LAUSR

Abstract Background Blood cultures (BC) are the diagnostic gold standard for candidemia, but sensitivity is <50%. T2 Candida (T2) is a novel, FDA-approved nanodiagnostic panel, which utilizes T2 magnetic resonance and a dedicated instrument to detect Candida within whole blood samples. Methods Candidemic adults were identified at 14 centers by diagnostic BC (dBC). Follow-up blood samples were collected from all patients (pts) for testing by T2 and companion BC (cBC). T2 was run-in batch at a central lab; results are reported qualitatively for three groups of spp. (Candida albicans/C. tropicalis (CA/CT), C. glabrata/C. krusei (CG/CK), or C. parapsilosis (CP)). T2 and cBC were defined as positive (+) if they detected a sp. identified in dBC. Results 152 patients were enrolled (median age: 54 yrs (18–93); 54% (82) men). Candidemia risk factors included indwelling catheters (82%, 125), abdominal surgery (24%, 36), transplant (22%, 33), cancer (22%, 33), hemodialysis (17%, 26), neutropenia (10%, 15). Mean times to Candida detection/spp. identification by dBC were 47/133 hours (2/5.5 d). dBC revealed CA (30%, 46), CG (29%, 45), CP (28%, 43), CT (11%, 17) and CK (3%, 4). Mean time to collection of T2/cBC was 62 hours (2.6 d). 74% (112) of patients received antifungal (AF) therapy prior to T2/cBC (mean: 55 hours (2.3 d)). Overall, T2 results were more likely than cBC to be + (P < 0.0001; Table), a result driven by performance in AF-treated patients (P < 0.0001). T2 was more likely to be + among patients originally infected with CA (61% (28) vs. 20% (9); P = 0.001); there were trends toward higher positivity in patients infected with CT (59% (17) vs. 23% (4; P = 0.08) and CP (42% (18) vs. 28% (12); P = 0.26). T2 was + in 89% (32/36) of patients with + cBC. Conclusion T2 was sensitive for diagnosing candidemia at the time of + cBC, and it was significantly more like to be + than cBC among AF-treated patients. T2 is an important advance in the diagnosis of candidemia, which is likely to be particularly useful in patients receiving prophylactic, pre-emptive or empiric AF therapy. Test results, n (%) Pt group (n) T2+ T2- cBC+ cBC- T2+/cBC+ T2+/cBC- T2-/cBC+ T2-/cBC- All (152) 69 
(45%) 83 
(55%) 36 
(24%) 116 
(76%) 32 
(21%) 37 
(24%) 4 
(3%) 79 
(52%) Prior AF (112) 55 
(49%) 57 
(51%) 23 
(20%) 89 
(80%) 20 
(18%) 35 
(31%) 3 
(3%) 54 
(48%) No AF (40) 14 
(35%) 26 
(65%) 13 
(32%) 27 
(68%) 12 
(30%) 2 
(5%) 1 
(2%) 25 
(62%) Disclosure D. P. Kontoyiannis, Pfizer: Research Contractor, Research support and Speaker honorarium; Astellas: Research Contractor, Research support and Speaker honorarium; Merck: Honorarium, Speaker honorarium; Cidara: Honorarium, Speaker honorarium; Amplyx: Honorarium, Speaker honorarium; F2G: Honorarium, Speaker honorarium; L. Ostrosky-Zeichner, Astellas: Consultant and Grant Investigator, Consulting fee and Research grant; Merck: Scientific Advisor and Speaker’s Bureau, Consulting fee and Speaker honorarium; Pfizer: Grant Investigator and Speaker’s Bureau, Grant recipient and Speaker honorarium; Scynexis: Grant Investigator and Scientific Advisor, Consulting fee and Grant recipient; Cidara: Grant Investigator and Scientific Advisor, Consulting fee and Research grant; S. Apewokin, T2 biosystems: Investigator, Research support; Astellas: Scientific Advisor, Consulting fee