What is immune reactivation syndrome in severely immunodeficient patients with HIV starting combination antiretroviral therapy that includes emtricitabine/tenofovir disoproxil?

Immune reactivation syndrome in severely immunodeficient patients with HIV starting combination antiretroviral therapy including emtricitabine/tenofovir disoproxil is an inflammatory reaction to asymptomatic or residual opportunistic pathogens that can cause serious illness or worsen symptoms, typically within the first weeks or months.