The efficacy and safety of early adjunctive methylprednisolone therapy in acute ischemic stroke patients with large infarct cores (ASPECTS score \< 6) and post-stroke lymphocytopenia remain unclear. These immunocompromised patients face higher mortality rates and poorer clinical outcomes, with limited effective treatment options currently available. This multicenter, randomized, double-blind, placebo-controlled, non-inferiority trial aims to demonstrate that early methylprednisolone administration combined with reperfusion therapy is non-inferior to placebo in terms of survival and functional outcomes at 90 days.