Performance of lateral flow device and galactomannan for the detection of Aspergillus species in bronchoalveolar fluid of patients at risk for invasive pulmonary aspergillosis

Abstract

Early diagnosis of invasive pulmonary aspergillosis (IPA) remains difficult due to the variable performance of the tests used. We compared the performance characteristics of Aspergillus lateral flow device (LFD) in bronchoalveolar lavage (BAL) vs. BAL-galactomannan (GM), for the diagnosis of IPA. 311 BAL specimens were prospectively collected from patients who underwent bronchoscopy from January to May 2013. Patients at risk for IPA were divided into haematological malignancy (HEM) and non-HEM groups: solid organ transplants (SOT) (lung transplant (LT) and non-LT SOT); chronic steroid use (CSU); solid tumour (STU) and others. We identified 96 patients at risk for IPA; 89 patients (93%) were in the non-HEM groups: SOT 57 (LT, 46, non-LT SOT, 11); CSU 21; STU 6, other 5. Only three patients met criteria for IA (two probable; one possible). Overall sensitivity (SS) was 66% for both and specificity (SP) was 94% vs. 52% for LFD and GM respectively. LFD and GM performance was similar in the HEM group (SS 100% for both and SP 83% vs. 100% respectively). LFD performance was better than GM among non-HEM SOT patients (P = 0.02). Most false-positive GM results occurred in the SOT group (50.8%), especially among LT patients (56.5%). LFD performance was superior with an overall SP of 95.6% in SOT (P < 0.002) and 97% in LT patients (P = 0.0008). LFD is a rapid and simple test that can be performed on BAL to rule out IPA.

Testing the performance of a prototype lateral flow device using bronchoalveolar lavage fluid for the diagnosis of invasive pulmonary aspergillosis in high‐risk patients

“…The prototype LFD assay has been studied in different populations at risk, including patients with haematological malignancies, solid organ transplant recipients, critically ill patients in the ICU and patients with chronic pulmonary disease . These studies varied with regard to the populations studied and the diagnostic criteria used to define IPA.…”

“…The Aspergillus LFD was performed on stored BAL fluid following methods described previously . Prototype LFD devices were purchased from OLM Diagnostics, Newcastle upon Tyne, UK in April 2015.…”

Clinical evaluation of the newly formatted lateral‐flow device for invasive pulmonary aspergillosis

“…The ease‐of‐use of the assay, requiring no pretreatment of bronchoalveolar lavage fluid (BALF), allows point‐of‐care testing, with results available within 15 minutes. To date, a prototype version of the test has been evaluated with more than 650 BALF samples across a number of studies, with an overall sensitivity of 73%, specificity of 90%, a positive predictive value (PPV) of 61%, and negative predictive value (NPV) of 94% for probable/proven IPA vs no IPA . As with other diagnostic tests for IPA such as the galactomannan [GM] ELISA, LFD sensitivity is reduced by mould‐active antifungal drugs .…”

Lateral Flow Assays for the Diagnosis of Invasive Aspergillosis: Current Status

“…Since then, BALF LFD testing has been evaluated in multicenter studies in intensive care unit patients [42••] and patients with underlying hematological malignancies [43], as well as a number of single-center studies [16••, 44–47]. The up-to-date performance of the LFD in BALF samples for different patient groups as well as the overall performance per sample are depicted in Table 1.…”

“… PPV positive predictive value, NPV negative predictive value a Data derived from published studies [8•, 16••, 28•, 32, 33, 39–47, 48••]: b Overall summarizes unique samples and is lower than the sum of subgroup samples, as some samples were classified into more than one subgroup…”