Prognostic value of procalcitonin in Legionella pneumonia.
The diagnostic reliability and prognostic implications of procalcitonin (PCT) (ng/ml) on admission in patients with community-acquired pneumonia (CAP) due to Legionella pneumophila are unknown. We retrospectively analysed PCT values in 29 patients with microbiologically proven Legionella-CAP admitted to the University Hospital Basel, Switzerland, between 2002 and 2007 and compared them to other markers of infection, namely, C-reactive protein (CRP) (mg/l) and leukocyte count (10(9)/l), and two prognostic severity assessment scores (PSI and CURB65). Laboratory analysis demonstrated that PCT values on admission were >0.1 in over 93%, >0.25 in over 86%, and >0.5 in over 82% of patients with Legionella-CAP. Patients with adverse medical outcomes (59%, n = 17) including need for ICU admission (55%, n = 16) and/or inhospital mortality (14%, n = 4) had significantly higher median PCT values on admission (4.27 [IQR 2.46-9.48] vs 0.97 [IQR 0.29-2.44], p = 0.01), while the PSI (124 [IQR 81-147] vs 94 [IQR 75-116], p = 0.19), the CURB65 (2 [IQR 1-2] vs 1 [1-3], p = 0.47), CRP values (282 [IQR 218-343], p = 0.28 vs 201 [IQR 147-279], p = 0.28), and leukocyte counts (12 [IQR 10-21] vs 12 [IQR 9-15], p = 0.58) were similar. In receiver operating curves, PCT concentrations on admission had a higher prognostic accuracy to predict adverse outcomes (AUC 0.78 [95%CI 0.61-96]) as compared to the PSI (0.64 [95%CI 0.43-0.86], p = 0.23), the CURB65 (0.58 [95%CI 0.36-0.79], p = 0.21), CRP (0.61 [95%CI 0.39-0.84], p = 0.19), and leukocyte count (0.57 [95%CI 0.35-0.78], p = 0.12). Kaplan-Meier curves demonstrated that patients with initial PCT values above the optimal cut-off of 1.5 had a significantly higher risk of death and/or ICU admission (log rank p = 0.003) during the hospital stay. In patients with CAP due to Legionella, PCT levels on admission might be an interesting predictor for adverse medical outcomes.
Haeuptle
J
J
Department of Internal Medicine, University Hospital Basel, Basel, Switzerland.
Zaborsky
R
R
Fiumefreddo
R
R
Trampuz
A
A
Steffen
I
I
Frei
R
R
Christ-Crain
M
M
Müller
B
B
Schuetz
P
P
D000368:Aged; D002097:C-Reactive Protein / Q000032:analysis; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D017714:Community-Acquired Infections / Q000382:microbiology*; D005260:Female; D006801:Humans; D016952:Legionella pneumophila / Q000302:isolation & purification*; D007877:Legionnaires' Disease / Q000175:diagnosis*; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011498:Protein Precursors / Q000097:blood*; D012372:ROC Curve; D012189:Retrospective Studies; D012720:Severity of Illness Index; D016019:Survival Analysis; D013557:Switzerland
C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide