Effect of involved Aspergillus species on galactomannan in bronchoalveolar lavage of patients with invasive aspergillosis

Abstract

Purpose. The detection of galactomannan (GM) in bronchoalveolar lavage (BAL) fluid is an important surrogate marker for the early diagnosis and therapeutic monitoring of invasive aspergillosis (IA), regardless of the involved species of Aspergillus. Here, we utilized the Platelia Aspergillus GM enzyme immunoassay (Bio-Rad) to evaluate the GM index in BAL fluid samples from patients with proven, probable or putative IA due to Aspergillusflavus versus Aspergillusfumigatus.Methodology. In a prospective study between 2009 and 2015, 116 BAL samples were collected from suspected IA patients referred to two university hospitals in Tehran, Iran.Key findings. According to European Organization for Research and Treatment of Cancer and Mycoses Study Group and Blot criteria, 35 patients were classified as IA patients, of which 33 cases tested positive for GM above 0.5 and, among these patients, 22 had a GM index !1. Twenty-eight were culture positive for A. flavus and seven for A. fumigatus. The GM index for A. flavus cases was between 0.5-6.5 and those of A. fumigatus ranged from 1 to 6.5. The sensitivity and specificity of a GM index !0.5 in cases with A. flavus were 86 and 88 % and for A. fumigatus patients were 100 and 73 %, respectively.Conclusion. Overall, the mean GM index in patients with A. fumigatus (3.1) was significantly higher than those of A. flavus (1.6; P-value=0.031) and the sensitivity of GM lower for A. flavus when compared to A. fumigatus. This finding has implications for diagnosis in hospitals and countries with a high proportion of A. flavus infections.

Pulmonary Metagenomic Sequencing Suggests Missed Infections in Immunocompromised Children

“…Combining nucleic acid tests with galactomannan can hasten diagnosis and improve clinical outcomes in some populations [48][49][50][51]; further, incorporation of immune function may also improve discrimination of colonization and invasive mycosis [52][53][54][55][56]. Importantly, for all nucleic acid-based tests, measurable Aspergillus yield varies among species and according to life stage, cell wall characteristics, and hydrophobicity [57]. Therefore, any future clinical mNGS assay will need to be benchmarked against numerous Aspergillus species as well as other medically relevant fungi in order to have the broadest utility.…”

Invasive Aspergillosis by Aspergillus flavus: Epidemiology, Diagnosis, Antifungal Resistance, and Management

“…In a study of hematologic malignancy patients by Hachem et al, the sensitivity of serum GM was higher with aspergillosis due to non- fumigatus Aspergillus species (49%) than those infected with A. fumigatus (13%), though non- fumigatus Aspergillus species were not specified in the study [55]. The mean BAL-GM index in pulmonary aspergillosis patients with A. flavus (GM Index 1.6) was lower than A. fumigatus (3.1; P = 0.031) and the sensitivity of GM detection was lower in A. flavus infections [56]. A study conducted by Badiee et al in children with IA demonstrated sensitivity and specificity of GM, (1→3)-β- d -glucan and PCR was 90% and 92%, 50% and 46%, and 80% and 96%, respectively [57].…”

Discrimination of Aspergillus flavus from Aspergillus oryzae by matrix‐assisted laser desorption/ionisation time‐of‐flight (MALDI‐TOF) mass spectrometry

“…In tropical and subtropical countries of the Middle-East, such as Iran, species of Aspergillus section Flavi are reportedly the main aetiological agents of invasive and non-invasive infections. 3,4 The taxonomy of this section is complex and is currently under development. 5 A large number of species in section Flavi are commonly observed plant pathogens producing several mycotoxins.…”