RT Journal Article
SR Electronic
T1 Fibrocytes in early and long-standing rheumatoid arthritis: a 6-month trial with repeated synovial biopsy, imaging and lung function test
JF RMD Open
JO RMD Open
FD EULAR
SP e001494
DO 10.1136/rmdopen-2020-001494
VO 7
IS 1
A1 Søren Andreas Just
A1 Christian Nielsen
A1 Jens Christian Werlinrud
A1 Pia Veldt Larsen
A1 Eva Kildall Hejbøl
A1 Helene Broch Tenstad
A1 Henrik Daa Schrøder
A1 Torben Barington
A1 Trine Torfing
A1 Frances Humby
A1 Hanne Lindegaard
YR 2021
UL http://rmdopen.bmj.com/content/7/1/e001494.abstract
AB Objectives To correlate the level of fibrocytes in peripheral blood, synovial tissue and in vitro culture in rheumatoid arthritis (RA) with changes in disease activity, imaging and pulmonary function.Methods Twenty patients with early RA (ERA) and 20 patients with long-standing RA (LRA) were enrolled in a 6-month prospective study. Sixteen patients undergoing wrist arthroscopy were healthy controls. Patients with RA underwent pulmonary function tests, ultrasound and synovial ultrasound-guided needle biopsy of the same wrist at baseline and 6 months. Wrist MRI was performed at baseline (all) and 6 months (ERA). Circulating fibrocytes were measured by flow cytometry, in vitro by the number of monocytes that were differentiated to fibrocytes and in synovial biopsies by counting in histological sections.Results Fibrocytes were primarily located around vessels and in the subintimal area in the synovium. Fibrocyte levels did not decline during the trial despite effective RA treatment. In the ERA group, increased synovitis assessed by ultrasound was moderate and strongly correlated with an increase in circulating and synovial fibrocyte levels, respectively. Increased synovitis assessed by MRI during the trial in the ERA group was moderately correlated with both increased numbers of circulating and cultured fibrocytes. Absolute diffusion capacity level was overall weakly negatively correlated with the level of circulating and synovial fibrocytes. The decline in diffusion capacity during the trial was moderately correlated with increased levels of synovial fibrocytes.Conclusion Our findings suggest that fibrocytes are involved in RA pathogenesis, both in the synovium and the reduction in lung function seen in a part of patients with RA.Trial registration number NCT02652299.