Interleukin-1 beta in pleural fluids of different etiologies. Its role as inflammatory mediator in empyema.
OBJECTIVE
To measure interleukin-1 beta (IL-1 beta) levels in pleural effusions of different etiologies and their relationship with several pleural inflammatory parameters, and to verify whether IL-1 beta can be used as diagnostic marker in the differential diagnosis of pleural diseases.


METHODS
One hundred two pleural effusions were analyzed using a monoclonal antibody enzyme-linked immunosorbent assay. Pleural fluids were classified as follows: transudates (n = 28), empyema (n = 14), parapneumonic (n = 13), tuberculous (n = 19), neoplastic (n = 17), and miscellaneous effusions (n = 11).


RESULTS
IL-1 beta was above 200 pg/mL in all the patients with empyema but only in three patients with other etiologies. Two of those three had parapneumonic effusions and the remaining one had a tuberculous pleurisy with a previous bacterial empyema. No significant relationships were found between pleural effusion IL-1 beta levels and the different inflammatory parameters analyzed. As a diagnostic criterion for empyema, pleural IL-1 beta concentration greater than 200 pg/mL had a sensitivity of 100%, a specificity of 96%, and a positive and negative predictive value of 0.82 and 1, respectively.


CONCLUSIONS
Our data suggest that IL-1 beta has a significant role in pyogenic infections of the pleural space but not in effusions of other etiologies. It could be used as a diagnostic marker of empyema.
Silva-Mejías
C
C
Infectious Diseases Unit, Hospital Universitario Virgen del Rocío, Sevilla, Spain.
Gamboa-Antiñolo
F
F
López-Cortés
L F
LF
Cruz-Ruiz
M
M
Pachón
J
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D016724:Empyema, Pleural / Q000175:diagnosis / Q000209:etiology / Q000378:metabolism*; D004654:Empyema, Tuberculous / Q000175:diagnosis / Q000209:etiology / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis*; D007375:Interleukin-1 / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D010996:Pleural Effusion / Q000737:chemistry* / Q000175:diagnosis / Q000209:etiology; D016066:Pleural Effusion, Malignant / Q000737:chemistry* / Q000175:diagnosis / Q000209:etiology; D018709:Statistics, Nonparametric
D015415:Biomarkers; D018836:Inflammation Mediators; D007375:Interleukin-1