β-D-glucan and S-adenosylmethionine serum levels for the diagnosis of Pneumocystis pneumonia in HIV-negative patients: a prospective study

J Infect. 2011 Jan;62(1):93-100. doi: 10.1016/j.jinf.2010.10.007. Epub 2010 Oct 21.

Abstract

Objective: To prospectively assess the diagnostic utility of S-adenosylmethionine (AdoMet) and (1→3)-β-D-glucan (β-D-glucan) serum markers for Pneumocystis pneumonia (PCP) in HIV-negative patients.

Methods: HIV-negative, immunocompromised patients suspected of PCP based on clinical presentation and chest imaging were included. PCP was confirmed or rejected by results of direct microscopy and/or real-time PCR on broncho-alveolar lavage (BAL) fluid. Measurement of serum β-D-glucan and AdoMet was performed on serum samples collected at enrollment and during follow-up. Both serum β-D-glucan and AdoMet were assessed for diagnostic accuracy and correlation with clinical and laboratory parameters.

Results: In 31 patients enrolled (21 PCP-positive, 10 PCP-negative), AdoMet levels did not discriminate between patients with and without PCP. Elevated serum β-D-glucan was a reliable indicator for PCP with a sensitivity of 0.90 and specificity of 0.89 at the 60 pg/ml cut-off. In PCP-positive patients β-D-glucan serum levels decreased during treatment and inversely correlated with Pneumocystis PCR cycle threshold values in BAL fluid.

Conclusions: The level of β-D-glucan--but not AdoMet--was diagnostic for PCP within the clinical context and may serve as marker for pulmonary fungal load and treatment monitoring.

MeSH terms

  • Aged
  • Biomarkers / blood
  • Female
  • HIV Seronegativity
  • Humans
  • Immunocompromised Host
  • Male
  • Middle Aged
  • Pneumocystis carinii / isolation & purification
  • Pneumonia, Pneumocystis / blood
  • Pneumonia, Pneumocystis / diagnosis*
  • Pneumonia, Pneumocystis / immunology
  • Prospective Studies
  • Proteoglycans
  • S-Adenosylmethionine / blood*
  • Sensitivity and Specificity
  • beta-Glucans / blood*

Substances

  • Biomarkers
  • Proteoglycans
  • beta-Glucans
  • polysaccharide-K
  • S-Adenosylmethionine