Evaluation and comparison of automated and manual ELISA for diagnosis of chronic pulmonary aspergillosis (CPA) in Indonesia
DIAGNOSTIC MICROBIOLOGY AND INFECTIOUS DISEASE
Authors: Setianingrum, Findra; Rozaliyani, Anna; Syam, Ridhawati; Adawiyah, Robiatul; Tugiran, Mulyati; Sari, Cut Yulia, I; Burhan, Erlina; Wahyuningsih, Retno; Rautemaa-Richardson, Riina; Denning, David W.
Abstract
Pulmonary tuberculosis (TB) is one of the common risk factors for chronic pulmonary aspergillosis (CPA). A positive Aspergillus IgG is a key element of the diagnosis of CPA but this has not been studied in Indonesia. We conducted studies with patients at the end of TB therapy in Indonesia. We performed receiver operating curve (ROC) analysis to determine the optimum cutoff of the Aspergillus-specific IgG level (Immulite and Dynamiker ELISA) in those patients who met criteria of CPA in relation to control groups. In 203 TB patients, 26 (13%) patients had clinical and radiological features of CPA. We derived optimum cutoffs for Immulite Aspergillus-specific IgG of 11.5 mg/L and Dynamiker anti-galactomannan IgG of 106.8 AU/mL (sensitivity 89% and 83%, specificity 78% and 51%, respectively). The currently accepted Aspergillus-specific IgG cutoff of Immulite and Dynamiker assays for CPA diagnosis may require slight adjustment for the Indonesian population. (C) 2020 Elsevier Inc. All rights reserved.
A novel glycosidase plate-based assay for the quantification of galactosylation and sialylation on human IgG
GLYCOCONJUGATE JOURNAL
Authors: Rebello, Osmond D.; Gardner, Richard A.; Urbanowicz, Paulina A.; Bolam, David N.; Crouch, Lucy I.; Falck, David; Spencer, Daniel I. R.
Abstract
Changes in human IgG galactosylation and sialylation have been associated with several inflammatory diseases which are a major burden on the health care system. A large body of work on well-established glycomic and glycopeptidomic assays has repeatedly demonstrated inflammation-induced changes in IgG glycosylation. However, these assays are usually based on specialized analytical instrumentation which could be considered a technical barrier for uptake by some laboratories. Hence there is a growing demand for simple biochemical assays for analyzing these glycosylation changes. We have addressed this need by introducing a novel glycosidase plate-based assay for the absolute quantification of galactosylation and sialylation on IgG. IgG glycoproteins are treated with specific exoglycosidases to release the galactose and/or sialic acid residues. The released galactose monosaccharides are subsequently used in an enzymatic redox reaction that produces a fluorescence signal that is quantitative for the amount of galactosylation and, in-turn, sialylation on IgG. The glycosidase plate-based assay has the potential to be a simple, initial screening assay or an alternative assay to the usage of high-end analytical platforms such as HILIC-FLD-MSn when considering the analysis of galactosylation and sialylation on IgG. We have demonstrated this by comparing our assay to an industrial established HILIC-FLD-MSn glycomic analysis of 15 patient samples and obtained a Pearson's r correlation coefficient of 0.8208 between the two methods.