CsA dosing regimen. (A) Rabbits in the 10- and 20-mg/kg CsA treatment groups were immune suppressed for 8 weeks before infection. Rabbits received daily CsA injections for the first week of treatment. After the loading phase, CsA injections were given every 3 days (maintenance phase). At 10 weeks after infection, these rabbits were euthanized and necropsied. (B) Rabbits in the delayed 20 mg/kg CsA treatment group were infected for 1 week before the start of CsA treatment. At 2 weeks after infection, the rabbits were given daily CsA injections for 1 week. After the loading phase, rabbits were put on the same maintenance schedule as the other CsA-treated groups. At 10 weeks after infection, rabbits were killed and necropsied. (C) CsA plasma concentration levels were measured during the loading phase and maintenance phase of CsA treatment. The dotted lines represent the therapeutic plasma concentration range seen in human patients.