False positive bronchoalveolar lavage galactomannan: Effect of host and cut‐off value. Issue 3 (25th November 2018)

• Record Type: Journal Article
• Authors: Farmakiotis, Dimitrios; Le, Audrey; Weiss, Zoe; Ismail, Nour; Kubiak, David W.; Koo, Sophia
• Is Part Of: Mycoses. Volume 62:Issue 3(2019)
• Page Start: 204
• Page End: 213
• Publication Date: 2018-11-25
• Subjects: aspergillosis -- Aspergillus -- galactomannan -- haematologic malignancy -- hematopoietic stem‐cell transplantation -- leukaemia -- mould -- transplantation; Pathogenic fungi -- Periodicals; Medical mycology -- Periodicals; 616.969
• DOI: 10.1111/myc.12867
• Languages: English
• ISSNs: 0933-7407

Abstract

Summary: Objectives: Bronchoalveolar lavage galactomannan (BAL‐GM) is a mycological criterion for diagnosis of probable invasive aspergillosis (IA) per European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORT‐MSG) consensus criteria, but its real‐world positive predictive value (PPV) has not been well‐studied. Our aim was to estimate the PPV of BAL‐GM in a contemporary cohort of patients with positive BAL‐GM. Methods: We identified consecutive patients with ≥1 positive BAL‐GM value (index ≥ 0.5) at Brigham and Women's Hospital from 11/2009 to 3/2016. We classified patients as having no, possible, probable, or proven IA, excluding BAL‐GM as mycological criterion. Results: We studied 134 patients: 54% had hematologic malignancy (HM), and 10% were solid organ transplant (SOT) recipients. A total of 42% of positive (≥0.5) BAL‐GM results were falsely positive (PPV 58%). The number of probable IA cases was increased by 23% using positive BAL‐GM as mycologic criterion alone. PPV was higher in patients with HM or SOT ( P < 0.001) and with use of higher thresholds for positivity (BAL‐GM ≥ 1 vs 1‐0.8 vs 0.8‐0.5: P = 0.002). Conclusions: 42% of positive BAL‐GM values were falsely positive. We propose a critical reassessment of BAL‐GM cutoff values in different patient populations. Accurate noninvasive tests for diagnosis of IA are urgently needed.