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

TitleTest performance of blood beta-glucan for Pneumocystis jirovecii pneumonia in patients with AIDS and respiratory symptoms.
Publication TypeJournal Article
Year of Publication2013
AuthorsWood BR, Komarow L, Zolopa AR, Finkelman MA, Powderly WG, Sax PE
JournalAIDS
Volume27
Issue6
Pagination967-72
Date Published2013 Mar 27
ISSN1473-5571
KeywordsAcquired Immunodeficiency Syndrome, AIDS-Related Opportunistic Infections, beta-Glucans, Biomarkers, Humans, Plasma, Pneumocystis jirovecii, Pneumonia, Pneumocystis, Predictive Value of Tests, Randomized Controlled Trials as Topic
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.

DOI10.1097/QAD.0b013e32835cb646
Alternate JournalAIDS
PubMed ID23698062
PubMed Central IDPMC4181577
Grant List1 U01 AI068634 / AI / NIAID NIH HHS / United States
5U01AI069472-05 / AI / NIAID NIH HHS / United States
U01 AI068634 / AI / NIAID NIH HHS / United States
U01 AI068636 / AI / NIAID NIH HHS / United States
UM1 AI069412 / AI / NIAID NIH HHS / United States