Leendert Trouw studied Biology in Leiden and already during his PhD training, at the Department of Nephrology in the LUMC, he became fascinated by autoantibodies and complement. This research, conducted in the lab of Prof. Dr. Daha , provided the explanation as to why anti-C1q autoantibodies contributed to renal damage in patients suffering from lupus, whereas the same antibodies were not harmful for healthy individuals. In order to gain more understanding of the role of complement in autoimmunity, Dr. Trouw moved to the lab of Prof. Dr. Blom, Lund University, in Malmo, Sweden. During this period Dr. Trouw focussed, now as a post-doc, especially on the role of endogenous complement inhibitors on the protection of dying and dead cells from excessive complement attack. To further develop himself in the field of complement and autoantibodies in a more clinical setting Dr. Trouw, now as a senior post-doc, started working with Prof. Dr. Huizinga and Prof. Dr. Toes at the Department of Rheumatology in the LUMC. Next to studies on the complement activating potential of ACPA (Rheumatoid Arthritis specific antibodies) and several genetic studies Dr. Trouw and his team set up a series of experiments that led to the identification of a new autoantibody in rheumatoid arthritis, the anti- CarP antibodies. After obtaining both an NWO VENI and an VIDI grant Dr. Trouw now focusses, as associate professor, on the role of complement in autoimmunity and on the characterisation of the anti- CarP antibody response . The team now consists of 1 post-doc, 5 PhD students and 3 technicians. The work of Dr. Trouw is currently supported by a fellowship from Janssen Biologics, INOVA diagnostics, NWO and the Dutch Arthritis Foundation. Recently Dr. Trouw obtained a prestigious ERC-consolidator grant which allows him to study with his team, now at the department of Immunology , the role of complement in the induction of antibody responses against post-translationally modified proteins.