Counterimmunoelectrophoresis in the diagnosis of acute infection

Clinical experience with counterimmunoelectrophoresis (CIE) in a large university teaching center was reviewed for 1,042 specimens from 667 patients over a 2,5-year period. Urine was the fluid tested most frequently, and infants six to 12 months of age were most frequently positive. For analysis, diagnostic categories were separated into meningitis and nonmeningitis infections. CIE identified 69% of the patients with meningitis, with an early diagnostic with an early diagnostic value over the Gram stain of 25% but with a residual diagnostic-value postculture report in only 9% of these patients. In patients with nonmeningitis infections, however, the early diagnostic value was 49% overall and 74% for pneumonia, with a residual diagnostic-value postculture report of 25% overall and 47% for pneumonia. Cross-reactions were observed in two patients. Thus, CIE appears to be most useful as an ancillary diagnostic test in culture-negative patients.