ANCA-associated vasculitis (AAV) is a systemic autoimmune disease characterized by necrotizing inflammation of small vessels, where dysregulated immune responses, including ANCA, and changes in T-cell regulation play a role. Immune checkpoints, as a network of costimulatory and coinhibitory pathways, regulate lymphocyte activation and peripheral tolerance. In AAV, there is an imbalance of these pathways including PD-1/PD-L1/PD-L2, CD28/CTLA-4, ICOS, CD40–CD40L, OX40, LAG-3, TIM-3, BTLA and CD27. Impaired inhibitory signaling together with increased costimulatory activity promotes sustained T-cell activation, T-B cell cooperation, and ANCA production, leading to vascular and renal damage. Checkpoint molecules in blood, urine, and kidney tissue correlate with disease activity, renal involvement, response to treatment, and risk of relapse, thus serving as potential biomarkers. The therapeutic landscape includes checkpoint modulation such as abatacept, PD-1 agonism, and strategies from other autoimmune diseases. Immune checkpoint dysregulation is a central feature of AAV pathophysiology with potential for accurate biomarkers and targeted immunotherapies.