Utility of Aspergillus Antigen Detection in Specimens Other than Serum Specimens

Aspergillus fumigatus Epidural Abscess and Postsurgical Wound Infection in an Immunocompetent Host

In this case, we present an immunocompetent patient who had a wound infection secondary to Aspergillus fumigatus after undergoing a neurosurgical procedure that was complicated by an epidural abscess. The patient was treated with voriconazole and responded favorably. We highlight the need for awareness of the possibility of an Aspergillus infection in people without any obvious immunocompromise and advocate for the inclusion of this opportunistic fungus in the workup of postneurosurgical infections and dura-based collections. A brief review of relevant literature is also included.

COVID-19-associated pulmonary aspergillosis in patients with severe SARS-CoV-2 infection: A single-center observational study from Greece

INTRODUCTION

COVID-19-associated pulmonary aspergillosis (CAPA) is a serious complication affecting patients with severe SARS-CoV-2 infection, and is associated with increased mortality.

OBJECTIVE

The objective of this study was to investigate potential risk factors, and to estimate the incidence and mortality in patients diagnosed with CAPA.

METHODS

A single-center retrospective observational study was conducted on patients admitted to the intensive care unit (ICU) with severe COVID-19 from October 2020 to May 2022. Patients with deterioration of their clinical status were evaluated with serum galactomannan (GM) for probable CAPA. Baseline demographic patient characteristics, vaccination status, and time period during which each patient was infected with SARS-CoV-2 were obtained, and risk stratification according to underlying comorbidities was performed in an effort to assess various risk factors for CAPA. The incidence of CAPA in the entire cohort was measured, and mortality rates in the CAPA and non-CAPA groups were calculated and compared.

RESULTS

Of 488 patients admitted to the ICU, 95 (19.4%) had deterioration of their clinical status, which prompted testing with serum GM. Positive serum testing was observed in 39/95 patients, with an overall CAPA incidence in the entire study cohort reaching 7.9% (39/488). The mortality rate was 75% (42/56) in the non-CAPA group that was tested for serum GM, and 87.2% (34/39) in the CAPA group (P = 0.041). Multivariable Cox regression hazard models were tested for 28- and 90-day survival from ICU admission. An invasive pulmonary aspergillosis (IPA) risk-stratified cox regression model corrected for the SARS-CoV-2 variant of the patient identified the diagnosis of probable CAPA and elevated procalcitonin (PCT) levels measured at least 10 days after ICU admission, as significantly associated with death in the IPA-risk subgroup only, with hazard ratio (HR): 3.687 (95% confidence interval [CI], 1.030-13.199, P = 0.045) for the diagnosis of probable CAPA, and HR: 1.022 (95% CI, 1.003-1.042, P = 0.026) for every 1 ng/mL rise in PCT.

CONCLUSIONS

Patients in the IPA-risk subgroup that were diagnosed with CAPA had a lower 90-day survival when compared to patients in the same group without a CAPA diagnosis.

Post-COVID-19 cavitary lung lesion due to Aspergillus flavus and Enterobacter cloacae in a patient suffering from COVID-19 pneumonia - a case report

The coronavirus disease 2019 (COVID-19) pandemic has manifested as a multifaceted paradigm but has primarily affected the respiratory system. Though a rare sequela after-COVID-19, we present a case of cavitary lung lesion in an adult patient, which manifested with common symptoms such as fever, cough and dyspnoea during the post-COVID-19 recovery period. Aspergillus flavus and Enterobacter cloacae were found to be the main causative organisms. Fungal and bacterial coinfection may be thought of in similar situations and appropriate treatment may be given to prevent further morbidity and mortality.

Subacute Invasive Pulmonary Aspergillosis (IPA) Is a Challenging Diagnosis

Aspergillus is a ubiquitous fungus whose clinical manifestations and prognosis after infection depend on the host's immune status. The disease can have an insidious course, making it a challenging diagnosis that should be considered in patients with risk factors. We report the case of a 78-year-old man with a known history of asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome and idiopathic pulmonary fibrosis on long-term therapy with high-dose oral corticosteroids, hypertension, dyslipidemia, type 2 diabetes, and hypo coagulated atrial fibrillation. He was admitted to the Emergency Department (ED) for dyspnea, productive cough, and wasting syndrome. Recent hospitalization due to pneumonia of the left upper lobe (LUE) with no agent isolation is worth mentioning, treated with levofloxacin. Due to slow improvement, he underwent bronchoscopy (BFC), which revealed friable bronchial mucosa, with isolation of Candida albicans in bronchial secretions (BS) but without evidence of neoplastic cells in the pathological anatomy (PA). He completed 14 days of itraconazole. He was discharged after partial clinical improvement. One week later, he was again admitted to a medical ward because of worsening respiratory symptoms and wasting syndrome. Laboratory findings included an elevated C-reactive protein (CRP) and sedimentation rate, hypoosmolar hyponatremia, hypoproteinemia, and hypoalbuminemia. The study of hyponatremia revealed the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), and the persistence of respiratory symptoms led us to perform a chest computed tomography (CT), which revealed a subsegmental LUE atelectasis. Due to suspicion of neoplasia, he repeated BFC with isolation of Aspergillus on the bronchoalveolar lavage (BAL) and PA. Subacute invasive pulmonary aspergillosis (IPA) was assumed and voriconazole was started. However, he had an unfavorable evolution with marked cachexia and hemorrhagic shock due to lower gastrointestinal bleeding as a complication of hypocoagulation resulting in death. Chronic exposure to corticosteroids and structural lung disease are recognized risk factors for Aspergillus infection. The presentation as a wasting syndrome associated with respiratory symptoms and SIADH raised suspicion for neoplasia, which was excluded. The PA was fundamental for the definitive diagnosis of IPA. The fatal outcome, probably attributable to late diagnosis, reinforces the importance of high clinical suspicion for Aspergillus infection in patients with risk factors.

Serologic biomarkers in Candida and Aspergillus infections of the central nervous system: a comparison of galactomannan, mannan, and β-1,3-D-gucan testing from serum and cerebrospinal fluid

BACKGROUND

The incidence of Aspergillus and Candida CNS infection, which are characterized by high mortality rates, is underestimated. This underdiagnosis presumably results from the limitations of available diagnostic tools and the need for invasive sampling. Little is known about the role of serologic biomarkers in the setting of CNS aspergillosis and candidiasis.

PATIENTS, MATERIALS, METHODS

Serum (19) and cerebrospinal fluid (CSF; 10) samples of 19 patients, whose CNS specimens yielded growth of Aspergillus or Candida, were analyzed for different biomarkers for fungal infection, i.e., galactomannan (GM), galactomannoprotein (GP), mannan, anti-mannan-antibodies, and β-1,3-D-glucan (BDG). Serum and CSF specimens of time-matched patients (two each for every case of fungal CNS infection) were included as controls.

RESULTS

GM, GP, and BDG seropositivity was found in one, two, and three of five cases of CNS aspergillosis. BDG and mannan / anti-mannan-antibody sensitivity in proven CNS candidiasis was 40 % and 20 %, respectively. Applying the serum cut off, sensitivity in CSF testing was 100 % for GM and BDG, and 50 % for mannans. While serum specificity for all assays ranged from 89 - 97 %, specificity for CSF BDG was only 70 %. No false positive GM results from CSF were obtained.

CONCLUSION

Sensitivity for diagnosing CNS aspergillosis and CNS candidiasis from serum is mediocre for all serological biomarkers. GM testing in CSF proved excellent performance. With a sensitivity of 100 % but a specificity of only 70 %, CSF BDG might be most useful when used in patients with a high pre-test probability.

Fungal Genomics in Respiratory Medicine: What, How and When?

Respiratory infections caused by fungal pathogens present a growing global health concern and are a major cause of death in immunocompromised patients. Worryingly, coronavirus disease-19 (COVID-19) resulting in acute respiratory distress syndrome has been shown to predispose some patients to airborne fungal co-infections. These include secondary pulmonary aspergillosis and mucormycosis. Aspergillosis is most commonly caused by the fungal pathogen Aspergillus fumigatus and primarily treated using the triazole drug group, however in recent years, this fungus has been rapidly gaining resistance against these antifungals. This is of serious clinical concern as multi-azole resistant forms of aspergillosis have a higher risk of mortality when compared against azole-susceptible infections. With the increasing numbers of COVID-19 and other classes of immunocompromised patients, early diagnosis of fungal infections is critical to ensuring patient survival. However, time-limited diagnosis is difficult to achieve with current culture-based methods. Advances within fungal genomics have enabled molecular diagnostic methods to become a fast, reproducible, and cost-effective alternative for diagnosis of respiratory fungal pathogens and detection of antifungal resistance. Here, we describe what techniques are currently available within molecular diagnostics, how they work and when they have been used.

Neuroinfectious Disease Emergencies

Neuroinfectious diseases can affect immunocompetent and immunosuppressed individuals and cause a variety of emergencies including meningitis, encephalitis, and abscess. Neurologic infections are frequently complicated by secondary injuries that also present emergently such as cerebrovascular disease, acute obstructive hydrocephalus, and seizure. In most cases, timely recognition and early treatment of infection can improve the morbidity and mortality of infectious neurologic emergencies.

Accuracy of galactomannan testing on tracheal aspirates in COVID-19-associated pulmonary aspergillosis

Objective

Our aim was to evaluate the performance of two galactomannan (GM) assays (Platelia Aspergillus EIA, Bio‐Rad^®, and Aspergillus GM LFA, IMMY^®) in tracheal aspirate (TA) samples of consecutive critically ill patients with COVID‐19.

Methods

We included critically ill patients, performed GM‐EIA and GM‐Lateral Flow Assay (GM‐LFA) in TA and followed them until development of COVID‐19‐associated pulmonary aspergillosis (CAPA) or alternate diagnosis. CAPA was defined according to the modified AspICU criteria in patients with SARS‐CoV‐2 infection. We estimated sensitivity, specificity, positive and negative predictive values for GM‐EIA, GM‐LFA, the combination of both or either positive results for GM‐EIA and GM‐LFA. We explored accuracy using different breakpoints, through ROC analysis and Youden index to identify the optimal cut‐offs. We described antifungal treatment and 30‐day mortality.

Results

We identified 14/144 (9.7%) patients with CAPA, mean age was 50.35 (SD 11.9), the median time from admission to CAPA was 8 days; 28.5% received tocilizumab and 30‐day mortality was 57%. ROC analysis and Youden index identified 2.0 OD as the best cut‐off, resulting in sensitivity and specificity of 57.1% and 81.5% for GM‐EIA and 60% and 72.6% for GM‐LFA, respectively.

Conclusions

The diagnostic performance of GM in tracheal aspirates improved after using a cut‐off of 2 OD. Although bronchoalveolar lavage testing is the ideal test, centres with limited access to bronchoscopy may consider this approach to identify or rule out CAPA.

Revision and Update of the Consensus Definitions of Invasive Fungal Disease From the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium

BACKGROUND

Invasive fungal diseases (IFDs) remain important causes of morbidity and mortality. The consensus definitions of the Infectious Diseases Group of the European Organization for Research and Treatment of Cancer and the Mycoses Study Group have been of immense value to researchers who conduct clinical trials of antifungals, assess diagnostic tests, and undertake epidemiologic studies. However, their utility has not extended beyond patients with cancer or recipients of stem cell or solid organ transplants. With newer diagnostic techniques available, it was clear that an update of these definitions was essential.

METHODS

To achieve this, 10 working groups looked closely at imaging, laboratory diagnosis, and special populations at risk of IFD. A final version of the manuscript was agreed upon after the groups' findings were presented at a scientific symposium and after a 3-month period for public comment. There were several rounds of discussion before a final version of the manuscript was approved.

RESULTS

There is no change in the classifications of "proven," "probable," and "possible" IFD, although the definition of "probable" has been expanded and the scope of the category "possible" has been diminished. The category of proven IFD can apply to any patient, regardless of whether the patient is immunocompromised. The probable and possible categories are proposed for immunocompromised patients only, except for endemic mycoses.

CONCLUSIONS

These updated definitions of IFDs should prove applicable in clinical, diagnostic, and epidemiologic research of a broader range of patients at high-risk.

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.

Fungal mycotic aneurysm in a patient with Aspergillus terreus chronic meningoencephalitis

Background:

Central nervous system involvement due to aspergillosis is an extremely serious entity, particularly in patients with severe neutropenia, hematological diseases, or post-transplant cases. Immunocompetent patients can be infected by intense exposure, particularly iatrogenic after invasive procedures.

Case Description:

We present the case of a 26-year-old male with a 1 year appendectomy background, which required epidural anesthesia. After that surgery, insidious headache presented, requiring mild analgesics for adequate control. In the following weeks, headaches increased and tomographic imaging revealed hydrocephalus. A ventriculoperitoneal shunt was placed, and empirical treatment for neurocysticercosis was established, but diagnosis was never confirmed. Sequentially, shunt dysfunction occurred twice, for which shunt replacement was performed. Cerebrospinal fluid and shunt’s catheter were cultured. Some days later, a filamentous fungus was isolated and finally identified as Aspergillus sp. Intravenous amphotericin B and fluconazole at therapeutic dosage were administered; however, a torpid clinical evolution was observed. After a 2-week antifungal scheme, the fungus was identified as Aspergillus terreus. The patient developed sudden rostrocaudal deterioration. Computed tomography imaging was done, revealing a 70 cc hematoma in the right operculoinsular region, midline shift, and a 9 mm saccular aneurysm at the bifurcation of the middle cerebral artery.

Conclusion:

Cerebral aspergillosis is a serious disease with high mortality in patients, particularly those without identifiable risk factors. The iatrogenic forms are serious, due to the delay of clinical diagnosis. It is important to have a high index of suspicion in patients with a history of invasive procedures such as epidural anesthesia or surgery, and who develop a persistent chronic headache or chronic meningitis.

Methods for rapid diagnosis of meningitis etiology in adults

Infectious meningitis can be caused by viral, bacterial or fungal pathogens. Despite widely available treatments, many types of infectious meningitis are still associated with significant morbidity and mortality. Delay in diagnosis contributes to poor outcomes. Cerebrospinal fluid cultures have been used traditionally but are time intensive and sensitivity is decreased by empiric treatment prior to culture. More rapid techniques such as the cryptococcal lateral flow assay (IMMY), GeneXpert MTB/Rif Ultra (Cepheid) and FilmArray multiplex-PCR (Biofire) are three examples that have drastically changed meningitis diagnostics. This review will discuss a holistic approach to diagnosing bacterial, mycobacterial, viral and fungal meningitis.

Detection of the 'Big Five' mold killers of humans: Aspergillus, Fusarium, Lomentospora, Scedosporium and Mucormycetes

Fungi are an important but frequently overlooked cause of morbidity and mortality in humans. Life-threatening fungal infections mainly occur in immunocompromised patients, and are typically caused by environmental opportunists that take advantage of a weakened immune system. The filamentous fungus Aspergillus fumigatus is the most important and well-documented mold pathogen of humans, causing a number of complex respiratory diseases, including invasive pulmonary aspergillosis, an often fatal disease in patients with acute leukemia or in immunosuppressed bone marrow or solid organ transplant recipients. However, non-Aspergillus molds are increasingly reported as agents of disseminated diseases, with Fusarium, Scedosporium, Lomentospora and mucormycete species now firmly established as pathogens of immunosuppressed and immunocompetent individuals. Despite well-documented risk factors for invasive fungal diseases, and increased awareness of the risk factors for life-threatening infections, the number of deaths attributable to molds is likely to be severely underestimated driven, to a large extent, by the lack of readily accessible, cheap, and accurate tests that allow detection and differentiation of infecting species. Early diagnosis is critical to patient survival but, unlike Aspergillus diseases, where a number of CE-marked or FDA-approved biomarker tests are now available for clinical diagnosis, similar tests for fusariosis, scedosporiosis and mucormycosis remain experimental, with detection reliant on insensitive and slow culture of pathogens from invasive bronchoalveolar lavage fluid, tissue biopsy, or from blood. This review examines the ecology, epidemiology, and contemporary methods of detection of these mold pathogens, and the obstacles to diagnostic test development and translation of novel biomarkers to the clinical setting.

Diagnosis of invasive fungal disease in children: a narrative review

Introduction: Invasive fungal diseases (IFD) represent important causes of morbidity and mortality in pediatrics. Early diagnosis and treatment of IFD is associated with better outcome and this entails the need to use fast and highly sensitive and specific methods that can support clinicians in the management of IFD.Areas covered: A narrative review was performed on conventional diagnostic methods such as culture, microscopy and histopathology are still gold standard but are burdened by a lack of sensitivity and specificity; on the other hand, imaging and noninvasive antigen-based such as beta-D-glucan, galactomannan and molecular biomarkers are the most convenient nonculture methods for diagnosis and monitoring effects of therapy. Aim of the present review is to summarize what is available in these fields at end of the second decade of the third millennium and look for future perspectives.Expert opinion: Promising and useful diagnostic methods have been applied in infectious disease diagnosis in clinical practice or in designing platforms. Unfortunately, most of them are not standardized or validated in pediatric population. However, clinicians should be aware of all innovative diagnostic tools to use in combination with conventional diagnostic methods for a better management of pathology and patient.

Urine Antigen Detection as an Aid to Diagnose Invasive Aspergillosis

Background

Establishing rapid diagnoses of invasive aspergillosis (IA) is a priority tests that detect galactomannan and β-d-glucan are available, but are technically cumbersome and rely on invasive sampling (blood or bronchoalveolar lavage).

Methods

We optimized a lateral flow dipstick assay using the galactofuranose-specific monoclonal antibody (mAb476), which recognizes urine antigens after Aspergillus fumigatus pulmonary infection in animals. Urine samples were obtained from a cohort of 78 subjects undergoing evaluation for suspected invasive fungal infections, and stored frozen until testing. Urine was processed by centrifugation through desalting columns and exposed to dipsticks. Reviewers blinded to clinical diagnoses graded results. Western blots were performed on urine samples from 2 subjects to characterize mAb476-reactive antigens.

Results

Per-patient sensitivity and specificity for diagnosis of proven or probable IA in the overall cohort was 80% (95% confidence interval [CI], 61.4%-92.3%) and 92% (95% CI, 74%-99%), respectively. In the subgroup with cancer, sensitivity was 89.5% (95% CI, 66.7%-98.7%) and specificity was 90.9% (95% CI, 58.7%-99.8%); among all others, sensitivity and specificity were 63.6% (95% CI, 30.8%-89.1%) and 92.9% (95% CI, 66.1%-99.8%), respectively. Eliminating lung transplant recipients with airway disease increased sensitivity in the noncancer cohort (85.7% [95% CI, 42.1%-99.6%]). Semiquantitative urine assay results correlated with serum galactomannan indices. Western blots demonstrated mAb476-reactive antigens in urine from cases, ranging between 26 kDa and 35 kDa in size.

Conclusions

Urine testing using mAb476 may be used as an aid to diagnose IA in high-risk patients.

Invasive fungal disease in patients undergoing umbilical cord blood transplantation after myeloablative conditioning regimen

OBJECTIVE

Characteristics and risk factors (RFs) of invasive fungal disease (IFD) have been little studied in the setting of umbilical cord blood transplantation (UCBT).

METHOD

We retrospectively included 205 single-unit myeloablative UCBT recipients with a median follow-up of 64 months.

RESULTS

Fifty-six episodes of IFD were observed in 48 patients (23%) at a median time of 123 days after stem cell infusion. Invasive mold disease (IMD) occurred in 42 cases, 38 of them (90%) caused by invasive aspergillosis whereas invasive yeast disease (IYD) occurred in 14 cases, most of them due to candidemia (n = 12, 86%). The 5-year cumulative incidence of IFD, IMDs, and IYDs was 24% 19%, and 7%, respectively. In multivariate analysis, three RFs for IMDs were identified: age >30 years (HR 3.5, P = 0.017), acute grade II-IV graft-versus-host disease (HR 2.3, P = 0.011), and ≥1 previous transplant (HR 3.1, P = 0.012). The probability of IMDs was 2.5%, 14%, and 33% for recipients with none, 1, or 2-3 RFs, respectively (P < 0.001). Among IFD, IMDs had a negative effect on non-relapse mortality in multivariate analysis (HR 1.6, P = 0.039). IMDs showed a negative impact on overall survival (HR 1.59, P = 0.018).

CONCLUSION

Invasive mold disease were very common and serious complication after UCBT.

Urine Antigen Detection as an Aid to Diagnose Invasive Aspergillosis

Background

Establishing rapid diagnoses of invasive aspergillosis (IA) is a priority tests that detect galactomannan and β-d-glucan are available, but are technically cumbersome and rely on invasive sampling (blood or bronchoalveolar lavage).

Methods

We optimized a lateral flow dipstick assay using the galactofuranose-specific monoclonal antibody (mAb476), which recognizes urine antigens after Aspergillus fumigatus pulmonary infection in animals. Urine samples were obtained from a cohort of 78 subjects undergoing evaluation for suspected invasive fungal infections, and stored frozen until testing. Urine was processed by centrifugation through desalting columns and exposed to dipsticks. Reviewers blinded to clinical diagnoses graded results. Western blots were performed on urine samples from 2 subjects to characterize mAb476-reactive antigens.

Results

Per-patient sensitivity and specificity for diagnosis of proven or probable IA in the overall cohort was 80% (95% confidence interval [CI], 61.4%-92.3%) and 92% (95% CI, 74%-99%), respectively. In the subgroup with cancer, sensitivity was 89.5% (95% CI, 66.7%-98.7%) and specificity was 90.9% (95% CI, 58.7%-99.8%); among all others, sensitivity and specificity were 63.6% (95% CI, 30.8%-89.1%) and 92.9% (95% CI, 66.1%-99.8%), respectively. Eliminating lung transplant recipients with airway disease increased sensitivity in the noncancer cohort (85.7% [95% CI, 42.1%-99.6%]). Semiquantitative urine assay results correlated with serum galactomannan indices. Western blots demonstrated mAb476-reactive antigens in urine from cases, ranging between 26 kDa and 35 kDa in size.

Conclusions

Urine testing using mAb476 may be used as an aid to diagnose IA in high-risk patients.

Central Nervous System Aspergillosis: An Unexpected Complication following Neurosurgery

Post-surgical aspergillosis is an uncommon complication that carries a high mortality rate in affected patients. The diagnosis is challenging given the lack of highly sensitive methods to isolate Aspergillus from surgical sites. Here, we present a case of post-surgical aspergillosis that occurred after the resection of acoustic neuroma in an immunocompetent patient. Imaging revealed leptomeningeal enhancement and a cerebellar extra-axial fluid collection adjacent to the right retrosigmoid craniotomy. The patient was taken to the operating room for debridement, where purulent fluid was obtained from subdural space. The diagnosis was achieved by histopathology and polymerase chain reaction (PCR) in brain tissue. Appropriate investigations failed to detect contamination in the operating room. The patient was successfully treated with 3 months of voriconazole. We highlight the importance of recognizing this uncommon complication and advocate for the use of molecular techniques to improve the diagnostic yield in central nervous system aspergillosis.

Use of Galactomannan Antigen and Aspergillus DNA Real-time Polymerase Chain Reaction as Routine Methods for Invasive Aspergillosis in Immunosuppressed Children in Greece

PURPOSE

Invasive aspergillosis (IA) remains a critical issue in immunosuppressed patients. Detection of galactomannan antigen (GM) in serum samples is included as a criterion of IA by the European Organization for the Research and Treatment of Cancer/Mycoses Study Group. Nevertheless, Aspergillus DNA detection by polymerase chain reaction (PCR) has not yet been included because clinical data validation is lacking. The present study describes the simultaneous performance of GM and PCR tests as routine methods for IA diagnosis.

METHODS

During the period January 2012 to December 2017, a total of 156 white children hospitalized in a tertiary children's hospital of Athens (97 boys and 59 girls; age range, 5 months-14 years) were examined as possible cases of IA. Patients were classified into 4 groups based on their underlying diseases: hematologic malignancies (107 of 156 [68.6%]), solid tumors (16 of 156 [10.2%]), primary immunodeficiency (12 of 156 [7.7%]), and hereditary immunodeficiency (21 of 156 [13.5%]). GM detection was made with the Platelia Aspergillus Ag kit (Bio-Rad Laboratories, Hercules, California). Sera with a cut-off index ≥0.5 on at least 2 separate blood collections were considered positive. Serum detection of Aspergillus DNA was conducted with real-time PCR MycAssay Aspergillus assay (Myconostica Ltd, Cambridge, United Kingdom). PCR positivity was determined by using a threshold of 38 cycles in at least 1 serum sample. Four or more successive samples per patient were tested.

FINDINGS

Overall, 28 of 156 patients (53 of 744 serum samples) were found positive. Eleven patients were positive using both methods (24 samples). Four children were positive only by PCR (6 samples), whereas 13 (23 samples) were positive only with GM in consecutive samples. Agreement of both methods, GM(+)/PCR(+) or GM(-)/PCR(-), was found in 139 patients (90% of total patients) and 715 samples (96.1% of total samples). The agreement of both methods was found: (1) 85% in patients with hematologic malignancies; (2) 100% in patients with solid tumors; (3) 97.5% in patients with primary immunodeficiency; and (4) 98.8% in patients with hereditary immunodeficiency. Overall disagreement was observed in 17 patients, in which the positive result in any of the 2 methods was estimated as true positive in conjunction with radiologic and other clinical findings.

IMPLICATIONS

The combination of GM and PCR, provided high diagnostic accuracy in consecutive samples (twice a week). Clinical, radiologic, and other laboratory findings should be taken into consideration in the evaluation of GM and PCR.

Diagnosis and management of Aspergillus diseases: executive summary of the 2017 ESCMID-ECMM-ERS guideline

The European Society for Clinical Microbiology and Infectious Diseases, the European Confederation of Medical Mycology and the European Respiratory Society Joint Clinical Guidelines focus on diagnosis and management of aspergillosis. Of the numerous recommendations, a few are summarized here. Chest computed tomography as well as bronchoscopy with bronchoalveolar lavage (BAL) in patients with suspicion of pulmonary invasive aspergillosis (IA) are strongly recommended. For diagnosis, direct microscopy, preferably using optical brighteners, histopathology and culture are strongly recommended. Serum and BAL galactomannan measures are recommended as markers for the diagnosis of IA. PCR should be considered in conjunction with other diagnostic tests. Pathogen identification to species complex level is strongly recommended for all clinically relevant Aspergillus isolates; antifungal susceptibility testing should be performed in patients with invasive disease in regions with resistance found in contemporary surveillance programmes. Isavuconazole and voriconazole are the preferred agents for first-line treatment of pulmonary IA, whereas liposomal amphotericin B is moderately supported. Combinations of antifungals as primary treatment options are not recommended. Therapeutic drug monitoring is strongly recommended for patients receiving posaconazole suspension or any form of voriconazole for IA treatment, and in refractory disease, where a personalized approach considering reversal of predisposing factors, switching drug class and surgical intervention is also strongly recommended. Primary prophylaxis with posaconazole is strongly recommended in patients with acute myelogenous leukaemia or myelodysplastic syndrome receiving induction chemotherapy. Secondary prophylaxis is strongly recommended in high-risk patients. We strongly recommend treatment duration based on clinical improvement, degree of immunosuppression and response on imaging.

Clinical and Pathological Correlation in Pediatric Invasive Pulmonary Aspergillosis

INTRODUCTION

Invasive' pulmonary aspergillosis (IPA) has been one of the major causes of mortality in immunocompromised patients. The gold standard method for a diagnosis of IPA is histopathological examination of the lung tissue; however, post-procedural bleeding limits the feasibility of lung biopsy. The European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and The National Institute of Allergy and Infectious Disease Mycoses Study Group (EORTC/MSG) defined IPA. The objective of this study was to validate the EORTC/MSG 2008 definition of IPA, compared with histopathology in the pediatric population.

METHODS

Histopathological examinations of lung tissues of children aged 1 month-18 years with respiratory tract infection at the time of obtaining biopsy were retrieved. Retrospective chart reviews for clinical characteristics were performed. IPA diagnosis was classified according to the EORTC/MSG 2008 definition.

RESULTS

During the 10-year period, there were 256 lung tissues, of which 58 specimens were suspected to have pulmonary infection. Fourteen patients (24%) were noted to have IPA. Seven patients (50%) with proven IPA were classified as probable, while the remaining 50% were classified as possible, and none were classified as no IPA, by using EORTC/MSG 2008 definition. Other 44 specimens demonstrated 14 (32%), 14 (32%), and 16 (36%) were classified as probable, possible, and no IPA, respectively. When comparing probable or possible IPA with no IPA, we found that the EORTC/MSG 2008 definition had 100% sensitivity, 36% specificity, 33% positive predictive value, and 100% negative predictive value in diagnosis of IPA.

CONCLUSION

Our study illustrated that the EORTC/MSG 2008 definition provided an excellent sensitivity but low specificity for diagnosing IPA.

Nucleic acid amplification methodologies for the detection of pulmonary mold infections

INTRODUCTION

The detection of pulmonary mold infections has historically required technically demanding methods obtained through invasive procedures. Nucleic acid amplification assays have the potential to circumvent the technical hurdles associated with diagnosis, but are not without potential pitfalls. Areas covered: In this paper, the authors review new assays for the diagnosis of pulmonary mold infections due to aspergillosis, mucormycosis, and hyalohyphomycoses as well as uncommon infections caused by dematiaceous molds. Expert commentary: Nucleic acid amplification assays have the potential to rapidly identify patients with invasive mycoses and could shorten the time to implementation of appropriate antimicrobial therapy. However, selection of appropriate patient populations will be crucial to ensure the highest Bayesian positive predictive value for any novel diagnostic platform.

Fatal Mycotic Aneurysm of the Basilar Artery Caused by Aspergillus fumigatus in a Patient with Pituitary Adenoma and Meningitis

Fungal infections of the central nervous system (CNS) frequently occur in immunosuppressed patients. Here, we describe the case of an immunocompetent 64-year-old man who presented with diplopia, right-sided hemiparesis, and a mild headache after cleaning and replacing nesting boxes of wild birds during the preceding months. Lumbar puncture revealed pleocytosis, elevated protein, and lactate levels in the cerebrospinal fluid (CSF). Initial imaging showed ischemia in the left thalamus and an enlargement of the sellar region. Antibiotic treatment and corticosteroids led to an initial improvement but was followed by rapid deterioration. Antibiotic treatment was modified and antifungal therapy was added. Eighteen days after admission, the patient died from a subarachnoid hemorrhage resulting from the rupture of a fusiform aneurysm of the basilar artery. Microbiological culture of CSF was negative, but a positive galactomannan assay suggested fungal infection which was corroborated by detection of Aspergillus fumigatus DNA in pan-fungal PCR and sequencing. The presence of septated hyphae in the wall of the basilar artery confirmed the diagnosis of a mycotic aneurysm caused by hyphomycetal infection. In addition, brain autopsy revealed the presence of an invasive adrenocorticotrophic hormone-producing pituitary adenoma with arrosion of the sellar bone. This process and its invasiveness likely facilitated the spread of the fungal pathogen from the sphenoid sinus to the dura mater and finally led to cerebral angioinvasion. Our case demonstrates the challenge to timely diagnose and effectively treat aspergillosis as a cause of CNS infection also in apparently immunocompetent patients. The potential of assays detecting fungal antigens and of PCR to facilitate a timely diagnosis is discussed.

Evaluation of serum galactomannan enzyme immunoassay at two different cut-offs for the diagnosis of invasive aspergillosis in patients with febrile neutropenia

BACKGROUND

Invasive aspergillosis (IA) is an increasingly common and fatal opportunistic fungal infection in patients with haematological diseases. Early diagnosis is difficult as mycological culture techniques have low sensitivity and the radiological tools have low specificity. Galactomannan enzyme immunoassay (GEI) detects galactomannan in the human serum with a reported sensitivity and specificity between 30% and 100%.

AIMS

The aim of this study was to analyse the role of GEI in diagnosis of IA in patients with febrile neutropenia and to evaluate the role of GEI in the diagnosis of IA as per the revised (2008) European Organization for Research and Treatment of Cancer-Mycoses Study Group (EORTC-MSG) criteria at two different optical density (OD) cut-offs of 0.5 and 1.0.

SETTING

This prospective study was conducted in Safdarjung Hospital, New Delhi, India.

METHODS

GEI testing was performed in adult patients of febrile neutropenia with evidence of IA. Results at two different OD indices (ODIs) of 0.5 and 1.0 were analysed. The evaluation of the diagnostic parameter, that is, GEI was measured in terms of sensitivity, specificity and positive and negative predictive value and was validated with the revised (2008) EORTC-MSG diagnostic criteria of IA.

RESULTS

One hundred and eleven patients had evidence of IA, of which 79 patients were GEI positive when cut-off ODI was 0.5, whereas with cut-off ODI 1.0, 55 patients were GEI positive.

CONCLUSION

ODI of 1.0 should be considered as positive while in patients with OD between 0.5 and 1.0, repeat sampling from the patient is recommended.

Central Nervous System Infections

This chapter provides an overview of infectious syndromes, pathogens, and diagnostic testing modalities for central nervous system infections in the immunocompromised host.

Special considerations for the diagnosis and treatment of invasive pulmonary aspergillosis

INTRODUCTION

The diagnosis and treatment of invasive pulmonary aspergillosis (IPA) are ongoing challenges in clinical practice. While important advances have recently been made, including enhanced diagnostic modalities as well as novel therapeutic and prophylactic options, more effective options are urgently needed as the population of immunocompromised patients continues to expand. Areas covered: In this paper, we review novel approaches to diagnosis of IPA, including multiplex PCR, Matrix Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry and provide a detailed review of the extended-spectrum triazole isavuconazole, which was approved in 2015 to treat IPA. Expert commentary: We explore burgeoning approaches to diagnosis, including the lateral flow assay, volatile organic compounds, and artificial olfactory technology, as well as novel antifungal agents to treat IPA such as SCY-078 and F901318.

Laboratory Diagnostics for Fungal Infections: A Review of Current and Future Diagnostic Assays

This article reviews the current diagnostic approaches, both serologic and molecular, for the detection of fungi associated with pulmonary disease. Classic serologic techniques, including immunodiffusion and complement fixation, both of which remain a cornerstone for fungal diagnostic testing, are reviewed and their performance characteristics presented. More recent advances in this field, including novel lateral-flow assays for fungal antigen detection, are also described. Molecular techniques for fungal identification both from culture and directly from patient specimens, including nucleic acid probes, mass spectrometry-based methods, nucleic acid amplification testing, and traditional and broad-range sequencing, are discussed and their performance evaluated.

Immunological Identification of Fungal Species

Immunodetection is described in this chapter as a technique for producing specific antibodies for antigen detection of the major human fungal pathogens. In the case of Candida spp., heat-killed cells are used to immunize mice over a couple of weeks and then splenocytes are isolated and further fused with myelomas to easily propagate the antibodies produced in the mice. The resulting antibodies follow a purification process where antibody levels and concentrations are determined. Fungal cells are also lysed to obtain whole cell extracts as a prior step for identification of antigens using immunoprecipitation. Finally, this method permits the production of specific antibodies against fungi and the identification of the respective antigens in an in vivo model.

Molecular diagnosis of invasive mycoses of the central nervous system

INTRODUCTION

In September 2012, the Centers for Disease Control and Prevention (CDC) began investigating an outbreak of fungal meningitis among patients who had received contaminated preservative-free methyl prednisolone acetate injections from the New England Compounding Center in Framingham, Massachusetts. Thousands of patients were potentially exposed to tainted corticosteroids, but establishing the diagnosis of fungal meningitis during the nationwide outbreak was difficult because little was known about the natural history of the disease. Areas covered: The challenges associated with this outbreak highlighted the need for rapid and reliable methodologies to assist in the diagnosis of invasive mycoses of the central nervous system (IMCNS), which may be devastating and difficult to treat. In this paper, we review the causative agents of these potentially-lethal infections, which include cryptococcal meningitis, cerebral aspergillosis, and hematogenous Candida meningoencephalitis. Expert commentary: While microscopy, culture, and histopathologic identification of fungal pathogens remain the gold standard for diagnosis, new platforms and species-specific assays have recently emerged, including lateral flow immunoassays (LFA), matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and multiplex PCR in conjunction with magnetic resonance (MR) to potentially aid in the diagnosis of IMCNS.

Lower Respiratory Tract Infections

This review will focus on the infectious etiologies and more common noninfectious causes of lower respiratory tract syndromes among major immunosuppressed populations. The changing epidemiology of infections in the era of highly active antiretroviral therapy (HAART) in the case of HIV-positive patients and the impacts of both newer immune-suppressant therapies and anti-infective prophylaxis for other immunocompromised hosts will be discussed, with emphasis on diagnostic approaches and practice algorithms.

Diagnosis of invasive fungal diseases in pediatric patients

INTRODUCTION

The optimal management of invasive fungal infections (IFIs) in children requires prompt and precise diagnosis that enables timely implementation of appropriate antifungal therapy and decreased use of unnecessary toxic antifungals. Areas covered: Traditional approaches such as culture, microscopy and histopathology remain the gold standard but are often not sufficiently sensitive and specific. These limitations have led to the development of alternative non-invasive diagnostic methods that in most cases detect fungal components, such as antigens or nucleic acids. To date, galactomannan and 1,3 β-D-glucan assays are the most efficient non-culture methods for diagnosis and monitoring of antifungal therapy. New technologies from nano-sciences are applied, like T2Candida assay. However, these are not standardized or validated in children. Herein, we focus on IFI diagnosis emphasizing current perspectives, interpretation difficulties, and need for further evaluation in pediatrics. Expert commentary: The new diagnostic tools may enhance diagnostic capacity in combination with traditional methods.

CNS infections in patients with hematological disorders (including allogeneic stem-cell transplantation)-Guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Diagnosis of CNS infections remains a great challenge in patients with hematological disorders since symptoms might both be masked and be mimicked by other conditions such as metabolic disturbances or consequences from antineoplastic treatment. Thus, awareness of this complication is crucial and any suspicion of a CNS infection should lead to timely and adequate diagnostics and treatment to improve the outcome in this population.

Infections of the central nervous system (CNS) are infrequently diagnosed in immunocompetent patients, but they do occur in a significant proportion of patients with hematological disorders. In particular, patients undergoing allogeneic hematopoietic stem-cell transplantation carry a high risk for CNS infections of up to 15%. Fungi and Toxoplasma gondii are the predominant causative agents. The diagnosis of CNS infections is based on neuroimaging, cerebrospinal fluid examination and biopsy of suspicious lesions in selected patients. However, identification of CNS infections in immunocompromised patients could represent a major challenge since metabolic disturbances, side-effects of antineoplastic or immunosuppressive drugs and CNS involvement of the underlying hematological disorder may mimic symptoms of a CNS infection. The prognosis of CNS infections is generally poor in these patients, albeit the introduction of novel substances (e.g. voriconazole) has improved the outcome in distinct patient subgroups. This guideline has been developed by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) with the contribution of a panel of 14 experts certified in internal medicine, hematology/oncology, infectious diseases, intensive care, neurology and neuroradiology. Grades of recommendation and levels of evidence were categorized by using novel criteria, as recently published by the European Society of Clinical Microbiology and Infectious Diseases.

Comparison of galactomannan, beta-D-glucan, and Aspergillus DNA in sera of high-risk adult patients with hematological malignancies for the diagnosis of invasive aspergillosis

BACKGROUND/AIM

Invasive aspergillosis (IA) is a fatal infection that is difficult to diagnose in immunocompromised patients. In this study, Aspergillus-specific DNA was searched using real-time PCR (RT-PCR) in serum samples. Galactomannan (GM) and/or beta-D-glucan (BDG) tests were previously performed on these samples for 70 neutropenic patients with hematological malignancy.

MATERIALS AND METHODS

The patients were categorized according to the criteria of the European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG). Among the patient serum samples, the first positive GM or BDG test sample and the median sample of GM or BDG test for negative patients were used to detect DNA levels by RT-PCR method (Light Cycler 480, Roche Molecular Biochemicals, Meylan, France) using a commercial kit (Way2Gene Fungi; Genmar, İzmir, Turkey).

RESULTS

When the proven and probable IA group were considered as real patients, sensitivity of Aspergillus-specific DNA test was 90%, specificity was 73.3%, positive predictive value was 81.8%, and negative predictive value was 84.6%.

CONCLUSION

This study found that searching for specific DNA by RT-PCR method has a sensitivity as high as the GM test. Although specificity was rather low, it was concluded that it can be used jointly with GM and BDG tests after decreasing contamination by severe laboratory applications.

Urine Galactomannan-to-Creatinine Ratio for Detection of Invasive Aspergillosis in Patients with Hematological Malignancies

Galactomannan (GM) testing of urine specimens may provide important advantages, compared to serum testing, such as easy noninvasive sample collection. We evaluated a total of 632 serial urine samples from 71 patients with underlying hematological malignancies and found that the urine GM/creatinine ratio, i.e., (urine GM level × 100)/urine creatinine level, which takes urine dilution into account, reliably detected invasive aspergillosis and may be a promising diagnostic tool for patients with hematological malignancies. (This study has been registered at ClinicalTrials.gov under registration no. NCT01576653.).

Aspergillus terreus Meningitis in Immunocompetent Patient: A Case Report

We present a description of a rare but dangerous case of fungal meningitis caused by Aspergillus terreus in an immunocompetent patient with a history of sinus disease.

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.

Diagnosis of Invasive Fungal Diseases in Hematological Malignancies: A Critical Review of Evidence and Turkish Expert Opinion (TEO-2)

One of the most problematic issues in hematological malignancies is the diagnosis of invasive fungal diseases. Especially, the difficulty of mycological diagnosis and the necessity of immediate intervention in molds have led to the adoption of “surrogate markers” that do not verify but rather strongly suggest fungal infection. The markers commonly used are galactomannan (GM), beta-glucan, and imaging methods. Although there are numerous studies on these diagnostic approaches, none of these markers serve as a support for the clinician, as is the case in human immunodeficiency virus (HIV) or cytomegalovirus (CMV) infections. This paper has been prepared to explain the diagnostic tests. As molecular tests have not been standardized and are not used routinely in the clinics, they will not be mentioned here.

Diagnostic Modalities for Invasive Mould Infections among Hematopoietic Stem Cell Transplant and Solid Organ Recipients: Performance Characteristics and Practical Roles in the Clinic

The morbidity and mortality of hematopoietic stem cell and solid organ transplant patients with invasive fungal infections (IFIs) remain high despite an increase in the number of effective antifungal agents. Early diagnosis leading to timely administration of antifungal therapy has been linked to better outcomes. Unfortunately, the diagnosis of IFIs remains challenging. The current gold standard for diagnosis is a combination of histopathology and culture, for which the sensitivity is <50%. Over the past two decades, a plethora of non-culture-based antigen and molecular assays have been developed and clinically validated. In this article, we will review the performance of the current commercially available non-cultural diagnostics and discuss their practical roles in the clinic.

Fungal encephalitis in human autopsy cases is associated with extensive neuronal damage but only minimal repair

AIMS

The present study aimed at examining neuronal injury and repair in post mortem brain sections of humans who died from fungal central nervous system infections.

METHODS

Histological and immunohistochemical abnormalities in 15 autopsy cases with fungal central nervous system infections from 1990 to 2008 were compared with findings in 10 age- und sex-matched control cases that died from acute non-neurological causes. The fungal pathogens were identified by culture or polymerase chain reaction and morphology in post mortem tissue. Seven patients with fungal encephalitis had either an organ transplantation or a malignant haematological disorder; five out of 15 did not have a classical predisposing illness but suffered from severe septic infections as the principal cause of immunosuppression, and three from alcoholism.

RESULTS

Fungal organisms detected were Aspergillus spp. and other moulds, Candida spp. and black yeast-like fungi including Cladosporium spp. Histological analyses identified microglial activation, astrocytosis and axonal injury in the white matter without additional demyelination as characteristic features of this infectious disease. An increased rate of hippocampal neuronal apoptosis was detected in fungal encephalitis, while the number of recently generated TUC-4 and calretinin-expressing neurones in the dentate gyrus did not differ between patients and controls.

CONCLUSIONS

Unlike in other infectious diseases of the nervous system where a coexistence of damage and repair was observed, fungal encephalitis is characterized by strong damage and minimal neuronal regeneration.

Biomarkers for invasive aspergillosis: the challenges continue

The incidence of invasive aspergillosis (IA), an opportunistic infection in immunocompromised individuals, is rising, but its early diagnosis remains challenging and treatment options are limited. Hence there is an urgent need to improve existing diagnostic procedures as well as develop novel approaches. The clinical usefulness of galactomannan and β-d-glucan, widely used assays detecting cell-wall antigens of Aspergillus, is unclear and depends on clinicians' awareness of their practical limitations. This leaves room for new methods that utilise genomic, proteomic and metabolomics approaches as well as novel detection procedures, for example point-of-care lateral-flow devices. Each of these strategies has its own limitations and it is likely that a combination of methods will be required to achieve optimal performance for the diagnosis of IA and subsequent appropriate patient management.