Laboratory diagnosis of invasive aspergillosis

Comparison of 1,3-β-d-glucan with galactomannan in serum and bronchoalveolar fluid for the detection of Aspergillus species in immunosuppressed mechanical ventilated critically ill patients

PURPOSE

Invasive pulmonary aspergillosis (IPA) is an important cause of morbidity/mortality in immunocompromised critically ill patients. New diagnostic strategies for early detection of IPA include the noninvasive biomarkers 1,3-β-d-glucan (BDG), serum, and bronchoalveolar (BAL) fluid galactomannan (GM). The aim of this study was to compare these markers for early detection of IPA in immunosuppressed critically ill patients.

METHODS

Between December 2014 and December 2015, 49 immunosuppressed patients with respiratory failure were treated at our intensive care unit (ICU). We compared the BDG Fungitell assay with GM Platelia assay in serum and BAL for early detection of IPA. All tests were performed initially after admission at the ICU.

RESULTS

In our study with 49 patients, 13 (26%) had probable IPA. These patients had a higher Acute Physiology And Chronic Health Evaluation II score (28 vs 23, P<.001), Sequential Organ Failure Assessment score (16 vs 14, P<.001), more neutropenia (77% vs 30%, P<.001), worse Horowitz Index (99 vs 73 P<.020), a longer ICU stay (26 vs 17 days, P<.044), and a higher mortality rate (77% vs 58%, P<.001) as compared with patients without probable IPA. The used biomarker BDG presented in patients with probable IPA showed significantly higher levels as compared with patients without probable IPA (375 [103-1000 pg/mL; P<.001] vs 64 [30-105 pg/mL; P < .001]). Comparison of BDG with GM showed that positive serum GM could be detected in only 4 (30%), whereas positive BAL GM could be detected in 12 (92%; mean optical density index, 3.7) of 13 probable IPA cases. These results can be expressed as an overall sensitivity of 88% and a specificity of 82% for probable IPA using the BDG Fungitell assay, a sensitivity of 35% and a specificity of 70% using the serum GM Platelia assay, and a sensitivity of 70% and a specificity of 94% using the BAL GM Platelia assay. The negative predictive values of the used tests were 94% for the BDG Fungitell assay, 94% for the serum GM Platelia assay, and 90% for the BAL GM Platelia assay.

CONCLUSION

1,3-β-d-Glucan may be a useful marker for patients under surveillance at risk for IPA. In critically ill patients with immunosuppression, early diagnosis of IPA may be improved by BDG as compared with serum GM. However, diagnostic performance and accuracy increase when BDG is run in parallel with GM from BAL; moreover, the association of the 2 parameters has also the advantage of detecting early and reliable IPA.

Practice Guidelines for the Diagnosis and Management of Aspergillosis: 2016 Update by the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Blood Aspergillus RNA is a promising alternative biomarker for invasive aspergillosis

A critical challenge for the successful application of antifungal therapies for invasive aspergillosis (IA) is a lack of reliable biomarkers to assess early treatment response. Patients with proven or probable IA were prospectively enrolled, and serial blood samples were collected at 8 specified time points during 12-week antifungal therapy. Total nucleic acid was extracted from 2.5 ml blood and tested for Aspergillus-specific RNA by a pan-Aspergillus real-time nucleic acid sequence-based amplification (NASBA) assay. Serum 1, 3-β-D-glucan (BG) and galactomannan (GM) were measured in parallel. Clinical outcome was evaluated at 6 and 12 weeks. Overall, 48/328 (14.6%) blood samples from 29/46 (63%) patients had positive NASBA detection at baseline and/or some point during the study. Positive NASBA results during the first 4 and 6 weeks of treatment are significantly associated with the 12-week outcome. Blood RNA load change during weeks 4-6 may be informative to predict outcome at 12 weeks. While independent of serum GM, the kinetic change of circulating Aspergillus RNA appears to be well correlated with that of BG on some patient individuals. Monitoring blood Aspergillus RNA during the first 4-6 weeks of antifungal treatment may help assess therapeutic response. Combination of circulating Aspergillus RNA and BG may be a useful adjunct to assess response.

Aspergillosis in Chronic Granulomatous Disease

Patients with chronic granulomatous disease (CGD) have the highest life-time incidence of invasive aspergillosis and despite the availability of antifungal prophylaxis, infections by Aspergillus species remain the single most common infectious cause of death in CGD. Recent developments in curative treatment options, such as haematopoietic stem cell transplantation, will change the prevalence of infectious complications including invasive aspergillosis in CGD patients. However, invasive aspergillosis in a previously healthy host is often the first presenting feature of this primary immunodeficiency. Recognizing the characteristic clinical presentation and understanding how to diagnose and treat invasive aspergillosis in CGD is of utmost relevance to improve clinical outcomes. Significant differences exist in fungal epidemiology, clinical signs and symptoms, and the usefulness of non-culture based diagnostic tools between the CGD host and neutropenic patients, reflecting underlying differences in the pathogenesis of invasive aspergillosis shaped by the nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase deficiency.

Efficiency of interleukin 6 and interferon gamma in the differentiation of invasive pulmonary aspergillosis and pneumocystis pneumonia in pediatric oncology patients

OBJECTIVE

Invasive pulmonary aspergillosis (IPA) and Pneumocystis pneumonia (PCP) are two types of pulmonary fungal infection that are not easy to differentiate. The purpose of this study was to investigate the role of inflammatory cytokines in the differential diagnosis of IPA and PCP.

METHODS

A total of 227 pediatric oncology patients diagnosed with acute pneumonia were enrolled. They were divided into three groups: IPA, PCP, and 'others'. The cytokine levels in these groups were compared, including interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-10, IL-6, IL-4, and IL-2.

RESULTS

Of the six cytokines, only IL-6 and IFN-γ levels were elevated in patients with acute pneumonia. IL-6 was comparable between patients with IPA and PCP (52.0 pg/ml vs. 25.8 pg/ml, p=0.092), while IFN-γ was much higher in patients with PCP (19.9 pg/ml vs. 8.9 pg/ml, p=0.001). The accuracy of IL-6 and the ratio of IL-6/IFN-γ in predicting IPA were 69.0% and 72.0%, respectively, while the accuracy of IFN-γ to predict PCP was 67.2%. IL-6 >140 pg/ml and IL-6/IFN-γ >9.0 presented specificities of 90% in predicting IPA, while IFN-γ >40 pg/ml presented specificity of 90% in predicting PCP.

CONCLUSIONS

IL-6 is predominantly elevated in IPA, while IFN-γ is significantly increased in PCP. These are helpful tools for the differential diagnosis of IPA and PCP.

Gastrointestinal Infections

Gastrointestinal infections in the immunocompromised host are caused by the common bacterial, viral, fungal, and parasitic agents that also cause infections in the immunocompetent host. Of special consideration is that immunocompromised patients may be at increased risk for infection or disease severity and by pathogens not seen in the competent host. This chapter reviews the various agents, risk factors, and diagnostic approaches to detect gastrointestinal infections in this patient population.

Comparison of Serum Galactomannan and 1,3-Beta-D-Glucan Determination for Early Detection of Invasive Pulmonary Aspergillosis in Critically Ill Patients with Hematological Malignancies and Septic Shock

INTRODUCTION

Invasive pulmonary aspergillosis (IPA) is an important cause of morbidity/mortality in critically ill patients with hematological malignancies. New diagnosis strategies include the noninvasive biomarkers 1,3-beta-D-glucan (BDG) and serum galactomannan (GM).

METHODS

For early detection of IPA, we compared BDG Fungitell assay with GM Platelia assay.

RESULTS

Twenty-two out of 30 patients (74 %) had elevated BDG levels (mean 306 pg/ml) beyond the cutoff of 80 pg/ml. GM levels were elevated in only 3 patients (10 %) over the ODI cutoff of >0.5. Following the BDG/GM and microbiological findings, 10 (34 %) cases were classified as probable IPA and 12 (40 %) as possible IPA. Eight (26 %) were classified as no IPA. An overall sensitivity of 90 % (95 % CI 86-96 %) and specificity of 85 % (95 % CI 79-86 %) was found for the BDG Fungitell assay in IPA. In contrast, an overall sensitivity of 30 % (95 % CI 26-38 %) and specificity of 98 % (95 % CI 94-100 %) was found for the GM Platelia assay. A false-negative rate of 70 % for probable IPA and 85 % for probable/possible IPA was detected for GM. The false-negative rate for BDG was 0 % in cases of probable IPA and 45 % in cases of possible cases.

CONCLUSION

BDG is a sensitive marker for patients' surveillance at risk of IPA. In patients with hematological malignancies and septic shock, early diagnosis of IPA might be significantly improved by BDG compared to GM, also considering that BDG has the advantage of detecting fungal diseases other than IPA.

Voriconazole is a safe and effective anti-fungal prophylactic agent during induction therapy of acute myeloid leukemia

Background:

Antifungal prophylaxis (AFP) reduces the incidence of invasive fungal infections (IFIs) during induction therapy of acute myeloid leukemia (AML). Posaconazole is considered the standard of care. Voriconazole, a generic cheaper alternative is a newer generation azole with broad anti-fungal activity. There is limited data on the use of voriconazole as a prophylactic drug.

Materials and Methods:

A single-center, prospective study was performed during which patients with AML undergoing induction chemotherapy received voriconazole as AFP (April 2012 to February 2014). Outcomes were compared with historical patients who received fluconazole as AFP (January 2011-March 2012, n = 66).

Results:

Seventy-five patients with AML (median age: 17 years [range: 1-75]; male:female 1.6:1) received voriconazole as AFP. The incidence of proven/probable/possible (ppp) IFI was 6.6% (5/75). Voriconazole and fluconazole cohorts were well-matched with respect to baseline characteristics. Voriconazole (when compared to fluconazole) reduced the incidence of pppIFI (5/75, 6.6% vs. 19/66, 29%; P < 0.001), need to start therapeutic (empiric + pppIFI) antifungals (26/75, 34% vs. 51/66, 48%; P < 0.001) and delayed the start of therapeutic antifungals in those who needed it (day 16 vs. day 10; P < 0.001). Mortality due to IFI was also reduced with the use of voriconazole (1/75, 1.3% vs. 6/66, 9%; P = 0.0507), but this was not significant. Three patients discontinued voriconazole due to side-effects.

Conclusion:

Voriconazole is an effective and safe oral agent for IFI prophylaxis during induction therapy of AML. Availability of generic equivalents makes this a more economical alternative to posaconazole.

Crayfish plague Aphanomyces astaci detected in redclaw crayfish, Cherax quadricarinatus in Taiwan

Between December 2013 and January 2014, five outbreaks of an unknown disease with moderate to high cumulative mortality were observed among the freshwater redclaw crayfish (Cherax quadricarinatus) populations at four crayfish farms in Miaoli and Changhua counties (northern Taiwan) and at one crayfish farm in Pingtung County (southern Taiwan). Polymerase chain reaction (PCR) analysis allowed the detection of Aphanomyces astaci DNA in dead crayfish. Histopathological examination revealed an infection of host tissue by fungal hyphae that presented as typical non-septate hyphae within the soft abdominal cuticle from the first to second segment and in the tail fan. In PCR assays completed for the detection of crayfish plague, an expected 568-bp product, specific for the A. astaci ITS gene, was obtained from all sub-adults and adults examined. In a comparison of our strains with the known strains of A. astaci in Europe, nucleotide sequence identities were very similar, with 99.8-100% sequence similarity in that gene region. Positive reactions to in situ hybridization, using a digoxigenin (DIG)-labelled DNA probe, further confirmed A. astaci as the causative agent. This is the first report concerning natural infection of A. astaci in freshwater redclaw crayfish in Asia.

Galactomannan in bronchoalveolar lavage fluid for diagnosis of invasive aspergillosis in non-hematological patients

BACKGROUND

The role of galactomannan (GM) in serum or bronchoalveolar lavage fluid (BALF) for the diagnosis of invasive pulmonary aspergillosis (IPA) has been extensively evaluated in hematological patients, however its performance in non-hematological patients is not well established.

METHODS

We performed a multicenter retrospective study in 3 university hospitals in Madrid, Spain between 2010 and 2014. The study population comprised patients with chronic obstructive pulmonary disease (COPD) and patients with immunosuppressive conditions in whom IPA was suspected and for whom BALF GM was available. Patients with hematological disorders were excluded.

RESULTS

A total of 188 patients (35 with COPD and 153 with immunosuppressive conditions) were analyzed, and 31 cases of IPA (proven or probable) were identified. The global sensitivity of BALF GM (optical density index [ODI] ≥ 1.0) was 77.4%; sensitivity was higher in patients with immunosuppressive conditions than in patients with COPD (81.8% vs 66.7%; p: 0.38). In COPD patients, the best performance was obtained for BALF GM (ODI ≥ 0.5), although sensitivity (88.9%) was similar to that of BALF fungal culture (88.9%). The sensitivity of GM in serum was very poor in both populations (36.4% and 11.6%, respectively).

CONCLUSIONS

In the present series, the diagnostic performance of BALF GM was good for IPA in non-hematological patients, especially in patients with immunosuppressive conditions.

Performance of lateral flow device and galactomannan for the detection of Aspergillus species in bronchoalveolar fluid of patients at risk for invasive pulmonary aspergillosis

Early diagnosis of invasive pulmonary aspergillosis (IPA) remains difficult due to the variable performance of the tests used. We compared the performance characteristics of Aspergillus lateral flow device (LFD) in bronchoalveolar lavage (BAL) vs. BAL-galactomannan (GM), for the diagnosis of IPA. 311 BAL specimens were prospectively collected from patients who underwent bronchoscopy from January to May 2013. Patients at risk for IPA were divided into haematological malignancy (HEM) and non-HEM groups: solid organ transplants (SOT) (lung transplant (LT) and non-LT SOT); chronic steroid use (CSU); solid tumour (STU) and others. We identified 96 patients at risk for IPA; 89 patients (93%) were in the non-HEM groups: SOT 57 (LT, 46, non-LT SOT, 11); CSU 21; STU 6, other 5. Only three patients met criteria for IA (two probable; one possible). Overall sensitivity (SS) was 66% for both and specificity (SP) was 94% vs. 52% for LFD and GM respectively. LFD and GM performance was similar in the HEM group (SS 100% for both and SP 83% vs. 100% respectively). LFD performance was better than GM among non-HEM SOT patients (P = 0.02). Most false-positive GM results occurred in the SOT group (50.8%), especially among LT patients (56.5%). LFD performance was superior with an overall SP of 95.6% in SOT (P < 0.002) and 97% in LT patients (P = 0.0008). LFD is a rapid and simple test that can be performed on BAL to rule out IPA.

ImmunoPET/MR imaging allows specific detection of Aspergillus fumigatus lung infection in vivo

Invasive pulmonary aspergillosis (IPA) is a life-threatening lung disease caused by the fungus Aspergillus fumigatus, and is a leading cause of invasive fungal infection-related mortality and morbidity in patients with hematological malignancies and bone marrow transplants. We developed and tested a novel probe for noninvasive detection of A. fumigatus lung infection based on antibody-guided positron emission tomography and magnetic resonance (immunoPET/MR) imaging. Administration of a [(64)Cu]DOTA-labeled A. fumigatus-specific monoclonal antibody (mAb), JF5, to neutrophil-depleted A. fumigatus-infected mice allowed specific localization of lung infection when combined with PET. Optical imaging with a fluorochrome-labeled version of the mAb showed colocalization with invasive hyphae. The mAb-based newly developed PET tracer [(64)Cu]DOTA-JF5 distinguished IPA from bacterial lung infections and, in contrast to [(18)F]FDG-PET, discriminated IPA from a general increase in metabolic activity associated with lung inflammation. To our knowledge, this is the first time that antibody-guided in vivo imaging has been used for noninvasive diagnosis of a fungal lung disease (IPA) of humans, an approach with enormous potential for diagnosis of infectious diseases and with potential for clinical translation.

From synthetic DNA to PCR product: detection of fungal infections using SERS

We report the use of silver hydroxylamine nanoparticles functionalised with single stranded monothiolated DNA for the detection of fungal infections. The four different species of fungi that were targeted wereCandida albicans,Candida glabrata,Candida kruseiandAspergillus fumigatus. Rational design of synthetic targets and probes was carried out by carefully analysing the 2-D folding of the DNA and then by global alignment of the sequences to ensure specificity. The effects of varying the concentrations of the DNA and dye surrounding the nanoparticles on the resultant surface enhanced Raman scattering (SERS) signal were also investigated to ensure compatibility of the probes in a multiplexed environment. Using principal components analysis (PCA) it was possible to detect the individual presence of each target and group them accordingly. The move to detect theC. kruseisingle stranded PCR product (ssPCR) was significant to demonstrate that the methodology could be employed for the detection and diagnosis of invasive fungal infections (IFDs) within a clinical setting. Initially the PCR product was subjected to an alkali shock method in order to separate the strands ready for detection using the nanoparticle probes system. This time 18 base probes were employed to enhance hybridisation efficiency and dextran sulfate was found to have a vital role in ensuring that detection of theC. kruseitarget was achieved. This demonstrated the use of DNA functionalised silver nanoparticle for the detection of clinically relevant DNA relating to a specific fungal infection and offers significant promise for future diagnostic applications.

Galactomannan detection for invasive aspergillosis in immunocompromised patients

BACKGROUND

Invasive aspergillosis is the most common life-threatening opportunistic invasive mycosis in immunocompromised patients. A test for invasive aspergillosis should neither be too invasive nor too great a burden for the already weakened patient. The serum galactomannan enzyme-linked immunosorbent assay (ELISA) seems to have the potential to meet both requirements.

OBJECTIVES

To obtain summary estimates of the diagnostic accuracy of galactomannan detection in serum for the diagnosis of invasive aspergillosis.

SEARCH METHODS

We searched MEDLINE, EMBASE and Web of Science with both MeSH terms and text words for both aspergillosis and the sandwich ELISA. We checked the reference lists of included studies and review articles for additional studies. We conducted the searches in February 2014.

SELECTION CRITERIA

We included cross-sectional studies, case-control designs and consecutive series of patients assessing the diagnostic accuracy of galactomannan detection for the diagnosis of invasive aspergillosis in patients with neutropenia or patients whose neutrophils are functionally compromised. The reference standard was composed of the criteria given by the European Organization for Research and Treatment of Cancer (EORTC) and the Mycoses Study Group (MSG).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed quality and extracted data. We carried out meta-analysis using the bivariate method. We investigated sources of heterogeneity by adding potential sources of heterogeneity to the model as covariates.

MAIN RESULTS

We included 54 studies in the review (50 in the meta-analyses), containing 5660 patients, of whom 586 had proven or probable invasive aspergillosis. When using an optical density index (ODI) of 0.5 as a cut-off value, the sensitivity of the test was 82% (73% to 90%) and the specificity was 81% (72% to 90%). At a cut-off value of 1.0 ODI, the sensitivity was 72% (65% to 80%) and the specificity was 88% (84% to 92%). At a cut-off value of 1.5 ODI, the sensitivity was 61% (47% to 75%) and the specificity was 93% (89% to 97%). None of the potential sources of heterogeneity had a statistically significant effect on either sensitivity or specificity.

AUTHORS' CONCLUSIONS

If we used the test at a cut-off value of 0.5 ODI in a population of 100 patients with a disease prevalence of 9% (overall median prevalence), two patients who have invasive aspergillosis would be missed (sensitivity 82%, 18% false negatives), and 17 patients would be treated unnecessarily or referred unnecessarily for further testing (specificity 81%, 19% false negatives). If we used the test at a cut-off value of 1.5 in the same population, that would mean that four invasive aspergillosis patients would be missed (sensitivity 61%, 39% false negatives), and six patients would be treated or referred for further testing unnecessarily (specificity 93%, 7% false negatives). These numbers should, however, be interpreted with caution because the results were very heterogeneous.

(1→3)-β-D-glucan and galactomannan testing for the diagnosis of fungal peritonitis in peritoneal dialysis patients, a pilot study

Fungal peritonitis is an uncommon but serious complication of peritoneal dialysis (PD) due to the fact that routine culture to recovered the etiologic agents are time consuming and KOH staining has very low sensitivity. Peritoneal (1→3)-β-D-glucan (BG) or galactomannan (GM), both fungal cell wall components, are candidate biomarkers of fungal peritonitis. Hence, a comparative cross-sectional analysis of peritoneal dialysis fluid (PDF) BG (Fungitell, Cape Cod, MA, USA) and GM (Platelia Aspergillus Ag kits, Bio-rad, France) from all PD patients with and without fungal peritonitis (13 cases, identified by culture), over a 1 year period, was performed. PDF of the fungal peritonitis group showed very high BG (494 ± 19 pg/ml) and high GM (3.41 ± 1.24) similar results were noted in specimens from cases of peritonitis with other causes, especially gram negative bacterial peritonitis. A BG cut-off value at 240 pg/ml and GM at 0.5 showed sensitivity/ specificity at 100%/ 83% and 77%/ 58%, respectively. A concomitantly positive GM reduced the false positive rate of BG from nonfungal peritonitis. In conclusion, BG and GM in peritoneal fluid with provisional cut-off values were applicable as surrogate biomarkers for the diagnosis of fungal peritonitis in PD patients.

Improved Detection of Invasive Pulmonary Aspergillosis Arising during Leukemia Treatment Using a Panel of Host Response Proteins and Fungal Antigens

Invasive pulmonary aspergillosis (IPA) is an opportunistic fungal infection in patients undergoing chemotherapy for hematological malignancy, hematopoietic stem cell transplant, or other forms of immunosuppression. In this group, Aspergillus infections account for the majority of deaths due to mold pathogens. Although early detection is associated with improved outcomes, current diagnostic regimens lack sensitivity and specificity. Patients undergoing chemotherapy, stem cell transplantation and lung transplantation were enrolled in a multi-site prospective observational trial. Proven and probable IPA cases and matched controls were subjected to discovery proteomics analyses using a biofluid analysis platform, fractionating plasma into reproducible protein and peptide pools. From 556 spots identified by 2D gel electrophoresis, 66 differentially expressed post-translationally modified plasma proteins were identified in the leukemic subgroup only. This protein group was rich in complement components, acute-phase reactants and coagulation factors. Low molecular weight peptides corresponding to abundant plasma proteins were identified. A candidate marker panel of host response (9 plasma proteins, 4 peptides), fungal polysaccharides (galactomannan), and cell wall components (β-D glucan) were selected by statistical filtering for patients with leukemia as a primary underlying diagnosis. Quantitative measurements were developed to qualify the differential expression of the candidate host response proteins using selective reaction monitoring mass spectrometry assays, and then applied to a separate cohort of 57 patients with leukemia. In this verification cohort, a machine learning ensemble-based algorithm, generalized pathseeker (GPS) produced a greater case classification accuracy than galactomannan (GM) or host proteins alone. In conclusion, Integration of host response proteins with GM improves the diagnostic detection of probable IPA in patients undergoing treatment for hematologic malignancy. Upon further validation, early detection of probable IPA in leukemia treatment will provide opportunities for earlier interventions and interventional clinical trials.

Galactomannan antigen detection using bronchial wash and bronchoalveolar lavage in patients with hematologic malignancies

BACKGROUND

The diagnosis of invasive pulmonary aspergillosis is challenging. It is unclear whether galactomannan (GM) results from bronchial wash (BW) and bronchoalveolar lavage (BAL) samples differ in a clinically meaningful way.

RESULTS

Ninety-six paired (BAL and BW) samples from 85 patients were included. The average age was 53 years, 61 % of the patients were male, and 74.1 % had an underlying diagnosis of AML/MDS (ALL 7.1 %, other hematologic malignancy 18.8 %). 57 (67.1 %) patients were neutropenic, and 56 (65.9 %) patients were receiving mold-active drugs at least 48 h prior to bronchoscopy. The overall agreement between GM detection from BW and BAL was 63.5 % (K = 0.152; 95 % CI 0.008-0.311) and 73 % (K = 0.149; 95 % CI 0.048-0.348) at cut off ≥0.5 and ≥1.0, respectively. Among 43 positive samples, using a GM cut-off of 0.5, 39 (90.5 %) were positive in BW samples whereas 12 (29.3 %) were positive in BAL samples. The median level of GM in BW (0.28) samples was significantly higher than in BAL (0.20) samples among 53 samples with negative results (P = 0.001). There was no statistically significant difference in the median GM values between the BW and BAL samples with positive results (P = 0.08). There was no significant difference in GM detection between samples with positive and negative results with regard to antifungal, beta lactam antibacterial treatment or neutropenia (60.5 vs 56.6 %; 53.9 vs 46 %; 65.1 vs 54.7 %, respectively).

CONCLUSION

This retrospective study examining two collection techniques suggests that BW may have higher diagnostic yield compared to bronchoalveolar lavage for GM detection.

(1→3)-β-d-Glucan and Galactomannan for Differentiating Chemical "Black Particles" and Fungal Particles Inside Peritoneal Dialysis Tubing

♦

BACKGROUND

Aseptic, sheet-like foreign bodies observed inside Tenckhoff (TK) catheter lumens (referred to as "black particles") are, on gross morphology, hardly distinguishable from fungal colonization because these contaminants adhere tightly to the catheter. Detection of fungal cell wall components using (1→3)-β-d-glucan (BG) and galactomannan index (GMI) might be an alternative method for differentiating the particles. ♦

METHODS

Foreign particles retrieved from TK catheters in 19 peritoneal dialysis patients were examined microscopically and cultured for fungi and bacteria. Simultaneously, a Fungitell test (Associates of Cape Cod, Falmouth, MA, USA) and a Platelia Aspergillus ELISA assay (Bio-Rad Laboratories, Marnes-La-Coquette, France) were used to test the spent dialysate for BG and GMI respectively. ♦

RESULTS

Of the 19 patients, 9 had aseptic black particles and 10 had fungal particles in their tubing. The fungal particles looked grainy, were tightly bound to the catheter, and appeared more "colorful" than the black particles, which looked sheet-like and could easily be removed by milking the tubing. Compared with effluent from patients having aseptic particles, effluent from patients with fungal particles had significantly higher levels of BG (501 ± 70 pg/mL vs. 46 ± 10 pg/mL) and GMI (10.98 ± 2.17 vs. 0.25 ± 0.05). Most of the fungi that formed colonies inside the catheter lumen were molds not usually found in clinical practice, but likely from water or soil, suggesting environmental contamination. Interestingly, in all 10 patients with fungal colonization, visualization of black particles preceded a peritonitis episode and TK catheter removal by approximately 1-3 weeks; in patients with aseptic particles, a 17-week onset to peritonitis was observed. ♦

CONCLUSIONS

In all patients with particle-coated peritoneal dialysis tubing, spent dialysate should be screened for BG and GMI. Manipulation of the TK catheter by squeezing, hard flushing, or even brushing to dislodge black particles should be avoided. Replacement of the TK catheter should be suspended until a cause for the particles is determined.

Polymerase chain reaction blood tests for the diagnosis of invasive aspergillosis in immunocompromised people

BACKGROUND

Invasive aspergillosis (IA) is the most common life-threatening opportunistic invasive mould infection in immunocompromised people. Early diagnosis of IA and prompt administration of appropriate antifungal treatment are critical to the survival of people with IA. Antifungal drugs can be given as prophylaxis or empirical therapy, instigated on the basis of a diagnostic strategy (the pre-emptive approach) or for treating established disease. Consequently there is an urgent need for research into both new diagnostic tools and drug treatment strategies. Newer methods such as polymerase chain reaction (PCR) to detect fungal nucleic acids are increasingly being investigated.

OBJECTIVES

To provide an overall summary of the diagnostic accuracy of PCR-based tests on blood specimens for the diagnosis of IA in immunocompromised people.

SEARCH METHODS

We searched MEDLINE (1946 to June 2015) and EMBASE (1980 to June 2015). We also searched LILACS, DARE, Health Technology Assessment, Web of Science and Scopus to June 2015. We checked the reference lists of all the studies identified by the above methods and contacted relevant authors and researchers in the field.

SELECTION CRITERIA

We included studies that: i) compared the results of blood PCR tests with the reference standard published by the European Organisation for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG); ii) reported data on false-positive, true-positive, false-negative and true-negative results of the diagnostic tests under investigation separately; and iii) evaluated the test(s) prospectively in cohorts of people from a relevant clinical population, defined as a group of individuals at high risk for invasive aspergillosis. Case-control studies were excluded from the analysis.

DATA COLLECTION AND ANALYSIS

Authors independently assessed quality and extracted data. For PCR assays, we evaluated the requirement for either one or two consecutive samples to be positive for diagnostic accuracy. We investigated heterogeneity by subgroup analyses. We plotted estimates of sensitivity and specificity from each study in receiver operating characteristics (ROC) space and constructed forest plots for visual examination of variation in test accuracy. We performed meta-analyses using the bivariate model to produce summary estimates of sensitivity and specificity.

MAIN RESULTS

Eighteen primary studies, corresponding to 19 cohorts and 22 data sets, published between 2000 and 2013 were included in the meta-analyses, with a median prevalence of IA (proven or probable) of 12.0% (range 2.5 to 30.8 %). The majority of people had received chemotherapy for a haematological malignancy or had undergone a hematopoietic stem cell transplant. Several PCR techniques were used among the included studies. The sensitivity and specificity of PCR for the diagnosis of IA varied according to the interpretative criteria used to define a test as positive. The mean sensitivity and specificity were 80.5% (95% CI; 73.0 to 86.3) and 78.5% (67.8 to 86.4) for a single positive test result, and 58.0% (36.5 to 76.8) and 96.2% (89.6 to 98.6) for two consecutive positive test results.

AUTHORS' CONCLUSIONS

PCR shows moderate diagnostic accuracy when used as screening tests for IA in high-risk patient groups. Importantly the sensitivity of the test confers a high negative predictive value (NPV) such that a negative test allows the diagnosis to be excluded. Consecutive positives show good specificity in diagnosis of IA and could be used to trigger radiological and other investigations or for pre-emptive therapy in the absence of specific radiological signs when the clinical suspicion of infection is high. When a single PCR positive test is used as diagnostic criterion for IA in a population of 100 people with a disease prevalence of 13.0% (overall mean prevalence), three people with IA would be missed (sensitivity 80.5%, 19.5% false negatives), and 19 people would be unnecessarily treated or referred for further tests (specificity of 78.5%, 21.5% false positives). If we use the two positive test requirement in a population with the same disease prevalence, it would mean that six IA people would be missed (sensitivity 58.0%, 42.1% false negatives) and three people would be unnecessarily treated or referred for further tests (specificity of 96.2%, 3.8% false positives). Galactomannan and PCR have good NPV for excluding disease but the low prevalence of disease limits the ability to rule in a diagnosis. The biomarkers are detecting different aspects of disease and the combination of both together is likely to be more useful.

Serological response and diagnostic value of recombinant candida cell wall protein enolase, phosphoglycerate kinase, and β-glucosidase

There are no specific signs and symtoms for invasive candidiasis (IC), which makes its diagnosis a challenge. Efforts have been made for decades to establish serological assays for rapid diagnosis of IC, but none of them have found widespread clinical use. Using a systemic candiasis murine model, serological response to recombinant proteins of enolase (rEno1), phosphoglycerate kinase (rPgk1), and β-glucosidase (rBgl2) were evaluated and rEno1 was found to possess the strongest immunoreactivity, followed by rPgk1 and rBgl2. Likewise, IgG antibody titers to rEno1, rPgk1, and rBgl2 in the positive sera of proven IC patients were determined by ELISA. Results show anti-rEno1 antibody possesses the highest titer, followed by rPgk1 and rBgl2. Antibodies against rEno1, rPgk1, and rBgl2 were detected by ELISA tests in a group of 52 proven IC patients or 50 healthy subjects, The sensitivity, specificity, positive and negative predictive values were 88.5, 90.0, 90.2, and 88.2% for anti-rEno1 detection, 86.5, 92.0, 91.8, and 86.8% for anti-rPgk1 detection, and 80.8, 90.0, 89.4, and 81.8% for anti-rBgl2 detection, respectively. The data clearly demonstrate that the recombinant proteins of Eno1, Pgk1, and Bgl2 are promising candidates for IC serodiagnosis. There's great possibility that the recombinant Eno1 will be more applicable in serodiagnosis and vaccine research on account of its strong serological response.

Polymerase chain reaction blood tests for the diagnosis of invasive aspergillosis in immunocompromised people

BACKGROUND

Invasive aspergillosis (IA) is the most common life-threatening opportunistic invasive mould infection in immunocompromised people. Early diagnosis of IA and prompt administration of appropriate antifungal treatment are critical to the survival of people with IA. Antifungal drugs can be given as prophylaxis or empirical therapy, instigated on the basis of a diagnostic strategy (the pre-emptive approach) or for treating established disease. Consequently there is an urgent need for research into both new diagnostic tools and drug treatment strategies. Newer methods such as polymerase chain reaction (PCR) to detect fungal nucleic acids are increasingly being investigated.

OBJECTIVES

To provide an overall summary of the diagnostic accuracy of PCR-based tests on blood specimens for the diagnosis of IA in immunocompromised people.

SEARCH METHODS

We searched MEDLINE (1946 to June 2015) and EMBASE (1980 to June 2015). We also searched LILACS, DARE, Health Technology Assessment, Web of Science and Scopus to June 2015. We checked the reference lists of all the studies identified by the above methods and contacted relevant authors and researchers in the field.

SELECTION CRITERIA

We included studies that: i) compared the results of blood PCR tests with the reference standard published by the European Organisation for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG); ii) reported data on false-positive, true-positive, false-negative and true-negative results of the diagnostic tests under investigation separately; and iii) evaluated the test(s) prospectively in cohorts of people from a relevant clinical population, defined as a group of individuals at high risk for invasive aspergillosis. Case-control studies were excluded from the analysis.

DATA COLLECTION AND ANALYSIS

Authors independently assessed quality and extracted data. For PCR assays, we evaluated the requirement for either one or two consecutive samples to be positive for diagnostic accuracy. We investigated heterogeneity by subgroup analyses. We plotted estimates of sensitivity and specificity from each study in receiver operating characteristics (ROC) space and constructed forest plots for visual examination of variation in test accuracy. We performed meta-analyses using the bivariate model to produce summary estimates of sensitivity and specificity.

MAIN RESULTS

Eighteen primary studies, corresponding to 19 cohorts and 22 data sets, published between 2000 and 2013 were included in the meta-analyses, with a median prevalence of IA (proven or probable) of 12.0% (range 2.5 to 30.8 %). The majority of people had received chemotherapy for a haematological malignancy or had undergone a hematopoietic stem cell transplant. Several PCR techniques were used among the included studies. The sensitivity and specificity of PCR for the diagnosis of IA varied according to the interpretative criteria used to define a test as positive. The mean sensitivity and specificity were 80.5% (95% CI; 73.0 to 86.3) and 78.5% (67.8 to 86.4) for a single positive test result, and 58.0% (36.5 to 76.8) and 96.2% (89.6 to 98.6) for two consecutive positive test results.

AUTHORS' CONCLUSIONS

PCR shows moderate diagnostic accuracy when used as screening tests for IA in high-risk patient groups. Importantly the sensitivity of the test confers a high negative predictive value (NPV) such that a negative test allows the diagnosis to be excluded. Consecutive positives show good specificity in diagnosis of IA and could be used to trigger radiological and other investigations or for pre-emptive therapy in the absence of specific radiological signs when the clinical suspicion of infection is high. When a single PCR positive test is used as diagnostic criterion for IA in a population of 100 people with a disease prevalence of 13.0% (overall mean prevalence), three people with IA would be missed (sensitivity 80.5%, 19.5% false negatives), and 19 people would be unnecessarily treated or referred for further tests (specificity of 78.5%, 21.5% false negatives). If we use the two positive test requirement in a population with the same disease prevalence, it would mean that six IA people would be missed (sensitivity 58.0%, 42.1% false negatives) and three people would be unnecessarily treated or referred for further tests (specificity of 96.2%, 3.8% false negatives). Galactamannan and PCR have good NPV for excluding disease but the low prevalence of disease limits the ability to rule in a diagnosis. The biomarkers are detecting different aspects of disease and the combination of both together is likely to be more useful.

Aspergillus colonization in patients with chronic obstructive pulmonary disease

Background and Purpose:

Chronic obstructive pulmonary disease (COPD) has been recognized as a risk factor for invasive aspergillosis. Airway colonization by Aspergillus species is a common feature of chronic pulmonary diseases. Nowadays, the incidence of COPD has increased in critically ill patients. The aim of the present study was to isolate and identify Aspergillus colonies in the respiratory tract of COPD patients.

Materials and Methods:

This study was performed on 50 COPD patients, who were aged above 18 years, and were in intensive care units of three hospitals in Sari, Iran, for at least six days. All the samples obtained from sputum, bronchoalveolar lavage, and tracheal aspirates were cultured for fungi each week. According to the conventional techniques, Aspergillus isolates were initially based on growth and standard morphological characteristics. To confirm the identification of grown Aspergillus, the partial beta-tubulin gene was sequenced using specific primers.

Results:

A total of 50 patients, who met our inclusion criteria, were enrolled in the study during 2012-14. The results showed that 27 (54%) and 23 (46%) of the participants were male and female, respectively. The majority of the patients developed dyspnea followed by hemoptysis, chest pain, and high fever. Corticosteroids and broad-spectrum antibacterial agents were administered to 75% and 80% of the patients, respectively. Based on the conventional and molecular approaches, A. fumigatus (seven cases; 43.7%), A. flavus (five cases; 31.2%), A. niger (one case; 6.2%), A. terreus (one case; 6.2%), A. orezea (one case; 6.2%), and A. tubingensis (one case; 6.2%) were recovered.

Conclusion:

Recovery of Aspergillus species from the respiratory tract of COPD patients with pneumonia indicates two possibilities: either colonization or invasive aspergillosis.

Application of Culture-Independent Rapid Diagnostic Tests in the Management of Invasive Candidiasis and Cryptococcosis

The diagnosis of invasive candidiasis (IC) and cryptococcosis is often complicated by slow and insensitive culture-based methods. Such delay results in poor outcomes due to the lack of timely therapeutic interventions. Advances in serological, biochemical, molecular and proteomic approaches have made a favorable impact on this process, improving the timeliness and accuracy of diagnosis with resultant improvements in outcome. This paper will serve as an overview of recent developments in the diagnostic approaches to infections due to these important yeast-fungi.

RNAseq analysis of Aspergillus fumigatus in blood reveals a just wait and see resting stage behavior

Background

Invasive aspergillosis is started after germination of Aspergillus fumigatus conidia that are inhaled by susceptible individuals. Fungal hyphae can grow in the lung through the epithelial tissue and disseminate hematogenously to invade into other organs. Low fungaemia indicates that fungal elements do not reside in the bloodstream for long.

Results

We analyzed whether blood represents a hostile environment to which the physiology of A. fumigatus has to adapt. An in vitro model of A. fumigatus infection was established by incubating mycelium in blood. Our model allowed to discern the changes of the gene expression profile of A. fumigatus at various stages of the infection. The majority of described virulence factors that are connected to pulmonary infections appeared not to be activated during the blood phase. Three active processes were identified that presumably help the fungus to survive the blood environment in an advanced phase of the infection: iron homeostasis, secondary metabolism, and the formation of detoxifying enzymes.

Conclusions

We propose that A. fumigatus is hardly able to propagate in blood. After an early stage of sensing the environment, virtually all uptake mechanisms and energy-consuming metabolic pathways are shut-down. The fungus appears to adapt by trans-differentiation into a resting mycelial stage. This might reflect the harsh conditions in blood where A. fumigatus cannot take up sufficient nutrients to establish self-defense mechanisms combined with significant growth.

Electronic supplementary material

The online version of this article (doi10.1186/s12864-015-1853-1) contains supplementary material, which is available to authorized users.

Pneumonia in the neutropenic cancer patient

PURPOSE OF REVIEW

Pneumonia is the leading cause of death among neutropenic cancer patients, particularly those with acute leukaemia. Even with empiric therapy, case fatality rates of neutropenic pneumonias remain unacceptably high. However, recent advances in the management of neutropenic pneumonia offer hope for improved outcomes in the cancer setting. This review summarizes recent literature regarding the clinical presentation, microbiologic trends, diagnostic advances and therapeutic recommendations for cancer-related neutropenic pneumonia.

RECENT FINDINGS

Although neutropenic patients acquire pathogens both in community and nosocomial settings, patients' obligate healthcare exposures result in the frequent identification of multidrug-resistant bacterial organisms on conventional culture-based assessment of respiratory secretions. Modern molecular techniques, including expanded use of galactomannan testing, have further facilitated identification of fungal pathogens, allowing for aggressive interventions that appear to improve patient outcomes. Multiple interested societies have issued updated guidelines for antibiotic therapy of suspected neutropenic pneumonia. The benefit of antibiotic medications may be further enhanced by agents that promote host responses to infection.

SUMMARY

Neutropenic cancer patients have numerous potential causes for pulmonary infiltrates and clinical deterioration, with lower respiratory tract infections among the most deadly. Early clinical suspicion, diagnosis and intervention for neutropenic pneumonia provide cancer patients' best hope for survival.

Antifungal agent utilization evaluation in hospitalized neutropenic cancer patients at a large teaching hospital

To evaluate pattern of using of three antifungal drugs: fluconazole, amphotericin B and voriconazole, at the hematology-oncology and bone marrow transplant wards of one large teaching hospital. In a prospective cross-sectional study, we evaluated the appropriateness of using antifungal drugs in patients, using Infectious Disease Society of America (IDSA) and National Comprehensive Cancer Network (NCCN) guidelines. All the data were recorded daily by a pharmacist in a form designed by a clinical pharmacist and infectious diseases specialist, for antifungals usage, administration, and monitoring. During the study, 116 patients were enrolled. Indications of prescribing amphotericin B, fluconazole, and voriconazole were appropriate according to guidelines in 83.4%, 80.6%, and 76.9% respectively. The duration of treatments were appropriate according to guidelines in 75%, 64.5%, and 71.1% respectively. The dose of voriconazole was appropriate according to guidelines in 46.2% of patients. None of the patients received salt loading before administration of amphotericin B. The most considerable problems with the mentioned antifungals were about the indications and duration of treatment. In addition, prehydration for amphotericin B and dosage of voriconazole were not completely compatible with the mentioned guidelines. A suitable combination of controlling the use of antifungals and educational programs could be essential for improving the general process of using antifungal drugs at our hospital.

Diagnosis of invasive aspergillosis: recent developments and ongoing challenges

BACKGROUND

Invasive aspergillosis is an infection with high morbidity and mortality that affects mostly immunocompromised individuals. Early identification and targeted treatment of the infection is essential to improve survival of affected patients. The purpose of our review is to highlight the most recent developments in diagnosis and screening for invasive aspergillosis (IA) along with the challenges associated with the development and validation of novel diagnostic approaches.

METHODS

Ovid MEDLINE and The Cochrane library were searched for studies that evaluated serologic, molecular and novel methodologies for the diagnosis of IA.

RESULTS

Traditional diagnostic approaches, such as histopathology and culture, are still considered the gold standard but lack sufficient sensitivity. Newer serologic techniques, such as galactomannan (GM) and beta-glucan, have already been incorporated into clinical guidelines, but recent evidence suggests that their performance might be limited in certain clinical settings. Molecular methods, such as the Aspergillus spp. polymerase chain reaction (PCR), have not yet found their place in clinical practice mainly due to lack of standardization. Novel methodologies, such as volatile organic compound detection and lateral flow devices, have recently been developed and promise noninvasive and rapid diagnosis of aspergillosis, while diagnostic algorithms that incorporate both GM and PCR have proven to be effective in early randomized trials as screening methods and can reduce the use of antifungal agents.

CONCLUSIONS

Diagnosis of IA remains challenging. Novel methodologies and the standardization of GM and PCR might provide more reliable diagnostic tools in the future.

Antibody testing in aspergillosis--quo vadis?

Humans are constantly exposed to airborne Aspergillus spores. Most develop Aspergillus-specific antibodies by adulthood. Persons with chronic lung disease or Aspergillus airway colonization often have raised levels of Aspergillus-specific immunoglobululin G (IgG). It is not known whether this signifies an increased risk of future aspergillosis.Chronic and allergic forms of pulmonary aspergillosis are estimated to affect over three million people worldwide. Antibody testing is central to diagnosis of these conditions, with raised Aspergillus-specific IgG in chronic pulmonary aspergillosis and raised Aspergillus-specific IgE in allergic aspergillosis. Antibody levels are also used to monitor treatment response in these syndromes. Acute invasive disease is less common. There is a more limited role for antibody testing in this setting as immunosuppression often results in delayed or absent antibody response.Many methods exist to detect Aspergillus-specific antibodies, but there are limited published data regarding comparative efficacy and reproducibility. We discuss the comparative merits of the available tests in the various clinical settings and their suitability for use in the resource-poor settings where the majority of cases of aspergillosis are thought to occur. We summarize the gaps in existing knowledge and opportunities for further study that could allow optimal use of antibody testing in this field.

Paving the way for predictive diagnostics and personalized treatment of invasive aspergillosis

Invasive aspergillosis (IA) is a life-threatening fungal disease commonly diagnosed among individuals with immunological deficits, namely hematological patients undergoing chemotherapy or allogeneic hematopoietic stem cell transplantation. Vaccines are not available, and despite the improved diagnosis and antifungal therapy, the treatment of IA is associated with a poor outcome. Importantly, the risk of infection and its clinical outcome vary significantly even among patients with similar predisposing clinical factors and microbiological exposure. Recent insights into antifungal immunity have further highlighted the complexity of host-fungus interactions and the multiple pathogen-sensing systems activated to control infection. How to decode this information into clinical practice remains however, a challenging issue in medical mycology. Here, we address recent advances in our understanding of the host-fungus interaction and discuss the application of this knowledge in potential strategies with the aim of moving toward personalized diagnostics and treatment (theranostics) in immunocompromised patients. Ultimately, the integration of individual traits into a clinically applicable process to predict the risk and progression of disease, and the efficacy of antifungal prophylaxis and therapy, holds the promise of a pioneering innovation benefiting patients at risk of IA.

Isavuconazole: a new extended spectrum triazole for invasive mold diseases

ABSTRACT 

Isavuconazole is the first broad spectrum prodrug triazole with efficacy against invasive fungal diseases including aspergillosis and mucormycosis. Characteristics include linear dose-proportional pharmacokinetics, intravenous and oral formulations allowing therapeutic streamlining, once daily dosing, absence of nephrotoxic solubilizing agents and excellent oral bioavailability independent of prandial status and gastric acidity. An open label noncomparator study demonstrated encouraging results for isavuconazole as primary or salvage therapy for a range of fungi including mucormycosis. Isavuconazole had fewer premature drug discontinuations and adverse events in the eye, hepatobiliary and psychiatry systems than the comparator agent, voriconazole in a randomized double-blind clinical trial. Cross-resistance of isavuconazole best correlates with voriconazole. In vitro resistance is not invariably predictive of clinical failure. Isavuconazole signals progress in pharmacokinetics, bioavailability and toxicity/tolerability supported by clinical efficacy from Phase III trials.

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.

Adrenal and hepatic aspergillosis in an immunocompetent patient

Invasive aspergillosis, an infection most frequently induced by Aspergillus fumigatus and Aspergillus flavus, typically occurs in immunocompromised patients and is usually transmitted through inhalation of Aspergillus spores. As the lungs are by far the most common site involved in invasive aspergillosis and invasive aspergillosis in immunocompetent hosts is very rare, there have been a few case reports of extra-pulmonary, disseminated invasive aspergillosis in immunocompetent persons. Herein, we report a case of an adult, male, immunocompetent patient with disseminated invasive aspergillosis that successively spread from the right adrenal gland to the left hepatic lobe. The patient was successfully treated through surgical excisions of his adrenal and hepatic masses followed by voriconazole therapy. To our knowledge, this is the first case report of invasive aspergillosis affecting the adrenal glands.

Overcoming antifungal resistance

Fungal infections have become one of the major causes of morbidity and mortality in immunocompromised patients. Despite increased awareness and improved treatment strategies, the frequent development of resistance to the antifungal drugs used in clinical settings contributes to the increasing toll of mycoses. Although a natural phenomenon, antifungal drug resistance can compromise advances in the development of effective diagnostic techniques and novel antifungals. In this review, we will discuss the advent of cellular-micro- arrays, microfluidics, genomics, proteomics and other state-of-the art technologies in conquering antifungal drug resistance.

Detection of galactomannan in bronchoalveolar lavage of the intensive care unit patients at risk for invasive aspergillosis

Background and Purpose:

Invasive aspergillosis (IA) is one of the most common life-threatening fungal infections among the critically ill patients including intensive care unit (ICU) patients. Delayed diagnosis and therapy may lead to poor outcomes. Diagnosis may be facilitated by a test for molecular biomarkers, i.e. detection of galactomannan (GM) antigen based on enzyme immunoassay, which is of increasing interest in the clinical settings for the diagnosis of IA. In the present study, we assessed GM testing of bronchoalveolar lavage (BAL) fluid as a tool for early diagnosis of IA among ICU patients who were at risk for developing IA.

Material and Methods:

A prospective study was performed in ICU patients with underlying predisposing conditions for IA between August 2010 and September 2011. BAL samples for direct microscopic examination, culture, and GM detection were obtained once or twice weekly. GM in BAL levels was measured using the Platellia Aspergillus EIA test kit. According to modified European Organization for the Research and Treatment of Cancer/ Mycoses Study Group (EORTC/MSG) criteria, patients were classified as having probable or possible IA.

Results:

Out of 43 suspected patients to IA, 13 (30.2%) cases showed IA. According to the criteria presented by EORTC/MSG, they were categorized as: 4 cases (30.8%) of possible IA and 9 (69.2%) of probable IA. Out of 21 BAL samples from patients with IA, 11 (52.4%) had at least one positive BAL GM index. Using a cutoff index of 0.5, the sensitivity and specificity, positive and negative predictive values of GM detection in BAL fluid were 100%, 85.7%, 65.7% and 96%, respectively. The sensitivity and specificity was 73% and 92.7% at cutoff ≥1.0, respectively. In 6 of 13 IA cases, BAL culture or direct microscopic examination remained negative, whereas GM in BAL was positive.

Conclusion:

Our data have revealed that the sensitivity of GM detection in BAL was better than that of conventional tests. It seems that GM detection in BAL is beneficial to establish or exclude the early diagnosis of IA in ICU patients.

Detection of Aspergillus-specific antibodies by agar gel double immunodiffusion and IgG ELISA in feline upper respiratory tract aspergillosis

Feline upper respiratory tract aspergillosis (URTA) is an emerging infectious disease. The aims of this study were: (1) to assess the diagnostic value of detection of Aspergillus-specific antibodies using an agar gel double immunodiffusion (AGID) assay and an indirect immunoglobulin G (IgG) ELISA; and (2) to determine if an aspergillin derived from mycelia of Aspergillus fumigatus, Aspergillus niger and Aspergillus flavus can be used to detect serum antibodies against cryptic Aspergillus spp. in Aspergillus section Fumigati. Sera from cats with URTA (group 1: n = 21) and two control groups (group 2: cats with other upper respiratory tract diseases, n = 25; group 3: healthy cats and cats with non-respiratory, non-fungal illness, n = 84) were tested. Isolates from cats with URTA comprised A. fumigatus (n = 5), A. flavus (n = 1) and four cryptic species: Aspergillus felis (n = 12), Aspergillus thermomutatus (Neosartorya pseudofischeri, n = 1), Aspergillus lentulus (n = 1) and Aspergillus udagawae (n = 1). Brachycephalic purebred cats were significantly more likely to develop URTA than other breeds (P = 0.013). The sensitivity (Se) of the AGID was 43% and the specificity (Sp) was 100%. At a cut-off value of 6 ELISA units/mL, the Se of the IgG ELISA was 95.2% and the Sp was 92% and 92.9% for groups 2 and 3 cats, respectively. Aspergillus-specific antibodies against all four cryptic species were detected in one or both assays. Assay Se was not associated with species identity. Detection of Aspergillus-specific antibodies by IgG ELISA has high Se and Sp for diagnosis of feline URTA.

A breath fungal secondary metabolite signature to diagnose invasive aspergillosis

BACKGROUND

Invasive aspergillosis (IA) remains a leading cause of mortality in immunocompromised patients, in part due to the difficulty of diagnosing this infection.

METHODS

Using thermal desorption-gas chromatography/mass spectrometry, we characterized the in vitro volatile metabolite profile of Aspergillus fumigatus, the most common cause of IA, and other pathogenic aspergilli. We prospectively collected breath samples from patients with suspected invasive fungal pneumonia from 2011 to 2013, and assessed whether we could discriminate patients with proven or probable IA from patients without aspergillosis, as determined by European Organization for Research and Treatment of Cancer/Mycoses Study Group consensus definitions, by direct detection of fungal volatile metabolites in these breath samples.

RESULTS

The monoterpenes camphene, α- and β-pinene, and limonene, and the sesquiterpene compounds α- and β-trans-bergamotene were distinctive volatile metabolites of A. fumigatus in vitro, distinguishing it from other pathogenic aspergilli. Of 64 patients with suspected invasive fungal pneumonia based on host risk factors, clinical symptoms, and radiologic findings, 34 were diagnosed with IA, whereas 30 were ultimately diagnosed with other causes of pneumonia, including other invasive mycoses. Detection of α-trans-bergamotene, β-trans-bergamotene, a β-vatirenene-like sesquiterpene, or trans-geranylacetone identified IA patients with 94% sensitivity (95% confidence interval [CI], 81%-98%) and 93% specificity (95% CI, 79%-98%).

CONCLUSIONS

In patients with suspected fungal pneumonia, an Aspergillus secondary metabolite signature in breath can identify individuals with IA. These results provide proof-of-concept that direct detection of exogenous fungal metabolites in breath can be used as a novel, noninvasive, pathogen-specific approach to identifying the precise microbial cause of pneumonia.

Fatal clinical course of probable invasive pulmonary aspergillosis with influenza B infection in an immunocompetent patient

Invasive pulmonary aspergillosis (IPA) is rarely reported in patients who have normal immune function. Recently, IPA risk was reported in nonimmunocompromised hosts, such as patients with chronic obstructive pulmonary disease and critically ill patients in intensive care units. Moreover, influenza infection is also believed to be associated with IPA among immunocompetent patients. However, most reports on IPA with influenza A infection, including pandemic influenza H1N1, and IPA associated with influenza B infection were scarcely reported. Here, we report probable IPA with a fatal clinical course in an immunocompetent patient with influenza B infection. We demonstrate IPA as a possible complication in immunocompetent patients with influenza B infection. Early clinical suspicion of IPA and timely antifungal therapy are required for better outcomes in such cases.

Treatment of infections by cryptic Aspergillus species

The best treatment for patients with invasive aspergillosis caused by cryptic Aspergillus species remains uncertain, mainly due to the limited clinical data that have been published so far. In face of this limitation, patients should be treated with standard first-line therapy for invasive aspergillosis, with therapy being modified according to in vitro susceptibility testing. In this review, we summarize the importance of cryptic Aspergillus species in modern medicine, including their prevalence, methods for detection and response to antifungal drugs.