Acknowledgements
We would like to thank Susana Hernandez Machado, Gloria Rostvall and Julia Norkko, for helping with sample collection and management and Vijay Joshua for helping with the CBA software. This study was conceived, designed and coordinated by NS, FF, KC, IG; VM. FF and ST contributed to data collection and clinical assessments. Experimental work was performed by NS in supervision of KC and VM. Rheumatoid Factor data was obtained by JR. The data analysis and interpretation were conducted by NS, FF, KC, VM, IG and the writing was drafted by FF and NS. This work was supported by The King Gustaf V 80th Birthday Fund, Stockholm County Council (ALF and for ST: combined clinical residency and PhD training program), The Swedish Rheumatism Association, Ingegerd Johansson’s Foundation, and The Swedish research council.