Polymorphisms in the interleukin 4, interleukin 13, and corresponding receptor genes are not associated with systemic sclerosis and do not influence gene expression.

OBJECTIVE: Polymorphisms in the genes encoding interleukin 4 (IL4), interleukin 13 (IL13), and their corresponding receptors have been associated with multiple immune-mediated diseases. Our aim was to validate these previous observations in patients with systemic sclerosis (SSc) and scrutinize the effect of the polymorphisms on gene expression in various populations of peripheral blood leukocytes. METHODS: We genotyped a cohort of 2488 patients with SSc and 2246 healthy controls from The Netherlands, Spain, United Kingdom, Italy, Germany, and France. Taqman assays were used to genotype single-nucleotide polymorphisms (SNP) in the following genes: (1) IL4 (-590C>T/rs2243250); (2) IL4 receptor alpha (IL4RA) (Q576R/rs1801275); (3) IL13 (R130Q/rs20541 and -1112C>T/rs1800925); and (4) IL13RA1 (43163G>A/rs6646259). The effect of these polymorphisms on expression of the corresponding genes was assessed using quantitative RT-PCR on RNA derived from peripheral blood B cells, T cells, plasmacytoid dendritic cells, monocytes, and myeloid dendritic cells. We investigated whether these polymorphisms influenced development of pulmonary complications over 15 years in patients with SSc. RESULTS: None of the investigated polymorphisms was associated with SSc or any SSc clinical subtype. We did not observe any effect on transcript levels in the cell subtypes or on development of pulmonary complications. CONCLUSION: Our data showed that polymorphisms in IL4, IL13, and their receptors do not play a role in SSc and do not influence the expression of their corresponding transcript in peripheral blood cells.

Registries in systemic sclerosis: a worldwide experience.

SSc is a multisystem disease characterized by an unpredictable course, high mortality and resistance to therapy. The complexity and severity of SSc is a growing burden on the health-care systems. As a result, researchers are seeking new therapeutic strategies for effectively managing these patients. Disease registries are used to support care management efforts for groups of patients with chronic diseases and are meaningful to capture and track key patient information to assist the physicians in managing patients. For these reasons, SSc surveys, research associations and consortiums are pivotal to conduct ongoing research and data collection to enhance disease knowledge and support research projects. Currently, there are several national SSc registries in the UK, Germany, USA, Canada, Brazil and Australia. There is also an international registry established by the European League Against Rheumatism scleroderma trial and research (EUSTAR) called minimal essential data set (MEDS) Online, which collects data from over 8000 patients from 92 centres worldwide, including 21 European centres and 9 centres outside Europe. By collecting, analysing and disseminating data on disease progression and patient responses to long-term disease management strategies, registries help to improve understanding of the disease and keep medical professionals up to date on the latest advances.