Incidence of Toxoplasma retinochoroiditis in patients with ankylosing spondylitis after using TNF-α blockers.

TNF-α blockers are associated with reactivation of latent granulomatous infections and almost 6% of the world population has some chorioretinitis (CR) caused by Toxoplasma gondii. Thus, the blockade of TNF-α could reactivate a latent toxoplasmosis infection (LTxI). This study was conducted to evaluate the prevalence and incidence of chronic and active CR related to T. gondii in patients with ankylosing spondylitis (AS). A total of 74 eyes from 37 active AS outpatients starting TNFα blockers were compared with 35 AS patients, matched to age and sex, under conventional therapy in a prospective and controlled trial. All patients underwent serological tests for T. gondii, as well as periodic ophthalmologic examination during 12months. Active CR was defined if a white, focal retinochoroidal lesion with overlying vitreous inflammation had been found. Retinochoroidal lesions with sharp edges, hyperpigmented borders and atrophic center were defined as CR scars. At baseline, no patient had active CR. From the 144 eyes examined, almost 6% had CR scars and only 2.1% had a typical toxoplasmic CR scar and all of them were negative for HLA-B27. During 12months of follow-up, no recurrence or new CR were observed. AS patients using TNF-α blockers do not have a higher risk of acute or chronic CR caused by T. gondii.