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.
Department of Infectious Diseases (C5P), Leiden University Medical Center, Leiden, The Netherlands. M.G.J.de_Boer@lumc.nl
Mark G J
MG
de Boer
Luc B S
LB
Gelinck
Bertrand D
BD
van Zelst
Wendy W J
WW
van de Sande
Luuk N A
LN
Willems
Jaap T
JT
van Dissel
Robert
R
de Jonge
Frank P
FP
Kroon
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