False positive bronchoalveolar lavage galactomannan: Effect of host and cut‐off value

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.

Diagnostic Value of Galactomannan in Bronchoalveolar Lavage Fluid for Chronic Respiratory Disease with Pulmonary Aspergillosis

“…The recovery amount should be more than 50%, as several tubes of recovery solution were mixed for GM detection to reduce the differences, which diluted the Aspergillus galactomannan. Therefore, the diagnosis of pulmonary aspergillosis should be combined with clinical manifestations, treatment response, and other factors for comprehensive judgment (29). In summary, our study demonstrates that yhe BALF GM test has diagnostic utility for chronic respiratory diseases cooccurring with pulmonary aspergillosis.…”

A bronchoalveolar lavage‐driven antimicrobial treatment improves survival in hematologic malignancy patients with detected lung infiltrates: A prospective multicenter study of the SEIFEM group

“…The optimal cut‐off of BAL GM has not been established yet. Some published studies suggested a higher positive predictive value of 1.0, others instead showed the best diagnostic performance of 0.5 while some reports highlighted the excellent sensitivity and specificity of 1.5 in the HM setting . By using the 0.5 cut‐off, we found 41 positive cases of BAL‐GM.…”

Disseminated Mucormycosis with Positive Aspergillus Galactomannan

“…Diagnosis of mucormycosis remains challenging and is often made by biopsy, because the yield of bronchoscopy is extremely low, since hyphae are angioinvasive in tissue, rather than the alveolar space [1]. Our case highlights these important limitations and the fact that galactomannan in blood or BAL has limited specificity and was likely false positive in this case [3]. The positive galactomannan could not have been caused by mucormycosis.…”