Cerebral toxoplasmosis after rituximab therapy for splenic marginal zone lymphoma: a case report and review of the literature

Abstract

Introduction: Toxoplasma gondii is a parasite estimated to infect one-third of the global population, surviving in tissues in a latent form. Although cerebral toxoplasmosis is predominantly recognized as an opportunistic infection in hosts immunocompromised secondary to human immunodeficiency virus or bone marrow transplant, there is increasing recognition that this infection can occur in patients receiving immunomodulating agents such as mAb therapy targeted against T-cells, B-cells and TNF. The indications for these therapies are expanding, resulting in a larger at-risk population for this rare but serious and potentially avoidable complication. Case Presentation: This is one of the few case reports of cerebral toxoplasmosis following rituximab-based chemotherapy in a patient with a haematological malignancy. We describe a patient presenting with focal neurological deficits and radiographic evidence of multi-focal cerebral ring-enhancing lesions following completion of rituximab therapy for splenic marginal zone lymphoma. Brain biopsy confirmed a diagnosis of cerebral toxoplasmosis. Antibiotic treatment with trimethoprim/sulfamethoxazole resulted in near-complete radiological and clinical resolution of the neurological deficits, and a return to baseline functional status. Conclusion: Reactivation of toxoplasmosis resulting in intracerebral disease is a potential severe and preventable complication of rituximab therapy. Further studies are required to assess the need both for screening and prescribing primary chemoprophylaxis for toxoplasmosis when initiating rituximab therapy.

Acute Toxoplasma Dissemination With Encephalitis in the Era of Biological Therapies

“…Safa et al [ 6 ] reported the case of a 71-year-old woman with reactivation of cerebral toxoplasmosis following rituximab therapy, highlighting the need to consider cerebral toxoplasmosis whenever patients receiving rituximab present with neurological deficits. Similarly, Holland et al [ 7 ] described the case of a 77-year-old woman who developed cerebral toxoplasmosis while on rituximab therapy. Morjaria et al [ 8 ] reported 3 cases of reactivation of Toxoplasma encephalitis, 2 of whom were receiving rituximab therapy.…”

“…We believe that the use of rituximab played a key role in the occurrence of toxoplasmosis in our patient. Indeed, opportunistic infections following completion of rituximab therapy may take place within the first months after its administration [ 6 , 7 ]. Although rituximab’s main mechanism of action is B-cell suppression, it is also hypothesized that it exerts its effects on T cells, as manifested by the occurrence of CD4+ T-cell driven opportunistic infections under rituximab therapy.…”

Toxoplasma Encephalitis in Atypical Hosts at an Academic Cancer Center

“…The most clinically apparent link between lymphoma and TE relates to the administration of purine analogs, corticosteroids, and other therapies known to affect cell-mediated immunity [ 5 , 11 ]. In addition to these drugs impairing cell-mediated immunity, patients in the first 2 cases described above received rituximab, which has been posited as a risk factor for TE, although evidence is anecdotal [ 12 , 13 ].…”

Comprehensive Overview of Toxoplasma gondii-Induced and Associated Diseases

“…The reactivation of chronic toxoplasmosis was also reported following chemotherapy administration. Indeed, several cases of reactivation of cerebral toxoplasmosis following rituximab therapy were described [57][58][59][60]. The reactivation of toxoplasmosis is also a concern in solid organ transplant recipients, either as a manifestation derived from an infected donor, a reactivation of chronic toxoplasmosis in the recipient, or to a much lesser extent, a primary acquired infection following transplantation.…”