The utility of bronchoalveolar lavage fluid and serum galactomannan assay in patients with nonresolving pneumonia in a tertiary care hospital

Abstract

Background The fungus aspergillus causes a plethora of diseases in humans. Invasive pulmonary aspergillosis (IPA), a serious opportunistic infection seen in immunosuppressed or hospitalized patients with severe underlying diseases, is associated with high rates of morbidity and mortality. The diagnosis of IPA is a challenge in general hospital population. This study was undertaken to evaluate the utility of galactomannan (GM) assay in bronchoalveolar lavage (BAL) fluid and serum for the diagnosis of IPA in patients with nonresolving pneumonia in a tertiary care hospital. Patients and methods Patients with nonresolving pneumonia for whom both BAL and serum GM assays, along with BAL culture for fungus, were evaluated from January 2016 to June 2017. Results A total of 64 patients had the tests done in the study period. All the patients had more than one associated underlying risk factor. Diabetes was seen in 35 (64.68%) patients and steroid intake in 34 (53.12%). Aspergillus flavus was the most common fungus cultured. Moreover, 14 of the culture positives had a serum GM level of more than 0.5 GM index, and all culture positives had BAL GM level of more than 0.5 GM index. Receiver operating characteristic curves revealed a cutoff of 0.91 for serum GM, which provides sensitivity of 66% and specificity of 63% and 1.01 for BAL GM, with a sensitivity of 88% and specificity as of 78%. The all-cause mortality of 78.8% was noted with both BAL and BAL GM positive (P=0.001). Conclusion A combination of clinical, radiological, culture, and GM assay of both BAL and serum would help in the diagnosis of IPA in hospitalized patients with nonresolving pneumonia.