Measuring (1,3)-β-D-glucan in tracheal aspirate, bronchoalveolar lavage fluid, and serum for detection of suspected Candida pneumonia in immunocompromised and critically ill patients: a prospective observational study.
BACKGROUND
While Candida pneumonia is life-threatening, biomarker measurements to early detect suspected Candida pneumonia are lacking. This study compared the diagnostic values of measuring levels of (1, 3)-β-D-glucan in endotracheal aspirate, bronchoalveolar lavage fluid, and serum to detect suspected Candida pneumonia in immunocompromised and critically ill patients.


METHODS
This prospective, observational study enrolled immunocompromised, critically ill, and ventilated patients with suspected fungal pneumonia in mixed intensive care units from November 2010 to October 2011. Patients with D-glucan confounding factors or other fungal infection were excluded. Endotracheal aspirate, bronchoalveolar lavage fluid and serum were collected from each patient to perform a fungal smear, culture, and D-glucan assay.


RESULTS
After screening 166 patients, 31 patients completed the study and were categorized into non-Candida pneumonia/non-candidemia (n = 18), suspected Candida pneumonia (n = 9), and non-Candida pneumonia/candidemia groups (n = 4). D-glucan levels in endotracheal aspirate or bronchoalveolar lavage were highest in suspected Candida pneumonia, while the serum D-glucan level was highest in non-Candida pneumonia/candidemia. In all patients, the D-glucan value in endotracheal aspirate was positively correlated with that in bronchoalveolar lavage fluid. For the detection of suspected Candida pneumonia, the predictive performance (sensitivity/specificity/D-glucan cutoff [pg/ml]) of D-glucan in endotracheal aspirate and bronchoalveolar lavage fluid was 67%/82%/120 and 89%/86%/130, respectively, accounting for areas under the receiver operating characteristic curve of 0.833 and 0.939 (both P < 0.05), respectively. Measuring serum D-glucan was of no diagnostic value (area under curve =0.510, P = 0.931) for the detection of suspected Candida pneumonia in the absence of concurrent candidemia.


CONCLUSIONS
D-glucan levels in both endotracheal aspirate and bronchoalveolar lavage, but not in serum, provide good diagnostic values to detect suspected Candida pneumonia and to serve as potential biomarkers for early detection in this patient population.
['Su|Kang-Cheng|KC|', 'Chou|Kun-Ta|KT|', 'Hsiao|Yi-Han|YH|', 'Tseng|Ching-Min|CM|', 'Su|Vincent Yi-Fong|VY|', 'Lee|Yu-Chin|YC|', 'Perng|Diahn-Warng|DW|', 'Kou|Yu Ru|YR|']
D000328:Adult D000368:Aged D015415:Biomarkers D001992:Bronchoalveolar Lavage Fluid D058387:Candidemia D002177:Candidiasis D016638:Critical Illness D042241:Early Diagnosis D005260:Female D006801:Humans D016867:Immunocompromised Host D007362:Intensive Care Units D008297:Male D008875:Middle Aged D011014:Pneumonia D011446:Prospective Studies D011509:Proteoglycans D012680:Sensitivity and Specificity D047071:beta-Glucans
(1,3)-β-D-glucan Bronchoalveolar lavage Candida pneumonia Critically ill patients Intensive care unit Diagnosis