Table 1. Characteristics of Patients with RA and Comparison of Variables between Patients with and without Anti-HBc.

	Total patients (n=39)	Patients with anti-HBc (n=15)	Patients without anti-HBc (n=24)	p value
Demographic data
Age (yr)	55.0 (46.3–62.0)	57.0 (48.5–68.5)	50.0 (43.0–61.5)	0.141
Female gender	28 (71.8)	10 (66.7)	19 (79.2)	0.391
Disease duration (month)	61.7 (21.4–152.3)	52.7 (20.9–121.5)	67.7 (22.2–170.2)	0.729
Serologic classification				0.999
Seropositive RA	35 (89.7)	14 (93.3)	21 (87.5)
Seronegative RA	4 (10.3)	1 (6.7)	3 (12.5)
Tocilizumab
DAS-28 ESR at initiation	7.0 (6.4–7.4)	7.2 (6.5–7.4)	6.9 (6.3–7.5)	0.581
Treatment duration (month)	10.8 (6.2–23.7)	9.4 (5.7–25.8)	11.0 (6.3–23.5)	0.436
Route of tocilizumab				0.658
Intravenous	33 (84.6)	12 (80.0)	21 (87.5)
Subcutaneous	6 (15.4)	3 (20.0)	3 (12.5)
Laboratory data at initiation of tocilizumab
Anti-HBs positive	24 (61.5)	12 (80.0)	12 (50.0)	0.093
AST (IU/L)	16.0 (13.0–20.0)	16.0 (13.0–21.5)	17.0 (14.0–20.0)	0.795
ALT (IU/L)	15.0 (9.3–25.8)	14.0 (9.3–19.8)	16.0 (9.0–27.0)	0.654
ESR (mm/hr)	61.0 (40.5–77.8)	62.0 (48.3–76.3)	54.0 (39.0–78.0)	0.603
CRP (g/mL)	13.6 (4.9–28.3)	16.5 (8.0–53.0)	13.0 (3.7–27.1)	0.319
Laboratory data at study enrollment
AST (IU/L)	20.0 (17.0–27.0)	20.0 (17.0–25.3)	20.5 (16.5–27.5)	0.977
ALT (IU/L)	23.0 (14.0–29.8)	22.0 (15.5–29.5)	24.0 (13.0–29.5)	0.840
ESR (mm/hr)	9.0 (3.0–21.5)	12.0 (4.5–21.0)	7.5 (2.5–21.0)	0.347
CRP (g/mL)	0.2 (0.1–0.8)	0.3 (0.2–0.9)	0.2 (0.1–0.7)	0.178

Anti-HBc, positive antibody to HBV core antigen; RA, rheumatoid arthritis; DAS, disease activity score; ESR, erythrocyte sedimentation rate; Anti-HBs, antibody to HBsAg; AST, aspartate aminotransferase; ALT, alanine aminotransferase; CRP, C-reactive protein.

Values are expressed as the median (interquartile range) or number (percentage).