Performance of the (1,3)-Beta-d-Glucan Assay on Bronchoalveolar Lavage Fluid for the Diagnosis of Invasive Pulmonary Aspergillosis

Detection of (1,3)-beta-d-glucan (BDG), a component of the cell wall of many fungi, was studied in bronchoalveolar lavage fluid (BALF) as a possible aid for the diagnosis of proven/probable invasive pulmonary aspergillosis (IPA). BDG was measured on stored BALF from 13 patients with EORTC/MSGERC defined proven/probable IPA and 26 matched control patients without IPA. The median BALF BDG was 80 pg/mL (range <?45–8240 pg/mL) in the IPA cohort and 148 pg/mL (range <?45–5460 pg/mL) in the non-IPA cohort. Using a positive cutoff of?≥?80 pg/mL, sensitivity was 54% and specificity was 38%. Higher cutoff values led to improvement in specificity but a dramatic decrease in sensitivity. ROC/AUC analysis was unable to identify an optimal cutoff value at which test performance was enhanced: AUC 0.43, 95% CI 0.24–0.63. When the BDG assay was performed on BALF, neither sensitivity nor specificity was sufficient for use in the diagnosis of IPA.

     

Usefulness of the Serum Galactomannan Assay for Early Response Assessment and Treatment Stratifications of Invasive Aspergillosis

The galactomannan (GM) Enzyme Immunoassay (EIA) is an upcoming tool not only for diagnosis but also monitoring of invasive Aspergillosis (IA). Various studies were performed over the last years to apply such a promising instrument correctly. New findings show the potential of this test to segregate affected patients into treatment responders and non-responders at a time point as early as 7–14 days after initiation of antifungal therapy. Current data suggest that serial GM testing in patients receiving antifungal therapy for IA is essential as GMI kinetics may offer the clinician a substantial support in decision making concerning early therapeutic stratifications. The correct interpretation of GM EIA results with respect to the individual context of the patient is, however, absolutely necessary. The following review shall give an overview about the GM-EIA as a tool for IA monitoring and therapy stratification.     

Clinical Usefulness of Procalcitonin and C-Reactive Protein as Outcome Predictors in Critically Ill Patients with Severe Sepsis and Septic Shock

Sepsis is a major cause of mortality and morbidity in critically ill patients. Procalcitonin (PCT) and C-reactive protein (CRP) are the most frequently used biomarkers in sepsis. We investigated changes in PCT and CRP concentrations in critically ill patients with sepsis to determine which biochemical marker better predicts outcome. We retrospectively analyzed 171 episodes in 157 patients with severe sepsis and septic shock who were admitted to the Samsung Medical Center intensive care unit from March 2013 to February 2014. The primary endpoint was patient outcome within 7 days from ICU admission (treatment failure). The secondary endpoint was 28-day mortality. Severe sepsis was observed in 42 (25%) episodes from 41 patients, and septic shock was observed in 129 (75%) episodes from 120 patients. Fifty-five (32%) episodes from 42 patients had clinically-documented infection, and 116 (68%) episodes from 99 patients had microbiologically-documented infection. Initial peak PCT and CRP levels were not associated with treatment failure and 28-day mortality. However, PCT clearance (PCTc) and CRP (CRPc) clearance were significantly associated with treatment failure (p = 0.027 and p = 0.030, respectively) and marginally significant with 28-day mortality (p = 0.064 and p = 0.062, respectively). The AUC for prediction of treatment success was 0.71 (95% CI, 0.61–0.82) for PCTc and 0.71 (95% CI, 0.61–0.81) for CRPc. The AUC for survival prediction was 0.77 (95% CI, 0.66–0.88) for PCTc and 0.77 (95% CI, 0.67–0.88) for CRPc. Changes in PCT and CRP concentrations were associated with outcomes of critically ill septic patients. CRP may not be inferior to PCT in predicting outcome in these patients.     

Detection of Invasive Pulmonary Aspergillosis in Haematological Malignancy Patients by using Lateral-flow Technology

Invasive pulmonary aspergillosis (IPA) is a leading cause of morbidity and mortality in haematological malignancy patients and hematopoietic stem cell transplant recipients¹. Detection of IPA represents a formidable diagnostic challenge and, in the absence of a ''gold standard'', relies on a combination of clinical data and microbiology and histopathology where feasible. Diagnosis of IPA must conform to the European Organization for Research and Treatment of Cancer and the National Institute of Allergy and Infectious Diseases Mycology Study Group (EORTC/MSG) consensus defining "proven", "probable", and "possible" invasive fungal diseases². Currently, no nucleic acid-based tests have been externally validated for IPA detection and so polymerase chain reaction (PCR) is not included in current EORTC/MSG diagnostic criteria.Identification of Aspergillus in histological sections is problematic because of similarities in hyphal morphologies with other invasive fungal pathogens³, and proven identification requires isolation of the etiologic agent in pure culture. Culture-based approaches rely on the availability of biopsy samples, but these are not always accessible in sick patients, and do not always yield viable propagules for culture when obtained.An important feature in the pathogenesis of Aspergillus is angio-invasion, a trait that provides opportunities to track the fungus immunologically using tests that detect characteristic antigenic signatures molecules in serum and bronchoalveolar lavage (BAL) fluids. This has led to the development of the Platelia enzyme immunoassay (GM-EIA) that detects Aspergillus galactomannan and a ''pan-fungal'' assay (Fungitell test) that detects the conserved fungal cell wall component (1 →3)-β-D-glucan, but not in the mucorales that lack this component in their cell walls^1,4. Issues surrounding the accuracy of these tests^1,4-6 has led to the recent development of next-generation monoclonal antibody (MAb)-based assays that detect surrogate markers of infection^1,5.Thornton⁵ recently described the generation of an Aspergillus-specific MAb (JF5) using hybridoma technology and its use to develop an immuno-chromatographic lateral-flow device (LFD) for the point-of-care (POC) diagnosis of IPA. A major advantage of the LFD is its ability to detect activity since MAb JF5 binds to an extracellular glycoprotein antigen that is secreted during active growth of the fungus only⁵. This is an important consideration when using fluids such as lung BAL for diagnosing IPA since Aspergillus spores are a common component of inhaled air. The utility of the device in diagnosing IPA has been demonstrated using an animal model of infection, where the LFD displayed improved sensitivity and specificity compared to the Platelia GM and Fungitell (1 → 3)-β-D-glucan assays⁷.Here, we present a simple LFD procedure to detect Aspergillus antigen in human serum and BAL fluids. Its speed and accuracy provides a novel adjunct point-of-care test for diagnosis of IPA in haematological malignancy patients.     

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)- β-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 β-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 β-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.     

Galactomannan Testing and the Incidence of Invasive Pulmonary Aspergillosis: A 10-Year Nationwide Population-Based Study in Taiwan

BackgroundThe clinical impact of the galactomannan (GM) test for the diagnosis of invasive pulmonary aspergillosis (IPA) is controversial. Our study evaluated the incidence and trends of IPA and GM testing in patients with aspergillus infections.MethodsWe conducted a nationwide inpatient population study using the Taiwan National Health Insurance Research Database. A total of 346 IPA (62.14% male) patients from the years 2002 to 2011 were identified for inclusion in the study.ResultsThe average incidence of IPA was 1.51 per million person-years. Over the study period, we observed an increasing trend from 0.94 to 2.06 per million person-years (P < 0.0001). We observed male predominance in IPA incidence (M/F: 1.85/1.15). Both males and females showed significantly increasing trends of IPA incidence over time (0.87 to 4.55 and 0.36 to 2.07 per million person-years for the males and females, respectively). GM testing for IPA significantly increased from 2002 to 2011, and the GM test was utilized more frequently for males than females. The increase in the incidence of IPA might be positively associated with the increase in GM testing over the past decade.ConclusionThe incidence rates of both IPA and GM testing have increased over time. GM testing is recommended for the early diagnosis of patients with suspected aspergillosis.     

血液恶性肿瘤患者化疗治疗预防侵袭性真菌感染的临床分析与研究

目的:侵袭性真菌感染在血液恶性肿瘤化疗患者中时常出现,其感染周期较长,且易产生抗药性,给患者带来极大痛苦,为了探讨血液恶性肿瘤患者侵袭性真菌感染的最佳临床预防方案,我院进行了相关研究.方法:选取2009年3月-2012年1月入住我院并接受治疗的血液恶性肿瘤患者156例,将所有患者随机分为观察组和对照组,每组患者78例,其中对照组传统预防方案,观察组采用伊曲康唑预防方案.两组患者化疗治疗后对两组患者的侵袭性真菌感染状况及药物不良反应,不良反应包括血压升高、转氨酶升高、肾功能衰竭、腹泻、皮疹、气胸、药物过敏等.同时对两组患者进行满意度调查.结果:观察组感染率低于对照组27个百分点(P＜0.05),不良反应低于对照组5.1个百分点(P＜0.05),观察组的满意度高于对照组6.4个百分点(P＜0.05),均具有显著性差异,具有统计学意义.结论:观察组由于在传统预防方案的基础上额外采用了伊曲康唑预防对患者进行预防,使得观察组的化疗感染率、不良反应状况均低于对照组,而满意度明显高于对照组,因此对血液恶性肿瘤患者化疗时应用伊曲康唑预防方案可以起到明显的侵袭性真菌感染预防效果,该方案值得进一步推广.     

The Performance of Real-Time PCR, Galactomannan, and Fungal Culture in the Diagnosis of Invasive Aspergillosis in Ventilated Patients with Chronic Obstructive Pulmonary Disease (COPD)

Emerging reports have associated chronic pulmonary obstructive disease (COPD) with invasive aspergillosis (IA), particularly in patients treated with mechanical ventilation and/or corticosteroids. This is a multicentre study in which COPD patients demonstrating a new lung infiltrate while being mechanically ventilated were prospectively evaluated for the presence of IA. From the 47 patients studied, Aspergillus fumigatus was recovered in culture in two patients (4.2%). While serum galactomannan (GM) was negative for 94% of patients, GM levels in respiratory samples were >0.5, >1.0 and >1.5 for 74.5, 40.5, and 21.3% of patients, respectively. PCR was positive for 10 patients in the study but did not differentiate Aspergillus colonization from infection. The combination of PCR and GM in respiratory samples may be an interesting alternative to diagnose IA in COPD patients.     

Evaluation of Commercially Available Real-Time Polymerase Chain Reaction Assays for the Diagnosis of Invasive Aspergillosis in Patients with Haematological Malignancies

Mycopathologia - Early diagnosis of invasive aspergillosis (IA) is a challenge. Non-specific clinical and radiologic findings, as well as difficulties in conventional diagnostic method application,...     

Untargeted Antifungal Treatment Strategies for Invasive Candidiasis in Non-neutropenic Critically Ill Patients: Current Evidence and Insights

Purpose of Review

The purpose of this study was to provide an overview and insights on important new concepts on untargeted antifungal treatment strategies, namely prophylaxis pre-emptive and empiric treatments for the management of invasive candidiasis (IC) in non-neutropenic critically ill patients.

Recent Findings

Recently, clinical practice guidelines provided recommendation for the management of IC. However, results from recent trials and systematic reviews questioned the effect of untargeted antifungal treatment strategies, especially in terms of survival benefits in non-neutropenic patients, even with septic shock.

Summary

Widespread use of untargeted antifungal treatment strategies seems not to be justified anymore. Future research should evaluate comprehensive diagnostic-therapeutic approaches, including the implementation of de-escalation. In the meanwhile, clinicians should take into account all available sources of information including clinical evaluation, risk factor assessment, scores, and surrogate biomarkers to tailor antifungal treatment before definitive microbiological diagnosis.

     

Early Prediction of Sepsis Incidence in Critically Ill Patients Using Specific Genetic Polymorphisms

Several diagnostic methods for the evaluation and monitoring were used to find out the pro-inflammatory status, as well as incidence of sepsis in critically ill patients. One such recent method is based on investigating the genetic polymorphisms and determining the molecular and genetic links between them, as well as other sepsis-associated pathophysiologies. Identification of genetic polymorphisms in critical patients with sepsis can become a revolutionary method for evaluating and monitoring these patients. Similarly, the complications, as well as the high costs associated with the management of patients with sepsis, can be significantly reduced by early initiation of intensive care.     

Challenges in Diagnosing Invasive Pulmonary Aspergillosis in Patients With COPD and Other Chronic Lung Disorders

Invasive pulmonary aspergillosis (IPA) is a necrotizing pneumonia caused by airborne opportunistic fungi of Aspergillus species. Patients with chronic obstructive pulmonary disease (COPD) or other chronic lung disorders (CLD) have emerged to be at risk for IPA, with a related mortality rate greater than 70%. Host factors playing a role in the occurrence of IPA in CLD patients differ from those in patients with hematologic disorders and may be largely responsible for a distinct pattern of the disease. Furthermore, these host factors affect the results of standard diagnostic procedures recommended for IPA. Therefore, the diagnosis of IPA in patients with COPD and other CLD remains challenging for physicians. This review puts into perspective the host factors contributing to the pathogenesis of IPA in CLD patients and discusses the use and interpretation of the main diagnostic tools currently available.     

早期液体复苏对感染性休克患者血流动力学的影响

目的：早期液体复苏对感染性休克患者血流动力学的影响。方法：选取2012年2月-2013年2月我院ICU收治的26例感染性休克患者作为研究对象,随机分为对照组和试验组,各13例。两组患者均采用PICCO监测,并根据早期复苏目标导向（Earlygoaldirectedtherapy,EGDT）进行早期液体复苏治疗。对照组和试验组复苏液分别为林格液和6％羟乙基淀粉130／0．4氯化钠溶液。分别于复苏开始时（Oh）、8h和24h收集患者的血流动力学参数。结果：两组患者CO及PAWP水平均随着时间的延长下降,而CI、CVP及SVR水平均随着时间的增加上升。除对照组CI外,与开始复苏（oh）相比较试验组和对照组的C0、CI、CVP、SVR及PAWP与开始复苏（O小时）相比较均有显著差异（P值均〈0．05）。经重复测量资料的．方差分析进行比较发现,与对照组相比较,试验组CVP和SVR上升水平及PAWP下降水平明显,差异具有统计学意义（P值均〈0．05）。结论：感染性休克患者使用6％羟乙基淀粉130／0．4氯化钠溶液进行复苏,能更好的改善患者的血流动力学指标。     

Serum Levels of TNF Receptor Ligands Are Dysregulated in Sepsis and Predict Mortality in Critically Ill Patients

IntroductionTNF superfamily members, including TNF-related weak inducer of apoptosis (TWEAK) and Glucocorticoid-Induced TNFR-Related Protein Ligand (GITRL) have been described as serum based biomarkers for inflammatory and immune mediated diseases. However, up to now the role of TWEAK and GITRL has not been analyzed in critical illness and sepsis.MethodsGITRL and TWEAK serum concentrations were measured in 121 critically ill patients (84 fulfilled with septic disease), in comparison to 50 healthy controls. Results were correlated with clinical data.ResultsSerum levels of TWEAK and GITRL were strongly decreased in critically ill patients compared with healthy controls. Concentrations of TWEAK (but not GITRL) were further decreased in patients with sepsis and correlated with routinely used markers of inflammation and bacterial infection such as C-reactive protein, procalcitonin and Interleukin-6. Notably, we failed to detect a correlation to other TNFR ligands such as TNF or APRIL. Finally, TWEAK levels of the upper quartile of the cohort were prognostic for mortality during ICU treatment.ConclusionTWEAK and GITRL levels were lower in intensive care unit medical patients. Levels of TWEAK were further decreased in septic patients, and alterations in TWEAK concentrations were linked to an unfavorable outcome. Together with recently published results on other TNFR ligands, these data indicate specific functions of the different TNFR ligands in septic diseases.     

Serum Concentrations of Trace Elements Zinc,Copper, Selenium,and Manganese in Critically Ill Patients

Biological Trace Element Research - We measured serum concentrations of trace elements and evaluated their clinical significance in relation to treatment outcomes of critically ill patients. A...     

Evaluation of a Model for Glycemic Prediction in Critically Ill Surgical Patients

We evaluated a neural network model for prediction of glucose in critically ill trauma and post-operative cardiothoracic surgical patients. A prospective, feasibility trial evaluating a continuous glucose-monitoring device was performed. After institutional review board approval, clinical data from all consenting surgical intensive care unit patients were converted to an electronic format using novel software. This data was utilized to develop and train a neural network model for real-time prediction of serum glucose concentration implementing a prediction horizon of 75 minutes. Glycemic data from 19 patients were used to “train” the neural network model. Subsequent real-time simulated testing was performed in 5 patients to whom the neural network model was naive. Performance of the model was evaluated by calculating the mean absolute difference percent (MAD%), Clarke Error Grid Analysis, and calculation of the percent of hypoglycemic (≤70 mg/dL), normoglycemic (>70 and <150 mg/dL), and hyperglycemic (≥150 mg/dL) values accurately predicted by the model; 9,405 data points were analyzed. The models successfully predicted trends in glucose in the 5 test patients. Clark Error Grid Analysis indicated that 100.0% of predictions were clinically acceptable with 87.3% and 12.7% of predicted values falling within regions A and B of the error grid respectively. Overall model error (MAD%) was 9.0% with respect to actual continuous glucose modeling data. Our model successfully predicted 96.7% and 53.6% of the normo- and hyperglycemic values respectively. No hypoglycemic events occurred in these patients. Use of neural network models for real-time prediction of glucose in the surgical intensive care unit setting offers healthcare providers potentially useful information which could facilitate optimization of glycemic control, patient safety, and improved care. Similar models can be implemented across a wider scale of biomedical variables to offer real-time optimization, training, and adaptation that increase predictive accuracy and performance of therapies.     

Causes of Death in a Contemporary Cohort of Patients with Invasive Aspergillosis

Information regarding the processes leading to death in patients with invasive aspergillosis (IA) is lacking. We sought to determine the causes of death in these patients, the role that IA played in the cause, and the timing of death. The factors associated with IA-related mortality are also analyzed. We conducted a multicenter study (2008-2011) of cases of proven and probable IA. The causes of death and whether mortality was judged to be IA-related or IA-unrelated were determined by consensus using a six-member review panel. A multivariate analysis was performed to determine risk factors for IA-related death. Of 152 patients with IA, 92 (60.5%) died. Mortality was judged to be IA-related in 62 cases and IA-unrelated in 30. The most common cause of IA-related death was respiratory failure (50/62 patients), caused primarily by Aspergillus infection, although also by concomitant infections or severe comorbidities. Progression of underlying disease and bacteremic shock were the most frequent causes of IA-unrelated death. IA-related mortality accounted for 98% and 87% of deaths within the first 14 and 21 days, respectively. Liver disease (HR 4.54; 95% CI, 1.69-12.23) was independently associated with IA-related mortality, whereas voriconazole treatment was associated with reduced risk of death (HR 0.43; 95% CI, 0.20-0.93). In conclusion, better management of lung injury after IA diagnosis is the main challenge for physicians to improve IA outcomes. There are significant differences in causes and timing between IA-related and IA–unrelated mortality and these should be considered in future research to assess the quality of IA care.