Antithymocyyte Serum Treatment of Hamstres Inoculated with a Measles Virus Isolated from a Patient with Subacute Sclerosing Panencephalitis

Abstract

Antithymocyte erum (ATS) treatment of hamsters inoculated with a strain of measles virus (Lec) isolated from a child with subecute sclerosing panencepbalitis resulted in acute neurologic abnormalities in intracranially inoculated, weanling hamsters normally refractory to diseaee caused by the virus. me incubation period uas 8–12 days. Virus could be isolated from the brains of the sick animals. Neutralizing antibody was present in lower titers in the sera of the ATS-treated hameters than in the sera of untreated virus control hamsters. At the time Am-treated hameters were ill, antibody cytotoxic for Lec virus-infected cells was found mainly in the sera of virus control hamsters having neutralizing antibody. Newborn hamsters inoculated intraperitoneally with virus did not show neurologic symptom unless treated with ATS. In these treated animals the incubation period was 3–6 weeks. The brain, spleen and lung of sow of the sick hamsters contained virus. No detectable neutralizing antibody uas present at the time of onset of illness. In those animls which survived infection, the antibody titers increased and have remined high over a period of 8–12 months, while the antibody titers of the virus control animls in the same experiments have decreased or remained negative.