Charles has now retired from clinical practice, but remains active in research and teaching. He is a clinician scientist with a particular interest in autoimmune kidney disease, including primary systemic vasculitis and anti-GBM disease. He previously led a large multidisciplinary vasculitis clinic, and has made a major contribution to many of the international clinical trials in this field. He also led, and still contributes to, a laboratory research program investigating mechanisms of autoimmunity and inflammation in glomerulonephritis.