DNA AMPLIFICATION IN EXPERIMENTAL PNEUMOCYSTOSIS - CHARACTERIZATION OF SERUM PNEUMOCYSTIS-CARINII DNA AND POTENTIAL PNEUMOCYSTIS-CARINII CARRIER STATES

DNA amplification has identified P. carinii DNA in diverse biologic sp ecimens, including the serum of patients with P. carinii pneumonia. To further examine the relationship between P. carinii DNA in serum and P. carinii infection, the corticosteroid-treated rat model of pneumocy stosis was studied. By 4 weeks of immunosuppression, P. carinii DNA wa s detected in rat lungs and by 6 weeks, in their serum. P. carinii DNA persisted in lung tissue as long as 5 months after the withdrawal of steroids. Serum DNA disappeared 2 weeks after steroids were withdrawn. Nonimmunocompromised, sentinel rats housed near immunocompromised, P. carinii-infected rats also were studied. Within 6 weeks, P. carinii D NA became detectable in lung and by 8 weeks, in serum. P. carinii DNA disappeared rapidly from lungs and sera after sentinel rats were isola ted away from corticosteroid-treated rats. These findings support the contagious transmission of P. carinii and suggest facile development o f P. carinii carrier states.