Diagnostic utility of the urine lipoarabinomannan assay for tuberculosis screening in patients with diabetes mellitus

ABSTRACT

Individuals with diabetes have a two- to four-fold increased risk of active tuberculosis (TB), and up to 30% of people with TB are more likely to have diabetes mellitus (DM). Commonly used methods for diagnosing TB include sputum smear microscopy, liquid culture of Mycobacterium tuberculosis (M. tuberculosis) with drug susceptibility testing, tuberculin testing, interferon-γ release assay, lipoarabinomannan (LAM) lateral flow assay, and Xpert MTB/RIF. In this context, this study was conducted to evaluate the diagnostic accuracy of the urine LAM assay in diagnosing TB in individuals with diabetes, as well as the agreement between urine LAM and sputum microscopy and cartridge-based nucleic acid amplification test (CBNAAT). A total of 61 patients with diabetes were included; two sputum samples were collected, one for microscopy and another for CBNAAT, and a urine sample was collected for the LAM assay. Of the 61 patients with diabetes, 47 (77%) were male and 14 (23%) were female. The mean age of the study population was 51.89 years. Of the 61 patients, 35 (57%) were positive by sputum microscopy, 39 (64%) by CBNAAT, and 36 (59%) by urine LAM assay. All patients who tested negative by CBNAAT also tested negative using the urine LAM assay and sputum microscopy, demonstrating complete consistency in results between these diagnostic methods for this subgroup. Hence, the urine LAM assay can be used as a screening test in patients who have difficulty providing sputum samples, as well as in patients with human immunodeficiency virus and pediatric patients.