title: Is Urinary Lipoarabinomannan the Result of Renal Tuberculosis? Assessment of the Renal Histology in an Autopsy Cohort of Ugandan HIV-Infected Adults.
abstract: OBJECTIVE
  The detection of urinary lipoarabinomannan (LAM), a mycobacterial cell wall component, is used to diagnose tuberculosis (TB). How LAM enters the urine is not known. To investigate if urinary LAM-positivity is the result of renal TB infection we correlated the outcomes of urinary LAM-antigen testing to renal histology in an autopsy cohort of hospitalized, Ugandan, HIV-infected adults.
  
  
  METHODS
  We performed a complete autopsy, including renal sampling, in HIV-infected adults that died during hospitalization after written informed consent was obtained from the next of kin. Urine was collected postmortem through post-mortem catheterisation or by bladder puncture and tested for LAM with both a lateral flow assay (LFA) and an ELISA assay. Two pathologists assessed the kidney histology. We correlated the LAM-assay results and the histology findings.
  
  
  RESULTS
  Of the 13/36 (36%) patients with a positive urinary LAM ELISA and/or LFA, 8/13 (62%) had renal TB. The remaining 5 LAM-positive patients had disseminated TB without renal involvement. Of the 23 LAM-negative patients, 3 had disseminated TB without renal involvement. The remaining LAM-negative patients had no TB infection and died mostly of fungal and bacterial infections. LAM LFA had a sensitivity of 81% and specificity of 100% to diagnose TB at any location, and the LAM ELISA a sensitivity of 63% and a specificity of 100%. 54% (7/13) LAM LFA-positive patients were not on anti-TB treatment at the time of death.
  
  
  CONCLUSIONS
  Renal TB infection explained LAM-positivity in the majority of patients. Patients with disseminated TB without renal involvement can also be diagnosed with LAM. This suggests that other mechanisms that lead to urinary LAM-positivity exist in a minority of patients.
authors.affiliation: Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium; Infectious Diseases Institute, Makerere University College of Health Sciences, Kampala, Uganda.
authors.forename: Janneke A
authors.initials: JA
authors.lastname: Cox
authors.affiliation: Department of Pathology, College of Health Sciences, Makerere University, Kampala, Uganda.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Lukande
authors.affiliation: Department of Pathology, College of Health Sciences, Makerere University, Kampala, Uganda; Department of Pathology, Mulago Hospital Complex, Kampala, Uganda.
authors.forename: Sam
authors.initials: S
authors.lastname: Kalungi
authors.affiliation: Department of Pathology, University Hospital Antwerp, University of Antwerp, Belgium.
authors.forename: Eric
authors.initials: E
authors.lastname: Van Marck
authors.affiliation: Department of Diagnostic Oncology & Molecular Pathology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: Koen
authors.initials: K
authors.lastname: Van de Vijver
authors.affiliation: Infectious Diseases Institute, Makerere University College of Health Sciences, Kampala, Uganda.
authors.forename: Andrew
authors.initials: A
authors.lastname: Kambugu
authors.affiliation: Joint Pathology Center, Silver Spring, United States of America.
authors.forename: Ann M
authors.initials: AM
authors.lastname: Nelson
authors.affiliation: Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium; Department of Epidemiology and Social Medicine, University of Antwerp, Belgium.
authors.forename: Robert
authors.initials: R
authors.lastname: Colebunders
authors.affiliation: Infectious Diseases Institute, Makerere University College of Health Sciences, Kampala, Uganda; Division of Infectious Diseases, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Yukari C
authors.initials: YC
authors.lastname: Manabe
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000652:urine; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000652:urine*; D006801:Humans; D007668:Kidney / Q000382:microbiology / Q000473:pathology*; D008070:Lipopolysaccharides / Q000652:urine*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D014398:Tuberculosis, Renal / Q000652:urine*; D014454:Uganda
chemical_list: D015415:Biomarkers; D008070:Lipopolysaccharides; C050016:lipoarabinomannan