Assessment of Serum Galactomannan Test Results of Pediatric Patients With Hematologic Malignancies According to Consecutive Positivity and Threshold Level in Terms of Invasive Aspergillosis Diagnosis: Cross-Sectional Research in a Tertiary Care Hospital.

The aim of this study was to evaluate the diagnostic utility of serum galactomannan (GM) positivity for invasive aspergillosis (IA) in children. Positive GM results between January 2015 and August 2017 were reviewed retrospectively in children with hematologic malignancies. Single and consecutive positive GM results were evaluated according to the different galactomannan index (GMI) (>0.5, >0.7, >1.0 and >1.5) values. There were 104 positive GM results of 70 patients. IA was identified in 29 patients (41.4%) (2 proven and 27 probable). For a single positive GMI of >0.5, >0.7, >1.0, and >1.5, the numbers were 104, 76, 57, and 32 and the positive predictive values (PPVs) were 39.4%, 43.2%, 47.2%, and 50.0%, respectively. The single GM positivity at different thresholds showed no difference between the IA and non-IA group (P>0.05). For 2 consecutive positive GMI values of >0.5, >0.7, >1.0, and >1.5, the numbers were 34, 20, 13, and 4, and the PPVs were 58.8%, 65.0%, 84.6%, and 100.0%, respectively. In the IA group, positivity was higher at all thresholds (P<0.05). According to our findings, consecutive GM positivity has higher PPVs independently from the cutoff value chosen. In pediatric patients with high risk, consecutive sampling should be preferred.

Utility of CT assessment in hematology patients with invasive aspergillosis: a post-hoc analysis of phase 3 data.

BACKGROUND: Pulmonary computed tomography (CT) scans are commonly used as part of the clinical criteria in diagnostic workup of invasive fungal diseases like invasive aspergillosis, and may identify radiographic abnormalities, such as halo signs or air-crescent signs. We assessed the diagnostic utility of CT assessment in patients with hematologic malignancies or those who had undergone allogeneic hematopoietic stem cell transplantation in whom invasive aspergillosis was suspected. METHODS: This post-hoc analysis assessed data from a prospective, multicenter, international trial of voriconazole (with and without anidulafungin) in patients with suspected invasive aspergillosis (IA; proven, probable, or possible, using 2008 European Organisation for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group criteria) [NCT00531479]. Eligible patients received at least one baseline lung CT scan. RESULTS: Of 395 patients included in this post-hoc analysis, 240 patients (60.8%) had 'confirmed' proven (9/240, 3.8%) or probable (231/240, 96.3%) invasive aspergillosis (cIA) and 155 patients (39.2%) had 'non-confirmed' invasive aspergillosis (all nIA; all possible IA (de Pauw et al., Clin Infect Dis 46:1813-21, 2008)). Mean age was 52.3 and 50.5 years, 56.3 and 60.0% of patients were male, and most patients were white (71.7 and 71.0%) in the cIA and nIA populations, respectively. Median baseline galactomannan was 1.4 (cIA) and 0.2 (nIA), mean Karnofsky score was 65.3 (cIA) and 66.8 (nIA), and mean baseline platelet count was 48.0 (cIA) and 314.1 (nIA). Pulmonary nodules (46.8% of all patients), bilateral lung lesions (37.5%), unilateral lung lesions (28.4%), and consolidation (24.8%) were the most common radiographic abnormalities. Ground-glass attenuation (cIA: 24.2%; nIA: 11.6%; P < 0.01) and pulmonary nodules (cIA: 52.5%; nIA: 38.1%; P < 0.01) were associated with cIA. Other chest CT scan abnormalities (including halo signs and air-crescent signs) at baseline in patients with hematologic malignancy or hematopoietic stem cell transplantation, and suspected IA, were not associated with cIA. CONCLUSIONS: These findings highlight the limitations in the sensitivity of chest CT scans for the diagnosis of IA, and reinforce the importance of incorporating other available clinical data to guide management decisions on individual patients, including whether empirical treatment is reasonable, pending full evaluation. TRIAL REGISTRATION: NCT00531479 (First posted on ClinicalTrials.gov on September 18, 2007).

Pharmacodynamics of isavuconazole in experimental invasive pulmonary aspergillosis: implications for clinical breakpoints.

OBJECTIVES: Isavuconazole, a novel triazole antifungal agent, has broad-spectrum activity against Aspergillus spp. and other pathogenic fungi. The isavuconazole exposure-response relationship in experimental invasive pulmonary aspergillosis using galactomannan index (GMI) suppression as a marker of disease clearance was explored. METHODS: The impact of exposure on GMI suppression in persistently neutropenic rabbits treated with isavuconazonium sulphate (isavuconazole-equivalent dosages of 20, 40 or 60 mg/kg every 24 h, after a 90 mg/kg loading dose) for 12 days was linked using mathematical modelling. Bridging to humans using population pharmacokinetic (PK) data from a clinical trial in invasive aspergillosis was performed using Monte Carlo simulations. RESULTS: Mean plasma isavuconazole AUC/MIC (EC50) of 79.65 (95% CI 32.2, 127.1) produced a half-maximal effect in GMI suppression. The inhibitory sigmoid Emax curve dropped sharply after an AUC/MIC of ≥30 and was near maximum (EC80) at ∼130. Bridging the experimental PK/pharmacodynamic (PD) target to human population PK data was then used to return to the rabbit model to determine a clinically relevant PD endpoint. The clinical dosing regimen used in the trial would result in a mean GMI of 4.3 ±â€Š1.8, which is a 50% reduction from the starting GMI in the experiment. CONCLUSIONS: The clinical trial results showing the non-inferiority of isavuconazole to voriconazole for all-cause mortality further support the PK-PD endpoint, thereby demonstrating the usefulness of the rabbit model and endpoint for isavuconazole and implications on interpretive breakpoints. Importantly, the analysis supports this model as an important tool for development of antifungal agents.

Evaluation of serum (1 → 3)-ß-D-glucan clinical performance: kinetic assessment, comparison with galactomannan and evaluation of confounding factors.

PURPOSE: We investigated the clinical performance of (1 → 3)-ß-D-glucan (BG), as an early marker of invasive fungal infections (IFI), in different clinical settings. METHODS: BG serum levels were assessed by Fungitell (Associates of Cape Cod, Inc), in parallel with galactomannan (GM) when requested by clinicians. By a prospective monocentric study, 270 episodes at risk or with suspect of IFI were enrolled, namely 58 proven-probable invasive aspergillosis (IA), 27 proven invasive candidiasis (IC), 11 possible IC, 16 P.jirovecii pneumonia (PJP), 4 episodes of other IFI and 154 non-IFI controls. RESULTS: We found that (a) the BG overall sensitivity, specificity, positive predictive value and negative predictive value (NPV) were 87.9, 80.5, 76.7 and 89.9 %, respectively; (b) the highest sensitivity was found in the IC groups, followed by PJP, IA and other IFI groups; (c) an association was observed between BG kinetics and patients outcome; (d) in the IA episodes, the combination of BG or GM vs GM alone increased sensitivity from 60.0 to 83.3 % in the haematological patients; (e) false-positive BG results were related to Gram-negative infections or infusion of polyclonal IgM-enriched immunoglobulins, where high levels of BG were indeed detected. CONCLUSION: Besides strengthening its overall good clinical performance, we provide evidence that serum BG correlates with clinical outcome and that, once used in combination with GM, BG allows to enhance IFI diagnosis rate. The high sensitivity and NPV, observed in the Intensive Care Unit setting, open to BG validation as a marker for assessment of antifungal treatment.

Meta-Analysis and Cost Comparison of Empirical versus Pre-Emptive Antifungal Strategies in Hematologic Malignancy Patients with High-Risk Febrile Neutropenia.

BACKGROUND: Invasive fungal disease (IFD) causes significant morbidity and mortality in hematologic malignancy patients with high-risk febrile neutropenia (FN). These patients therefore often receive empirical antifungal therapy. Diagnostic test-guided pre-emptive antifungal therapy has been evaluated as an alternative treatment strategy in these patients. METHODS: We conducted an electronic search for literature comparing empirical versus pre-emptive antifungal strategies in FN among adult hematologic malignancy patients. We systematically reviewed 9 studies, including randomized-controlled trials, cohort studies, and feasibility studies. Random and fixed-effect models were used to generate pooled relative risk estimates of IFD detection, IFD-related mortality, overall mortality, and rates and duration of antifungal therapy. Heterogeneity was measured via Cochran's Q test, I2 statistic, and between study τ2. Incorporating these parameters and direct costs of drugs and diagnostic testing, we constructed a comparative costing model for the two strategies. We conducted probabilistic sensitivity analysis on pooled estimates and one-way sensitivity analyses on other key parameters with uncertain estimates. RESULTS: Nine published studies met inclusion criteria. Compared to empirical antifungal therapy, pre-emptive strategies were associated with significantly lower antifungal exposure (RR 0.48, 95% CI 0.27-0.85) and duration without an increase in IFD-related mortality (RR 0.82, 95% CI 0.36-1.87) or overall mortality (RR 0.95, 95% CI 0.46-1.99). The pre-emptive strategy cost $324 less (95% credible interval -$291.88 to $418.65 pre-emptive compared to empirical) than the empirical approach per FN episode. However, the cost difference was influenced by relatively small changes in costs of antifungal therapy and diagnostic testing. CONCLUSIONS: Compared to empirical antifungal therapy, pre-emptive antifungal therapy in patients with high-risk FN may decrease antifungal use without increasing mortality. We demonstrate a state of economic equipoise between empirical and diagnostic-directed pre-emptive antifungal treatment strategies, influenced by small changes in cost of antifungal therapy and diagnostic testing, in the current literature. This work emphasizes the need for optimization of existing fungal diagnostic strategies, development of more efficient diagnostic strategies, and less toxic and more cost-effective antifungals.

Impact and cost of the serum galactomannan assay at a tertiary care facility.

BACKGROUND: Invasive aspergillosis carries a high mortality with a rising prevalence in immunocompromised hosts. Diagnosis of invasive aspergillosis is challenging and delays in treatment are associated with poor outcomes. The galactomannan assay (GM), a non-culture-based surrogate marker of fungal infection, is widely used in diagnosis. It is unknown whether this assay impacts clinical decision making. We evaluated whether GM testing results in earlier initiation of antifungal therapy and is cost effective. METHODS: We carried out a retrospective review of the electronic medical records of all patients undergoing GM at a 907-bed tertiary-care general hospital from July 11, 2011, to June 12, 2012. Records of patients with a positive GM were individually reviewed to determine the timing of the assay result, presence and timing of relevant culture data, whether BAL GM was performed, radiology data consistent with invasive aspergillosis, and the timing of initiation of antifungal therapy. For each case, it was determined whether GM results impacted the decision to initiate antifungal therapy. RESULTS: Forty-six nonduplicate GM samples were positive (>0.5) of 1419 performed. Results were considered to be false positives in 18 cases by care teams. In 21 cases, antifungal therapy was initiated before the assay result based on clinical suspicion, culture data, and/or radiology. The serum GM was performed 164 times at a cost of $21,789 for a single positive result effecting modification of patient care. CONCLUSION: Serum GM testing at a tertiary-care institution is commonly used but infrequently impacts clinical decision making with major financial burden.

Performance of serum biomarkers for the early detection of invasive aspergillosis in febrile, neutropenic patients: a multi-state model.

BACKGROUND: The performance of serum biomarkers for the early detection of invasive aspergillosis expectedly depends on the timing of test results relative to the empirical administration of antifungal therapy during neutropenia, although a dynamic evaluation framework is lacking. METHODS: We developed a multi-state model describing simultaneously the likelihood of empirical antifungal therapy and the risk of invasive aspergillosis during neutropenia. We evaluated whether the first positive test result with a biomarker is an independent predictor of invasive aspergillosis when both diagnostic information used to treat and risk factors of developing invasive aspergillosis are taken into account over time. We applied the multi-state model to a homogeneous cohort of 185 high-risk patients with acute myeloid leukemia. Patients were prospectively screened for galactomannan antigenemia twice a week for immediate treatment decision; 2,214 serum samples were collected on the same days and blindly assessed for (1->3)- ß-D-glucan antigenemia and a quantitative PCR assay targeting a mitochondrial locus. RESULTS: The usual evaluation framework of biomarker performance was unable to distinguish clinical benefits of ß-glucan or PCR assays. The multi-state model evidenced that the risk of invasive aspergillosis is a complex time function of neutropenia duration and risk management. The quantitative PCR assay accelerated the early detection of invasive aspergillosis (P = .010), independently of other diagnostic information used to treat, while ß-glucan assay did not (P = .53). CONCLUSIONS: The performance of serum biomarkers for the early detection of invasive aspergillosis is better apprehended by the evaluation of time-varying predictors in a multi-state model. Our results provide strong rationale for prospective studies testing a preemptive antifungal therapy, guided by clinical, radiological, and bi-weekly blood screening with galactomannan antigenemia and a standardized quantitative PCR assay.

Earlier response assessment in invasive aspergillosis based on the kinetics of serum Aspergillus galactomannan: proposal for a new definition.

BACKGROUND: Current criteria for assessing treatment response of invasive aspergillosis (IA) rely on nonspecific subjective parameters. We hypothesized that an Aspergillus-specific response definition based on the kinetics of serum Aspergillus galactomannan index (GMI) would provide earlier and more objective response assessment. METHODS: We compared the 6-week European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) response criteria with GMI-based response among 115 cancer patients with IA. Success according to GMI required survival with repeatedly negative GMI for ≥2 weeks. Time to response and agreement between the 2 definitions were the study endpoints. RESULTS: Success according to EORTC/MSG and GMI criteria was observed in 73 patients (63%) and 83 patients (72%), respectively. The GMI-based response was determined at a median of 21 days after treatment initiation (range, 15-41 days), 3 weeks before the EORTC/MSG time point, in 72 (87%) of 83 responders. Agreement between definitions was shown in all 32 nonresponders and in 73 of the 83 responders (91% overall), with an excellent κ correlation coefficient of 0.819. Among 10 patients with discordant response (EORTC/MSG failure, GMI success), 1 is alive without IA 3 years after diagnosis; for the other, aspergillosis could not be detected at autopsy. The presence of other life-threatening complications in the remaining 8 patients indicates that IA had resolved. CONCLUSIONS: The Aspergillus-specific GMI-based criteria compare favorably to current response definitions for IA and significantly shorten time to response assessment. These criteria rely on a simple, reproducible, objective, and Aspergillus-specific test and should serve as the primary endpoint in trials of IA.

Retrospective assessment of ß-D-(1,3)-glucan for presumptive diagnosis of fungal infections.

ß-D-(1,3)-glucan (BG) is a component of the cell walls of many fungal organisms. Our aims were to investigate the feasibility of the BG assay and its contribution to early diagnosis of different types of invasive fungal infections (IFI) commonly diagnosed in a tertiary care centre. The BG serum levels of 28 patients diagnosed with six IFI [13 probable invasive aspergillosis (IA), 2 proven IA, 2 zygomycosis, 3 fusariosis, 3 cryptococcosis, 3 candidaemia and 2 pneumocystosis] were retrospectively evaluated. The kinetic variations in BG serum levels from the 15 patients diagnosed with IA were compared with those of the galactomannan antigen (GM). In 5/15 cases of IA, BG was positive earlier than GM (time lapse from 4 to 30 days), in 8/15 cases, BG was positive at the same time as GM and, in 2/15 cases, BG was positive after GM. For the five other fungal diseases, BG was highly positive at the period of diagnosis except for the two cases of zygomycosis and one of the three cases of fusariosis. This study, which reflects the common activity of a tertiary care centre, confirms that BG detection could be of interest for IFI screening in patients with haematological malignancies.

[Economical evaluation of the treatment of invasive aspergillosis in pediatric oncology patients. Santiago. Chile]. / Estudio de costo del tratamiento de la aspergilosis invasora en pacientes oncológicos pediátricos. Santiago. Chile.

INTRODUCTION: Invasive aspergillosis (IA) is a serious opportunistic infection in immunocompromised patients. Transplant recipients and patients with cancer represent the highest risk group. The antifungal treatment involves prolonged hospitalization and high economic resources. OBJECTIVE: to estimate costs represented by IA as an intercurrent complication of oncologic treatment. PATIENTS AND METHOD: Retrospective case-control study. Estimation of the cost of treatment in pediatric oncologic patients with IA in the Hospital Luis Calvo Mackenna during the years 2007-2008 was done. A control for each case of IA paired by sex, age, number of diagnosis and clinical department was selected. RESULTS: There were 13 patients during the observation period. The attributable cost of treatment of aspergillosis was US $23,600 and the cost for each indicator was: hospital days US $16,500; antifungal therapy US $7,000; and serum galactomannan US $100. DISCUSSION: In this study, the cost of treating IA is mainly due to hospitalization and antifungal medications. Three patients acquired IA in spite of staying in a protected environment.

Estudio de costo del tratamiento de la aspergilosis invasora en pacientes oncológicos pediátricos: Santiago. Chile / Economical evaluation of the treatment of invasive aspergillosis in pediatric oncology patients: Santiago. Chile

Introducción: La aspergilosis invasora (AI) es una infección oportunista grave en pacientes inmunocompro- metidos. Pacientes receptores de transplantes y oncológicos representan el grupo de mayor riesgo. El tratamiento antifúngico involucra hospitalización prolongada y altos recursos económicos. Objetivo: Estimar los costos involucrados en el tratamiento de la AI como complicación intercurrente en pacientes con cáncer. Pacientes y Método: Estudio caso-control, retrospectivo. Estima el costo del tratamiento de AI en pacientes pediátricos oncológicos del Hospital Luis Calvo Mackenna durante los años 2007 y 2008. Resultados: Se incluyeron 13 pacientes con AI y sus respectivos 13 controles. El costo atribuible de la hospitalización en aquellos pacientes que cursaron con AI fue de US $23.600. El costo atribuible para cada indicador fue: US $16.500 para días de hospitalización; US $7.000 para medicamentos antifúngicos y US $100 para galactomanano sérico. Discusión: En este estudio, el costo del tratamiento de AI se debe principalmente a la estadía hospitalaria y fármacos antifúngicos. Encontramos tres pacientes que desarrollaron AI estando en ambiente protegido.

Introduction: Invasive aspergillosis (IA) is a serious opportunistic infection in immunocompromised patients. Transplant recipients and patients with cancer represent the highest risk group. The antifungal treatment involves prolonged hospitalization and high economic resources. Objective: to estimate costs represented by IA as an intercurrent complication of oncologic treatment. Patients and Method: Retrospective case-control study. Estimation of the cost of treatment in pediatric oncologic patients with IA in the Hospital Luis Calvo Mackenna during the years 2007-2008 was done. A control for each case of IA paired by sex, age, number of diagnosis and clinical department was selected. Results: There were 13 patients during the observation period. The attributable cost of treatment of aspergillosis was US $ 23,600 and the cost for each indicator was: hospital days US $ 16,500; antifungal therapy US $ 7,000; and serum galactomannan US $ 100. Discussion: In this study, the cost of treating IA is mainly due to hospitalization and antifungal medications. Three patients acquired IA in spite of staying in a protected environment.

Assessment of the lightcycler PCR assay for diagnosis of invasive aspergillosis in paediatric patients with onco-haematological diseases.

A reliable diagnosis of invasive aspergillosis (IA) is hampered by the difficulty in obtaining suitable tissue samples. To evaluate the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the LightCycler PCR for the diagnosis of IA, 536 blood samples were collected over a 22-month period from 62 paediatric patients (median age 10 years, range 1-18) considered at risk of IA. The galactomannan antigen (GM) and fungal DNA were assessed on serial blood samples. IA was diagnosed in eight of 62 patients (13%): proven, five, probable, three. Sensitivity, specificity, PPV and NPV of LightCycler PCR varied according to the number of positive samples used to define positivity: 88%; 37%; 17% and 95% for single sample positivity; and 63%, 81%, 33% and 94% for serial sample positivity respectively. The concordance between positivity of LightCycler PCR assay and the diagnosis of IA was 79%. The single positivity of LightCycler PCR assay showed a good sensitivity for the diagnosis of IA in paediatric patients. The high NPV makes LightCycler PCR a promising tool in addition to GM testing to design a strategy of pre-emptive antifungal therapy, although further validation studies are needed.

Assessment of Platelia Aspergillus enzyme immunoassay for the diagnosis of invasive aspergillosis.

BACKGROUND AND PURPOSE: This study investigated the diagnostic value of Platelia Aspergillus enzyme immunoassay (EIA) for galactomannan (GM) antigen in patients at risk of invasive aspergillosis (IA), and its association with clinical course and outcome. METHODS: A total of 304 blood samples were collected from 189 patients at risk of IA during a 1-year period at a tertiary referral center. Classification of IA was made on the basis of the European Organization for Research and Treatment of Cancer case definitions. RESULTS: Of the 189 patients, 5 had proven IA, 9 had probable IA, 26 had possible IA, and 149 had no IA. Diagnostic levels of GM were detected in 80% of proven and in 77% of probable IA cases. The overall sensitivity, specificity, and positive and negative predictive values for this assay, using a 1.5 index cut-off value, were 78.6%, 93.9%, 55.0%, and 97.9%, respectively. With the 0.5 index cut-off value, the sensitivity would increase to 100%. A close relationship was found between clinical course and the kinetics of GM indices in survivors. CONCLUSIONS: The Platelia Aspergillus EIA is a useful screening test for the detection of IA. Regular monitoring of the kinetics of GM-EIA indices is a useful predictor of clinical course and outcome.

Assessment of a commercial sandwich ELISA in the diagnosis of aspergillosis in falcons.

A commercial sandwich elisa (Platelia Aspergillus EIA; Bio-Rad) developed for the detection of galactomannan, a major cell wall constituent of Aspergillus species, was tested for its efficacy in the diagnosis of aspergillosis in falcons. Ninety serum samples from 50 aspergillosis-positive falcons and 182 samples from 142 aspergillosis-negative falcons were tested. The sensitivity of the test was only 12 per cent and its specificity was 95 percent. The test was therefore unsatisfactory for detecting galactomannan in the serum samples and cannot be used as a screening test for aspergillosis in falcons.