scholarly journals Efficacy of the new β-D-glucan measurement kit for diagnosing invasive fungal infections, as compared with that of four conventional kits

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255172
Author(s):  
Yuuki Bamba ◽  
Kei Nagano ◽  
Hiroshi Moro ◽  
Hideyuki Ogata ◽  
Mariko Hakamata ◽  
...  
Keyword(s):  
Measurement Method ◽  
Diagnostic Performance ◽  
Fungal Infections ◽  
Pneumocystis Pneumonia ◽  
Invasive Fungal Infections ◽  
Clinical Samples ◽  
Clinical Diagnoses ◽  
European Regulations ◽  
Pre Treatment ◽  
Positive Results

Background Each of the currently available (1→3)-β-D-glucan (BDG) measurement kits follows a different measurement method and cut-off value. Comparisons of diagnostic performance for invasive fungal infections (IFIs) are desirable. Additionally, ecological considerations are becoming increasingly important in the development of new measurement kits. Methods The plasma BDG levels in clinical samples were measured using the following currently available kits: the Fungitec G test MKII, the Fungitec G test ES, Fungitell, the β-Glucan test Wako, and the newly developed Wako kit (Wako-Eu). Wako-Eu uses a pre-treatment solution that conforms to European regulations for the registration, evaluation, authorisation, and restriction of chemicals. The values obtained for the samples using each kit were studied and compared. Results Of the 165 patients evaluated, 12 had IFIs, including pneumocystis pneumonia, aspergillosis, and candidiasis. BDG values obtained using the kits were moderately correlated with each other. Clinical diagnoses of the evaluated cases indicated that 21 false positives were diagnosed by at least one kit. The sensitivity of the Fungitell kit was relatively low, but those of the other four were over 90%. The specificity was above 90% for all kits. For positive predictive value, the Wako and the Wako-Eu methods were superior to the others owing to fewer false positive results. Conclusions The newly developed Wako-Eu method, which considers ecological concerns, shows diagnostic performance equivalent to that of its predecessor. To improve the diagnostic accuracy of IFIs, it is necessary to interpret the results carefully, giving due consideration to the characteristics of each measurement kit.

scholarly journals Comparative performance and cycle threshold values of 10 nucleic acid amplification tests for SARS-CoV-2 on clinical samples

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252757
Author(s):  
Miyuki Mizoguchi ◽  
Sohei Harada ◽  
Koh Okamoto ◽  
Yoshimi Higurashi ◽  
Mahoko Ikeda ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Diagnostic Performance ◽  
Nucleic Acid Amplification ◽  
Clinical Samples ◽  
Nucleic Acid Amplification Tests ◽  
Cycle Threshold ◽  
E Gene ◽  
Viral Copy Number ◽  
Gene Test ◽  
Positive Results

Background A number of nucleic acid amplification tests (NAATs) for SARS-CoV-2 with different reagents have been approved for clinical use in Japan. These include research kits approved under emergency use authorization through simplified process to stabilize the supply of the reagents. Although these research kits have been increasingly used in clinical practice, limited data is available for the diagnostic performance in clinical settings. Methods We compared sensitivity, specificity, and cycle threshold (Ct) values obtained by NAATs using 10 kits approved in Japan including eight kits those receiving emergency use authorization using 69 frozen-stored clinical samples including 23 positive samples with various Ct values and 46 negative samples. Results Viral copy number of the frozen-stored samples determined with LightMix E-gene test ranged from 0.6 to 84521.1 copies/μL. While no false-positive results were obtained by any of these tests (specificity: 100% [95% CI, 88.9%-100%]), sensitivity of the nine tests ranged from 68.2% [95% CI, 45.1%-86.1%] to 95.5% [95% CI, 77.2%-99.9%] using LightMix E-gene test as the gold standard. All tests showed positive results for all samples with ≥100 copies/μL. Significant difference of Ct values even among tests amplifying the same genetic region (N1-CDC, N2) was also observed. Conclusion Difference in the diagnostic performance was observed among NAATs approved in Japan. Regarding diagnostic kits for emerging infectious diseases, a system is needed to ensure both rapidity of reagent supply and accuracy of diagnosis. Ct values, which are sometimes regarded as a marker of infectivity, are not interchangeable when obtained by different assays.

scholarly journals Multiplex PCR Based Strategy for Detection of Fungal Pathogen DNA in Patients with Suspected Invasive Fungal Infections

2020 ◽  
Vol 6 (4) ◽  
pp. 308
Author(s):  
Joana Carvalho-Pereira ◽  
Filipa Fernandes ◽  
Ricardo Araújo ◽  
Jan Springer ◽  
Juergen Loeffler ◽  
...  
Keyword(s):  
Fungal Infections ◽  
Fungal Species ◽  
Cross Reactivity ◽  
Invasive Fungal Infections ◽  
Clinical Samples ◽  
Correct Identification ◽  
Colony Pcr ◽  
Pcr Multiplex ◽  
Pathogen Dna ◽  
Species Specific

A new and easy polymerase chain reaction (PCR) multiplex strategy, for the identification of the most common fungal species involved in invasive fungal infections (IFI) was developed in this work. Two panels with species-specific markers were designed, the Candida Panel for the identification of Candida species, and the Filamentous Fungi Panel for the identification of Aspergillus species and Rhizopusarrhizus. The method allowed the correct identification of all targeted pathogens using extracted DNA or by colony PCR, showed no cross-reactivity with nontargeted species and allowed identification of different species in mixed infections. Sensitivity reached 10 to 1 pg of DNA and was suitable for clinical samples from sterile sites, with a sensitivity of 89% and specificity of 100%. Overall, the study showed that the new method is suitable for the identification of the ten most important fungal species involved in IFI, not only from positive blood cultures but also from clinical samples from sterile sites. The method provides a unique characteristic, of seeing the peak in the specific region of the panel with the correct fluorescence dye, that aids the ruling out of unspecific amplifications. Furthermore, the panels can be further customized, selecting markers for different species and/or resistance genes.

scholarly journals 1701. Differences in Diagnostic Performance of β-d-Glucan Testing in Patients with Varying Degrees of Susceptibility to Invasive Fungal Infections

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S623-S623
Author(s):  
Eliel Nham ◽  
Si-Ho Kim ◽  
Hyunjoo Lee ◽  
Jae-Hoon Ko ◽  
Kyungmin Huh ◽  
...  
Keyword(s):  
Risk Factors ◽  
High Risk ◽  
Diagnostic Performance ◽  
Fungal Infections ◽  
Pneumocystis Pneumonia ◽  
Host Factors ◽  
European Organization ◽  
High Risk Patients ◽  
Risk Patients ◽  
Group A

Abstract Background Usefulness of β-d-glucan (BDG) testing in high-risk patients for invasive fungal infection (IFI) diagnosis has been well demonstrated. However, data on its usefulness in patients without risk factors are limited. We evaluated differences in the diagnostic performance of BDG testing in patients with varying degrees of susceptibility to IFI. Methods From April 2017 to May 2018, all consecutive patients (≥18year-old) who were performed BDG testing (Beijing Gold Mountainriver Tech) were enrolled. Patients were classified into three groups: Group A for patients with host factors defined by 2008 European Organization for Research and Treatment of Cancer-Mycoses Study Group diagnostic (EORTC-MSG) criteria, Group B for patients with malignancy receiving recent chemotherapy within 1 month without host factors, and Group C for others. Cases of proven and probable IFI defined by EORTC-MSG criteria, Pneumocystis pneumonia and all fungemia were considered as true IFIs. Sensitivity, specificity, positive and negative predictive value (PPV and NPV) were calculated with a cut-off value for positivity ≥80 pg/mL. Results Among 473 eligible patients, 190, 142, and 141 patients were classified into group A, B, and C, respectively. Rates of true IFI were significantly different in each group (57/190, 19/142, and 10/141 in each group, P < 0.001). Sensitivities were 0.83, 0.68, and 0.70 and specificities were 0.62, 0.59, and 0.63 in group A, B, and C, respectively. PPVs were considerably different among three groups (PPV for 0.48, 0.20, and 0.12; NPV for 0.89, 0.92 and 0.97 in each group, respectively). Conclusion The BDG test is a useful assay for IFI diagnosis; however, the clinical interpretation should be different by patient risks. Whereas BDG testing could be considered as a tool for predicting IFI in high-risk patients, it only could be a tool for excluding IFI in patient without risk factors. Disclosures All authors: No reported disclosures.

scholarly journals New Panfungal Real-Time PCR Assay for Diagnosis of Invasive Fungal Infections

2016 ◽  
Vol 54 (12) ◽  
pp. 2910-2918 ◽  
Author(s):  
Clara Valero ◽  
Laura de la Cruz-Villar ◽  
Óscar Zaragoza ◽  
María José Buitrago
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Fungal Infections ◽  
Melting Curve ◽  
Fungal Species ◽  
Invasive Fungal Infections ◽  
Clinical Samples ◽  
Melting Curve Analysis ◽  
Pcr Assay ◽  
Suitable Alternative

The diagnosis of invasive fungal infections (IFIs) is usually based on the isolation of the fungus in culture and histopathological techniques. However, these methods have many limitations often delaying the definitive diagnosis. In recent years, molecular diagnostics methods have emerged as a suitable alternative for IFI diagnosis. When there is not a clear suspicion of the fungus involved in the IFI, panfungal real-time PCR assays have been used, allowing amplification of any fungal DNA. However, this approach requires subsequent amplicon sequencing to identify the fungal species involved, increasing response time. In this work, a new panfungal real-time PCR assay using the combination of an intercalating dye and sequence-specific probes was developed. After DNA amplification, a melting curve analysis was also performed. The technique was standardized by using 11 different fungal species and validated in 60 clinical samples from patients with proven and probable IFI. A melting curve database was constructed by collecting those melting curves obtained from fungal species included in the standardization assay. Results showed high reproducibility (coefficient of variation [CV] < 5%; r > 0.95) and specificity (100%). The overall sensitivity of the technique was 83.3%, with the group of fungi involved in the infection detected in 77.8% of the positive samples with IFIs covered by molecular beacon probes. Moreover, sequencing was avoided in 67.8% of these “probe-positive” results, enabling report of a positive result in 24 h. This technique is fast, sensitive, and specific and promises to be useful for improving early diagnosis of IFIs.

scholarly journals Clinical evaluation of an in-house panfungal real-time PCR assay for the detection of fungal pathogens

Infection ◽  
2020 ◽  
Vol 48 (3) ◽  
pp. 345-355 ◽  
Author(s):  
Iris Camp ◽  
Gabriele Manhart ◽  
Claudia Schabereiter-Gurtner ◽  
Kathrin Spettel ◽  
Brigitte Selitsch ◽  
...  
Keyword(s):  
Clinical Evaluation ◽  
Fungal Pathogens ◽  
Fungal Infections ◽  
Wide Spectrum ◽  
Invasive Fungal Infections ◽  
Diagnostic Tools ◽  
Clinical Samples ◽  
Pcr Assay ◽  
Blood Samples ◽  
Panfungal Pcr

Abstract Purpose Due to an increasing incidence of invasive fungal infections, the availability of reliable diagnostic tools for the fast detection of a wide spectrum of fungal pathogens is of vital importance. In this study, we aimed to conduct an extensive clinical evaluation of a recently published in-house panfungal PCR assay on samples from suspected invasive fungal infections. Methods Overall 265 clinical samples from 232 patients with suspected invasive fungal disease (96 deep airway samples, 60 sterile fluids, 50 tissue biopsies, and 59 blood samples) were included. All samples underwent standard culture-based diagnostics and were additionally analyzed with our panfungal PCR assay. Results Overall, 55.1% of agreement between culture and the panfungal PCR was observed; in 17% of all samples partial concordance was noted, while results between culture and our PCR assay were not in agreement in 27.9%. Our panfungal assay performed better in samples from normally sterile sites, while samples from the deep airways yielded the highest rate of discordant (39.6%) results. In two tissue and three blood samples an invasive pathogen was only detected by PCR while cultures remained negative. Conclusion In combination with routine methods, our panfungal PCR assay is a valuable diagnostic tool. Patients at risk for invasive fungal infections might profit from the reduced time to pathogen identification.

scholarly journals Difficulties in using 1,3-β-d-glucan as the screening test for the early diagnosis of invasive fungal infections in patients with haematological malignancies – high frequency of false-positive results and their analysis

2010 ◽  
Vol 59 (9) ◽  
pp. 1016-1022 ◽  
Author(s):  
Zdenek Racil ◽  
Iva Kocmanova ◽  
Martina Lengerova ◽  
Barbora Weinbergerova ◽  
Lucie Buresova ◽  
...  
Keyword(s):  
Fungal Infections ◽  
Screening Method ◽  
Invasive Fungal Infections ◽  
Haematological Malignancies ◽  
Serum Samples ◽  
Assay Performance ◽  
Patients At Risk ◽  
Anticancer Treatment ◽  
Positive Results ◽  
Limited Usefulness

We have evaluated the contribution of the 1,3-β-d-glucan (BG) assay for the screening of invasive fungal infections (IFIs) in patients with haematological malignancies. Serum samples from patients at risk of IFI were collected twice a week and retrospectively tested using the BG assay. BG screening was performed on 1143 samples from 91 patients during 104 anticancer treatment cycles. Proven and probable cases of IFI occurred in 9 (8.7 %) treatment cycles. Depending on the criterion of positivity used (1× >60 pg ml−1, 1× >80 pg ml−1, 2× >60 pg ml−1 or 2× >80 pg ml−1) the sensitivity and specificity were 89, 89, 67 and 44 %, and 20, 48, 33 and 56 %, respectively. Although the test was marked as positive in 82, 68, 54 and 45 % of all the treatment cycles, in the majority of cases, these positivities were probably false. The major limit of the BG test was an extremely low positive predictive value (10 to 12 %). We have analysed mucositis, candida colonization, bacteraemia, use of antimicrobials, erythrocyte and thrombocyte filtered blood products, collecting tubes or sampling via venous catheters. Even though no factor is a major source of BG, it could at least partially influence BG assay performance. Thus, BG detection has a limited usefulness as a screening method for IFIs in patients with haematological malignancies.

Sign in / Sign up

Export Citation Format

Share Document