title: Markers to differentiate between Kaposi's sarcoma and tuberculous pleural effusions in HIV-positive patients.
abstract: BACKGROUND
  Kaposi's sarcoma (KS) and tuberculosis (TB) commonly cause pleural effusions in high human immunodeficiency virus (HIV) burden resource-limited countries. Differentiating between them is challenging, as pleural biopsy and TB culture are rarely available.
  
  
  OBJECTIVE
  To identify markers to differentiate between TB effusions and KS effusions in HIV-positive patients, and to compare liquid culture and Xpert MTB/RIF in pleural fluid.
  
  
  METHODS
  Fifty HIV-positive patients with pleural effusions recruited in Malawi underwent pleural ultrasound and aspiration. Fluid visual inspection, cell count, bacterial culture, glucose/protein, solid and liquid TB culture and Xpert were performed.
  
  
  RESULTS
  The mean age of the patients was 32 years; 30/50 (60%) were male and 29 (58%) had cutaneous/oral KS. Thirteen (26%) pleural fluid samples were liquid culture-positive for TB, while 9/13 (69%) were Xpert-positive. Three (10.3%) KS patients had culture-positive TB effusions; 17 (58.6%) had KS effusions. The relative risk of TB in KS patients increased with limited KS, loculated fluid and low glucose. Eleven (52.3%) non-KS patients had culture-positive TB effusions associated with male sex, straw-coloured fluid and fibrin stranding on ultrasound.
  
  
  CONCLUSIONS
  KS patients were most likely to have KS effusion, but TB should be considered. Most non-KS patients had TB, supporting the use of World Health Organization guidelines. Xpert identified two thirds of liquid culture-positive results.
authors.affiliation: College of Medicine, University of Malawi, Blantyre, Malawi; Queen Elizabeth Central Hospital, Blantyre.
authors.forename: M
authors.initials: M
authors.lastname: Coleman
authors.affiliation: Queen Elizabeth Central Hospital, Blantyre, Malawi.
authors.forename: L J
authors.initials: LJ
authors.lastname: Finney
authors.affiliation: College of Medicine, University of Malawi, Blantyre, Malawi; Queen Elizabeth Central Hospital, Blantyre, Malawi.
authors.forename: D
authors.initials: D
authors.lastname: Komrower
authors.affiliation: Queen Elizabeth Central Hospital, Blantyre, Malawi.
authors.forename: A
authors.initials: A
authors.lastname: Chitani
authors.affiliation: College of Medicine, University of Malawi, Blantyre, Malawi.
authors.forename: J
authors.initials: J
authors.lastname: Bates
authors.affiliation: Department of Pathology and Medical Laboratory Sciences, College of Medicine, Blantyre, Malawi.
authors.forename: G A
authors.initials: GA
authors.lastname: Chipungu
authors.affiliation: London School of Hygiene & Tropical Medicine, Infectious and Tropical Diseases, London, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, TB Research Unit, Blantyre, Malawi.
authors.forename: E
authors.initials: E
authors.lastname: Corbett
authors.affiliation: College of Medicine, University of Malawi, Blantyre, Malawi; Queen Elizabeth Central Hospital, Blantyre, Malawi.
authors.forename: T J
authors.initials: TJ
authors.lastname: Allain
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D015658:HIV Infections / Q000150:complications*; D006801:Humans; D008295:Malawi; D008297:Male; D008875:Middle Aged; D010996:Pleural Effusion / Q000175:diagnosis* / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods; D011446:Prospective Studies; D012514:Sarcoma, Kaposi / Q000175:diagnosis* / Q000821:virology; D014396:Tuberculosis, Pleural / Q000175:diagnosis* / Q000382:microbiology; D055815:Young Adult