Blood (1->3)-beta-D-glucan as a diagnostic test for HIV-related Pneumocystis jirovecii pneumonia

Clin Infect Dis. 2011 Jul 15;53(2):197-202. doi: 10.1093/cid/cir335.

Abstract

(See the editorial commentary by Morris and Masur, on pages 203-204.)

Background: Improved noninvasive diagnostic tests for Pneumocystis jirovecii pneumonia (PCP) are needed. We evaluated the test characteristics of plasma (1 → 3)-β-D-glucan (β-glucan) for HIV-related PCP among a large group of patients presenting with diverse opportunistic infections (OIs).

Methods: The study population included all 282 participants in AIDS Clinical Trials Group A5164, a study of early versus deferred antiretroviral therapy in conjunction with initial therapy of acute OIs. Baseline plasma samples were assayed for β-glucan, with standard assay reference values defining ≥ 80 pg/mL as positive. Before this analysis, diagnosis of PCP was independently adjudicated by 2 study investigators after reviewing reports from study sites.

Results: A total of 252 persons had a β-glucan result that could be analyzed, 173 (69%) of whom had received a diagnosis of PCP. Median β-glucan with PCP was 408 pg/mL (interquartile range [IQR], 209-500 pg/mL), compared with 37 pg/mL (IQR, 31-235 pg/mL) without PCP (P < .001). The sensitivity of β-glucan dichotomized at 80 pg/mL for the diagnosis of PCP was 92% (95% confidence interval [CI], 87%-96%), and the specificity was 65% (95% CI, 53%-75%); positive and negative predictive values were 85% (95% CI, 79%-90%) and 80% (95% CI, 68%-89%) respectively, based on the study prevalence of 69% of patients with PCP. Rates of abnormal lactate dehyrogenase levels did not differ significantly between those with and without PCP.

Conclusions: Blood (1 → 3)-β-D-glucan is strongly correlated with HIV-related PCP. In some clinical centers, this may be a more sensitive test than the induced sputum examination and could reduce the need for both bronchoscopy and empirical therapy of PCP.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Diagnostic Tests, Routine / methods*
  • Female
  • HIV Infections / complications*
  • Humans
  • Male
  • Plasma / chemistry
  • Plasma / immunology
  • Pneumocystis carinii / chemistry*
  • Pneumocystis carinii / immunology
  • Pneumonia, Pneumocystis / diagnosis*
  • Predictive Value of Tests
  • Sensitivity and Specificity
  • beta-Glucans / blood*
  • beta-Glucans / immunology

Substances

  • beta-Glucans
  • polysaccharide-K