Toxoplasma gondii is a protozoan parasite that causes opportunistic infection in immunocompromised individuals. The parasite forms latent tissue cysts that are refractory to current treatments and give rise to life-threatening reactivated infection following immune suppression. Previously, we showed that guanabenz sharply reduces brain cyst count in BALB/c mice harboring latent toxoplasmosis; however, whether cyst count would change once drug treatment stopped was not addressed. In the present study, we observed a rebound in brain cysts following the discontinuation of guanabenz or a guanabenz-pyrimethamine combination therapy. The re-expansion of brain cysts was not accompanied by symptoms of acute toxoplasmosis. We also tested whether the rebound in cyst counts could be ameliorated by administering pyrimethamine during or after guanabenz treatment.

弓形虫是一种原生动物寄生虫，会在免疫功能低下的个体中引起机会性感染。寄生虫形成潜伏的组织囊肿，这些囊肿对目前的治疗无效，并在免疫抑制后引起危及生命的再激活感染。以前，我们发现 guanabenz 可显着减少携带潜伏弓形虫病的 BALB/c 小鼠的脑囊肿数量。然而，药物治疗停止后囊肿计数是否会改变尚未得到解决。在本研究中，我们观察到停止胍那苄或胍那苄-乙胺嘧啶联合治疗后脑囊肿反弹。脑囊肿的再扩大不伴有急性弓形虫病的症状。我们还测试了是否可以通过在 guanabenz 治疗期间或之后施用乙胺嘧啶来改善囊肿计数的反弹。