Rabbits with inactive retinochoroiditic scars due to experimental toxoplasmosis were subjected to a series of intravenous inoculations of antilymphocyte serum. Two out of five rabbits so treated developed reactivation of their retinochoroiditic lesions. All of a similar group of rabbits treated with intravenous inoculations of normal horse serum developed reactivations of their lesions. Some mechanisms considered responsible for the breakdown of these healed lesions are discussed.
Nozik RA, O'Connor GR. Studies on Experimental Ocular Toxoplasmosis in the RabbitIII. Recurrent Inflammation Stimulated by Systemic Administration of Antilymphocyte Serum and Normal Horse Serum. Arch Ophthalmol. 1971;85(6):718–722. doi:10.1001/archopht.1971.00990050720013