Baseline expression of PGE₂ pathway enzymes in the synovium of early arthritis patients classified as UA>UA, UA>RA or RA>RA at baseline>after 2 years of follow-up.

UA: unclassified arthritis; RA: rheumatoid arthritis; UA>UA both at baseline and after 2 years of follow-up classified as UA; UA>RA: classified as UA at baseline and as RA after 2 years of follow-up; RA>RA: classified as RA both at baseline and after 2 years of follow-up. mPGES-1: microsomal prostaglandin E synthase-1; COX: cyclooxygenase; Values expressed as integrated optical density (IOD)/mm2; median (IQR: interquartile range) Baseline expression of PGE2 pathway enzymes in the synovium of early arthritis patients classified as UA>UA, UA>RA or RA>RA at baseline>after 2 years of follow-up.