A 54-year-old woman underwent cord blood transplantation in second remission of acute myeloid leukemia. She tested positive for anti-toxoplasma IgG antibody before transplantation. After neutrophil engraftment, she complained of foggy vision, but brain MRI showed no abnormality. Thereafter, interstitial shadows in the lungs gradually worsened, and respiratory failure progressed rapidly, resulting in death. The autopsy revealed toxoplasma cysts and free tachyzoites in organs throughout the body, including the heart, lungs, liver, and bone marrow, suggesting disseminated toxoplasmosis as the cause of death. Toxoplasmosis after hematopoietic stem cell transplantation is caused by reactivation of toxoplasma in previously infected recipients and, if disseminated, can involve any tissue in the body. Because of the rapid and fatal course of the disease, it is necessary to recognize the high risk of reactivation in antibody-positive patients and to provide appropriate prophylaxis and testing. An insurance reimbursement system for PCR tests and therapeutic agents has not yet been established in Japan, and further improvement is desirable.
Keywords: Cord blood transplantation; Cyst; Disseminated toxoplasmosis; Tachyzoite.