Table 1

Changes within immune cells from patients with arthralgia

First author (ref)	Type of cell	Participants	Findings
Chalan et al9	Absolute number of naïve T cells, T central memory, effector memory and terminally differentiated effector memory T cells	Patients with seropositive arthralgia	Compared with healthy individuals no differences in these cells
	Effector memory T cells and terminally differentiated effector memory T cells	Patients with seropositive arthralgia and patients with newly diagnosed RA	Elevated in patients with seropositive arthralgia compared with RA
	CD4⁺CD161⁺ T cells	Patients with seropositive arthralgia	Increased in patients with seropositive arthralgia compared with healthy controls and patients with RA
	Th17/Th1 double positive cells	Patients with seropositive arthralgia	Increased in patients with seropositive arthralgia compared with healthy controls and patients with RA
Chalan et al8	Absolute and frequency of CD3⁺CD4⁺ T cells CD3⁺CD8⁺ T cells CD19⁺ B cells	Seropositive patients with arthralgia, healthy controls, patients with early seropositive RA and patients with seronegative RA	No differences
	NK cells	Patients with seropositive arthralgia, seropositive RA and healthy controls	Less NK cells in patients with seropositive arthralgia and seropositive RA compared with healthy controls
	CD56^dim NK cells	Patients with seropositive arthralgia, patients with seropositive RA and healthy controls	Number not frequency decreased in seropositive arthralgia and seropositive RA compared with healthy controls
	CD56^bright NK cells	Patients with seropositive arthralgia, patients with seropositive RA and healthy controls	Number not different
Janssen et al10	Fr I (CD45RA⁺FoxP3^low) Fr II (CD45RA⁺FoxP3^high)	Patients with seropositive arthralgia (n=34 of whom 14 developed RA)	No differences
Janssen et al10	Fr III (CD45RA⁻FoxP3^low)	Patients with seropositive arthralgia (n=34 of whom 14 developed RA)	Increased compared with healthy control
Lübbers et al11	Conventional memory CD27⁺ B cells activated CD80⁺ B cells	Patients with seropositive arthralgia (22 developed arthritis within ≤1 year, 18 developed arthritis after >1 year and 73 did not develop arthritis)	Decrease of these cells early RA to healthy control
Ramwadhdoebe et al31	CD4⁺CD69⁺ (activated or tissue resident CD4 T cells)	At risk (patients with arthralgia but within follow-up no arthritis developed)	CD4⁺CD69⁺ more in at risk compared with healthy controls in blood but not in lymph nodes (LN)
Ramwadhdoebe et al31	CD4⁺IL-17⁺IL-10⁺and CD4⁺IFNg⁺IL-10⁺	At risk and healthy controls	In LN tissue decreased in at risk compared with healthy controls (frequencies very low)

IFN, interferon; IL, interleukin; RA, rheumatoid arthritis.