Investigation of urine lipoarabinomannan in human immunodeficiency virus patients with or without coinfection with Tuberculosis in Iran

Abstract

© 2016 Objective/background Tuberculosis (TB) remains the leading cause of AIDS-related deaths among adults in countries with resource limitations. The emergence of the Xpert MTB/RIF rapid molecular assay and its subsequent World Health Organization endorsement in 2010 transformed the TB-diagnostic landscape. Xpert provided diagnostic accuracy that was far superior to that of the sputum-smear microscopy test previously used. The detection of mycobacterial lipoarabinomannan (LAM) antigen in urine has emerged as a potential point-of-care test for TB. LAM antigen is a lipopolysaccharide present in mycobacterial cell walls which is released from metabolically active or degenerating bacterial cells and appears to be present only in people with active TB. Urine-based testing has advantages over sputum-based testing because urine is easy to collect and store and lacks the infection control risks associated with sputum collection. A previously study reported that urinary-LAM testing is a rapid, low-cost, ante-mortem diagnosis for human immunodeficiency virus (HIV)-associated TB. The objective of this study was to investigate the levels of LAM in HIV patients referred to the Mashih Daneshvari Hospital Tehran, Iran. Methods Urine from 31 HIV patients without TB, 33 HIV patients with pulmonary TB, and eight HIV patients with extrapulmonary TB was analyzed for LAM using enzyme-linked immunosorbent assay kits (Mybiosource, San Diego, CA, USA). Results The plasma levels of LAM in pulmonary TB/HIV patients was 7.67 ± 2.3 ng/ml compared with 4.5 ± 1.6 ng/ml in extrapulmonary TB/HIV and 6.7 ± 1.2 ng/ml in HIV patients without TB. There was no significant difference in urine LAM levels between the three groups. Conclusion Our results highlight the limitations of using urine LAM levels for differentiating HIV-associated TB patients in Iran.