Differentially expressed genes and further validation.

In total, 15 of the 112 examined genes were significantly differentially expressed between the “poor” and “good” or “very poor” and “good” patient cohorts in our microarray data. Thirteen of those genes were proposed as potentially prognostic blood biomarkers in earlier studies, as stated in the “Reference” column. Two genes, IL17RC and IL17RA, have not been directly linked to long-term disease progression so far but are believed to play important roles in the context of autoimmunity. They were expressed at lower levels in the “very poor” group. The custom probe set (GeneCard) and t-test p-values are given for the analysis of our data. We validated the results using the data from Gurevich et al. and Singh et al. A gene was considered confirmed by their data if it was differentially expressed between patients with moderate and severe disease courses in the same manner as in our data. The respective Affymetrix original probe sets and CodeLink Bioarray probes used for the quantification of the genes' expression are given in the table. Five of the 15 genes were not measured in the study by Singh et al. ns = not significant. ok = confirmed.