A total of eleven proteins were overabundant in acute PMR compared with naïve RA and affected in the patient treatment (SAA1, SERPINA3, KRT10, ORM1, IGLV3-9, SAA2-SAA4; SAA4, HPR, GPX3, SERPINA1, C3, PGLYRP2). Here, SAA4 is linked to rheumatoid arthritis.