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Objective Alsace is a region in eastern France with a population of ∼2 million. All residents have high access to health care and an accredited referral center for SSc. Seeking care outside of this region is difficult because of the peculiar geography. The aim of this study was to assess the prevalence and spatial variation of systemic sclerosis (SSc) in eastern France. Methods Data for SSc patients were obtained from 3 sources (all general practitioners and community specialists, capillaroscopy centers, and all public and private hospital records) and were used to estimate the prevalence of SSc. Surviving patients who resided in Alsace on January 1, 2008 and fulfilled the American College of Rheumatology and/or the LeRoy and Medsger criteria were included in this study. The clinical characteristics of the patients were also assessed. Potentially incomplete case ascertainment was corrected by capture–recapture analyses. Geographic disparities were assessed by spatial cluster analysis and by comparing our results with those for other geographic areas in the world for which data derived using similar methodology were available. Results The review of 499 potential cases identified a total of 244 SSc patients. A trend toward a west-to-east gradient was observed but did not reach statistical significance. According to log-linear modeling, an estimated 83.87 additional cases were missed. Thus, the SSc prevalence was 228.42 cases per million adult inhabitants of Alsace (95% confidence interval 203.70–253.14); this prevalence was significantly higher than that in 2 other regions of France and comparable with the reported prevalence in Detroit, Michigan. Conclusion The stringent methodology used in the current study is very likely to provide an accurate estimation of the prevalence of SSc. Design similarity with 3 other surveys extends the scope of the results by identifying geographic disparities that were previously indistinguishable due to methodologic differences.

Much interest was stirred in recent years by the evidence that rheumatoid factors (RF) variable regions are encoded by a restricted set of V genes, with little or no somatic mutations, that are often overexpressed in the fetal repertoire. This is reminiscent of what has been observed for natural autoantibodies. However, these data come from studies of monoclonal RF (mRF) isolated from patients with lymphoproliferative disorders who usually do not present autoimmune symptoms. The molecular characterization of RF during autoimmune diseases such as rheumatoid arthritis (RA) has been hampered for some time because of their polyclonality; recently using the polymerase chain reaction method, we have demonstrated that RF kappa variable regions from a patient with RA were encoded by V kappa III genes known to code for mRF but that these genes had undergone somatic mutations with a pattern suggesting an antigen-driven maturation. Because an important role of the light chain third complementarity-determining region (CDR3) in anti-IgG reactivity and idiotype expression has already been suspected for RF, we now report the molecular characterization of the junction regions of these rearranged V kappa gens. Surprisingly, our data show that in 55% of the cases there is addition of a proline and/or glycine amino acid residue at the recombination site between V kappa and J kappa. The sequence analysis of our patients' germ-line Vg and J kappa 4 genes segments and their flanking regions demonstrates that the additional codons are not readily explicable by recombination between germ-line sequences and probably result from an N addition process. Since we could not find such an additional codon in 15 previously published mRF kappa chains we suggest that "pathogenic" RF during RA and mRF derive from different, although overlapping, B cell subsets. Moreover, since additional codons at the recombination site of V kappa and J kappa seem exceptional in expressed human kappa chains and because the resulting amino acid residue is a proline in most cases, we think that RF kappa chain CDR3 is under a very strong selective pressure during RA.