12 weeks after IMI diagnosis.

RESULTS

Forty-eight patients (30 males) were identified, 30 (63%) of whom had a proven IMI. The most prevalent mold were Aspergillus species (40%), followed by Mucorales (20%) and Fusarium species (11%). Acute leukemia was the most common underlying malignancy (39 patients, [81%]). Twenty-three (59%) of them had refractory leukemia. Neutropenia was present at the day of IMI diagnosis in 67% of the patients. Sixty-two percent of the patients received prior corticosteroids. The dominant site of infection was the lungs (79%), followed by skin (29%) and sinuses (10%). Seventy-one percent of patients had radiological findings suggestive of fungal pneumonia (either nodules or masses). The mainstay of antifungal therapy was a lipid formulation of amphotericin B. Antifungal therapy resulted in 54% response rate (33% complete) at 12 weeks. The crude 12-week mortality rate was 31%. Logistic regression analysis demonstrated that monocytopenia (P = .013), malnutrition (P = .012), and intensive care admission in the month prior to IMI diagnosis (P = .027) were risk factors for death within 12 weeks.

CONCLUSIONS

Although Aspergillus spp. was the most common mold in our pediatric cancer population, the epidemiology of the IMIs was diverse. Adults and children share similar risk factors for and epidemiology of IMIs.

Importance of pharmacokinetic considerations for selecting therapy in the treatment of invasive fungal infections

Invasive fungal infections continue to be a significant cause of morbidity and mortality among at-risk patients. Over the last decade, the epidemiology of invasive mycoses has been defined by increasing rates of infection caused by azole-resistant yeast (Candida glabrata, Candida krusei), Aspergillus, and in some centers, non-Aspergillus moulds, such as Fusarium species, Scedosporium species, and Mucorales. Early and appropriate antifungal therapy is crucial for a favorable clinical outcome. When selecting antifungal therapy--especially during the initial acute phases of treatment--spectrum of activity and pharmacokinetic characteristics are key treatment considerations. Important pharmacokinetic considerations for selecting antifungal therapy in the treatment of invasive fungal infections include drug-drug interactions and variability in adsorption that may limit efficacy during the early phase of treatment, poor oral availability, and variable tissue distribution. A patient's underlying condition and pharmacogenetics also may affect the pharmacokinetics of antifungal drugs, resulting in interpatient pharmacokinetic differences.

Radiological and clinical findings of 25 patients with invasive pulmonary aspergillosis: retrospective analysis of 2150 liver transplantation cases

OBJECTIVE

The purpose of this study was to evaluate the radiological and clinical findings of invasive pulmonary aspergillosis (IPA) after liver transplantation.

METHODS

This study included 25 consecutive liver transplant recipients with histologically confirmed IPA after liver transplantation. Radiological examinations performed for diagnosis were available in all patients. Clinical findings and changes in clinical response and radiological findings after treatment were also evaluated.

RESULTS

3 main radiological findings were identified: nodules, 64% (16/25); masses, 36% (9/25); and consolidations in a patchy pattern, 20% (5/25). A tree-in-bud pattern was found in 12% (3/25) of patients. In 8 (32%) of 25 patients, we found a combination of 2 or more of these signs: 5 (20%) patients presented with concurrent nodules accompanied by patchy consolidations and/or tree-in-bud, and 3 (12%) patients showed masses accompanied by large consolidations. A halo sign was observed in 20 (80%) of 25 patients. Hypodense sign and cavitary lesions were encountered in 17 (68%) of 25 patients. Follow-up radiological findings after treatment showed improvement in 18 patients, no change in 4 patients and progression in 3 patients. There were three aspergillosis-associated deaths during the follow-up period. The onset time of IPA was a median of 31 days after transplantation. The most common symptom at diagnosis was fever (n=15). None of the 25 patients had leukopaenia at the time of the diagnosis of IPA.

CONCLUSIONS

The most common radiological findings of IPA after liver transplantation are multiple nodules with or without halo sign, masses and consolidations, which usually appear about 1 month after transplantation.

Detection of galactomannan in bronchoalveolar lavage fluid samples of patients at risk for invasive pulmonary aspergillosis: analytical and clinical validity

Invasive pulmonary aspergillosis (IPA) is frequent and often fatal in immunosuppressed patients. Timely diagnosis of IPA improves survival but is difficult to make. We examined the analytical and clinical validity of galactomannan (GM) testing of bronchoalveolar lavage (BAL) fluid in diagnosing IPA in a mixed population by retrospectively reviewing records of 251 consecutive at-risk patients for whom BAL fluid GM testing was ordered. The performance of the enzyme immunoassay was evaluated by using a range of index cutoffs to define positivity. Three samples were associated with proven IPA, 56 were associated with probable IPA, 63 were associated with possible invasive fungal disease (IFD), and 129 were associated with no IFD. Using a BAL fluid GM index of ≥0.8 (optimal optical density [OD] index cutoff identified by a receiver operating characteristic curve), the sensitivity in diagnosing proven and probable IPA was 86.4%, and the specificity was 90.7%. At this cutoff, positive and negative predictive values were 81% and 93.6%, respectively. However, an OD index value of ≥3.0 corresponded to a 100% specificity, thus ruling the disease in, irrespective of the pretest probability. Conversely, an OD index cutoff of <0.5 corresponded to a high sensitivity, virtually always ruling the disease out. For all values in between, the posttest probability of IPA depends largely on the prevalence of disease in the at-risk population and the likelihood ratio of the OD index value. Detection of GM in BAL fluid samples of patients at risk of IPA has an excellent diagnostic accuracy provided results are interpreted in parallel with clinico-radiological findings and pretest probabilities.

Prognosis of invasive pulmonary aspergillosis in patients with hematologic diseases in Korea

Background

The aim of this study was to investigate therapeutic outcomes and assess factors associated with therapeutic outcomes in hematologic patients with invasive pulmonary aspergillosis (IPA).

Methods

We analyzed all consecutive cases of IPA in adults with hematologic diseases from January 2008 to January 2009 at a Catholic Hematopoietic Stem Cell Transplantation (HSCT) Center in Seoul, Korea.

Results

A total of 54 patients were identified. Underlying diseases were acute myelogenous leukemia (n=25), acute lymphoblastic leukemia (n=10), myelodysplastic syndrome (n=7), chronic myelogenous leukemia (n=3), multiple myeloma (n=3), severe aplastic anemia (n=2) and other hematologic diseases (n=4). Twenty six patients (48.2%) were assessed as having a favorable response, of which 16 patients (29.6%) showed complete response. Overall 12-week mortality and IPA attributable mortality were 38.9% (n=21) and 33.3% (n=18), respectively. In multivariate analysis, uncontrolled underlying disease (odds ratio [OR], 7.31; 95% confidence interval [CI], 1.49~35.94; p=0.014) was associated with an unfavorable response, and for 12-week mortality, uncontrolled underlying disease (OR, 11.79; 95% CI, 1.49~93.46; p=0.020) and hypoalbuminemia (OR, 9.89; 95% CI, 1.42~68.99; p=0.021) were significantly poor prognostic factors.

Conclusion

IPA still remains as a poor therapeutic outcome, especially in patients with refractory hematologic diseases.

Aspergillus infection and extracorporeal membrane oxygenation support

BACKGROUND

The clinical characteristics of patients with Aspergillus isolation while supported on extracorporeal membrane oxygenator (ECMO) remain unclear.

OBJECTIVES

We present a case report of angioinvasive Aspergillus infection on an infant supported on ECMO and also investigate outcomes among patients with Aspergillus infection reported to the Extracorporeal Life Support Organization (ELSO) registry.

DESIGN

Case report and retrospective analysis of ELSO registry data set from 1985 to 2009.

SETTING

One hundred and seventy ECMO centers contributing data to the ELSO registry.

PATIENTS

Single case report and patients 0 to 90 years of age with Aspergillus infection requiring ECMO support as reported to the ELSO registry.

METHODS

Besides presenting details of our institutional case, we compared clinical characteristics and outcomes between pediatric and adult patients with Aspergillus isolation. Risk factors for in-hospital mortality were investigated. Kaplan-Meier estimates for freedom from death on ECMO for pediatric and adult patients were investigated.

MEASUREMENTS AND MAIN RESULTS

(a) we report a case with Aspergillus supported on ECMO, (b) the ELSO registry yielded 46 patients with 59% (n = 27) in the pediatric data set (≤20 years of age) and 41% (n = 19) in the adult data set (>20 years of age) with Aspergillus infection requiring ECMO support. Overall survival to hospital discharge was 30% (14/46) with 22% (6/27) in children as compared to 42% (8/18) in adults (P = .19). Table 1 shows a comparison of clinical characteristics between children and adults. The comparison between adults and pediatric groups differed significantly in age (P = .0001), more use of venoarterial ECMO in children (P = .028). The median age of pediatric group was 1.95 years (range 0-17.3 years) versus 30.2 years (range 22-60 years) among adults.

CONCLUSIONS

Aspergillus infection/colonization is associated with a 70% overall mortality among patients supported on ECMO. The ELSO registry data confirms that Aspergillus infection among ECMO supported patients occurs often in hosts who do not have known immunodeficiencies. The case stresses the need for a high level of suspicion for Aspergillus infection in nonimproving lung disease in patients on ECMO support.

Infections in Leukemia and Hematopoietic Stem Cell Transplantation

Infections are one of the most common complications in patients diagnosed with leukemia and serve as a major obstacle to treatment. Through the early 1970s, infections were the most common cause of death in patients diagnosed with acute leukemia, but improvement in treatment and supportive care over the past few decades, coupled with expanded prophylaxis and prevention regimens, have led to reduction in both the frequency and severity of infections. Regardless, due in part to an aging cancer population and the diversity of cancer treatments and procedures, infectious diseases remain a major cause of morbidity and mortality in patients with leukemia.

Imaging studies for diagnosing invasive fungal pneumonia in immunocompromised patients

PURPOSE OF REVIEW

The aim is to review imaging advances in invasive fungal pneumonia in cancer and transplant recipients and how their use can help guide treatment.

RECENT FINDINGS

Early chest computed tomographic (CT) imaging of immunocompromised patients with neutropenic fever leads to improved survival. Some of the typical CT findings of invasive fungal pneumonia are transitory and are most common during the first week of symptoms. The reversed halo sign, an early sign of disease, is more common in mucormycosis. During the first 10 days of infection, invasive fungal pneumonia nodules may grow on follow-up CT scans, but this does not necessarily equate to worsening disease. Because of the excessive radiation of chest CT and because pulmonary nodule size typically expands during the first few weeks of treatment, follow-up CT scans should be ordered only when therapy changes are dependent on imaging findings.

SUMMARY

Early chest CT imaging in immunocompromised patients suspected of having invasive fungal pneumonia can help identify disease early, leading to improved outcome.

Diagnosis of invasive fungal infections in hematology and oncology--guidelines from the Infectious Diseases Working Party in Haematology and Oncology of the German Society for Haematology and Oncology (AGIHO)

Invasive fungal infections (IFIs) are a primary cause of morbidity and mortality in patients with hematological malignancies. Establishing a definite diagnosis of IFI in immunocompromised patients is particularly challenging and time consuming, but delayed initiation of antifungal treatment increases mortality. The limited overall outcome has led to the strategy of initiating either 'empirical' or 'preemptive' antifungal therapy before the final diagnosis. However, diagnostic procedures have been vastly improved in recent years. Particularly noteworthy is the introduction of newer imaging techniques and non-culture methods, including antigen-based assays, metabolite detection and molecular detection of fungal DNA from body fluid samples. Though varying widely in cancer patients, the risk of IFI is highest in those with allogeneic stem cell transplantation and those with acute leukemia. The AGIHO presents recommendations for the diagnosis of IFIs with risk-adapted screening concepts for febrile episodes in patients with haemato-oncological disorders.

Phase II dose escalation study of caspofungin for invasive Aspergillosis

Our objective was to evaluate the maximum tolerated dose of caspofungin for invasive aspergillosis (IA). The safety and pharmacokinetics of escalating dosages of caspofungin were investigated in IA. Eight patients each received caspofungin 70, 100, 150, or 200 mg once a day (QD). Dose-limiting toxicity (DLT) was defined as the same non-hematological treatment-related adverse event of grade ≥ 4 in 2 of 8 patients or ≥ 3 in 4 of 8 patients in a cohort. A total of 46 patients (median age, 61 years; 21 female; 89% with hematological malignancies) received caspofungin (9, 8, 9, and 20 patients in the 70-, 100-, 150-, and 200-mg cohorts) for a median of 24.5 days. Plasma pharmacokinetics were linear across the investigated dosages and followed a two-compartment model, with weight as the covariate on clearance and sex as the covariate on central volume of distribution. Simulated peak plasma concentrations at steady state ranged from 14.2 to 40.6 mg/liter (28%), trough concentrations from 4.1 to 11.8 mg/liter (58%), and area under the concentration-time curve from 175 to 500 mg/liter/h (32%) (geometric mean, geometric coefficient of variation). Treatment was well tolerated without dose-limiting toxicity. The rate of complete or partial responses was 54.3%, and the overall mortality at 12-week follow-up was 28.3%. In first-line treatment of invasive aspergillosis, daily doses of up to 200 mg caspofungin were well tolerated and the maximum tolerated dose was not reached. Pharmacokinetics was linear. Response rates were similar to those previously reported for voriconazole and liposomal amphotericin.

Infections in patients with hematologic neoplasms and hematopoietic stem cell transplantation: neutropenia, humoral, and splenic defects

Infections are common in patients with hematologic neoplasms and following allogeneic hematopoietic transplantation. Neutropenia and defects in adaptive B-cell-mediated immunity and/or lack of splenic function predispose patients to a host of diverse and often serious infections. It is important to recognize that patients who undergo treatment for hematologic neoplasms may have mixed immune defects, and their vulnerability to infection may continue to change, in part as a reflection of the dynamic developments in the practice of oncology. The main obstacle in providing targeted, evidence-based antimicrobial treatment is the unpredictable results of even the new generation of diagnostic assays. A definite diagnosis for most end-organ opportunistic diseases requires tissue samples that are seldom available. Because immune defects may coexist, empirical therapy is directed toward a wide spectrum of pathogens. Real-time information about innate and adaptive immune functions and the role of acute and chronic phase molecules may improve target-specific therapy.

The diagnostic value of halo and reversed halo signs for invasive mold infections in compromised hosts

The halo sign is a CT finding of ground-glass opacity surrounding a pulmonary nodule or mass. The reversed halo sign is a focal rounded area of ground-glass opacity surrounded by a crescent or complete ring of consolidation. In severely immunocompromised patients, these signs are highly suggestive of early infection by an angioinvasive fungus. The halo sign and reversed halo sign are most commonly associated with invasive pulmonary aspergillosis and pulmonary mucormycosis, respectively. Many other infections and noninfectious conditions, such as neoplastic and inflammatory processes, may also manifest with pulmonary nodules associated with either sign. Although nonspecific, both signs can be useful for preemptive initiation of antifungal therapy in the appropriate clinical setting. This review aims to evaluate the diagnostic value of the halo sign and reversed halo sign in immunocompromised hosts and describes the wide spectrum of diseases associated with them.