摘要篇首： Pneumocystis pneumonia (PCP) is one of the most critical and life-threatening infections in immunocompromised patients with AIDS (especially CD4+ T cell less than 0.2×109/L), hematological malignancies, organ transplantation or connective tissue diseases.1It is caused by a fungus called Pneumocystis firoveci (P. jiroveci, formerly called P. carinii).2Despite treatment with trimethoprim-sulfamethoxazole (TMP/SMZ) and corticosteroids, the morbidity of this disease is often high because of late treatment or contraindications of sulfanilamide. New therapeutic approaches are therefore warranted. Caspofungin, a beta-1, 3-glucan synthesis inhibitor, has shown activity against P. jiroveci in experimental animals,3but clinical trials about this are rare.4-8We here report our clinical experience with caspofungin in salvage treatment of severe PCP in a patient with chronic myelomonocytic leukemia (CMML) and uremia.