Specificity of Cardiolipin Antigens in Tests for Syphilis

Abstract

Approx. 15,000 serums were subjected to a battery of 4 tests including Standard Kahn, Kolmer complement-fixation, cardiolipin microflocculation, and cardiolipin complement-fixation. The serums represented an unselected group of individuals from a large general hospital. Weakly positive or positive cardiolipin reactions and negative Kahn and Kolmer reactions were obtained with 991 serums representing 654 individuals. Of 454 patients on whom adequate clinical and social histories were available, 43.2% gave acceptable history of previous syphilitic infection or clinical evidence of a current lesion. Another 30% of these patients gave suspicious histories, history of other venereal diseases, or positive Kahn or Kolmers on previous or later serums. Cardiolipin antigens were of particular value in the diagnosis of cardiovascular and neurosyphilis, and in eliciting previously withheld syphilitic history. The authors suggest that the cardiolipin reactivity is due to increased sensitivity without loss of specificity.