Higher infliximab and adalimumab trough levels are associated with fistula healing in patients with fistulising perianal Crohn’s disease

Table 1 Patient demographics and disease characteristics

	Infliximab (n = 66)	Adalimumab (n = 48)
Median age, yr (IQR)	36.0 (28.8-43.3)	34.5 (29.0-51.8)
A1, n (%)	2 (3.0)	7 (14.6)
A2, n (%)	52 (78.8)	26 (54.2)
A3, n (%)	9 (13.6)	13 (27.1)
Female gender, n (%)	28 (42.4)	14 (29.2)
Mean weight, kg (SD)	80.9 (18.7)	82.1 (21.4)
Mean BMI, kg/m2 (SD)	28.1 (4.8)	28.5 (5.5)
Median age at diagnosis of Crohn’s disease (IQR)	26.0 (21.0-34.0)	24.0 (19.0-41.3)
Current smoker, n (%)	12 (18.2)	5 (10.4)
Disease location
Ileal, n (%)	16 (24.2)	17 (35.4)
Colonic, n (%)	26 (39.4)	7 (14.6)
Ileocolonic, n (%)	15 (22.7)	18 (37.5)
No luminal disease, n (%)	4 (6.1)	2 (4.2)
Upper gastrointestinal involvement, n (%)	4 (6.1)	2 (4.2)
Stricturing, n (%)	10 (15.2)	11 (22.9)
Penetrating, n (%)	7 (10.6)	17 (35.4)
Median duration on anti-TNF agent, wk (IQR)	144.0 (80.0-280.0)	180.0 (107.3-309.8)
Anti-TNF dosing, n (%)
IFX, 5 mg/kg/8 wk	47	-
IFX, 7.5 mg/kg/8 wk	1	-
IFX, 10 mg/kg/8 wk	12	-
IFX, 15 mg/kg/8 wk	1	-
IFX, 20 mg/kg/8 wk	1	-
IFX, 5 mg/kg/6 wk	3	-
IFX, 10 mg/kg/6 wk	1	-
ADA, 40 mg fortnightly	-	37
ADA, 40 mg weekly	-	11
Concurrent steroids, n (%)	0 (0.0)	1 (2.1)
Concurrent aminosalicylates, n (%)	4 (6.1)	5 (10.4)
Combination with immunomodulator, n (%)	46 (69.7)	29 (60.4)
Methotrexate, n (%)	8 (12.1)	8 (16.7)
6-mercaptopurine, n (%)	9 (13.6)	7 (14.6)
Azathioprine, n (%)	29 (43.9)	14 (29.2)
Concurrent allopurinol, n (%)	10 (15.2)	4 (8.3)
Mean albumin, g/L (SD)	39.9 (4.9)	40.2 (4.7)
Median CRP, mg/L (IQR)	1.4 (0.7-5.5)	2.3 (1.2-5.2)

ADA: Adalimumab; BMI: Body mass index; CRP: C-reactive protein; IFX: Infliximab; IQR: Interquartile range; SD: Standard deviation; TNF: Tumor necrosis factor.