MUCORALES POLYMERASE CHAIN REACTION TESTING IN IMMUNOCOMPROMISED PATIENTS: ASSESSING THE PREVALENCE OF MUCORMYCOSIS IN A HIGH-RISK POPULATION
Study overview
This is a retrospective, non-interventional, observation study among different tertiary care centers in Europe.
The study investigates the epidemiology of mucormycosis in patients considered to be at risk for invasive fungal diseases (IFD) by assessing routinely collected bronchoalveolar lavage fluid (BALF), blood, urine samples and biopsies for presence of Mucorales DNA. For assessing the prevalence of mucormycosis and Mucorales species distribution, all samples that have been collected from patients at risk for IFD as part of clinical routine work-up and stored at -80°C within the last 10 years at the Medical University of Graz, Division of Infectious Diseases will be tested for Mucorales PCR with the MucorGenius® real-time polymerase chain reaction (RT- PCR) assay (Pathonostics®, Maastrich, The Netherlands). In addition, selected samples from patients with mucormycosis will be retrospectively collected at the Medical University in Graz and samples from patients with mucormycosis will be provided by the ECMM Fungal Diagnostics Consortium.
The MucorGenius® RT-PCR assay is commercially available, IVD approved and targets a pan-mucormycetes target. In addition, the assay can differentiate among the most abundant Mucorales species.
In total, approximately 2,200 samples from 1,500 individual patients will be evaluated within this study.
Co-Principal Investigator (PIs)
Priv.-Doz. Dr. Dr. Juergen Prattes, FECMM
Assoc.-Prof. Priv.-Doz. Dr. Martin Hoenigl, FECMM
Medical University of Graz
Department of Internal Medicine
Division of Infectious Diseases
Auenbruggerplatz 15
8036 Graz, Austria
Investigators
Dr. med. Karl Dichtl
Dr. med. univ. Matthias Egger
Univ.-Prof. Dr. Harald Kessler
International Collaborators via the ECMM Fungal Diagnostics Consortium
Dr. Robina Aerts, UZ Leuven, Belgium
Prof. Dr. Johan Maertens, UZ Leuven, Belgium
Prof. Dr. Joost Wauters, UZ Leuven, Belgium
Prof. Katrien Lagrou, UZ Leuven, Belgium
Dr. Yuri Vanbiervliet, UZ Leuven, Belgium
Dr. Eelco Meijer, Nijmegen/Westerdijk, Netherlands
Prof. Silke Schelenz, Kings College, London
Priv.-Doz. Dr. med. Philipp Koehler, Cologne, Germany
Rationale
Detailed data on the prevalence of mucormycosis in patients at risk for IFDs are needed to develop adequate local management strategies for this devastating infection. Currently available diagnostic approaches are limited to conventional culture and sequencing methods. Both come with several limitations, making clinical application difficult.
The newly introduced Mucorales PCR approach may significantly increase our diagnostic capacities and give us a solid overview of the prevalence of this disease.
Primary objective
To evaluate the period prevalence of mucormycosis in patients routinely tested for pulmonary fungal infections by applying revised 2019 EORTC/MSGERC consensus definitions criteria (adding of MucorGenius® results as mycological criterion)
Secondary objectives
To evaluate the frequency of mixed-mold infections (including mucormycosis) in patients routinely tested for pulmonary fungal infections
To evaluate the distribution of Mucorales species causing mucormycosis in patients with different baseline characteristics routinely tested for pulmonary fungal infections
To evaluate the diagnostic performance of the MucorGenius® RT-PCR in routinely collected bronchoalveolar lavage fluid (BALF) from patients at risk for IFDs
To evaluate the diagnostic performance of MucorGenius® RT-PCR in other routinely collected specimen (e.g., blood, urine, biopsies, etc.) obtained from patients at risk for IFDs
Exploratory objectives
To evaluate the correlation of fungal burden assessed by MucorGenius® RT-PCR and mucormycosis attributed mortality
To evaluate the correlation of fungal burden assessed by MucorGenius® RT-PCR in BALF, blood and urine samples
To evaluate the impact of MucorGenius® RT-PCR results on epidemiology of IFDs
To evaluate the burden of Mucorales DNA in patients with proven/probable mucormycosis and/or with a positive MucorGenius® RT-PCR result
To correlate results of the MucorGenius® RT-PCR with composition of the respiratory mycobiome
Primary end point
Period prevalence of proven and probable mucormycosis according to the revised 2019 EORTC/MSGERC and FUNDICU consensus definitions, as applicable, at day 90 after routine sampling of the corresponding samples
Secondary end points
Period prevalence of mixed mold infections (mucormycosis plus a second pulmonary mold infection) at day 90 after routine sampling of the corresponding samples
Percentage of different Mucorales species causing proven or probable mucormycosis at day 90 after routine sampling of the corresponding samples
Sensitivity, specificity, positive predictive value and negative predictive value of the MucorGenius® RT-PCR in BALF for diagnosing proven or probable mucormycosis according to the EORTC/MSGERC consensus definitions (exclusion of MucorGenius® as diagnostic criterion)
Sensitivity, specificity, positive predictive value and negative predictive value of the MucorGenius® RT-PCR in other routinely collected specimen (e.g., blood, urine, biopsies, etc.) for diagnosing proven or probable mucormycosis according to the EORTC/MSGERC consensus definitions (exclusion of MucorGenius® as diagnostic criterion)
Exploratory end points
Mucormycosis attributed mortality rate 90 days after diagnosis of mucormycosis in patients with high- and low fungal burden, assessed by MucorGenius® RT-PCR
Correlation of fungal burden in different specimens
Number of patients that are re-classified when applying the revised EORTC/MSGERC consensus definitions
Absolute and relative change of fungal burden in patients with proven/probable mucormycosis and/or with a positive MucorGenius® RT-PCR result
Correlation of composition of the respiratory mycobiome with MucorGenius® RT-PCR results
Investigational device
MucorGenius® RT-PCR assay
The MucorGenius® PCR assay (PathoNostics®, Maastricht, The Netherlands) represents the first commercially available real-time PCR assay that was designed to target the 28S rRNA gene from Rhizopus spp., Mucor spp., Lichtheimia spp., Cunninghamella spp., and Rhizomucor spp.; the leading pathogens causing mucormycosis. Data from small studies in patients with hematological malignancies indicated that this RT-PCR is a sensitive tool to screen for Mucorales DNA in clinical samples. However, larger confirmatory studies are needed before broad application of this tool in clinical routine.
Comparator device
The results of the MucorGenius® RT-PCR will be compared to the EORTC/MSG criteria for IFD. The EORTC/MSG criteria are established criteria developed for uniform definition of IFDs in clinical studies.
Number of samples
Approximately 2,200
Inclusion criteria
- Sample is from a patient 18 years of age or older at time of BALF sampling
- Sample is from a patient that has proven mucormycosis AND/OR one of the risk factors listed in Section 6.3, ±14 days of the time the corresponding sample was taken.
- Patient had undergone bronchoscopy and BALF sampling as part of the clinical routine work up, due to suspicion of pulmonary infection
- Sufficient amount of BALF (≥1 mL) is left after routine-work up
- Urine samples and biopsies may only be included in case they were collected within ±72h of the corresponding BALF sample
- Sufficient amount of blood or urine (≥1 mL) is left after routine-work up
Exclusion criteria
- Insufficient BAL volume available after routine work-up
Statistics
Statistical analysis will be performed by an investigator (M.E.) under the supervision of the PIs (J.P. and M.H.).
The period prevalence of mucormycosis in this study cohort will be calculated by dividing the frequency of patients with proven/probable mucormycosis by the whole study cohort. Samples from patients with proven or probable mucormycosis used to enrich the study cohort with cases of mucormycosis will not be included in epidemiological calculations, as this would result in an artificial overestimation of the actual frequency.
Sensitivity, Specificity, PPV, NPV, PAP, PAN, and Positive/Negative Likelihood ratios will be calculated along with their respective 2-sided 95% confidence interval according to the equation below:
| Proven/Probable mucormycosis | No mucormycosis | |
| MucorGenius® RT-PCR positive | A | B |
| MucorGenius® RT-PCR negative | C | D |
Sensitivity: A/(A+C)x100
Specificity: D/(D+B)x100
PPV: A/(A+B)x100
NPV: D/(D+C)x100
LR+: [A/(A+C)] / [B/(B+D)]
LR-: [C/(A+C)] / [D/(B+D)]
GCP compliance
The present study will be conducted in accordance with the valid versions of the trial protocol and the internationally recognized Good Clinical Practice Guidelines (ICH- GCP), including archiving of essential documents.
Financing
This study is funded by an Investigator-Sponsored Research Agreement with Pfizer Inc. and by an ECMM pilot study grant.