Christopher T Ritchlin, MD, MPH, is Professor of Medicine and Chief of Allergy, Immunology & Rheumatology, University of Rochester Medical Center in Rochester, New York. His research efforts are directed towards understanding the mechanisms that underlie pathologic bone resorption and new bone formation in psoriatic arthritis (PsA) and rheumatoid arthritis (RA). Using a translational approach, investigators in his lab are analyzing the cell surface molecules expressed by osteoclast and dendritic cell precursors with the goal to identify susceptibility and response biomarkers in patients with inflammatory arthritis. The lab is also studying the effect of anti-TNF agents on dendritic cell differentiation in RA and PsA patients. In addition, collaborative studies are underway with the lab of Dr Eddie Schwarz to understand the mechanisms that are responsible for bone marrow edema as recorded on magnetic resonance imaging scans in inflammatory arthritis. The bulk of this work is performed in animal models but insights gained from these studies are applied to the study of human joint diseases such as psoriatic and rheumatoid arthritis. Dr Ritchlin is also the Director of the Clinical Immunology Research Unit where he is the principal investigator on several clinical trials testing the efficacy of anti-TNF agents and other biologic molecules in the treatment of psoriatic and rheumatoid arthritis and ankylosing spondylitis.