Contribution of the determination of soluble antigens to the diagnosis of Streptococcus pneumoniae pneumopathies

We studied the diagnostic value of the detection of soluble pneumococcal antigens by counter-immunoelectrophoresis (ES) in patients with pneumonia. Pneumococcal antigens were detected in blood, urine and pleural fluid. 59 patients were distributed into 3 groups: (Group 1) - 19 patients with a non-pneumococcal, but bacteriologically-proven pneumonia, (Group 2)-32 patients with a bacteriologically confirmed pneumococcal pneumonia, (Group 3)-8 patients with a non-bacteriologically proven pneumonia, but with pneumococcal antigens. No Group 1 patients had pneumococcal antigens. In Group 2 pneumococcal antigens were present in 15 cases. The sensitivity of ES in the detection of soluble pneumococcal antigens (APS) in the blood, urine and pleural fluid during pneumococcal pneumonias was 57.5%. There was a diagnostic benefit when compared to bacteriological analysis alone of 20%. We believe that ES is a useful complementary examination to classical bacteriology.