The detection of precipitating antibodies in equine infectious anemia and partial purification of the antigen

Summary

Spleens from 12 ponies experimentally infected with the virus of equine infectious anemia (EIA) were evaluated as antigen sources against sera from known infected and normal horses using the Ouchterlony double diffusion technique. Spleens from 4 normal horses served as controls. Two of the 12 infected spleens could be used as antigen for detecting precipitating antibodies when the spleens were frozen and thawed, minced and placed in the antigen wells. When 9 of the infected spleens were treated to partially purify and concentrate the antigen, all 9 could be used as antigen. Using partially purified antigen, precipitating antibodies could not be detected in any of 107 non-EIA infected sera while antibodies could be demonstrated in 71 of 83 sera from infected horses. The 12 non-reacting sera were from 10 horses infected 14 days or less, from one horse infected 15 days, and from one horse infected 25 days. Eighty-two of 83 horses infected from 18 days to 5 1/2 years had precipitating antibodies detectable by this technique. A precipitinogen can be partially purified from EIA infected spleens and used to detect precipitating antibodies in EIA infected horses.