Clinical characterisation of pneumonia caused by atypical pathogens combining classic and novel predictors.
The aim of this study was to characterise community-acquired pneumonia (CAP) caused by atypical pathogens by combining distinctive clinical and epidemiological features and novel biological markers. A population-based prospective study of consecutive patients with CAP included investigation of biomarkers of bacterial infection, e.g., procalcitonin, C-reactive protein and lipopolysaccharide-binding protein (LBP) levels. Clinical, radiological and laboratory data for patients with CAP caused by atypical pathogens were compared by univariate and multivariate analysis with data for patients with typical pathogens and patients from whom no organisms were identified. Two predictive scoring models were developed with the most discriminatory variables from multivariate analysis. Of 493 patients, 94 had CAP caused by atypical pathogens. According to multivariate analysis, patients with atypical pneumonia were more likely to have normal white blood cell counts, have repetitive air-conditioning exposure, be aged <65 years, have elevated aspartate aminotransferase levels, have been exposed to birds, and have lower serum levels of LBP. Two different scoring systems were developed that predicted atypical pathogens with sensitivities of 35.2% and 48.8%, and specificities of 93% and 91%, respectively. The combination of selected patient characteristics and laboratory data identified up to half of the cases of atypical pneumonia with high specificity, which should help clinicians to optimise initial empirical therapy for CAP.
Masiá
M
M
Infectious Diseases Unit, Internal Medicine Department, Elche. Electronic address: marmasia@ya.com.
Gutiérrez
F
F
Infectious Diseases Unit, Internal Medicine Department, Elche.
Padilla
S
S
Infectious Diseases Unit, Internal Medicine Department, Elche.
Soldán
B
B
Infectious Diseases Unit, Internal Medicine Department, Elche.
Mirete
C
C
Infectious Diseases Unit, Internal Medicine Department, Elche.
Shum
C
C
Respiratory Medicine Section, Hospital General Universitario de Elche, Elche.
Hernández
I
I
Public Health Department, Universidad Miguel Hernández, San Juan de Alicante, Elche, Alicante, Spain.
Royo
G
G
Microbiology Section, Hospital General Universitario de Elche, Elche, Alicante, Spain.
Martin-Hidalgo
A
A
Infectious Diseases Unit, Internal Medicine Department, Elche.
D000209:Acute-Phase Proteins; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000032:analysis; D002116:Calcitonin / Q000097:blood; D015740:Calcitonin Gene-Related Peptide; D002352:Carrier Proteins / Q000097:blood; D017714:Community-Acquired Infections / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology* / Q000821:virology; D005260:Female; D006801:Humans; D007877:Legionnaires' Disease / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood; D008875:Middle Aged; D015999:Multivariate Analysis; D018410:Pneumonia, Bacterial / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology*; D011024:Pneumonia, Viral / Q000175:diagnosis / Q000453:epidemiology; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood; D012680:Sensitivity and Specificity; D012698:Serologic Tests; D000099231:Lipopolysaccharide-Binding Protein
D000209:Acute-Phase Proteins; D002097:C-Reactive Protein; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide; D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D011498:Protein Precursors; D000099231:Lipopolysaccharide-Binding Protein; C000606589:CALCA protein, human