title: Predictive and prognostic properties of TB-LAM among HIV-positive patients initiating ART in Johannesburg, South Africa.
abstract: While the diagnostic properties of the TB LAM urine assay (LAM) have been well-described, little is known about its predictive and prognostic properties at ART initiation in a routine clinic setting. We describe the predictive and prognostic properties of LAM in HIV-positive patients initiating ART at an urban hospital in Johannesburg, South Africa. Retrospective study of HIV-positive adults (>18 years) who initiated standard first-line ART between February 2012 and April 2013 and had a LAM test at initiation. In HIV-positive patients with no known TB at ART initiation, we assessed the sensitivity, specificity and positive/negative likelihood ratios of LAM to predict incident TB within 6 months of ART initiation. In addition, in patients with a TB diagnosis and on TB treatment <3 months at ART initiation, we measured the CD4 response at 6 months on ART. Of the 274 patients without TB at ART initiation, 65% were female with median CD4 count of 213 cells/mm(3). Among the 14 (5.1%) patients who developed active TB, none were urine LAM +ve at baseline. LAM had poor sensitivity (0.0% 95% CI 0.00-23.2) to predict incident TB within 6 months of initiation. We analyzed 22 patients with a confirmed TB diagnosis at initiation separately. Of these, LAM +ve patients (27%) showed lower CD4 gains compared to LAM negative patients (median increase 103 vs 199 cells/mm(3); p = 0.08). LAM has limited value for accurately predicting incident TB in patients with higher CD4 counts after ART initiation. LAM may help identify TB/HIV co-infected patients at ART initiation who respond more slowly to treatment and require targeted interventions to improve treatment outcomes. Larger studies with longer patient follow-up are needed.
authors.affiliation: Department of Infectious Diseases, Sahlgrenska University Hospital, Gothenburg, 40032, Sweden.
authors.forename: Alexander
authors.initials: A
authors.lastname: d'Elia
authors.affiliation: Health Economics and Epidemiology Research Office, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, 2193, South Africa.
authors.forename: Denise
authors.initials: D
authors.lastname: Evans
authors.affiliation: Clinical HIV Research Unit, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, 2193, South Africa.
authors.forename: Lynne
authors.initials: L
authors.lastname: McNamara
authors.affiliation: Health Economics and Epidemiology Research Office, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, 2193, South Africa ; Right To Care, Helen Joseph Hospital, Perth Road, Johannesburg, 2092, South Africa.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Berhanu
authors.affiliation: Clinical HIV Research Unit, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, 2193, South Africa ; Right To Care, Helen Joseph Hospital, Perth Road, Johannesburg, 2092, South Africa.
authors.forename: Ian
authors.initials: I
authors.lastname: Sanne
authors.affiliation: Department of Infectious Diseases, Sahlgrenska University Hospital, Gothenburg, 40032, Sweden.
authors.forename: Elisabet
authors.initials: E
authors.lastname: Lönnermark
mesh_terms: D000328:Adult; D018791:CD4 Lymphocyte Count; D060085:Coinfection; D005260:Female; D015658:HIV Infections / Q000150:complications*; D006801:Humans; D008070:Lipopolysaccharides / Q000652:urine*; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013019:South Africa; D014376:Tuberculosis / Q000150:complications / Q000175:diagnosis*
chemical_list: D008070:Lipopolysaccharides; C050016:lipoarabinomannan
keywords: Antiretroviral therapy; HIV; Mycobacterium; South Africa; TB LAM; lipoarabinomannan