Lipoarabinomannan as a Point-of-Care Assay for Diagnosis of Tuberculosis: How Far Are We to Use It?

Abstract

Tuberculosis (TB) is still a severe public health problem; the current diagnostic tests have limitations that delay treatment onset. Lipoarabinomannan (LAM) is a glycolipid that is a component of the cell wall of the bacillus Mycobacterium tuberculosis, the etiologic agent of TB. This glycolipid is excreted as a soluble form in urine. The World Health Organization has established that the design of new TB diagnostic methods is one of the priorities within the EndTB Strategy. LAM has been suggested as a biomarker to develop diagnostic tests based on its identification in urine, and it is one of the most prominent candidates to develop point-of-care diagnostic test because urine samples can be easily collected. Moreover, LAM can regulate the immune response in the host and can be found in the serum of TB patients, where it probably affects a wide variety of host cell populations, consequently influencing the quality of both innate and adaptive immune responses during TB infection. Here, we revised the evidence that supports that LAM could be used as a tool for the development of new point-of-care tests for TB diagnosis, and we discussed the mechanisms that could contribute to the low sensitivity of diagnostic testing.

Value of urine-based lipoarabinomannan (LAM) antigen tests for diagnosing tuberculosis in children: systematic review and meta-analysis

“…The detection of LAM has been endorsed as a diagnostic tool by WHO, and enzyme-linked immunosorbent assays (ELISA) and lateral flow assays are commercially available ( Whitelaw and Sturm, 2010 ). During M. tuberculosis infection, LAM exists in various body fluids; therefore, it can be an ideal candidate biomarker for the detection of M. tuberculosis ( Flores et al., 2021 ). In recent years, novel urine-based LAM antigen detection technology has been developed, including the Fujifilm SILVAMP TB LAM (Fuji LAM) test and the Alere Determine TB LAM Ag (Alere LAM) test ( Bulterys et al., 2019 ).…”

The Value of FujiLAM in the Diagnosis of Tuberculosis: A Systematic Review and Meta-Analysis

“…Lipoarabinomannan (LAM) is a specific component of the cell envelope of M. tuberculosis ( 7 ). During M. tuberculosis infection, LAM exists in a variety of body fluids; therefore, it can be an ideal candidate biomarker for detecting M. tuberculosis ( 8 ). More meaningfully, Nathavitharana et al found that using lateral flow lipoarabinomannan assay (LF-LAM) as part of a TB diagnostic testing strategy likely reduced mortality and probably resulted in a slight increase in anti-tuberculosis therapy initiation in HIV patients ( 9 ).…”

Drug-resistant tuberculosis: advances in diagnosis and management

“…Nonsputum based tests are required in particular for diagnosis of EPTB, people living with HIV and in children. The next-generation lipoarabinomannan (LAM) test are showing improved performance over original LAM tests [7,8], but don’t detect TB drug resistance. WHO guidelines on TB diagnosis, updated in 2021, summarize the current evidence and recommendations on TB diagnosis [9].…”