Late-Onset Cerebral Toxoplasmosis After Allogeneic Hematopoietic Stem Cell Transplantation

Abstract

Patient: Male, 44Final Diagnosis: Cerebral toxoplasmosis after HSCTSymptoms: Hemiparesis • muscle weaknessMedication: —Clinical Procedure: —Specialty: HematologyObjective:Unusual clinical courseBackground:Toxoplasmosis is an uncommon but potentially fatal complication following allogeneic hematopoietic stem cell transplantation (HCT). Post-transplant toxoplasmosis is often a reactivation of prior infection and typically occurs within the first 6 months of transplant. Herein, we report that cerebral toxoplasmosis may occur 22 months after allogeneic hematopoietic stem cell transplantation.Case Report:We describe a case of cerebral toxoplasmosis that occurred 22 months after an allogeneic HCT while the patient was on aerosolized pentamidine for Pneumocystis jiroveci pneumonia (PCP) prophylaxis. The disease was only diagnosed after brain biopsy because of atypical MRI appearance of the cerebral lesion and negative Toxoplasma gondii IgG antibody test result in the cerebrospinal fluid (CSF). The patient received pyrimethamine and sulfadiazine treatment, with dramatic improvement after several months. The patient is alive 2 years after infection diagnosis, with no evidence of disease and is off Toxoplasma prophylaxis.Conclusions:Cerebral toxoplasmosis can occur late after allogeneic HCT while patients are on immunosuppression therapy, with atypical features on imaging studies and negative Toxoplasma gondii IgG antibody test result in the CSF. Pre-transplant serologic screening for T. gondii antibodies in allogeneic transplant candidates is warranted. Brain biopsy can be a helpful diagnostic tool for cerebral lesions.

The Outcomes of Mesenchymal Stem Cells Therapy for Experimental Toxoplasmosis

“…Similarly, Etewa et al, [49] in their histopathological study of brain sections of spiramycin treated mice, reported the presence of few numbers of Toxoplasma cysts encircled by mild inflammatory cellular reaction. These findings were explained by Khalaf et al, [50] , who attributed these changes to immunosuppression that flares up cerebral toxoplasmosis. In our study, the recorded reaction may be due to the infection itself or the response to the tested SCs.…”

Toxoplasmic encephalitis of basal ganglia with tumor‐like features proven by pathogen‐specific polymerase chain reaction and direct DNA sequencing

“…PCR techniques have been developed for noninvasive diagnosis, and can also be used for the diagnosis of cerebral toxoplasmosis, which contribute to rapid diagnosis and monitoring of treatment efficacy. However, to avoid false negative results of PCR, some authors still emphasize the role of serology in the diagnostics of toxoplasmosis, as well as a combination of serology and PCR techniques . Hu et al .…”

Toxoplasmosis after allogeneic haematopoietic cell transplantation—disease burden and approaches to diagnosis, prevention and management in adults and children

“…The risk of reactivation correlates with the degree of immunosuppression and is associated with low CD4 þ lymphocyte counts [23,24]. Toxoplasmosis usually develops within the first 6 months after allogeneic HCT, with a peak incidence in the second and third months [5,25]. However, late cases of toxoplasmosis beyond the first 6 months may occur in the context of chronic graft-versus-host disease and its treatment [26,27].…”