Evaluation of the Diagnostic Accuracy and Clinical Utility of Fungal Profile Plus Polymerase Chain Reaction Assay in Pulmonary Infections

Impact of Aspergillus PCR on the management of invasive aspergillosis: A tertiary care hospital experience during the COVID-19 pandemic

AIM

To assess the impact of Aspergillus PCR on managing invasive aspergillosis (IA) in routine patient management.

METHODS

A retrospective study included 235 patients who had Aspergillus PCR tests performed on respiratory samples (bronchoalveolar lavage, non-bronchoscopic lavage, and sputum) from November 2020 to April 2022.

RESULTS

Of 293 tests, 11.9% were PCR positive. Positive PCR results did not alter IA diagnostic categories. The decision on antifungal treatment was based on PCR results in nine of the 54 treated patients. Ten patients with positive PCR were not treated due to clinical improvement while awaiting results.

CONCLUSION

The utility of Aspergillus PCR was constrained by the use of non-validated samples and delays in reporting, reducing its impact on management decisions during a time when bronchoscopy was limited due to COVID-19. To enhance its clinical effectiveness and cost-efficiency, implementing a diagnostic algorithm for appropriate use is essential.

Molecular Diagnostics for Invasive Molds: From Lab to Bedside

This review highlights the current state of molecular diagnostic modalities to detect invasive fungal infections, with a focus on molds in immunocompromised children and adults. Molecular diagnostics may also be utilized to detect antifungal drug resistance. Although both pathogen-specific and pathogen-agnostic assays may be beneficial in more rapidly identifying fungal infection with less invasive sampling in high-risk populations, the clinical implementation and interpretation of these tests must consider several important factors, including anatomic site and type of specimen, host characteristics, use of antifungal prophylaxis, and timing of specimen collection.

Evaluating the clinical utility of Aspergillus, Mucorales, and Nocardia bronchoalveolar PCRs for the diagnosis of invasive pulmonary infections in patients with hematological malignancies

Invasive pulmonary infections are a significant cause of morbidity and mortality in patients with hematological malignancies and hematopoietic stem cell transplantation (HCT) recipients. A delay in identifying a causative agent may result in late initiation of appropriate treatment and adverse clinical outcomes. We examine the diagnostic utility of PCR-based assays in evaluating invasive pulmonary infections from bronchoalveolar lavage (BAL). Patients with hematological malignancies and HCT recipients who underwent bronchoscopy with BAL from January 2020 to January 2024 for unexplained pulmonary infiltrates and had ≥1 PCR targeting Aspergillus, Mucorales, or Nocardia (Eurofins-Viracor, KS) were reviewed. Testing for microbiology and pathology except BAL PCRs to identify the etiology of pulmonary infiltrate was defined as standard-of-care. Invasive fungal diseases were defined as per European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium (EORTC/MSGERC) 2020 guidelines. Pulmonary nocardiosis was defined by a combination of clinical, radiographic, and microbiologic criteria. Of 134 patients, 77 were HCT recipients, and 70% were on antifungal agents. Thirty-two were diagnosed with infection with one of the three target pathogens, including 20 with probable or proven invasive pulmonary aspergillosis (IPA), seven with mucormycosis, and three with nocardiosis. For IPA, 19 were diagnosed by standard-of-care, and one (5%) was solely diagnosed by Aspergillus PCR. Mucorales PCR was positive in three of seven cases of proven mucormycosis, but the cultures were negative in all. All three nocardiosis cases were detected by PCR and culture. In our cohort, PCR targeting Mucorales and Nocardia can improve the early detection of invasive pulmonary infection, whereas Aspergillus PCR has a low added value when done in conjunction with standard-of-care, including BAL galactomannan.IMPORTANCEInvasive pulmonary infections are a significant cause of morbidity and mortality in immunocompromised patients. Timely diagnosis of invasive pulmonary infection reduces the time to targeted treatment initiation and improves clinical outcomes. The recent European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium (EORTC/MSGERC) update included the addition of serum or bronchoalveolar lavage (BAL) PCR as a method to determine probable Aspergillus disease. This reflects an increased utilization of PCR-based assays in the diagnosis of fungal diseases. Although PCR assays for Aspergillus diagnosis have been well characterized in the literature, their additive clinical utility in conjunction with BAL galactomannan index measurements remains unclear. Moreover, only a few reports characterize the analytic and clinical performance of Mucorales and Nocardia PCR.

Not Just an Oxymoron: The Utilitarian's Guide to Antimicrobial Stewardship in Transplant Infectious Diseases

Solid organ transplant and hematopoietic cell transplant patients face an increased risk of infectious diseases, greater exposure to antibiotics, and heightened risk of multidrug-resistant organisms (MDROs) due to their immunosuppressed state. Antimicrobial stewardship programs (ASP) are essential in reducing the incidence of MDRO by conserving antimicrobial use, minimizing treatment durations, and improving the appropriate use of diagnostic testing. However, the role of ASP in transplant infectious diseases (TID) is still evolving, necessitating greater collaboration between ASP and transplant programs. This collaboration will mitigate infection risks, reduce infection-associated costs, and improve outcomes. This article reviews the key components for implementing ASP in TID, especially for those that are establishing or growing their ASP to include TID, including specific goals, structure and funding, ASP initiatives (including antibiotic allergy delabeling, diagnostic stewardship, and antiviral/antifungal stewardship), metrics, and educational opportunities.

The performance of bronchoalveolar lavage Aspergillus PCR testing in solid organ transplant recipients with invasive pulmonary aspergillosis

BACKGROUND

Invasive aspergillosis affects solid organ transplant (SOT) recipients, carrying a high risk of mortality and morbidity in this population. Rapid and accurate diagnosis is essential to ensure the initiation of correct antifungal therapy. We aimed to evaluate the performance of the bronchoalveolar lavage (BAL) Eurofins Viracor Aspergillus PCR (AspPCR) in diagnosing invasive pulmonary aspergillosis (IPA) in SOT recipients.

METHODS

We conducted a multicenter retrospective study of SOT recipients in Arizona from February 2019 to December 2022 who had AspPCR done at the time of the clinical encounter. Probable IPA was defined as a positive BAL culture with Aspergillus spp. with clinical and imaging findings of IPA per EORTC/MSGERC criteria.

RESULTS

Ninety-nine SOT recipients with 131 encounters with BAL AspPCR testing were included. The median age was 66, the majority were White, non-Hispanics (60%), and males (66%). Among the participants, 93 lung transplant recipients with 87 of the encounters received antifungal prophylaxis active against Aspergillus spp. Sixty-four encounters had BAL galactomannan (GM), all of which had BAL GM <1 OD, and one case had a serum GM of 10 OD. Nine cases met the definition of IPA. The sensitivity of the BAL AspPCR was 67% (95% CI 30%-93%), and the specificity was 98% (95% CI 93%-99%).

CONCLUSION

BAL AspPCR had moderate sensitivity and high specificity in identifying IPA in our cohort of SOT recipients. Further studies in populations with a higher prevalence of IPA are needed to evaluate the performance of this test.

Persistent fever after coronavirus disease 2019 in liver/kidney transplant recipient

In this case, a 64-year-old male with a history of simultaneous orthotopic liver transplant and cadaveric renal transplant presented five years prior presented with persistent fevers two days after a positive SARS-CoV-2 nasal PCR. A CT scan of the chest on hospital day nine revealed innumerable 1-2 mm nodules in a miliary pattern throughout the lung. (1,3)-β-D-glucan on hospital day 11 was 133 pg/mL. In this article, the approach, diagnostic and management strategies for patients with persistent fevers after diagnosis of COVID-19 in a transplant recipient are discussed.

Emerging Diagnostics and Therapeutics for Invasive Fungal Infections

Recently, there have been significant advances in the diagnosis and management of invasive fungal infections. Compared with traditional fungal diagnostics, molecular assays promise improved sensitivity and specificity, the ability to test a range of samples (including noninvasive samples, ie, blood), the detection of genetic mutations associated with antifungal resistance, and the potential for a faster turnaround time. Antifungals in late-stage clinical development include agents with novel mechanisms of action (olorofim and fosmanogepix) and new members of existing classes with distinct advantages over existing antifungals in toxicity, drug-drug interactions, and dosing convenience (oteseconazole, opelconazole, rezafungin, ibrexafungerp, encochleated amphotericin B).