Hi ANCA Vasculitis is a type of autoimmune disorder in which ANCA (Anti-Neutrophilic Cytoplasmic Antibody) are found. These ANCA attacks neutrophils as a result of which WBC cells attacks walls of small blood vessels and cause inflammation. The disease affects multiple body organs such as kidney, lungs, skin, joints etc. Bronchoscopy will help to assess the extent of damage to lungs. Biopsy will help to see the tissue damage. Rituxan is an Immunosuppressive drug which prevents the tendency of immune system to attack itself. In case of further doubts, please feel free to write back to me. Regards Dr Prashik Meshram