Evaluation of the Dynamiker® Fungus (1-3)-ß-D-Glucan Assay for the Diagnosis of Invasive Aspergillosis in High-Risk Patients with Hematologic Malignancies.

INTRODUCTION: The Dynamiker® Fungus (1-3)-ß-D-glucan assay (DFA) allows the testing of samples in smaller batches compared to the well-established Fungitell® assay (FA) making the assay cost-effective in centers with small numbers of samples. Evaluations of its performance for the diagnosis of invasive aspergillosis (IA) are limited. Therefore, we compared the two assays and evaluated their clinical performance in diagnosing IA. METHODS: A total of 60 adult hematology patients were screened for IA, 13 with probable IA, 19 with possible IA, and 28 with no IA. Serum specimens (n = 166) were collected twice-weekly and tested for (1-3)-ß-D-glucan (BDG) using FA and DFA which were compared quantitatively with Spearman rank correlation analysis and qualitatively with the Chi-square test. Agreement and error rates were determined using FA as the reference method. Sensitivity, specificity, and positive predictive and negative predictive values in diagnosing IA were calculated. RESULTS: The performance of the DFA was highly consistent with that of the FA, both quantitatively (rs = 0.913) and qualitatively (kappa = 0.725). The agreement was 85% with 8% minor, no major, and 7% very major errors (FA+/DFA-). Using a cut-off value of 20 pg/mL for DFA, very major errors were reduced to 1%, although 5% major errors were detected. BDG levels were lower with DFA than FA (slope 0.653 ± 0.031). Sensitivity, specificity, positive predictive value, and negative predictive value (NPV) was 67%, 53%, 44%, and 74% for FA, and 53%, 67%, 49%, and 71% for DFA, respectively. The optimal BDG positivity threshold calculated did not lead to significant test quality improvement for either assay. However, a higher % of patients with probable IA (62%) had ≥ 2 consecutive positive specimens compared to patients with no IA (FA-BDG 26%, p = 0.10, and DFA-BDG 10%, p = 0.01) leading to improved sensitivity and NPV (71% and 85% for DFA, and 95% and 96% for FA, respectively). CONCLUSION: DFA could be a valuable alternative to the FA, particularly in laboratories with small numbers of samples. The results of the BDG testing should be carefully interpreted in the high-risk setting of patients with hematologic malignancies. Higher NPV was found using as criterion ≥ 2 consecutive positive samples for diagnosing IA.

A Prospective Multicenter Cohort Surveillance Study of Invasive Aspergillosis in Patients with Hematologic Malignancies in Greece: Impact of the Revised EORTC/MSGERC 2020 Criteria.

Data concerning the incidence of invasive aspergillosis (IA) in high-risk patients in Greece are scarce, while the impact of the revised 2020 EORTC/MSGERC consensus criteria definitions on the reported incidence rate of IA remains unknown. A total of 93 adult hematology patients were screened for IA for six months in four tertiary care Greek hospitals. Serial serum specimens (n = 240) the sample was considered negative by PCR were collected twice-weekly and tested for galactomannan (GM) and Aspergillus DNA (PCR) detection. IA was defined according to both the 2008 EORTC/MSG and the 2020 EORTC/MSGERC consensus criteria. Based on the 2008 EORTC/MSG criteria, the incidence rates of probable and possible IA was 9/93 (10%) and 24/93 (26%), respectively, while no proven IA was documented. Acute myeloid leukemia was the most (67%) common underlying disease with most (82%) patients being on antifungal prophylaxis/treatment. Based on the new 2020 EORTC/MSGERC criteria, 2/9 (22%) of probable and 1/24 (4%) of possible cases should be reclassified as possible and probable, respectively. The episodes of probable IA were reduced by 33% when GM alone and 11% when GM + PCR were used as mycological criterion. The incidence rate of IA in hematology patients was 10%. Application of the 2020 EORTC/MSGERC updated criteria results in a reduction in the classification of probable IA particularly when PCR is not available.

Performance, Correlation and Kinetic Profile of Circulating Serum Fungal Biomarkers of Invasive Aspergillosis in High-Risk Patients with Hematologic Malignancies.

As conventional microbiological documentation of invasive aspergillosis (IA) is difficult to obtain, serum fungal biomarkers are important adjunctive diagnostic tools. Positivity rates and the kinetic profiles of galactomannan (GM), 1,3-ß-D-glucan (BDG) and Aspergillus DNA (PCR) were studied in high-risk patients with hematologic malignancies. GM, BDG and PCR data from serial serum specimens (n = 240) from 93 adult hematology patients with probable (n = 8), possible (n = 25) and no (n = 60) IA were retrospectively analyzed. Positivity rates and sensitivity/specificity/positive/negative predictive values (NPV) of each fungal biomarker alone and in combination were estimated. The three markers were compared head-to-head and correlated with various biochemical, demographic and patient characteristics. The positivity rates for patients with probable/possible/no IA were 88%/8%/0% for GM (X2 = 55, p < 0.001), 62%/46%/35% for BDG (X2 = 2.5, p = 0.29), 62%/33%/27% for PCR (X2 = 3.9, p = 0.15), 50%/4%/0% for GM + BDG and GM + PCR (X2 = 31, p < 0.001), 50%/8%/22% for BDG + PCR (X2 = 6.5, p = 0.038) and 38%/4%/0% for GM + BDG + PCR (X2 = 21, p < 0.001). Higher agreement (76%) and negative correlation (rs = -0.47, p = 0.0017) was found between GM index and PCR Ct values. The sensitivity and NPV was 45-55% and 90-92% when biomarkers assessed alone and increased to 75-90% and 93-97%, respectively when combined. Weak significant correlations were found between GM, PCR and BDG results with renal/liver function markers (r = 0.11-0.57) with most GM+ and PCR+ samples found in the first and second week of clinical assessment, respectively and BDG later on. Different positivity rates, time profiles and performances were found for the three biomarkers advocating the combination of GM with PCR for the early diagnosis of IA, whereas the high NPV of combined biomarkerscould help excluding IA.

Impact of a non-compulsory antifungal stewardship program on overuse and misuse of antifungal agents in a tertiary care hospital.

OBJECTIVES: To assess the impact of an antifungal stewardship (AFS) program on appropriate use, consumption and acquisition costs of antifungals, and on clinical outcomes (in-hospital-mortality, in-hospital-length-of-stay). METHODS: The study was conducted at a 535-bed tertiary-care hospital and had three consecutive periods. A) Observational period (10 months): all antifungal prescriptions were prospectively evaluated. B) Educational intervention to increase the awareness on proper antifungals use. C) Implementation of a non-compulsory AFS program (10 months) based on prospective audit and feedback. Interrupted time series analysis has been used to assess the impact of the intervention. RESULTS: During the pre-interventional period 198 AF prescriptions for 147 patients, have been evaluated compared to 181 prescriptions in 138 patients during the AFS period. Statistical analysis showed a significant immediate drop of inappropriate prescriptions after intervention with a significantly declining trend thereafter, and a significant drop of the total consumption of antifungals immediately after the intervention with a significant declining trend thereafter. All-cause, in-hospital- mortality was stable during the pre-intervention period with a significant declining trend after the AFS program implementation, although no immediate intervention effect could be established. Comparison of pre-and post-interventional periods showed significant reduction in acquisition costs (-26.8%, p<0.001) but no difference regarding the total number of bed-days (107,654 vs. 102,382), and mean length of hospital-stay (5.19 vs. 4.96 days, p=NS). CONCLUSIONS: The implementation of a non-compulsory AFS program resulted in significant improvement in the quality of prescriptions and reduction in antifungals consumption and acquisitions costs, without affecting the overall in-hospital-mortality and mean in-hospital-length-of-stay.