title: Serum and bal beta-D-glucan for the  diagnosis of Pneumocystis pneumonia in HIV  positive patients.
abstract: OBJECTIVE
  The diagnosis of patients with pulmonary infiltrates and human immunodeficiency virus (HIV) infection remains a challenge. In current clinical practice the gold standard for Pneumocystis jirovecii pneumonia (PCP) diagnosis remains the identification of the organism in bronco alveolar lavage (BAL) using microscopy (e.g., silver stain). (1->3)-β -d-glucan (BG) is a polysaccharide that is present within the cell wall of Pneumocystis and other fungi.
  
  
  METHODS
  We analyzed serum and BAL lavage fluid from a cohort of 119 patients that did have HIV, a diagnosis of pneumonia and underwent bronchoscopy (FOB) for diagnosis of PCP.
  
  
  RESULTS
  The discriminative power of serum BG for the diagnosis of PCP in this group of patients was very high. Using a cutoff of 300 pg/mL, the sensitivity, specificity, positive predictive value(PPV) and negative predictive value (NPV) were 91%, 92%, 89% and 93% respectively. A model for ROC with just serum BG (N = 108) had an AUC of 0.95. Serum procalcitonin (PCT) and BAL BG were not as accurate for the diagnosis of PCP. For BAL BG using a cutoff of 783 pg/mL, the sensitivity,specificity, positive predictive value (PPV) and negative predictive value (NPV) were 72%, 79%,72% and 79% respectively. The differences between the medians for serum PCT between the group with a without PCP did not reach statistical significance (p = 0.6137).
  
  
  CONCLUSIONS
  The measurement of serum BG should be incorporated in the diagnostic work up of HIV positive patients with dyspnea and infiltrates on chest X X-ray. Our study confirms the diagnostic value of serum BG previously reported by others but we add a cutoff value that we believe is more accurate for patients with AIDS and suspicion of PCP.
authors.affiliation: School of Medicine, Tulane University, New Orleans, LA, USA. dsalerno@tulane.edu
authors.forename: D
authors.initials: D
authors.lastname: Salerno
authors.forename: D
authors.initials: D
authors.lastname: Mushatt
authors.forename: L
authors.initials: L
authors.lastname: Myers
authors.forename: Y
authors.initials: Y
authors.lastname: Zhuang
authors.forename: N
authors.initials: N
authors.lastname: de la Rua
authors.forename: E J
authors.initials: EJ
authors.lastname: Calderon
authors.forename: D A
authors.initials: DA
authors.lastname: Welsh
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000175:diagnosis* / Q000276:immunology; D000328:Adult; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D018791:CD4 Lymphocyte Count; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011020:Pneumonia, Pneumocystis / Q000175:diagnosis* / Q000276:immunology; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D047071:beta-Glucans / Q000032:analysis* / Q000097:blood
chemical_list: D015415:Biomarkers; D047071:beta-Glucans