Gene expression patterns in systemic juvenile
idiopathic arthritis are diff erent from those of other
subtypes, and include upregulation of genes related toinnate immunity and complement systems, and of a
group of mostly haemopoietic genes.43 The next challenge
will be to relate these molecular profi les to specifi c
immune pathways and the clinical manifestations to
individual pathways. Thus gene expression profi ling can
provide a basis for a novel molecular method of
classifi cation of patients at disease onset, which could
help to better predict treatment response and thus guide
individual treatment regimens