1 Division of Rheumatology, Department of Medicine (Solna), Karolinska Institutet, Stockholm, Sweden; Division of Rheumatology, Department of Internal Medicine 3, Medical University of Vienna, Vienna, Austria. Electronic address: paul.studenic@ki.se.
2 Division of Rheumatology, Department of Medicine (Solna), Karolinska Institutet, Stockholm, Sweden; Academic Specialist Center, Stockholm Health Services, Region Stockholm, Sweden. Electronic address: susanne.karlfeldt@sll.se.
3 Rheumatology Unit, University of Perugia, Perugia, Italy. Electronic address: alessia.alunno82@gmail.com.