Diagnosis Of Invasive Aspergillosis Research Articles

Galactomannan Antigen Assay for the Diagnosis of Invasive Aspergillosis: A Study from a Tertiary Care Hospital of Central India

Invasive Aspergillosis (IA) is a severe and fatal infection, especially in immunocompromised patients. Galactomannan is a polysaccharide antigen present in the cell wall of Aspergillus species, which is secreted into the blood and other body fluids during hyphal growth. Therefore, detecting galactomannan antigen is very useful in diagnosing IA, along with clinical features and radiological findings. The study period was one year (January 2022 to December 2022). The data was collected retrospectively from the medical records and case sheets of all clinically suspected invasive aspergillosis patients. Galactomannan antigen assay was performed using an FDA-approved Platelia Aspergillus EIA test kit, and results were interpreted according to the manufacturer’s instructions (Cut off > 0.5). A total of 236 clinically suspected Invasive Aspergillosis cases were enrolled in the study. Galactomannan positivity was predominantly seen in patients aged 40 – 60 years, with male preponderance. Of 236 patients, 14.40% were immunocompromised, and 85.59% were immunocompetent. According to EORTC/MSG definitions, we got one proven IA case, 21 probable cases (8.89%), and nine (3.81%) possible cases. In immunocompetent individuals also, we observed 48.72% (115/236) galactomannan positivity, especially in old Pulmonary Tuberculosis (PTB) patients. Galactomannan positivity was higher in Broncho alveolar lavage (BAL) samples (n=70, 85.36%) than in serum samples (n=77, 46.67%). We found culture positivity of 14.06%, with Aspergillus fumigatus being the commonest isolate, followed by Aspergillus flavus. There is increased positivity of galactomannan in BAL samples compared to serum; hence BAL is a better specimen for diagnosis of Invasive Pulmonary Aspergillosis (IPA).

Utility of an in-house real-time PCR in whole blood samples as a minimally invasive method for early and accurate diagnosis of invasive mould infections.

Invasive mould infections (IMIs) are a leading cause of death in patients with compromised immune systems. Proven invasive mould infection requires detection of a fungus by histopathological analysis of a biopsied specimen, sterile culture, or fungal DNA amplification by PCR in tissue. However, the clinical performance of a PCR assay on blood samples taken from patients suspected of invasive mould disease has not been fully evaluated, particularly for the differential diagnosis of invasive aspergillosis (IA) and invasive Mucormycosis (IM). To assess the diagnostic utility of our previously validated in-house real-time PCR in blood samples for diagnosis of invasive aspergillosis and mucormycosis in patients with suspected invasive mould infection. All patients with suspected invasive mould infection were prospectively enrolled from May 2021 to July 2021. Conventional fungal diagnosis was performed using tissue and respiratory samples. In-house PCR was performed on blood samples and its diagnostic performance evaluated. A total of 158 cases of suspected invasive mould infection were enrolled in the study. The sensitivity and specificity of in-house PCR performed on blood samples was found to be 92.5% and 81.4% respectively for diagnosis of probable IA, and 65% and 84.62% respectively for diagnosis of proven and probable IM. It was also able to detect 3 out of 5 cases of possible IM where no other microbiological evidence of IM was obtained. This assay could be helpful in minimally invasive diagnosis of IMIs for patients in whom invasive sampling is not feasible, especially as a preliminary or screening test. It can help in early diagnosis, anticipating conventional laboratory confirmation by days or weeks. Possible correlation between fungal load and mortality can help in initiating aggressive treatment for patients with high initial fungal load.

Baseline chest computed tomography for diagnosis of invasive aspergillosis in patients with acute myeloid leukaemia treated with intensive chemotherapy: A retrospective single-centre cohort study.

Invasive pulmonary aspergillosis (IPA) is a relatively common infection in patients with acute myeloid leukaemia (AML), and is associated with high mortality rates. Optimising early detection is key to reduce the burden of IPA in this population. In this retrospective cohort study, we evaluated the added value of baseline chest CT before start of classical induction chemotherapy. Adult patients receiving first-line intensive chemotherapy for AML were included if a baseline chest CT scan was available (±7 days). Data were collected from the electronic health record. IPA was classified using the EORTC/MSGERC 2020 consensus definitions. Between 2015 and 2019, 99 patients were included. During first-line treatment, 29/99 (30%) patients developed a probable IPA. Baseline chest CT was abnormal in 61/99 (62%) and 14/61 (23%) patients had typical radiological signs for IPA. An abnormal scan showed a trend towards higher risk for IPA (hazard ratio (HR): 2.12; 95% CI 0.95-4.84). Ground glass opacities were a strong predictor for developing IPA (HR 3.35: 95% CI 1.61-7.00). No probable/proven IPA was diagnosed at baseline; however, a bronchoalveolar lavage (BAL) at baseline was only performed in seven patients. Twelve-week mortality was higher in patients with IPA (7/26, 27% vs. 5/59, 8%; p = .024). Baseline chest CT scan could be an asset in the early diagnosis of IPA and contribute to risk estimation for IPA. In patients with an abnormal baseline CT, performing a BAL should be considered more frequently, and not only in patients with radiological findings typical for IPA.

Time-resolved fluoroimmunoassay for Aspergillus detection based on anti-galactomannan monoclonal antibody from stable cell line

Invasive Aspergillosis is a high-risk illness with a high death rate in immunocompromised people due to a lack of early detection and timely treatment. Based on immunology study, we achieved an efficient production of anti-galactomannan antibody by Chinese hamster ovary (CHO) cells and applied it to time-resolved fluoroimmunoassay for Aspergillus galactomannan detection. We first introduced dual promoter expression vector into CHO host cells, and then applied a two-step screening strategy to screen the stable cell line by methionine sulfoximine pressurization. After amplification and fermentation, antibody yield reached 4500 mg/L. Then we conjugated the antibodies with fluorescent microspheres to establish a double antibody sandwich time-resolved fluoroimmunoassay, which was compared with the commercial Platelia™ Aspergillus Ag by clinical serum samples. The preformed assay could obtain the results in less than 25 min, with a limit of detection for galactomannan of approximately 1 ng/mL. Clinical results of the two methods showed that the overall percent agreement was 97.7% (95% CI: 96.6%–98.4%) and Cohen's kappa coefficient was 0.94. Overall, the assay is highly consistent with commercial detection, providing a more sensitive and effective method for the rapid diagnosis of invasive aspergillosis.

Low specificity of Aspergillus spp. ELITe MGB assay, and potential risks in management of invasive aspergillosis

ObjectivesIn recent years, commercial molecular tools for diagnosis of invasive aspergillosis have emerged, requiring evaluation to ensure quality. Here we assessed the specificity of Aspergillus spp.-ELITe MGB Assay a commercial assay tergeting 18S gene of Aspergillus spp. Design and methodsAs part of a method validation, we evaluate the specificity of the Aspergillus spp.-ELITe MGB Assay by testing fourteen culture based samples of sequenced non-Aspergillus fungal species. The benefits of a pre-lysis treatment was evaluated in parallel on serial dilutions of an Aspergillus fumigatus strain. ResultsOur findings revealed cross-reactivity in five strains using the 50 copies/mL cut-off recommended by the manufacturer, suggesting potential diagnostic errors and inappropriate management of patients. Pre-lysis treatment does not affect the limit of detection at serial dilution. ConclusionsIn conclusion, the Aspergillus spp. ELITe MGB Assay exhibits limited specificity in culture-based samples, underscoring the importance of careful utilization in laboratories. Further studies are warranted to better comprehend of the impact of this cross-reactivity on clinical samples.

Clinical Characteristics of Patients with Hematologic Malignancies and Invasive Aspergillosis: A Cross-sectional Clinical Report from Iran

Background: The incidence of invasive aspergillosis (IA) has significantly increased in recent decades. In patients with hematologic malignancies (HM), IA is associated with higher mortality rates. Objectives: This study aimed to assess the clinical features of IA in patients with HM. Methods: In this retrospective study, we used the hospital information system (HIS) database to extract clinical and paraclinical characteristics of patients with various HMs who received a diagnosis of probable or proven IA during their hospitalization at Imam Khomeini Hospital Complex in Tehran, Iran, between March 2018 and March 2022. Results: After evaluating 350 patients with HM, 51 patients with IA (14.6%) were identified, of whom 40 cases (78.4%) were probable and 11 (21.6%) were proven. Among these, 34 individuals (66.7%) were male. The most common symptoms were fever (n = 23, 62.7%), cough (n = 20, 39.2%), and fever that did not respond to antibiotic therapy (n = 16, 31.4%). The most prevalent malignancies were AML (n = 28, 54.9%), ALL (n = 16, 31.4%), and lymphoma (n = 7, 13.7%). Out of the 51 patients with HM and IA, 48 (94.1%) had abnormal findings on chest CT scans, with the majority (n = 31, 72.1%) showing a nodule with a halo sign. Aspergillus flavus (n = 19/24, 79.2%) was the most commonly isolated species. Initially, patients received liposomal amphotericin B or caspofungin as empiric antifungal therapy, which was then switched to voriconazole once the diagnosis of IA was probable or proven. Eight patients (15.6%) died. Conclusions: Patients with HM presenting with fever and cough should undergo close monitoring for IA. A higher incidence of IA is observed in AML patients, and voriconazole could be considered as antifungal prophylaxis in HM patients. A. flavus is likely the most frequent cause of IA in Iranian patients with HM.

Diagnostic performance of serum galactomannan and β-D-glucan for invasive aspergillosis in suspected patients: A meta-analysis.

Serum galactomannan (GM) and β-D-glucan (BG) are known markers of invasive aspergillosis (IA). The aim of this meta-analysis was to evaluate the efficiency of serum GM and BG as diagnostic markers of symptomatic IA infection and compare the performance of the combined tests with that of either test individually. A literature search was carried out using PubMed, Web of Science, and EMBASE databases to include relevant studies published in English up to May 2023. The quality assessment was performed using Review Manager 5.3 software. A bivariate model was applied to pool diagnostic parameters using Stata 14.0 software. We used Cochrane I2 index to assess heterogeneity and identify the potential source of heterogeneity by meta-regression. Paired t tests were used to compare the value of GM and BG for IA diagnosis when used in combination or alone. Sixteen studies were eligible for inclusion in the meta-analysis. For proven or probable IA, serum GM and BG yielded a pooled sensitivity of 0.53 (95% CI 0.40-0.66) vs 0.72 (95% CI 0.61-0.81) and a pooled specificity of 0.94 (95% CI 0.91-0.97) vs 0.82 (95% CI 0.73-0.88). The area under the curve (AUC) of ROC was 0.90 (95% CI 0.87-0.92) vs 0.83 (95% CI 0.80-0.86) for all studies. The pooled sensitivity and specificity for IA diagnosis by combined GM and BG assays (GM/BG) were 0.84 (95% CI 0.69-0.86) and 0.76 (95% CI 0.69-0.81), respectively. The sensitivity of the combined GM/BG test to diagnose IA was higher than of the GM or BG test alone. Serum GM and BG tests had a relatively high accuracy for IA diagnosis in suspected patients. The diagnostic accuracy of both assays is comparable, and the diagnostic sensitivity is further improved by the combined detection of the 2 markers.

Utility and Drawbacks of Biomarkers in Diagnosis of Invasive Aspergillosis in Critically Ill Patients.

Background: Hematopoietic stem cell transplant recipients, patients with hematological malignancies, and individuals experiencing neutropenia after anti-cancer medication are at high risk of developing invasive aspergillosis (IA). Furthermore, IA is being seen more frequently in different groups of people, including those receiving solid organ transplants, individuals with solid tumors or autoimmune disorders, and patients in intensive care units. High death rates are linked to diagnostic delays. The purpose of this study is to give a summary of the available data regarding the effectiveness of various tests of biomarkers and to talk about their benefits, limitations, and interpretation in a range of patient categories. Methods: We searched the published English language literature using MEDLINE and EMBASE databases from January 2010 to October 2023. All studies about biomarker testing for the diagnosis of IA were included in the review. Results: As valuable supplementary instruments for the early identification of IA, biomarker detection tests may play a part in the diagnosis of IA and tracking treatment response. Nevertheless, there are differences between patient populations and these biomarkers’ sensitivity and specificity are not at their best. So, biomarker testing should be targeted at the right population and the right situation to offer the optional benefit in the approach of IA diagnosis and management. Conclusion: Within the context of various clinical samples (serum, bronchoalveolar lavage fluid, cerebrospinal fluid), as well as distinct patient groups (once-hematological patients, recipients of solid organ transplants, and other patients at risk of IA), this review examines the importance, clinical utility and drawbacks of biomarkers testing for the diagnosis of IA in the critically ill patients.

Detection of Aspergillus Galactomannan in Blood for Early Diagnosis of Pulmonary Aspergillosis in HIV Positive Subjects with and without Tuberculosis in Calabar, Nigeria

This study was aimed at determining the prevalence of pulmonary aspergillosis using Aspergillus galactomannan detection in human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/ AIDS) subjects with and without tuberculosis. The study was a prospective cohort study carried out at the University of Calabar Teaching Hospital and Dr. Lawrence Henshaw Memorial Hospital in Calabar. Subjects were HIV-positive patients with and without tuberculosis. Blood and sputum samples were obtained from 215 subjects who consented to the study. A structured questionnaire was administered to assess demograph¬ic data and medical history. Sputum samples were subjected to direct microscopy, culture, and Ziehl-Nel¬seen test. Aspergillus galactomannan assay and CD4 counts were performed on the blood samples. The results of Aspergillus galactomannan-positive subjects were communicated to the attending Physicians for proper patient management. Aspergillus species were recovered from 35(16.3%) sputum samples. Asper¬gillus fumigatus was the most encountered isolate 18(8.4%). The most common presenting symptoms were cough 35(100%) and fatigue 30(85.7%). Out of the 35 subjects with Aspergillus isolates, 21(60.0%) had TB, 9(25.7%) had no TB and 5(14.3%) had co-morbidity of HIV and TB. All the subjects with aspergillosis had CD4 counts less than 200 cellsμl-1 and there was a statistically significant association between pulmonary aspergillosis and CD4 levels (H=7.02; p = 0.03). Galactomannan assay could be used for early diagnosis of invasive aspergillosis and timely management of patients as it is sensitive, cost-effective, and has a turna¬round time of less than 1 hour compared to culture methods.

Performance of the Aspergillus galactomannan lateral flow assay with a digital reader for the diagnosis of invasive aspergillosis: a multicenter study

PurposeThe objective of this multicenter study was to compare the diagnostic performance of lateral flow assay (LFA) and enzyme-linked immunosorbent assay (ELISA) to detect the Dynamiker Aspergillus Galactomannan levels in serum and bronchoalveolar lavage fluid (BALF) samples for I.MethodsWe registered 310 clinically suspected Aspergillus infection patients from December 2021 to February 2023 and classified them into subgroups as the “IA group” and “non-IA group” based on the latest EORTC/MSG guidelines. The immunoassays were analyzed by LFA and ELISA respectively.ResultsGalactomannan was examined using LFA, and serum and BALF samples demonstrated sensitivities of 82.57% and 89.47%, specificities of 90.76% and 92.00%, PPVs of 89.11% and 96.23%, and NPVs of 85.04% and 79.31%, respectively. Galactomannan was observed using two assays in serum and BALF samples and showed PPAs of 95.11% and 93.33%, NPAs of 89.19% and 96.30%, and TPAs of 92.47% and 94.25%, respectively. The ROC curve demonstrated that LFA had optimum diagnostic value when the index value (I value) = 0.5, the sensitivity was 84.94%, and the specificity was 90.97%.ConclusionCompared to the ELISA method, the LFA has shown excellent performance for the diagnosis of IA in serum and BALF sample and can be used as an assay for the early diagnosis of patients with IA. The dynamic change in galactomannan levels may be useful for assessing treatment response.

Successful treatment of multiple intracerebral aspergillosis with voriconazole alone in an Egyptian diabetic patient with autoimmune hemolytic anemia

Aspergillosis is a common fungus that lives in soil and decaying vegetation. Inhalation of the spores causes infection mostly in immunocompromised patients. Invasive aspergillosis has an extremely high mortality, and a definitive diagnosis requires histopathological evidence of deep tissue invasion or positive culture; however, this evidence is often difficult to obtain due to the critical nature of the patients in these situations. The sensitivity of culture in this setting is also low. The galactomannan test is a recent antigen–antibody serologic test that depends on detecting an antigen which is a molecule found in the cell wall of aspergillus species. A positive result supports the diagnosis of invasive aspergillosis. We present a case of multiple intracerebral brain abscesses in an immunosuppressed patient due to an aspergillus species diagnosed by the galactomannan test with an excellent response to the treatment with the novel voriconazole alone, without any surgical intervention, and the purpose is to alert the physicians, neurologists, and infectious disease specialists to consider the intracranial aspergillosis among the differential diagnosis of the acute onset encephalitis especially in immunocompromised patients as early diagnosis and treatment may be life-saving.

Culture-independent diagnostic approaches for invasive aspergillosis in solid organ transplant recipients.

Prompt and accurate diagnosis of invasive aspergillosis (IA) is crucial for immunocompromised patients, including those who have received a solid organ transplant (SOT). Despite their low sensitivity, microscopic detection and conventional culture are considered the 'gold standard' methods. In conjunction with conventional culture, culture-independent assays such as serum galactomannan testing and Aspergillus polymerase chain reaction (PCR) have been incorporated into the diagnostic process for IA. The recently revised consensus definitions from the European Organization for Research and Treatment of Cancer and the Mycosis Study Group have adjusted the threshold for positive galactomannan testing based on the sample type, and have excluded 1,3-β-D-glucan testing as a mycological criterion. Following extensive standardization efforts, positive Aspergillus PCR tests using serum, plasma, or bronchoalveolar lavage fluid have been added. However, there are limited studies evaluating the clinical utility of these culture-independent assays for the early diagnosis of IA in SOT recipients. Therefore, further research is required to determine whether these assays could aid in the early diagnosis of IA in SOT recipients, particularly in relation to the organ transplanted. In this review, we examine the culture-independent diagnostic methods for IA in SOT recipients, as well as the clinical utility of these assays.

A-368 Aspergillus Galactomannan Lateral Flow Assay with Digital Reader for the Diagnosis of Invasive Aspergillosis

Abstract Background The Novel Aspergillus Galactomannan Lateral Flow Assay(Quic GM) from Dynamiker Biotechnology (Tianjin) Co., Ltd is a fluorescent immunochromatographic cassette test using a monoclonal antibody against GM with Digital Reader (Figure 1), which was rapid and easy to operate compared with the traditional GM ELISA assay. Here we conducte a comparative study between the Dynamiker Quic GM and the Platelia GM (Bio-Rad, USA) to validate the performance of the novel assay for the diagnosis of Invasive Aspergillosis (IA). Methods A total of 573 serum samples and 97 BALF samples with proven IA (Serum n = 9, BALF n = 2), probable IA (Serum n = 174, BALF n = 25), possible IA (Serum n = 98, BALF n = 16) and patients not fulfilling 2019 EORTC/MSG guideline IA criteria (control, Serum n = 292, BALF n = 54) were included. All the samples were tested in parallel using the Quic GM and Platelia GM. Results The total coincidence rate of Quic GM compared with Platelia GM was 97.91% (Kappa value was 0.95 > 0.75), 97.94% (Kappa value was 0.95 > 0.75) and 97.91% (Kappa value was 0.95 > 0.75) in serum samples, BALF samples and serum+BALF samples, respectively (Table 1). The concentrations generated by Quic GM and Platelia GM were linearly correlated (Serum: slope = 0.97, r2 = 0.96, P < 0.0001; BALF: slope = 0.95, r2 = 0.94, P < 0.0001) (Figure 2). Conclusion In conclusion, the Dynamiker Quic GM yielded significant consistency with Bio-Rad Platelia GM ELISA, and showed good performances for IA diagnosis, with the benefit of a relatively short handling time (around 20 min).

An Overview of Systematic Reviews of Polymerase Chain Reaction (PCR) for the Diagnosis of Invasive Aspergillosis in Immunocompromised People: A Report of the Fungal PCR Initiative (FPCRI)-An ISHAM Working Group.

This overview of reviews (i.e., an umbrella review) is designed to reappraise the validity of systematic reviews (SRs) and meta-analyses related to the performance of Aspergillus PCR tests for the diagnosis of invasive aspergillosis in immunocompromised patients. The methodological quality of the SRs was assessed using the AMSTAR-2 checklist; the quality of the evidence (QOE) within each SR was appraised following the GRADE approach. Eight out of 12 SRs were evaluated for qualitative and quantitative assessment. Five SRs evaluated Aspergillus PCR on bronchoalveolar lavage fluid (BAL) and three on blood specimens. The eight SRs included 167 overlapping reports (59 evaluating PCR in blood specimens, and 108 in BAL), based on 107 individual primary studies (98 trials with a cohort design, and 19 with a case-control design). In BAL specimens, the mean sensitivity and specificity ranged from 0.57 to 0.91, and from 0.92 to 0.97, respectively (QOE: very low to low). In blood specimens (whole blood or serum), the mean sensitivity ranged from 0.57 to 0.84, and the mean specificity from 0.58 to 0.95 (QOE: low to moderate). Across studies, only a low proportion of AMSTAR-2 critical domains were unmet (1.8%), demonstrating a high quality of methodological assessment. Conclusions. Based on the overall methodological assessment of the reviews included, on average we can have high confidence in the quality of results generated by the SRs.

Systematic fungal biomarker or polymerase chain reaction testing in lung transplant recipients: Retrospective analysis to optimize their use.

Among lung transplant recipients, serial bronchoscopies are performed frequently. Often, serial galactomannan (GM), 1,3-β-d-glucan (BDG), and Pneumocystis jirovecii (PJ) testing is performed with these broncho-alveolar lavages (BALs) as standard of care with limited data to support their routine use. After Institutional Review Board approval, we retrospectively collected all blood and BAL GM, BDG, and PJ test results from January 2015 to July 20, 2022. Primary data collection from the Northwestern Medicine EDW was supplemented by manual chart review. During the study period, 236 lung transplant recipients were cared for by our center. Of these patients, 217 (91.9%) had 1418 GM tests performed; 61 (4.3%) were positive (index ≥1). Fungal cultures were requested for most BAL-GM (90.7%). Out of duplicates in same BAL, results discrepancy was minimal (3.4%). 172 (72.9%) had BDG tests were performed; 25.6% were positive. Thirteen patients had multiple BDG during one hospitalization (mean 2.3 tests); none of the negative test repeated became positive. Eleven negative BDG were seen in patients with invasive aspergillosis (IA). Note that, 577 PJ testing were performed (direct fluorescent antibody [n = 494] or polymerase chain reaction [PCR] [n = 80], or both [n = 3]) in 174 different patients. None were positive. Despite supplemental GM, BDG, and Pneumocystis jirovecii pneumonia PCR being performed routinely on lung transplant recipients undergoing BAL at our center, the data suggests a more tailored approach may be appropriate. There is no role for routine serial testing with these assays during a single hospitalization. BDG confers no added-value over GM with cultures for IA diagnosis.

Galactomannan as a Diagnostic Test for Invasive Pulmonary Aspergillosis in a Patient with Primary Immunodeficiency: Case Report

Introduction: Aspergillosis continues to be the most frequent fungal infection in the hematopoietic stem cell transplanted patient, however, in other types of immunocompromised states, such as primary immunodeficiencies, are scarce. Therefore, many times the diagnosis of invasive aspergillosis is often a diagnostic challenge for the clinician, so we highlight the usefulness of galactomannan in immunocompromised patients for the diagnosis of aspergillosis. Background: Invasive aspergillosis together with chronic pulmonary aspergillosis and allergic bronchopulmonary aspergillosis, constitute the clinical forms of aspergillosis. Aspergillus fumigatus-complex is the most frequent etiological agent, the increase in immunosuppressive treatments and the greater use of corticoids have led to a greater prominence of aspergillosis in recent years. The use of galactomannan and imaging tests complement the microbiological limitations in the diagnosis of these patients, the mortality of invasive forms depends on the clinical form and the type of host. Objective: To demonstrate the importance of galactomannan as a noninvasive diagnostic test for invasive pulmonary aspergillosis, in centers with limited resources where it is not possible to perform a histopathological study. Case presentation: We present the case of an 18-year-old male patient with immunodeficiency due to T lymphocyte immunoregulation dysfunction, who developed invasive pulmonary aspergillosis with a positive galactomannan test. Conclusions: Our case report reflects the diagnosis of ante-mortem invasive pulmonary aspergillosis in an adult patient with primary T-lymphocyte immunodeficiency, non-neutropenic, in whom a histopathological study to optimize the diagnosis was not possible, and whose only tool we had was the measurement of GM. Abbreviations: GM= Galactomannan

Superior Accuracy of Aspergillus Plasma Cell-Free DNA Polymerase Chain Reaction Over Serum Galactomannan for the Diagnosis of Invasive Aspergillosis.

Invasive aspergillosis (IA) in immunocompromised hosts carries high morbidity and mortality. Diagnosis is often delayed because definitive diagnosis requires invasive specimen collection, while noninvasive testing with galactomannan is moderately accurate. Plasma cell-free DNA polymerase chain reaction (cfDNA PCR) represents a novel testing modality for the noninvasive diagnosis of invasive fungal disease (IFD). We directly compared the performance of Aspergillus plasma cfDNA PCR with serum galactomannan for the diagnosis of IA during routine clinical practice. We conducted a retrospective study of all patients with suspected IFD who had Aspergillus plasma cfDNA PCR testing at Stanford Health Care from 1 September 2020 to 30 October 2022. Patients were categorized into proven, probable, possible, and no IA based on the EORTC/MSG definitions. Primary outcomes included the clinical sensitivity and specificity for Aspergillus plasma cfDNA PCR and galactomannan. Overall, 238 unique patients with Aspergillus plasma cfDNA PCR test results, including 63 positives and 175 nonconsecutive negatives, were included in this study. The majority were immunosuppressed (89.9%) with 22.3% 30-day all-cause mortality. The overall sensitivity and specificity of Aspergillus plasma cfDNA PCR were 86.0% (37 of 43; 95% confidence interval [CI], 72.7-95.7) and 93.1% (121 of 130; 95% CI, 87.4-96.3), respectively. The sensitivity and specificity of serum galactomannan in hematologic malignancies/stem cell transplants were 67.9% (19 of 28; 95% CI, 49.3-82.1) and 89.8% (53 of 59; 95% CI, 79.5-95.3), respectively. The sensitivity of cfDNA PCR was 93.0% (40 of 43; 95% CI, 80.9-98.5) in patients with a new diagnosis of IA. Aspergillus plasma cfDNA PCR represents a more sensitive alternative to serum galactomannan for noninvasive diagnosis of IA.

Clinical Accuracy and Utility of Plasma Microbial Cell-Free DNA Whole-Genome Sequencing for the Diagnosis of Invasive Aspergillosis in Patients with Hematologic Malignancies or Coronavirus Disease 2019.

We evaluated the clinical accuracy and utility of whole-genome sequencing (WGS) of plasma microbial cell-free DNA (cfDNA) as a novel non-invasive method in diagnosing invasive aspergillosis (IA) in patients with hematologic malignancy (HM) or coronavirus disease 2019 (COVID-19). Adults with HM or COVID-19 and suspected IA were recruited. IA cases were retrospectively diagnosed according to EORTC/MSG definitions and ECMM/ISHAM criteria for HM and COVID-19 patients, respectively. The results of cfDNA WGS were compared with the conventional diagnosis. Microbial cfDNA WGS was performed 53 times from 41 participants (19 from HM, 16 from COVID-19, and 7 from the control group). In participants with HM, Aspergillus cfDNA was detected in 100% of proven IA and 91.7% of probable IA cases. In participants with COVID-19, 50.0% of probable IA were positive for Aspergillus in cfDNA WGS. Concordance between Aspergillus cfDNA detection and proven/probable IA conventional diagnosis was significantly higher in participants with HM than in those with COVID-19. IA diagnosed using EORTC/MGS definitions showed significantly high concordance between Aspergillus cfDNA detection and proven/probable IA. Aspergillus cfDNA detection strongly correlated with proven/probable IA diagnosed using EORTC/MSG definitions and could be used as an additional diagnostic tool for IA.

The Novel Monoclonal IgG1-Antibody AB90-E8 as a Diagnostic Tool to Rapidly Distinguish Aspergillus fumigatus from Other Human Pathogenic Aspergillus Species.

In most cases, invasive aspergillosis (IA) is caused by A. fumigatus, though infections with other Aspergillus spp. with lower susceptibilities to amphotericin B (AmB) gain ground. A. terreus, for instance, is the second leading cause of IA in humans and of serious concern because of its high propensity to disseminate and its in vitro and in vivo resistance to AmB. An early differentiation between A. fumigatus and non-A. fumigatus infections could swiftly recognize a potentially ineffective treatment with AmB and lead to the lifesaving change to a more appropriate drug regime in high-risk patients. In this study, we present the characteristics of the monoclonal IgG1-antibody AB90-E8 that specifically recognizes a surface antigen of A. fumigatus and the closely related, but not human pathogenic A. fischeri. We show immunostainings on fresh frozen sections as well as on incipient mycelium picked from agar plates with tweezers or by using the expeditious tape mount technique. All three methods have a time advantage over the common procedures currently used in the routine diagnosis of IA and outline the potential of AB90-E8 as a rapid diagnostic tool.

Implementation of Lateral Flow Assays for the Diagnosis of Invasive Aspergillosis in European Hospitals: A Survey from Belgium and a Literature Review of Test Performances in Different Patient Populations.

Diagnosis of invasive aspergillosis is based on a combination of criteria, of which the detection of Aspergillus galactomannan (GM) often is decisive. To date, the most commonly used method to determine GM is an enzyme-linked immune assay (EIA). But since a few years lateral flow assays (LFAs) were introduced, providing the possibility for rapid single sample testing. More and more LFAs are entering the market, but, although often being equated, all use their own antibodies, procedures and interpretation criteria. A recent European survey revealed that about 24-33% of laboratories implemented a lateral flow assay on-site. We conducted a survey at 81 Belgian hospital laboratories regarding the implementation of LFAs in their centre. In addition, we performed an extensive review of all publicly available studies on the performance of lateral flow assays to diagnose invasive aspergillosis. Response rate to the survey was 69%. Of the 56 responding hospital laboratories, 6 (11%) used an LFA. The Soña Aspergillus galactomannan LFA (IMMY, Norman, Oklahoma, USA) was used in 4/6 centres, while two centres used the QuicGM (Dynamiker, Tianjin, China) and one centre used the FungiXpert Aspergillus Galactomannan Detection K-set LFA (Genobio [Era Biology Technology], Tianjin, China). One centre used 2 distinct LFAs. In 3/6 centres, the sample is sent to another lab for confirmation with GM-EIA when the LFA result is positive and in 2/6 when the LFA results is negative. In one centre, a confirmatory GM-EIA is always performed in house. In three centres the LFA result is used as a complete substitute for GM-EIA. Available LFA performance studies are very diverse and results vary in function of the study population and type of LFA. Apart from the IMMY and OLM LFA, only very limited performance data are available. From two out of three LFAs used in Belgium, no clinical performance studies are published in literature. A large variety of LFAs are used in Belgian Hospitals, some of which no clinical validation studies are published. These results do likely have implications for other parts of Europe and for the rest of the world as well. Due to the variable performance of LFA tests and the limited validation data available, each laboratory must check the available performance information of the specific test considered for implementation. In addition, laboratories should perform an implementation verification study.