Lateral flow urine lipoarabinomannan assay for extrapulmonary tuberculosis diagnosis in adults who are HIV-positive

Background The diagnosis of extrapulmonary tuberculosis (EPTB) in patients with HIV remains a challenge for clinicians. The World Health Organization recommends the detection of lipoarabinomannan (LAM) for diagnosing pulmonary tuberculosis in patients with HIV. A new generation of urine LAM tests (FujiLAM®) is available. However, studies regarding its accuracy are limited. Objective This study aimed to evaluate the accuracy of urine LAM tests using FujiLAM® for diagnosing EPTB in patients with HIV. Methods A cross-sectional study using urine samples of patients at Cipto Mangunkusumo Hospital, Indonesia, was performed from January 2020 to December 2020. Fresh urine was applied to the FujiLAM®. Patients were grouped into definitive, probable, and non-TB groups. The diagnostic accuracy of the urine LAM test was compared with other Mycobacterium tuberculosis specimen gold standard tests. Results Among 62 patients, 16 patients (25.8%) had definitive diagnosis of EPTB. Among those with definitive TB, an urine LAM test yielded a sensitivity of 75% (95% confidence interval [CI]: 47.62-92.73%) and specificity of 73.91% (95% CI: 87-85.73%). Meanwhile, compared with all diagnostic tests (definite + probable TB), FujiLAM® had a sensitivity value of 61% (95% CI 43.36-76.86%) and a specificity value of 92.31% (95% CI 74.87-99.05%). Conclusion The FujiLAM® test is a feasible method for diagnosing EPTB in patients with HIV.