Test performance of blood beta-glucan for Pneumocystis jirovecii pneumonia in patients with AIDS and respiratory symptoms.

Abstract

OBJECTIVE:

The objective of this study was to define the test characteristics of plasma beta-glucan for diagnosis of Pneumocystis jirovecii pneumonia (PCP) in AIDS patients with respiratory symptoms.

DESIGN:

Analysis of baseline blood samples in a randomized strategy study of patients with acute opportunistic infections, limited to participants with respiratory symptoms.

METHODS:

Participants in the 282-person ACTG A5164 trial had baseline plasma samples assayed for beta-glucan testing. As part of A5164 trial, two study investigators independently adjudicated the diagnosis of PCP. Respiratory symptoms were identified by investigators from a list of all signs and symptoms with an onset or resolution in the 21 days prior to or 14 days following study entry. Beta-glucan was defined as positive if at least 80 pg/ml and negative if less than 80 pg/ml.

RESULTS:

Of 252 study participants with a beta-glucan result, 159 had at least one respiratory symptom, 139 of whom had a diagnosis of PCP. The sensitivity of beta-glucan for PCP in participants with respiratory symptoms was 92.8% [95% confidence interval (CI) 87.2-96.5], and specificity 75.0% (95% CI 50.9-91.3). Among 134 individuals with positive beta-glucan and respiratory symptoms, 129 had PCP, for a positive predictive value of 96.3% (95% CI 91.5-98.8). Fifteen of 25 patients with a normal beta-glucan did not have PCP, for a negative predictive value of 60% (95% CI 38.7-78.9).

CONCLUSION:

Elevated plasma beta-glucan has a high predictive value for diagnosis of PCP in AIDS patients with respiratory symptoms. We propose an algorithm for the use of beta-glucan as a diagnostic tool on the basis of the pretest probability of PCP in such patients.

• Authors: Brian R Wood, Lauren Komarow, Andrew R Zolopa, Malcolm A Finkelman, William G Powderly, Paul E Sax
• Journal: AIDS (London, England) (AIDS) Vol. 27 Issue 6 Pg. 967-972 (Mar 27 2013) ISSN: 1473-5571 [Electronic] England
• PMID: 23698062 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Biomarkers
• beta-Glucans

Topics

• AIDS-Related Opportunistic Infections (diagnosis, pathology)
• Acquired Immunodeficiency Syndrome (complications)
• Biomarkers (blood)
• Humans
• Plasma (chemistry)
• Pneumocystis carinii (chemistry)
• Pneumonia, Pneumocystis (diagnosis, pathology)
• Predictive Value of Tests
• Randomized Controlled Trials as Topic
• beta-Glucans (blood)