CD4 and tuberculosis: Urinary TB lipoarabinomannan (TB-LAM) assay detects the presence of LAM, a cell wall protein of M.tb, especially in HIV-infected people with low CD4 counts, and Xpert MTB/RIF Ultra also detects the presence of M.tb DNA in urine18–20; however, the results of TB-LAM detection have been suboptimal, and there is a paucity of M.tb DNA in urine.