Rheumatoid factor isotypes in relation to antibodies against citrullinated peptides and carbamylated proteins before the onset of rheumatoid arthritis

Table 1 Demographic data for the 321 pre-symptomatic, 187 patients with RA and 492 control subjects

	Control subjects (n = 492)	Pre-symptomatic individuals (n = 321)	RA patients (n = 187)
Female sex, %	71.5	77.9	74.3
Median age, yr (IQR)	51.1 (20.1)	50.3 (20.0)^a	57.1 (15.3)
Ever smoker, n/total (%)	221/462 (47.8)	197/308 (64.0)^b	123/184 (66.8)^b
HLA-shared epitope^c, n (%)	224/481 (46.5)	198/304 (65.1)^b	118/187 (63.1)^b

RA rheumatoid arthritis, IQR interquartile range, HLA human leucocyte antigen
^aMedian age, as calculated for all samples when collected (n = 598) at a median (IQR) of 62. (7.2) years before the onset of RA symptoms
^b p < 0.001 cases compared with controls
^cHLA-shared epitope = HLA-B1*0101/0401/0404/0405/0408

ISSN: 1478-6362