Capillary electrophoresis as a method to determine underivatized urinary lipoarabinomannans, a biomarker of active tuberculosis caused byMycobacterium tuberculosis

Abstract

Tuberculosis is a devastating contagious disease caused by Mycobacterium tuberculosis. This is the first report describing the development of novel capillary electrophoresis methods to detect lipoarabinomannans shed into the blood circulation by replicating bacteria. The novelty of the methods is the detection without derivatization. The lipoarabinomannan is detected owing to the ionization of the diverse functional groups of the structure, such as the multibranched mannan domain or the phosphatidyl group. Four alkaline solutions were used; normal polarity in three of them and reversed polarity in one. Urinary lipoarabinomannans by saccharide domains were identified with direct absorbance detection. The accuracy and the analytical sensitivity were then validated with cello-, manno- and xylooligosaccharides. Lipoarabinomannan detection was feasible within 20 min (RSD 2.1%). This method worked at the dynamic range of 0.1-10 μg/mL. With reversed polarity, indirect absorbance detection, and pH 9.0 electrolyte were used, the analytes migrated already within 5 min (RSD 0.01%). Inorganic nonabsorbing ions were used for this method optimization. This improvement resulted in the detection limit of 1 pg/mL in water and in the linear dynamic range of 1 pg/mL to 10 ng/mL. In conclusion, the described method has great potential as a point-of-care assay for clinical use.

Urine lipoarabinomannan glycan in HIV-negative patients with pulmonary tuberculosis correlates with disease severity

“…This study indicates that it is possible to detect urinary LAM during active pulmonary TB, that detection does not require physiologic or immunologic consequences of HIV infection ( 8 , 9 ), and that detection is not limited to patients with TB colonization of the kidney ( 10 ). Instead, as others have suspected ( 7 , 29 ), the LAM antigen concentration in HIV-negative patients is below the level of sensitivity of previous immunoassays, and the urinary LAM may be obscured by interfering LAMbinding substances in the urine protein matrix ( 7 ). The high-affinity copper dye bait for LAM introduced in this study effectively sequesters LAM away from any potential urine-binding protein and concentrates the LAM by a large factor, depending on the input volume of the urine and the output total volume of the nanocages.…”

Capillary zone electrophoresis of lipoarabinomannan by multi‐layered concentration

“…Several publications describe about ionization of neutral saccharides in a highly alkaline electrolyte in CE [19, 20, 25, 27, 28, 31]. In the present study, several electrolyte solutions were tested to obtain ionized saccharides and to lower their concentrations for quantification.…”

“…The work has novelty value in the investigation of electrophoretic properties of LAM, although very preliminary research on LAM has already been described by Sirén et al. [28].…”

Quantification of pyrazinamide, isoniazid, acetyl‐isoniazid, and rifampicin by a high‐performance liquid chromatography method in human plasma from patients with tuberculosis

“…Tuberculosis (TB) is an infectious disease responsible for the death of millions of people every year around the world [1,2]. Plasma concentrations of isoniazid (INH) and rifampicin (RMP) may be different between subjects mainly due to genetic factors, which influence the pharmacokinetics behavior of these drugs.…”