GENOMICS STUDY GROUP

In the genomics workshop held at the EWRR in Marseille on the 27 February lively discussions were held on the progress of genomics research. Two general overviews were presented by Tom Huizinga (Department of Rheumatology, Leiden University Medical Centre, The Netherlands) and Gerd Burmester (Department of Rheumatology and Clinical Immunology, Charité University Clinic, Berlin, Germany), which served as a starting point for the discussions.

It was emphasised that much progress has been made in the identification of genetic regions involved in the susceptibility to rheumatoid arthritis (RA). However, these regions are still broad, and great problems have arisen in identifying the risk genes involved. As each population is unique and has developed under different evolutionary pressures, the linkage between different genetic markers may be different in different populations. The number of families with the same homogenous genetic background needed to identify risk genes should be calculated, given that current data on multicase families have led to an estimation that at least 5000 such multicase families are needed. Other sources of information are required to make progress.

Dr Burmester presented results from array data on resting versus activated macrophages, based on the hypothesis that gene expression profiles in activated macrophages are indicative for pathogenetic pathways in RA. He demonstrated the presence of some of these clusters of monocyte activation genes in monocytes from patients with RA. Moreover, he showed that the expression of a number of these gene clusters could be down regulated if those patients with active RA were treated with the anti-tumour necrosis factor monoclonal antibody, adalimumab.

Lars Klareskog (Karolinska, Stockholm, Sweden) suggested that the time had come to integrate these different sources of information into one project, in which data on transmission and association of genetic variants were combined with data on expression and data on pathophysiology to identify mechanisms to cure autoimmune diseases.

It was agreed that such an integrated project would be designed for the next deadline.