Cerebral toxoplasmosis in an adolescent post allogeneic hematopoietic stem cell transplantation: successful outcome by antiprotozoal chemotherapy and CD4+ T-lymphocyte recovery.

Toxoplasmosis is a rare opportunistic infection in pediatric allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients and associated with severe T-cell deficiency. Here, we report the successful management of cerebral toxoplasmosis in a 15-year-old adolescent 4 months post allo-HSCT for non-Hodgkin lymphoma through rapid invasive diagnostics, long-term antiprotozoal chemotherapy, and an hematopoietic stem cell boost for persistently poor graft function. While supportive care and antiprotozoal chemotherapy achieved stabilization, definite improvement only occurred following recovery of CD4(+) T lymphocytes to >100 cells/μL. At 5 years after the diagnosis of toxoplasmosis, the patient is in continuing remission with normalized clinical and imaging findings.