High Performance of Systematic Combined Urine Liboarabinomannan Test and Sputum Xpert MTB/RIF for Tuberculosis Screening in Severely Immunosuppressed Ambulatory Adults With Human Immunodeficiency Virus

Abstract

Background: In people with human immunodeficiency virus (PWH), the World Health Organization-recommended tuberculosis (TB) 4-symptom screen (W4SS) targeting those who need molecular rapid testing may be suboptimal. We assessed the performance of different TB screening approaches in severely immunosuppressed PWH enrolled in the guided-treatment group of the STATIS trial (NCT02057796).

Methods: Ambulatory PWH with no overt evidence of TB and CD4 count <100 cells/µL were screened for TB prior to antiretroviral therapy (ART) initiation with W4SS, chest radiograph (CXR), urine lipoarabinomannan (LAM) test, and sputum Xpert MTB/RIF (Xpert). Correctly and wrongly identified cases by screening approaches were assessed overall and by CD4 count threshold (≤50 and 51-99 cells/µL).

Results: Of 525 enrolled participants (median CD4 count, 28 cells/µL), 48 (9.9%) were diagnosed with TB at enrollment. Among participants with a negative W4SS, 16% had either a positive Xpert, a CXR suggestive of TB, or a positive urine LAM test. The combination of sputum Xpert and urine LAM test was associated with the highest proportion of participants correctly identified as TB (95.8%) and non-TB cases (95.4%), with proportions equally high among participants with CD4 counts above or below 50 cells/µL. Restricting the use of sputum Xpert, urine LAM test, or CXR to participants with a positive W4SS reduced the proportion of wrongly and correctly identified cases.

Conclusions: There is a clear benefit to perform both sputum Xpert and urine LAM tests as TB screening in all severely immunosuppressed PWH prior to ART initiation, not only in those with a positive W4SS. Clinical Trials Registration. NCT02057796.

Keywords: HIV; diagnosis; screening; tuberculosis.