TABLE 1.

Basic patient characteristics

Parameter	Result
Median age (range), yearsa	48 (18–79)
Patient sex (male/female)	32/25
Median interval since first diagnosis (range), years	25 (1-50)
Immunosuppression, no.a
MTX monotherapy ≥10 mg/week	7
TNF-α inhibitor (adalimumab/infliximab/etanercept/certolizumab), plus MTX co-medication max. 10 mg/week	18
IL-17 inhibitor (secukinumab/ixekizumab)	11
IL-12/23 inhibitor (ustekinumab)	8
IL-23 inhibitor (guselkumab/tildrakizumab)	13

^a At the time of first blood sampling.