Concurrent Ocular and Cerebral Toxoplasmosis in a Liver Transplant Patient Treated with Anti-CD40 Monoclonal Antibody

Abstract

Toxoplasma gondii, an obligate intracellular parasitic protozoon, usually causes a mild, acute infection followed by a latent asymptomatic phase with tissue cysts or a chronic form with recurrent retinochoroiditis. However, immunocompromised patients can cause disseminated disease due to the reactivation of the latent tissue cysts or due to a primary infection. Here, we present a rare case of bilateral ocular toxoplasmosis and concurrent subacute toxoplasma encephalitis in a 70-year-old patient on anti-CD40 treatment following his liver transplant. The diagnosis was confirmed by PCR of anterior chamber fluid and brain biopsy, and no other sites of disseminated disease were detected on PET-CT. The patient has been treated with sulfamethoxazole-trimethoprim 800/160 mg with virtually complete resolution of the neurological and ocular symptoms. Iatrogenic blockade of the CD40 pathway may elicit a particular susceptibility for CNS reactivation of T. gondii.

Figure 1

MRI imaging (T2 images, sagittal view) at presentation (a) and during follow-up (b) 5 weeks of TMP-SFX twice daily; (c) 20 weeks follow-up, of which 6 weeks of TMP-SFX 4 times a day and 14 weeks twice daily. Gradual improvement of the lesion was seen during treatment (highlighted by arrow).

Figure 2

Ocular features at presentation and during follow-up. (a) The left eye showed a white retinitis lesion along the superotemporal arcade (colour fundus picture). (b) Adjacent Kyrieleis arteritis (arrow) and ischaemia on fluorescein angiography at first visit. (d) Optical coherence tomography demonstrates the full-thickness retinitis (arrow) with limited adjacent vitritis. (c) With treatment, the lesion gradually became atrophic ((e) 2 months follow-up) and vascular supply was restored via a collateral artery.