Toxoplasmosis mimicking CMV chorioretinitis in newly diagnosed PLWH: a case report

Abstract

Background: cytomegalovirus (CMV) retinitis, cerebral and ocular toxoplasmosis are common infections in patients with acquired immunodeficiency syndrome (AIDS). Material and methods: this is a case of a 46-year-old female with previous Kaposi's sarcoma, diagnosed with an HIV infection two weeks prior to hospitalization. Blood test at diagnosis showed a CD4+ count of 77 cell/μL and HIV-RNA 3.758.745 copies/mL. Therapy with bictegravir/emtricitabine/tenofovir alafenamide fumarate was started and clinical, viroimmunological and microbiological investigations were performed.

Results: the patient went to our hospital for the onset of left occipito-parietal headache and blurred vision. Brain CT and MRI were performed which did not show focal lesions or vascular alterations. Syphilis serology was negative, Toxoplasma gondii serology showed positive IgG and negative IgM, serum CMV-DNA was 31.184 IU/mL. Eye fundus evidenced intraretinal hemorrhages, fluorescein angiography and computed optical tomography documented cottony exudates, retinal hemorrhages and vitreous involvement. Therapy with valganciclovir was initiated for suspicion of CMV retinitis. About a month later, the patient reported blurred vision for which she was re-admitted. Ocular fundus showed a cottony lesion near the macula. Molecular test on vitreous body was positive for Toxoplasma gondii, while on cerebrospinal fluid it was negative; in addition, an MRI of the brain with contrast medium was performed which showed an area of altered hyperintense signal compatible with a diagnosis of Toxoplasma gondii uveitis and neurotoxoplasmosis. Therapy with pyrimethamine and clindamycin (allergy for sulfonamide reported by the patient) was started. Allergy counseling was performed with the execution of allergy tests (patch test) with negative result; therefore the administration of clindamycin was replaced with sulfadiazine. A month following the start of anti-toxoplasma therapy, there was a clinical and radiological improvement.

Conclusions: despite progressive developments in the management of PLWH, in this case two different kind of opportunistic infection are found in a late-presenter patient. In particular, two aspects can be highlighted. The first one is that, in the setting of an highly impaired immune system, clinical presentation can be deceptive and more than one opportunistic infection can be observed together in the same patient. The second aspect is that after starting antiretroviral therapy, a rapid improvement of viro-immunologic parameters has been documented, probably leading to an immune reconstitution inflammatory syndrome (IRIS).

Keywords: CMV; PLWH; Toxoplasmosis; chorioretinitis.

Figure 1

A: absence of lesion. B: area of altered hyperintense signal in the right anterior perforated white matter on T2-weighted/FLAIR sequences, with marginal enhancement after administration of contrast agent, with a maximum axial diameter of 7 mm and minimal perilesional vasogenic edema.