Interestingly, we observed that IAR convertors displayed higher levels of CRP (p < 0.01), SAA (p < 0.01), Leptin (p = 0.09) and PP (p < 0.05) (Supplementary Fig. 4), when compared to individuals that did not convert, thus displaying levels like the one observed in established seropositive RA patients. This evidence concerns the gene LEP and rheumatoid arthritis.