Early diagnosis and monitoring of mucormycosis by detection of circulating DNA in serum: retrospective analysis of 44 cases collected through the French Surveillance Network of Invasive Fungal Infections (RESSIF)

Abstract

The main objective of this study was to assess the diagnostic performance of a set of three Mucorales quantitative PCR assays in a retrospective multicentre study. Mucormycosis cases were recorded thanks to the French prospective surveillance programme (RESSIF network). The day of sampling of the first histological or mycological positive specimen was defined as day 0 (D0). Detection of circulating DNA was performed on frozen serum samples collected from D-30 to D30, using quantitative PCR assays targeting Rhizomucor, Lichtheimia, Mucor/Rhizopus. Forty-four patients diagnosed with probable (n = 19) or proven (n = 25) mucormycosis were included. Thirty-six of the 44 patients (81%) had at least one PCR-positive serum. The first PCR-positive sample was observed 9 days (range 0-28 days) before diagnosis was made using mycological criteria and at least 2 days (range 0-24 days) before imaging. The identifications provided with the quantitative PCR assays were all concordant with culture and/or PCR-based identification of the causal species. Survival rate at D84 was significantly higher for patients with an initially positive PCR that became negative after treatment initiation than for patients whose PCR remained positive (48% and 4%, respectively; p <10). The median time for complete negativity of PCR was 7 days (range 3-19 days) after initiation of l-AmB treatment. Despite some limitations due to the retrospective design of the study, we showed that Mucorales quantitative PCR could not only confirm the mucormycosis diagnosis when other mycological arguments were present but could also anticipate this diagnosis. Quantification of DNA loads may also be a useful adjunct to treatment monitoring.

Is It Time to Include CT “Reverse Halo Sign” and qPCR Targeting Mucorales in Serum to EORTC-MSG Criteria for the Diagnosis of Pulmonary Mucormycosis in Leukemia Patients?

“…Indeed, 13 of 13 patients with proven PM had positive tests (33/60 positive sera), confirming that the qPCR assays are a valuable tool in the monitoring and the early diagnosis of PM in patients at risk of IFI, as recently reported by Millon et al [11]. Identically, in the same period, 6 of 6 patients with possible PM with CT RHS (group 2) had positive qPCR (19/27 positive sera).…”

Application of Mass Spectrometry Technology to Early Diagnosis of Invasive Fungal Infections

“…Some progress has recently been made in the diagnosis of MM by real-time PCR in specialized centers (31–36), but none of the serological tests currently on the market are efficient for the diagnosis of MM. Our study clearly demonstrates that MS-DS could fill this gap as a new serological marker for MM, becoming positive before the establishment of a clinical diagnosis.…”

Prevalence of the reversed halo sign in neutropenic patients compared with non‐neutropenic patients: Data from a single‐centre study involving 27 patients with pulmonary mucormycosis (2003‐2016)

“…Clinical and biological data (included underlying disease, clinical symptoms leading to the diagnosis of PM, neutropenia, duration of neutropenia, and outcome), mycological data obtained by biopsy and/or respiratory samples as bronchoalveolar lavage (BAL) (direct examination and culture of clinical samples, see Table ) and Mucorales DNA detection by PCR on serum, as described in Millon et al., radiological data (conventional X‐ray and CT scans), and antifungal therapy, were analyzed. Search for concomitant non‐ Mucorales invasive pulmonary infection, such as IPA (according to the 2008 EORTC/MSG definitions) was also investigated.…”