- Tumor necrosis factor-alpha inhibitors treatment is accosiated with several side effects. The most common are injection side reactions, headache, nausea and infections. The more rare are development of systemic autoimmune diseases. We describe two patients, who developed ANCA associated vasculitis during Tumor necrosis factor alpha inhibitors treatment. The diagnosis was confirmed by appropriate tissue picture, CT scan and laboratory findings. Our case series are unique, because vasculitis appeared after many years of the treatment and during complete patient's remission of there main illness.