Multicenter Prospective Study of Biomarkers for Diagnosis of Invasive Candidiasis in Children and Adolescents

Abstract

Background: Diagnosis of invasive candidiasis (IC) relies on insensitive cultures; the relative utility of fungal biomarkers in children is unclear.

Methods: This multinational observational cohort study enrolled patients aged >120 days and <18 years with concern for IC from 1 January 2015 to 26 September 2019 at 25 centers. Blood collected at onset of symptoms was tested using T2Candida, Fungitell (1→3)-β-D-glucan, Platelia Candida Antigen (Ag) Plus, and Platelia Candida Antibody (Ab) Plus assays. Operating characteristics were determined for each biomarker, and assays meeting a defined threshold considered in combination. Sterile site cultures were the reference standard.

Results: Five hundred participants were enrolled at 22 centers in 3 countries, and IC was diagnosed in 13 (2.6%). Thirteen additional blood specimens were collected and successfully spiked with Candida species, to achieve a 5.0% event rate. Valid T2Candida, Fungitell, Platelia Candida Ag Plus, and Platelia Candida Ab Plus assay results were available for 438, 467, 473, and 473 specimens, respectively. Operating characteristics for T2Candida were most optimal for detecting IC due to any Candida species, with results as follows: sensitivity, 80.0% (95% confidence interval, 59.3%-93.2%), specificity 97.1% (95.0%-98.5%), positive predictive value, 62.5% (43.7%-78.9%), and negative predictive value, 98.8% (97.2%-99.6%). Only T2Candida and Platelia Candida Ag Plus assays met the threshold for combination testing. Positive result for either yielded the following results: sensitivity, 86.4% (95% confidence interval, 65.1%- 97.1%); specificity, 94.7% (92.0%-96.7%); positive predictive value, 47.5% (31.5%-63.9%); and negative predictive value, 99.2% (97.7%-99.8%).

Conclusions: T2Candida alone or in combination with Platelia Candida Ag Plus may be beneficial for rapid detection of Candida species in children with concern for IC.

Clinical trials registration: NCT02220790.

Keywords: Pediatrics; biomarkers; invasive candidiasis.

Conflict of interest statement

Potential conflicts of interest. B. T. F. receives funding from the Food and Drug Administration, Pfizer, and Merck and serves as a paid chair of a data and safety monitoring board (DSMB) for Astellas. R. H. serves on advisory boards for Quidel and Inflammatix; receives ASM Press book royalties (personal payments); and serves as a member of the board of directors for the Clinical Laboratories Standards Institute and as immediate past president for the Pan-American Society for Clinical Virology (both unpaid). T. E. Z. provides consultant services for T2 Biosystems and Nabriva Therapeutics. D. E. Y.’s institution receives funding from Merck, Astellas, Marion Merrel Dow Fund, Viracor-Eurofins (laboratory testing services to institution for investigator-initiated research), and Chimerix. D. E. Y. is now employed by the National Institute of Allergy and Infectious Diseases, NIH, which has paid for conference registration and fees, but this research was conducted while he was employed by Children’s Mercy Kansas City and the University of Missouri–Kansas City School of Medicine. D. E. Y. also reports serving as unpaid technical advisor to nonprofit organizations Cover the Globe and Maipelo Trust, which provide human immunodeficiency virus services to migrant or displaced children and families in Botswana. A. R. H. has patent 10,160,974 issued (Engineered cytokine- and chemokine-expressing Candida albicans strains and methods of use; no royalties collected); reports grant support from the NIH (grant K08DE026189 from the National Institute of Dental and Craniofacial Research and NIH pass-through via Duke grants [DOMINIC]); and reports serving on the Central Review Board for Non-Invasive Diagnosis of Pediatric Pulmonary Invasive Mold infections (DOMINIC) (unpaid). L. D. I. received institutional support for contracted clinical research from Astellas, Merck, Takeda, Ansun Biopharma, and Viracor-Eurofins; is a paid consultant for Takeda and paid chair of a DSMB for Merck; and serves as president of The International Society for Heart and Lung Transplantation. W. J. M. receives support from Adagio Therapeutics, Ansun Biopharma, Astellas, AstraZeneca, Eli Lilly, Enanta Pharmaceuticals, Janssen, Karius, Merck, Genentech, Gilead, Moderna, Melinta, Nabriva, Tetraphase, and Seqirus; reports consulting fees from Seqirus (to institution), the US Attorney’s Office, Southern District of Illinois (to self), McQuade Blasko Law Offices (to self), Finley Law Firm (to self), Doherty & Progar (to self), Phelan, Tucker, Mullen, Walker, Tucker, Gelman (to self), and Bailes, Craig, Yon & Sellards (to self); and reports participation on DSMB or advisory boards for Adagio Therapeutics and ProventionBio (payments to self). E. R. receives funding from Merck Sharp & Dohme (MSD), Merck, Pfizer, and Gilead; reports consulting fees from MSD and Pfizer (paid to institution); reports honoraria for lectures paid to their institution from Pfizer, MSD, and Gilead; reports travel support/payment of registration from Vianex, Pfizer, and MSD; and reports participation on advisory board(s) for MSD and Pfizer. P. K. S. reports grants from Astellas and Merck (to institution for work as clinical trial site). D. B. was a consultant for Teleflex. D. B. reports consulting fees from Precision Health (consulting agreement as of August 2021), for providing advice on the selection of polymerase chain reaction panels for outpatients in long-term care facilities and educating the Medical Science Liason team on their use) and Karius Diagnostics (where D. B. has been employed full time since 28 June 2021, as medical director in the Medical Affairs Division); Karius offers metagenomic next-generation sequencing for pathogens from plasma). As a full-time Karius employee, D. B. has the option to purchase stocks in the future during the initial public offering (the timing of the initial public offering is not yet known). D. B. continue to have a faculty appointment at Johns Hopkins All Children’s Hospital and hospital privileges (per diem). N. H. was a consultant for Moderna; receives funding from NIH, the Centers for Disease Control and Prevention, Quidel, and Sanofi; and serves as a Pediatric Infectious Diseases Society board member. G. M. receives funding from Astellas. P. S. P. receives support from Pfizer (research grant), Grifols, CSL Behring, Takeda, and Gilead (education and research grants); reports payment/honoraria from Pfizer and Gilead and payment for expert testimony from Gilead; reports participation on DSMB or an advisory board for Pfizer. C. M. S. reports receiving an NIH grant for the BIOPIC study, during the conduct of the study. M. G. reports NIH funding, outside the submitted work; receives royalties for being a textbook editor for Elsevier; reports personal consulting fees from ITB-Med; reports a personal honorarium for a lecture from Medscape; reports personal payments for serving on an advisory board for ATARA Biotherapeutics; and serves on the DSMB and as a consultant for Bristol Myers Squibb. S. B. H. reports honoraria for lectures on coronavirus disease 19 in Texas and office infection control from the Centers for Disease Control and Prevention. W. J. S. serves on the scientific advisory board of Sfunga (personal payments). All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.

© The Author(s) 2022. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Figures

Figure 1.

Testing algorithm for the Fungitell (1→3)-β-D-glucan assay. Abbreviation: CV, coefficient of variation.

Figure 2.

Application of exclusion criteria to determine evaluable specimens for analysis. Gray boxes represent participants excluded from analysis. Results of 29 T2Candida assays were reported as invalid, included 5 specimens with instrument errors during assay performance and 24 whose results were invalidated owing to failure of the internal positive control. Abbreviations: BIOPIC, BIOmarkers in Pediatric Invasive Candidiasis; EDTA, ethylenediaminetetraacetic acid; SST, serum separation tube.

Figure 3.

Processing of specimens for subjects enrolled under specimen spiking protocol. Gray boxes represent specimens excluded from analysis. Abbreviations: EDTA, ethylenediaminetetraacetic acid; SST, serum separation tube.