The diagnostic performance of galactomannan detection in invasive pulmonary aspergillosis with severe and critically ill influenza

Abstract

Objective: To analyze the diagnostic performance of serum and bronchoalveolar lavage fluid (BALF) galactomannan (GM) test in invasive pulmonary aspergillosis(IPA) with severe and critically ill influenza. Methods: A retrospective study was performed for 157 patients with severe and critically ill influenza admitted to the Department of Pulmonary and Critical Care Medicine of the First Affiliated Hospital of Wenzhou Medical University from December 2017 to April 2019.Clinical characteristics and serum and BALF GM values were collected. The patients were divided into an IPA group (n=18) and a non-IPA group (n=139). The definition of IPA modified from AspICU algorithm taken as the gold standard (The corresponding clinical manifestations, imaging manifestations and microbiological diagnostic criteria should be met simultaneously), the performance of serum and BALF GM test and their combination to IPA with influenza were analyzed respectively and receiver operating characteristic curve (ROC) was drawn. Results: A total of 157 cases were enrolled, 95 were critically ill, and the mortality of IPA with influenza was 55.6%(10/18). The APACHE Ⅱ score, PSI score, urea nitrogen, influenza severity (Percentage of critically ill influenza) and invasive ventilator in IPA group were (16±6), (110±31), 10.7 (8.4, 17.8) mmol/L, 88.9% and 66.7%, respectively, which were significantly higher than those in non-IPA group [(10±5), (83±30), 5.2 (3.6, 7.6) mmol/L, 56.8% and 24.5%, P<0.05]. All patients received serum GM test and 32 patients performed BALF GM test at the same time. When the cut-off valve of serum GM test was 0.5 μg/L, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 66.7% (12/18), 95.0% (132/139), 63.2% (12/19) and 95.7% (132/138) respectively. When the cut-off value of BALF GM test was 1.0 μg/L, the sensitivity, specificity, PPV and NPV were 80%(8/10),86.4%(19/22),72.7%(8/11)and 90.5%(19/21)respectively. The BALF GM cut-off value of 0.88 μg/L showed the highest diagnostic efficacy for IPA, for which the sensitivity and specificity were 90%(9/10) and 86.4%(19/22). The areas under the ROC curve of serum GM, BALF GM, and the combination of them were 0.81, 0.85, and 0.94 respectively. The difference was statistically significant (P<0.05) and the combined diagnosis efficiency was higher. Conclusions: Critically ill influenza patients should be alert for IPA. The sensitivity of serum GM test in the diagnosis of IPA with influenza was low, while the NPV was high. The optimum BALF GM cut-off value was 0.88 μg/L. The combination with BALF and serum GM test can improve the diagnostic performance.