Toxoplasmosis-Associated Immune Reconstitution Inflammatory Syndrome in a Patient with Newly Diagnosed HIV/AIDS

Background: Cerebral toxoplasmosis is a common cause of central nervous system (CNS) lesions in advanced HIV, and initiation of antiretroviral therapy (ART) can precipitate immune reconstitution inflammatory syndrome (IRIS). Toxoplasma-related IRIS is rare but poses significant diagnostic and therapeutic challenges. Case Presentation: We report a 40-year-old male with advanced HIV (CD4 <35 cells/mm3, viral load 540,000 copies/mL) who initially presented with seizures and multiple ring-enhancing supratentorial lesions. Serology and cerebrospinal fluid (CSF) polymerase chain reaction (PCR) confirmedToxoplasma gondii, and he was treated with high-dose sulfamethoxazole-trimethoprim, dexamethasone, and ART. A lymph node biopsy revealed granulomatous inflammation with intracellularHistoplasmaspecies. One month later, following brief interruption of anti-toxoplasma therapy, he developed recurrent seizures and radiographic progression despite ART adherence. Repeat evaluation excluded other infections or malignancy. Brain biopsy confirmedT. gondii, and IRIS was diagnosed. The patient improved with re-initiation of high-dose anti-toxoplasma therapy, corticosteroids, and seizure prophylaxis. Discussion: This case illustrates paradoxical toxoplasmosis-associated IRIS in the context of advanced HIV and concurrent opportunistic infection. Early recognition, exclusion of alternative diagnoses, and continuation of ART with targeted antimicrobial therapy are essential. Conclusion: Clinicians should maintain a high index of suspicion for IRIS in HIV patients with CNS toxoplasmosis who deteriorate after ART initiation, particularly in those with profound immunosuppression and coexisting infections.