However, anti-PTX3 antibodies were not associated with serostatus independently of PtGA (OR 0.57, 95% CI 0.22, 1.46; P = 0.242), meaning that higher PtGA in seronegative RA patients was the main reason for more prevalent anti-PTX3 antibodies in this subgroup. This evidence concerns the gene PTX3 and rheumatoid arthritis.