Table 1. Clinical features and treatment of RA, OA, PsA, and SpA patients included in the study.

	RA patients n = 12	OA patients n = 5	PsA patients n = 4	SpA patients n = 5
Sex, no. males/females	2/10	2/3	4/0	1/4
Age, years median (range)	62 (49–80)	63 (50–67)	41 (36–54)	41 (33–57)
DoD, months median (range)	90 (2–414)	24 (12–100)	85 (2–180)	288 (0–384)
IgM-RF, no. positive/negative	9/3	n/a	n/a	5/0
ACPA, no. positive/negative	11/1	n/a	n/a	5/0
No medication, no.	0	3	2	2
NSAIDs, no.	8	2	2	0
MTX, no.	11	0	0	3
DMARDs, no.	7	0	0	2

No  =  number of patients; DoD  =  duration of disease; IgM-RF  =  immunoglobulin M-rheumatoid factor; ACPA  =  anti-citrullinated peptide antibodies; MTX  =  Methotrexate; NSAIDs  =  non-steroidal anti-inflammatory drugs; DMARDs: disease-modifying anti-rheumatic drugs; n/a  =  not available.