Diagnóstico etiológico dos derrames pleurais através do teste de aglutinação de partículas de látex

Abstract

Introduction: An increase in the incidence of pleural effusion in children has been reported since the last decade in international research centers, perhaps due to inappropriate use of antibiotics, or delayed diagnosis, or presence of unusual etiologic agents. According to the Guidelines of the British Thorax Society, the identification of the infecting organism in the pleural fluid varies from 8 to 76% according to the technique used (culture, Gram stain, polymerase chain reaction). Objective: To evaluate the applicability of the latex particle agglutination test (LPAT) to detect antigens of different serotypes of Streptococcus pneumoniae and Haemophilus influenzae type b in patients with pleural effusion, through the comparison with the contraimunoeletroforese (CIE).Methods: Between 1996 and 2003, were collected and submitted to LPAT and CIE, 418 samples of pleural fluid from children and adolescents younger than 18 years of age with clinical symptoms compatible with parapneumonic effusion or pleural empyema. Results: The sensitivity and specificity of LPAT compared with CIE were 98.5% (95% CI, 92.5 99.9) and 83.3% (95% CI, 79.1 86.9), respectively, while the positive and negative predictive values were respectively 52.0% (95% CI, 43.2 60.7) and 99.7% (95% CI, 98.3 - 99.9). Conclusions: LPAT as an immunodiagnostic test is a simple technique, easy execution, cost-effective and useful in etiologic diagnosis of pleural effusion,beyond the little influence of the previous use of antibiotics.