Prospective clinical evaluation of lower cut-offs for galactomannan detection in adult neutropenic cancer patients and haematological stem cell transplant recipients

Aspergillus Lateral Flow Assay with Digital Reader for the Diagnosis of COVID-19 Associated Pulmonary Aspergillosis (CAPA): A multicenter study

This multicenter study evaluated the IMMY Aspergillus Galactomannan Lateral Flow Assay (LFA) with automated reader for diagnosis of pulmonary aspergillosis in patients with COVID-19-associated acute respiratory failure (ARF) requiring intensive care unit (ICU) admission between 03/2020 and 04/2021. A total of 196 respiratory samples and 148 serum samples (n = 344) from 238 patients were retrospectively included, with a maximum of one of each sample type per patient. Cases were retrospectively classified for COVID-19-associated pulmonary aspergillosis (CAPA) status following the 2020 consensus criteria, with the exclusion of LFA results as a mycological criterion. At the 1.0 cutoff, sensitivity of LFA for CAPA (proven/probable/possible) was 52%, 80% and 81%, and specificity was 98%, 88% and 67%, for bronchoalveolar lavage fluid (BALF), nondirected bronchoalveolar lavage (NBL), and tracheal aspiration (TA), respectively. At the 0.5 manufacturer’s cutoff, sensitivity was 72%, 90% and 100%, and specificity was 79%, 83% and 44%, for BALF, NBL and TA, respectively. When combining all respiratory samples, the receiver operating characteristic (ROC) area under the curve (AUC) was 0.823, versus 0.754, 0.890 and 0.814 for BALF, NBL and TA, respectively. Sensitivity and specificity of serum LFA were 20% and 93%, respectively, at the 0.5 ODI cutoff. Overall, the Aspergillus Galactomannan LFA showed good performances for CAPA diagnosis, when used from respiratory samples at the 1.0 cutoff, while sensitivity from serum was limited, linked to weak invasiveness during CAPA. As some false-positive results can occur, isolated results slightly above the recommended cutoff should lead to further mycological investigations.

Influenza- and COVID-19-Associated Pulmonary Aspergillosis: Are the Pictures Different?

Invasive pulmonary aspergillosis (IPA) in intensive care unit patients is a major concern. Influenza-associated acute respiratory distress syndrome (ARDS) and severe COVID-19 patients are both at risk of developing invasive fungal diseases. We used the new international definitions of influenza-associated pulmonary aspergillosis (IAPA) and COVID-19-associated pulmonary aspergillosis (CAPA) to compare the demographic, clinical, biological, and radiological aspects of IAPA and CAPA in a monocentric retrospective study. A total of 120 patients were included, 71 with influenza and 49 with COVID-19-associated ARDS. Among them, 27 fulfilled the newly published criteria of IPA: 17/71 IAPA (23.9%) and 10/49 CAPA (20.4%). Kaplan–Meier curves showed significantly higher 90-day mortality for IPA patients overall (p = 0.032), whereas mortality did not differ between CAPA and IAPA patients. Radiological findings showed differences between IAPA and CAPA, with a higher proportion of features suggestive of IPA during IAPA. Lastly, a wide proportion of IPA patients had low plasma voriconazole concentrations with a higher delay to reach concentrations > 2 mg/L in CAPA vs. IAPA patients (p = 0.045). Severe COVID-19 and influenza patients appeared very similar in terms of prevalence of IPA and outcome. The dramatic consequences on the patients’ prognosis emphasize the need for a better awareness in these particular populations.

Fatal Invasive Pulmonary Aspergillosis in COVID-19 Patient with Acute Myeloid Leukemia in Iran

Although patients with severe immunodeficiency and hematological malignancies has been considered at highest risk for invasive fungal infection, patients with severe pneumonia due to influenza, and severe acute respiratory syndrome coronavirus (SARS-CoV) are also at a higher risk of developing invasive pulmonary aspergillosis (IPA). Recently, reports of IPA have also emerged among SARS-CoV-2 infected patients admitted to intensive care units (ICUs). Here, we report a fatal case of probable IPA in an acute myeloid leukemia patient co-infected with SARS-CoV-2 and complicated by acute respiratory distress syndrome (ARDS). Probable IPA is supported by multiple pulmonary nodules with ground glass opacities which indicate halo sign and positive serum galactomannan results. Screening studies are needed to evaluate the prevalence of IPA in immunocompromised patients infected with SARS-CoV-2. Consequently, testing for the presence of Aspergillus in lower respiratory secretions and galactomannan in consecutive serum samples of COVID-19 patients with timely and targeted antifungal therapy based on early clinical suspicion of IPA are highly recommended.

Genetic Risk Surveillance for Invasive Aspergillosis in Hematology Patients: A Prospective Observational Study

INTRODUCTION

The association between genetic background and the risk of invasive aspergillosis (IA) has not been addressed in Thailand. We conducted genetic risk surveillance for IA among Thai hematologic patients.

METHODS

We conducted a prospective observational cohort study including moderate- to high-risk hematology patients at Ramathibodi Hospital. IA occurrence, relevant clinical data, and genetic analyses were assessed. Odds ratios (ORs) of IA were assessed for the presence of the selected single nucleotide polymorphism genotype using logistic regression.

RESULTS

A total of 357 patients were enrolled. The most common hematologic disease was non-Hodgkin lymphoma (45.1%). IA was diagnosed in 36 patients (10.10%). The C allele of IL10_rs1800896 was associated with an increased risk of IA (adjusted OR 5.297; 95% confidence interval [CI] 2.032-13.809, p = 0.001). In multivariate Cox regression analysis, prolonged neutropenia and the C allele of IL10_rs1800896 were associated with IA (hazard ratio [HR] 12.585; 95% CI 3.866-40.967, p < 0.001 and HR 2.449; 95% CI 1.097-5.468, p = 0.042, respectively).

CONCLUSIONS

Carrying the C allele of IL10_rs1800896 was associated with an increased risk of IA among moderate- to high-risk Thai patients with hematologic diseases. This finding can potentially lead to a novel risk stratification scheme to further prevent IA in resource-limited settings.

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.

Clinical Characteristics and Predictors of Mortality in Critically Ill Influenza Adult Patients

Severe influenza is associated with high morbidity and mortality. The aim of this study was to investigate the factors affecting the clinical outcomes of critically ill influenza patients. In this retrospective study, we enrolled critically ill adult patients with influenza at the Kaohsiung Chang Gung Memorial Hospital in Taiwan. We evaluated the demographic, clinical, and laboratory findings and examined whether any of these measurements correlated with mortality. We then created an event-based algorithm as a simple predictive tool using two variables with statistically significant associations with mortality. Between 2015 and 2018, 102 critically ill influenza patients (median age, 62 years) were assessed; among them, 41 (40.1%) patients died. Of the 94 patients who received oseltamivir therapy, 68 (72.3%) began taking oseltamivir 48 h after the onset of illness. Of the 102 patients, the major influenza-associated complications were respiratory failure (97%), pneumonia (94.1%), acute kidney injury (65.7%), adult respiratory distress syndrome (ARDS) (51%), gastrointestinal bleeding (35.3%), and bacteremia (16.7%). In the multivariate regression model, high lactate levels, ARDS, acute kidney injury, and gastrointestinal bleeding were independent predictors of mortality in critically ill influenza patients. The optimal lactate level cutoff for predicting mortality was 3.7 mmol/L with an area under curve of 0.728. We constructed an event-associated algorithm that included lactate and ARDS. Fifteen (75%) of 20 patients with lactate levels 3.7 mmol/L and ARDS died, compared with only 1 (7.7%) of 13 patients with normal lactate levels and without ARDS. We identified clinical and laboratory predictors of mortality that could aid in the care of critically ill influenza patients. Identification of these prognostic markers could be improved to prioritize key examinations that might be useful in determining patient outcomes.

Diagnosis of invasive fungal diseases in haematology and oncology: 2018 update of the recommendations of the infectious diseases working party of the German society for hematology and medical oncology (AGIHO)

Invasive fungal diseases (IFD) are a primary cause of morbidity and mortality in patients with haematological malignancies. These infections are mostly life-threatening and an early diagnosis and initiation of appropriate antifungal therapy are essential for the clinical outcome. Most commonly, Aspergillus and Candida species are involved. However, other Non-Aspergillus moulds are increasingly identified in case of documented IFD. For definite diagnosis of IFD, a combination of diagnostic tools have to be applied, including conventional mycological culture and non-conventional microbiological tests such as antibody/antigen and molecular tests, as well as histopathology and radiology. Although varying widely in cancer patients, the risk of invasive fungal infection is highest in those with allogeneic stem cell transplantation and those with acute leukaemia and markedly lower in patients with solid cancer. Since the last edition of Diagnosis of Invasive Fungal Diseases recommendations of the German Society for Hematology and Oncology in 2012, integrated care pathways have been proposed for the management and therapy of IFDs with either a diagnostic driven strategy as opposed to a clinical or empirical driven strategy. This update discusses the impact of this additional evidence and effective revisions.

A strategy for designing voriconazole dosage regimens to prevent invasive pulmonary aspergillosis based on a cellular pharmacokinetics/pharmacodynamics model

Background

Invasive pulmonary aspergillosis (IPA) is a life-threatening disease in immunosuppressed patients. Voriconazole is commonly used to prevent and treat IPA in the clinic, but the optimal prophylactic antifungal regimen is unknown. The objective of this study was to clarify the mechanism underlying how voriconazole prevents IPA based on a target cellular pharmacokinetics/pharmacodynamics model, with the aim of identifying a way to design an optimal prophylactic antifungal regimen.

Methods

A nystatin assay was used to establish a target-cells model for A. fumigatus infection. An inhibitory effect sigmoid E_max model was developed to explore the cellular PK/PD breakpoint, and Monte Carlo simulation was used to design the prophylactic antifungal regimen.

Results

The intracellular activity of voriconazole in the target cells varied with its concentration, with the minimum inhibitory concentration (MIC) being an important determinant. For A. fumigatus strains AF293 and AF26, voriconazole decreased the intracellular inoculum by 0.79 and 0.84 lg cfu, respectively. The inhibitory effect sigmoid E_max model showed that 84.01% of the intracellular inoculum was suppressed by voriconazole within 24 h, and that a PK/PD value of 35.53 for the extracellular voriconazole concentration divided by MIC was associated with a 50% suppression of intracellular A. fumigatus. The Monte Carlo simulation results showed that the oral administration of at least 200 mg of voriconazole twice daily was yielded estimated the cumulative fraction of response value of 91.48%. Concentration of voriconazole in the pulmonary epithelial lining fluid and the plasma of > 17.77 and > 1.55 mg/L, respectively, would ensure the PK/PD > 35.53 for voriconazole against most isolates of A. fumigatus and may will be benefit to prevent IPA in clinical applications.

Conclusions

This study used a target cellular pharmacokinetics/pharmacodynamics model to reveal a potential mechanism underlying how voriconazole prevents IPA and has provided a method for designing voriconazole prophylactic antifungal regimen in immunosuppressed patients.

Diagnostic Approaches for Invasive Aspergillosis-Specific Considerations in the Pediatric Population

Invasive aspergillosis (IA) is a major cause of morbidity and mortality in children with hematological malignancies and those undergoing hematopoietic stem cell transplantation. Similar to immunocompromised adults, clinical signs, and symptoms of IA are unspecific in the pediatric patient population. As early diagnosis and prompt treatment of IA is associated with better outcome, imaging and non-invasive antigen-based such as galactomannan or ß-D-glucan and molecular biomarkers in peripheral blood may facilitate institution and choice of antifungal compounds and guide duration of therapy. In patients in whom imaging studies suggest IA or another mold infection, invasive diagnostics such as bronchoalveolar lavage and/or bioptic procedures should be considered. Here we review the current data of diagnostic approaches for IA in the pediatric setting and highlight the major differences of performance and clinical utility of the tests between children and adults.

Diagnosis and empirical treatment of fever of unknown origin (FUO) in adult neutropenic patients: guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Fever may be the only clinical symptom at the onset of infection in neutropenic cancer patients undergoing myelosuppressive chemotherapy. A prompt and evidence-based diagnostic and therapeutic approach is mandatory. A systematic search of current literature was conducted, including only full papers and excluding allogeneic hematopoietic stem cell transplant recipients. Recommendations for diagnosis and therapy were developed by an expert panel and approved after plenary discussion by the AGIHO. Randomized clinical trials were mainly available for therapeutic decisions, and new diagnostic procedures have been introduced into clinical practice in the past decade. Stratification into a high-risk versus low-risk patient population is recommended. In high-risk patients, initial empirical antimicrobial therapy should be active against pathogens most commonly involved in microbiologically documented and most threatening infections, including Pseudomonas aeruginosa, but excluding coagulase-negative staphylococci. In patients whose expected duration of neutropenia is more than 7 days and who do not respond to first-line antibacterial treatment, specifically in the absence of mold-active antifungal prophylaxis, further therapy should be directed also against fungi, in particular Aspergillus species. With regard to antimicrobial stewardship, treatment duration after defervescence in persistently neutropenic patients must be critically reconsidered and the choice of anti-infective agents adjusted to local epidemiology. This guideline updates recommendations for diagnosis and empirical therapy of fever of unknown origin in adult neutropenic cancer patients in light of the challenges of antimicrobial stewardship.

Comparison of real-time PCR, nested PCR, and galactomannan antigen detection by enzyme-linked immunosorbent assay in sera for diagnosis of invasive aspergillosis

Conventional methods for diagnosis of invasive aspergillosis (IA) lack sensitivity and specificity. Serological methods still have many cases of cross-reactivity. However, molecular techniques seem to arise as a rapid approach, specific and direct that could be used in the diagnosis of IA. In this study, we analyzed 88 serum samples from patients of having IA using GM-ELISA test, nested PCR with primers for the rRNA 18S of Aspergillus genus and real time PCR specific for A. fumigatus. Among the 88 samples, 64 of them had positive GM titers and 23 had positive nested PCRs; 18 of the 23 PCR-positive samples were also GM-positive. On the other hand, 18 samples were detected positive by reel time PCR; 13 positive samples were also detecting positive by nested PCR. QPCR revealed 26 % of the patients with IA, while nested PCR and galactomannan ELISA revealed respectively 34 % and 94 % of the patients with IA. Probable IA was diagnosed in 18 and possible IA was diagnosed in 6 episodes. Forty-four episodes were defined as not having IA. The positive and negative predictive values were respectively 100 %, and 88 % for QPCR, 100 % and 97 % for nested PCR, and 28 % and 60 % for GM test. These results suggesting that combined use of methods might improve the diagnosis of IA.

Current Algorithms in Fungal Diagnosis in the Immunocompromised Host

Invasive fungal diseases (IFDs) are a major cause of morbidity and mortality in immunocompromised patients such as patients with hematological malignancies or allogeneic hematopoietic stem cell transplant recipients. Whereas the definite diagnosis of IFD requires invasive diagnostic procedures, imaging and noninvasive diagnostic assays may help in decision making with regard to the institution and the choice of antifungal agents, the duration of therapy, surgical intervention, and monitoring of fungal manifestations.Unfortunately, signs and symptoms of IFD are often nonspecific in the immunocompromised patient. Therefore, in immunocompromised patients with suspected IFD, all samples collected need to be cultured for fungi, and, in the case of specimens obtained by invasive diagnostic procedures, also microscopically examined. For high sensitivity of the cultural and microscopic approaches, specific media and stains, respectively, are crucial. Non-culture based method such as the detection of galactomannan or ß-d-glucan and molecular tools such as polymerase chain reaction may help in the early diagnosis of IFD. Imaging studies may be indicative for IFD, but invasive diagnostics such as bronchoalveolar lavage and/or biopsy should be pursued in order to identify the causative pathogen. This chapter summarizes the current knowledge on diagnosing IFD and proposes practical help in the use of diagnostic tools.

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.

(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.

Nonspecific elevation of serum Aspergillus galactomannan antigen levels in patients with rheumatoid arthritis

BACKGROUND

Infections are an important cause of morbidity and mortality in patients with rheumatoid arthritis. Patients receiving immunosuppressive or anti-tumor necrosis factor (TNF) agents are vulnerable to fungal infections, including those derived from Aspergillus species. Detection of the Aspergillus galactomannan antigen in serum is useful for the early diagnosis of invasive aspergillosis in patients with hematological malignancies. However, its usefulness for detecting early invasive aspergillosis in rheumatoid arthritis patients remains unestablished.

METHODS

Galactomannan antigen levels were measured in 340 patients (311 female patients). For patients who exhibited galactomannan antigen levels ≥0.5 during the initial examination, a second examination was performed 3-6 months later. Conventional blood tests and chest radiography were also performed.

RESULTS

Elevated galactomannan antigen levels (≥0.5) were observed in 62 (18.2%) of 340 patients during the initial examination. A second examination was performed in 56 of 62 patients, 50 of whom exhibited elevated antigen levels. Elevated antigen levels were not associated with the use of any drug including anti-TNF agents. Serum galactomannan antigen levels were correlated with the albumin/globulin ratio (r=-0.19, p<0.001), γ-globulin (%; r=0.17, p=0.001), and hemoglobin concentration (r=-0.15, p=0.005). No patient was clinically diagnosed with invasive aspergillosis during the study period.

CONCLUSIONS

Serum galactomannan antigen levels are frequently elevated in a nonspecific manner in patients with rheumatoid arthritis.

Novel antifungal drugs against fungal pathogens: do they provide promising results for treatment?

The febrile neutropenia episodes of hematological patients and their outcomes were evaluated with respect to fungal pathogens and antifungal therapy in this retrospective study. All patients, who were older than 14 years of age and developed at least one neutropenic episode after chemotherapy due to hematological cancer from November 2010 to November 2012, were included into the study. We retrospectively collected demographic, treatment, and survival data of 126 patients with neutropenia and their 282 febrile episodes. The mean Multinational Association for Supportive Care in Cancer score was 17.18 ± 8.27. Systemic antifungal drugs were initiated in 22 patients with 30 culture-proven invasive fungal infections (IFIs), 25 attacks of 19 patients with probable invasive pulmonary aspergillosis (IPA), 42 attacks of 38 patients with possible IPA, and 31 attacks of 30 patients with suspected IFI. Voriconazole (VOR), caspofungin and liposomal amphotericin B were used to treat 72 episodes of 65 patients, 45 episodes of 37 patients and 34 episodes of 32 patients as a first-line therapy, respectively. Unfavorable conditions of our hematology ward are thought to increase the number of cases with invasive pulmonary aspergillosis and VOR use. It should be taken into consideration that increased systemic and per oral VOR usage predisposes patients to colonization and infection with azole-resistant fungal strains. Catheters should be removed in cases where patients' conditions are convenient to remove it. Acute myeloblastic leukemia cases that are more likely to develop invasive fungal infections should be monitored closely for early diagnosis and timely initiation of antifungal drugs which directly correlates with survival rates.

Molecular epidemiology and in-vitro antifungal susceptibility of Aspergillus terreus species complex isolates in Delhi, India: evidence of genetic diversity by amplified fragment length polymorphism and microsatellite typing

Aspergillus terreus is emerging as an etiologic agent of invasive aspergillosis in immunocompromised individuals in several medical centers in the world. Infections due to A. terreus are of concern due to its resistance to amphotericin B, in vivo and in vitro, resulting in poor response to antifungal therapy and high mortality. Herein we examined a large collection of molecularly characterized, geographically diverse A. terreus isolates (n = 140) from clinical and environmental sources in India for the occurrence of cryptic A. terreus species. The population structure of the Indian A. terreus isolates and their association with those outside India was determined using microsatellite based typing (STR) technique and Amplified Fragment Length Polymorphism analysis (AFLP). Additionally, in vitro antifungal susceptibility of A. terreus isolates was determined against 7 antifungals. Sequence analyses of the calmodulin locus identified the recently described cryptic species A. hortai, comprising 1.4% of Aspergillus section Terrei isolates cultured from cases of aspergilloma and probable invasive aspergillosis not reported previously. All the nine markers used for STR typing of A. terreus species complex proved to be highly polymorphic. The presence of high genetic diversity revealing 75 distinct genotypes among 101 Indian A. terreus isolates was similar to the marked heterogeneity noticed in the 47 global A. terreus population exhibiting 38 unique genotypes mainly among isolates from North America and Europe. Also, AFLP analysis showed distinct banding patterns for genotypically diverse A. terreus isolates. Furthermore, no correlation between a particular genotype and amphotericin B susceptibility was observed. Overall, 8% of the A. terreus isolates exhibited low MICs of amphotericin B. All the echinocandins and azoles (voriconazole, posaconazole and isavuconazole) demonstrated high potency against all the isolates. The study emphasizes the need of molecular characterization of A. terreus species complex isolates to better understand the ecology, acquisition and transmission of this species.

Molecular and nonmolecular diagnostic methods for invasive fungal infections

Invasive fungal infections constitute a serious threat to an ever-growing population of immunocompromised individuals and other individuals at risk. Traditional diagnostic methods, such as histopathology and culture, which are still considered the gold standards, have low sensitivity, which underscores the need for the development of new means of detecting fungal infectious agents. Indeed, novel serologic and molecular techniques have been developed and are currently under clinical evaluation. Tests like the galactomannan antigen test for aspergillosis and the β-glucan test for invasive Candida spp. and molds, as well as other antigen and antibody tests, for Cryptococcus spp., Pneumocystis spp., and dimorphic fungi, have already been established as important diagnostic approaches and are implemented in routine clinical practice. On the other hand, PCR and other molecular approaches, such as matrix-assisted laser desorption ionization (MALDI) and fluorescence in situ hybridization (FISH), have proved promising in clinical trials but still need to undergo standardization before their clinical use can become widespread. The purpose of this review is to highlight the different diagnostic approaches that are currently utilized or under development for invasive fungal infections and to identify their performance characteristics and the challenges associated with their use.

Bloodstream infections in patients with hematological malignancies: which is more fatal - cancer or resistant pathogens?

Background

The primary objective of this study was to report the incidence of bloodstream infections (BSIs) and clinically or microbiologically proven bacterial or fungal BSIs during neutropenic episodes in patients with hematological malignancies.

Methods

In this retrospective observational study, all patients in the hematology department older than 14 years who developed febrile neutropenia during chemotherapy for hematological cancers were evaluated. Patients were included if they had experienced at least one neutropenic episode between November 2010 and November 2012 due to chemotherapy in the hematology ward.

Results

During 282 febrile episodes in 126 patients, 66 (23%) episodes of bacteremia and 24 (8%) episodes of fungemia were recorded in 48 (38%) and 18 (14%) patients, respectively. Gram-negative bacteria caused 74% (n=49) of all bacteremic episodes. Carbapenem-resistant Gram-negative bacteria (n=6) caused 12% and 9% of Gram-negative bacteremia episodes and all bacteremia episodes, respectively. Carbapenem-resistant Gram-negative bacteria included Acinetobacter baumannii (n=4), Pseudomonas aeruginosa (n=1), and Serratia marcescens (n=1). Culture-proven invasive fungal infection occurred in 24 episodes in 18 cases during the study period, with 15 episodes in ten cases occurring in the first study year and nine episodes in eight cases in the second study year. In 13 of 18 cases (72%) with bloodstream yeast infections, previous azole exposure was recorded. Candida parapsilosis, C. glabrata, and C. albicans isolates were resistant to voriconazole and fluconazole.

Conclusion

BSIs that occur during febrile neutropenic episodes in hematology patients due to Gram-negative bacteria should be treated initially with non-carbapenem-based antipseudomonal therapy taking into consideration antimicrobial stewardship. Non-azole antifungal drugs, including caspofungin and liposomal amphotericin B, should be preferred as empirical antifungal therapy in the events of possible or probable invasive fungal infections with an absence of pulmonary findings due to increase azole resistance.

Exploring azole antifungal drug resistance in Aspergillus fumigatus with special reference to resistance mechanisms

ABSTRACT: 

Aspergillus fumigatus, a ubiquitously distributed opportunistic pathogen, is the global leading cause of aspergillosis. Azole antifungals play an important role in the management of aspergillosis. However, over a decade, azole resistance in A. fumigatus isolates has been increasingly reported with variable prevalence worldwide and it is challenging the effective management of aspergillosis. The high mortality rates observed in patients with invasive aspergillosis caused by azole-resistant A. fumigatus (ARAF) isolates pose serious challenges to the clinical microbiologist for timely identification of resistance and appropriate therapeutic interventions. The majority of ARAF isolates contain alterations in the cyp51A gene; however, there have been increasing reports on non-cyp51A mutations contributing to azole resistant phenotypes. This review highlights the emergence and various mechanisms implicated in the development of azole resistance in A. fumigatus. We further present recent developments related to the environmental route in the emergence of ARAF isolates and discuss the therapeutic options available.

Nonmolecular methods for the diagnosis of respiratory fungal infections

Diagnosis of invasive fungal pneumonias by conventional culture methods is difficult to assess and often delayed. Nonmolecular fungal markers have emerged as an important adjunctive tool to support their diagnosis in combination with other clinical, radiologic, and microbiological criteria of invasive fungal diseases. Concerns about the sensitivity and specificity of some tests in different patient populations should lead to warnings about their widespread use. None can identify the emerging and particularly deadly fungal pathogens responsible for mucormycosis. The role of nonmolecular fungal markers should be better defined in combination with other microbiological and radiologic tools in preemptive antifungal strategies.

Galactomannan antigen detection in the diagnosis of invasive aspergillosis

Invasive aspergillosis is a serious and lethal infection among immunocompromised patients, with reported mortality rates as high as 74-92%. The high mortality is related to the severe immunosuppression experienced by these patients as well as the difficulties for physicians in arriving at a timely diagnosis. Definitive diagnostic procedures (tissue biopsy for histopathology and culture) are often precluded by severe cytopenias and coagulation abnormalities. The development of minimally invasive, nonculture diagnostic methods is a major advance in the early diagnosis of invasive aspergillosis. Galactomannan is a heteropolysaccharide (mannan core and side residues of galactofuranosyl units) present in the cell wall of Aspergillus spp. The double sandwich enzyme immunoassay, which detects galactomannan in serum samples, has been available in Europe for almost a decade and in the USA since May 2003, for the diagnosis of invasive aspergillosis. However, availability of the double galactomannan enzyme immunoassay is center variable in the USA and, although its analytical performance in the diagnosis of invasive aspergillosis is well documented, its routine use in clinical practice is limited. As an adjunct in the diagnosis and management of invasive aspergillosis, incorporation of the galactomannan enzyme immunoassay into clinical trials will help to further define its role.

Respiratory infections

The respiratory tract is a common site of infection in cancer patients and is associated with substantial moribidity and mortality in this population. Cancer, chemotherapy, and radiation can all cause noninfectious pulmonary infiltrates and respiratory symptoms that can masquerade as a respiratory tract infection. Cancer patients are at a particular risk for infection by a wide variety of different viruses, fungi, and bacteria that can be difficult to treat. Although noninvasive diagnostics have significantly improved recently, patients with severe pneumonia and those not responding to usual therapy should be candidates for aggressive diagnostic testing and tissue sampling. Initial therapy should be carefully chosen and individually tailored to account for the individual patient's underlying risk factors for multi-drug-resistant pathogens, viral pathogens, or fungi. Once diagnostic testing returns, therapy should be altered to appropriately narrow the spectrum of coverage.

Aspergillus tracheobronchitis causing subtotal tracheal stenosis in a liver transplant recipient

Invasive aspergillosis is recognized as one of the most significant opportunistic infections after liver transplantation. Diagnosis of invasive aspergillosis in transplant recipients has been proven to be challenging, and optimal approach to the treatment of invasive aspergillosis is still controversial. We here present an unusual case of Aspergillus tracheobronchitis in the setting of liver transplantation. A 47-year-old female patient with persistent dry cough after liver transplantation developed respiratory insufficiency and was readmitted to the intensive care unit 55 days after liver transplantation. A CT scan revealed subtotal tracheal stenosis; bronchoscopy was performed, and extended white mucus coverings causative of the tracheal stenosis were removed. Microbiological assessment isolated Aspergillus fumigatus. The diagnosis was obstructive Aspergillus tracheobronchitis. The patient was started on a treatment of voriconazole 200 mg orally twice daily, adjusted to a trough level of 1-4 mg/L. For further airway management, a tracheal stent had to be implanted. The patient is alive and well 28 months after liver transplantation. Invasive aspergillosis should be considered a possible etiology in liver transplant patients presenting with unspecific symptoms such as persistent dry cough. Optimal strategies for improved and early diagnosis as well as prophylaxis need to be defined.

Clinical Efficacy and Tolerability of Caspofungin in a Renal Transplant Patient withAspergillus flavusLung Infection: Case Report

Organ transplant recipients are at increased risk for severe invasive aspergillosis, and amphotericin deoxycholate has been the standard treatment for many years. Currently, however, lipid formulations are preferred due to their few side effects. Also, a number of new antifungal drugs have been developed including new azoles and echinocandins. Caspofungin is the first of the echinocandin derivatives patented to treat patients with invasive aspergillosis who are refractory or intolerant to other therapies. A renal transplant patient on immunosuppressive treatment with chronic hepatitis B virus infection was admitted with fever, hemophthisis and lung consolidation, diagnosed to be probably caused by Aspergillus flavus. The patient developed cholestatic hepatitis most likely related to itraconazole. Clinical failure and in vitro itraconazole resistance of the isolate was also documented while the patient was receiving itraconazole at a reduced dosage. Caspofungin was administered once a day as ambulatory treatment and was well tolerated. Clinical improvement was observed after 6 weeks of treatment and no hepatic toxicity was documented. Caspofungin seems to be a potentially useful antifungal agent in renal transplant patients with invasive aspergillosis. Further evaluation of the efficacy of caspofungin is needed.

Does the current treatment of invasive fungal infection need to be reviewed?

Invasive fungal infections (IFIs) are becoming more frequent due to the increasing number of patients at risk. Over the last decade, their prognosis has improved with the diagnostic and therapeutic advances, including new antifungals. In the two years, from 2007 to 2009, antifungal consumption increased by 27%, 67 times more than antibacterial consumption, albeit with great differences between hospitals. The scientific evidence of the indications for antifungal prophylaxis and targeted antifungal therapy is strong; however, it is weak for empirical antifungal therapy, which is the most common indication. Antifungals are not harmless, since they are associated with a wide range of adverse effects and drug interactions, favor the development of resistance, contribute to other fungal superinfections and cause significant healthcare spending. Therefore, the question arises whether this extraordinary increase in consumption is justified, whether the use of antifungals is optimal, or whether it is necessary to reconsider the current treatment of IFIs instead.

Fungal pathogens and primary antifungal prophylaxis in patients with hematological malignancies: one year experience

BACKGROUND

Febrile neutropenia (FN) is generally a complication of cancer chemotherapy in patients with hematological malignancies.

OBJECTIVE

To evaluate the febrile neutropenia episodes of hematological patients and their outcomes with respect to fungal pathogens, primary antifungal prophylaxis antifungal therapy.

METHODS

All consecutive patients older than 14 years of age and who developed febrile neutropenia episodes from September 2010 to November 2011 were incorporated into this study.

RESULTS

In total, we retrospectively evaluated 86 consecutive patients and their 148 neutropenic episodes. Of the 86 patients, 45 were male and the mean age was 47,65±15,06 years (range: 17-82 years). The mean MASCC score was 18,72 ± 9,43. Systemic antifungal drug was initiated to 17 patients with probable fungal infection and 12 patients with possible fungal infection. Of seven patients who received posaconazole prophylaxis, five were treated with systemic fungal infection due to possible fungal infection.

CONCLUSIONS

It is obvious that more studies focused on primary prophylaxis are needed and primary or secondary antifungal prophylaxis should be evaluated in terms of provided benefits and disadvantages. Timely and appropriately initiated antifungal treatment is one of the most important factors for a good prognosis for recovery from a neutropenic phase.

Antimicrobial therapy of febrile complications after high-dose chemotherapy and autologous hematopoietic stem cell transplantation--guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

More than 18,000 autolgous transplantation were performed in Europe in the year 2009. It as a routine procedure in experienced centres. Even if there is a low mortality rate, infections are a major issue after transplantation, occurring in more than 60 % of the patients. In this review we discuss all aspects of infections after autologous stem transplantation, including epidemiology, diagnostics, therapeutic algorithms, prophylaxis and supportive therapy.

A novel extraction method combining plasma with a whole-blood fraction shows excellent sensitivity and reproducibility for patients at high risk for invasive aspergillosis

Diagnosis of invasive aspergillosis (IA) is still a major problem in routine clinical practice. Early diagnosis is essential for a good patient prognosis. PCR is a highly sensitive method for the detection of nucleic acids and could play an important role in improving the diagnosis of fungal infections. Therefore, a novel DNA extraction method, ultraclean production (UCP), was developed allowing purification of both cellular and cell-free circulating fungal DNA. In this prospective study we evaluated the commercially available UCP extraction system and compared it to an in-house system. Sixty-three patients at high risk for IA were screened twice weekly, and DNA extracted by both methods was cross-analyzed, in triplicate, by two different real-time PCR assays. The negative predictive values were high for all methods (94.3 to 100%), qualifying them as screening methods, but the sensitivity and diagnostic odds ratios were higher using the UCP extraction method. Sensitivity ranged from 33.3 to 66.7% using the in-house extracts to 100% using the UCP extraction method. Most of the unclassified patients showed no positive PCR results; however, single-positive PCR replicates were observed in some cases. These can bear clinical relevance but should be interpreted with additional clinical and laboratory data. The PCR assays from the UCP extracts showed greater reproducibility than the in-house method for probable IA patients. The standardized UCP extraction method yielded superior results, with regard to sensitivity and reproducibility, than the in-house method. This was independent of the PCR assay used to detect fungal DNA in the sample extracts.

Evaluation of fungal-specific fluorescent labeled echinocandin probes as diagnostic adjuncts

The diagnosis of invasive fungal infections from radiographic imaging is non-specific and problematic. As a first step toward increasing specificity, we describe the development of a broad-spectrum fungal-specific targeting molecule, which when modified with a fluorescent label fully retains its targeting properties, and provides a basis for future imaging applications.

A clinical algorithm to diagnose invasive pulmonary aspergillosis in critically ill patients

RATIONALE

The clinical relevance of Aspergillus-positive endotracheal aspirates in critically ill patients is difficult to assess.

OBJECTIVES

We externally validate a clinical algorithm to discriminate Aspergillus colonization from putative invasive pulmonary aspergillosis in this patient group.

METHODS

We performed a multicenter (n = 30) observational study including critically ill patients with one or more Aspergillus-positive endotracheal aspirate cultures (n = 524). The diagnostic accuracy of this algorithm was evaluated using 115 patients with histopathologic data, considered the gold standard. Subsequently, the diagnostic workout of the algorithm was compared on the total cohort (n = 524), with the categorization based on the diagnostic criteria of the European Organization for the Research and Treatment of Cancer/Mycoses Study Group.

MEASUREMENTS AND MAIN RESULTS

Among 115 histopathology-controlled patients, 79 had proven aspergillosis. The algorithm judged 86 of 115 cases to have putative aspergillosis. This diagnosis was confirmed in 72 and rejected in 14 patients. The algorithm judged 29 patients to have Aspergillus colonization. This was confirmed in 22 and rejected in 7 patients. The algorithm had a specificity of 61% and a sensitivity of 92%. The positive and negative predictive values were 61 and 92%, respectively. In the total cohort (n = 524), 79 patients had proven invasive pulmonary aspergillosis (15.1%). According to the European Organization for the Research and Treatment of Cancer/Mycoses Study Group criteria, 32 patients had probable aspergillosis (6.1%) and 413 patients were not classifiable (78.8%). The algorithm judged 199 patients to have putative aspergillosis (38.0%) and 246 to have Aspergillus colonization (46.9%).

CONCLUSIONS

The algorithm demonstrated favorable operating characteristics to discriminate Aspergillus respiratory tract colonization from invasive pulmonary aspergillosis in critically ill patients.

Dectin-1 and DC-SIGN polymorphisms associated with invasive pulmonary Aspergillosis infection

The recognition of pathogen-derived structures by C-type lectins and the chemotactic activity mediated by the CCL2/CCR2 axis are critical steps in determining the host immune response to fungi. The present study was designed to investigate whether the presence of single nucleotide polymorphisms (SNPs) within DC-SIGN, Dectin-1, Dectin-2, CCL2 and CCR2 genes influence the risk of developing Invasive Pulmonary Aspergillosis (IPA). Twenty-seven SNPs were selected using a hybrid functional/tagging approach and genotyped in 182 haematological patients, fifty-seven of them diagnosed with proven or probable IPA according to the 2008 EORTC/MSG criteria. Association analysis revealed that carriers of the Dectin-1(rs3901533 T/T) and Dectin-1(rs7309123 G/G) genotypes and DC-SIGN(rs4804800 G), DC-SIGN(rs11465384 T), DC-SIGN(7248637 A) and DC-SIGN(7252229 C) alleles had a significantly increased risk of IPA infection (OR = 5.59 95%CI 1.37-22.77; OR = 4.91 95%CI 1.52-15.89; OR = 2.75 95%CI 1.27-5.95; OR = 2.70 95%CI 1.24-5.90; OR = 2.39 95%CI 1.09-5.22 and OR = 2.05 95%CI 1.00-4.22, respectively). There was also a significantly increased frequency of galactomannan positivity among patients carrying the Dectin-1(rs3901533_T) allele and Dectin-1(rs7309123_G/G) genotype. In addition, healthy individuals with this latter genotype showed a significantly decreased level of Dectin-1 mRNA expression compared to C-allele carriers, suggesting a role of the Dectin-1(rs7309123) polymorphism in determining the levels of Dectin-1 and, consequently, the level of susceptibility to IPA infection. SNP-SNP interaction (epistasis) analysis revealed significant interactions models including SNPs in Dectin-1, Dectin-2, CCL2 and CCR2 genes, with synergistic genetic effects. Although these results need to be further validated in larger cohorts, they suggest that Dectin-1, DC-SIGN, Dectin-2, CCL2 and CCR2 genetic variants influence the risk of IPA infection and might be useful in developing a risk-adapted prophylaxis.

Clinical utility and prognostic value of galactomannan in neutropenic patients with invasive aspergillosis

Invasive aspergillosis (IA) is a major cause of morbidity and mortality in profoundly neutropenic patients. Delayed diagnosis and therapy may lead to poor outcomes.

AIMS

The objective of this study was to assess the performance characteristics of the galactomannan (GM) assay in serum and bronchoalveolar lavage specimens for the diagnosis of IA in neutropenic patients with hematological malignancies. We also evaluated the prognostic outcome.

PATIENTS AND METHODS

A total of 1198 serum samples and 42 BAL from 235 neutropenic patients were tested with a GM elisa platelia test. We used Cox modeling of time to 6- and 12-week mortality for GM level at the time of diagnosis (GM0) and GM decay in the week following diagnosis in proven and probable IA patients with more than two GM values.

RESULTS

There were three proven, 55 probable, and four possible cases of IA. The sensitivity and specificity of the GM test were 96.8% and 82.4% respectively. In BAL samples, sensitivity was 86% and the specificity 93%. BAL GM was more sensitive than microscopy (22.2%) and BAL culture (38.9%). Among patients with proven/probable IA, serum and BAL GM were in agreement for 92.8% of paired samples. The hazard ratio (HR) of GM0 and 1-week GM decay per unit increase in Aspergillus enzyme immunoassay (EIA) was 1.044 (95% CI, 0.738 to 1.476) and 0.709 (95% CI, 0.236 to 2.130) respectively.

CONCLUSION

We found good correlation between the GM0 and GM decay combination and outcome of IA patients. The GM is a useful tool for diagnosis and monitoring of IA.

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

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