Cerebral Toxoplasmosis in a Rheumatoid Arthritis Patient on Immunosuppressive Therapy

Cerebral toxoplasmosis is a life-threatening infection most commonly found in immunocompromised hosts such as acquired immunodeficiency syndrome (AIDS) or transplant patients. However, it is not known to affect patients with chronic inflammatory disorders on immunosuppressive therapy. We describe the case of a 70-year-old female with rheumatoid arthritis (RA) on chronic therapy with methotrexate and infliximab, who presented to the hospital after two weeks of right-sided weakness. Imaging revealed bilateral ring-enhancing lesions in the basal ganglia (left greater than right). A diagnosis of cerebral toxoplasmosis was made on brain biopsy. Apart from the immunosuppressive therapy and owning a cat, she had no other risk factors for developing the infection. The patient's immunosuppressive medications were discontinued, and she was started on high-dose trimethoprim-sulfamethoxazole (TMP-SMX). Upon literature review using PubMed, we found seven other published reports on similar cases of toxoplasmosis in RA patients on immunosuppressive therapy; however, there was a lack of recommendations for diagnosis, treatment, and prophylaxis in this patient population. With the growing use of immunosuppressive therapies in chronic inflammatory disorders, further data is needed regarding the management of toxoplasmosis in these patients. This case report is an investigation of the relationship between immunosuppressive medications in RA patients and cerebral toxoplasmosis and an exploration of the available recommendations for its management.