β-D-glucan and S-adenosylmethionine serum levels for the diagnosis of Pneumocystis pneumonia in HIV-negative patients: a prospective study.
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.
de Boer
Mark G J
MG
Department of Infectious Diseases (C5P), Leiden University Medical Center, Leiden, The Netherlands. M.G.J.de_Boer@lumc.nl
Gelinck
Luc B S
LB
van Zelst
Bertrand D
BD
van de Sande
Wendy W J
WW
Willems
Luuk N A
LN
van Dissel
Jaap T
JT
de Jonge
Robert
R
Kroon
Frank P
FP
D000368:Aged; D015415:Biomarkers / Q000097:blood; D005260:Female; D018023:HIV Seronegativity; D006801:Humans; D016867:Immunocompromised Host; D008297:Male; D008875:Middle Aged; D045363:Pneumocystis carinii / Q000302:isolation & purification; D011020:Pneumonia, Pneumocystis / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D011446:Prospective Studies; D011509:Proteoglycans; D012436:S-Adenosylmethionine / Q000097:blood*; D012680:Sensitivity and Specificity; D047071:beta-Glucans / Q000097:blood*
D015415:Biomarkers; D011509:Proteoglycans; D047071:beta-Glucans; C010770:polysaccharide-K; D012436:S-Adenosylmethionine