Limitations of Countercurrent Immunoelectrophoresis (CIE) in the Diagnosis of Empyema

Abstract

Infectious agents are the most common cause of pleural effusions in children, developing more commonly during the course of bacterial pneumonias and less frequently associated with viral, mycobacterial, and fungal respiratory infections. Immunologic techniques, such as countercurrent immunoelectrophoresis (CIE), are often more valuable than cultures in establishing a specific etiologic diagnosis in children. In seven of the ten cases of empyema in childhood reported by Siegel et al,1 CIE was positive, while cultures of blood and pleural fluid were negative. Antibiotics had been given in each of these seven cases of sterile pleural effusion. The article by Holsclaw and Schaeffer in this issue of Chest (see page 867) reports the successful use of this technique to identify the specific etiologic agent in sterile pleural effusion in a puzzling case clinically suggestive of rheumatic fever or varicella prodrome. CIE is a rapid and sensitive method for identifying as little as .05 to 0.1 µg of several different types of pneumococcal antigens or Hemophilus influenzae, type B (Hi B) antigen. This is an especially useful diagnostic method when the patient previously has been given antimicrobial drugs or the infection has become subacute.