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

Table 3 Differences in patients on adalimumab with and without fistula healing

	Patients with fistula healing (n = 37)	Patients without fistula healing (n = 11)	P value
Median age, yr (IQR)	33.0 (28.5-52.0)	44.9 (33.0-52.0)	0.254
Female gender, n (%)	10 (27.0)	4 (36.4)	0.550
Mean weight, kg (SD)	82.5 (22.3)	79.7 (16.7)	0.812
Mean BMI, kg/m2 (SD)	29.2 (5.9)	25.5 (2.7)	0.241
Median age at diagnosis of Crohn’s disease (IQR)	24.0 (18.0-42.0)	30.0 (19.0-41.0)	0.570
A1, n (%)	6 (16.2)	1 (9.1)	-
A2, n (%)	19 (51.4)	7 (63.6)	-
A3, n (%)	10 (27.0)	3 (27.3)	-
Current smoker, n (%)	5 (13.5)	0 (0.0)	0.198
Location
Ileal, n (%)	12 (32.4)	5 (45.5)	-
Colonic, n (%)	5 (13.5)	2 (18.2)	-
Ileocolonic, n (%)	15 (40.5)	3 (27.3)	-
No luminal disease, n (%)	2 (5.4)	0 (0.0)	-
Upper gastrointestinal involvement, n (%)	2 (5.4)	1 (9.1)	-
Stricturing, n (%)	9 (24.3)	2 (18.2)	0.644
Penetrating, n (%)	14 (37.8)	3 (27.3)	0.481
Median duration on anti-TNF agent, wk (IQR)	194.5 (124.3-311.3)	122.5 (79.8-319.3)	0.318
Dose escalated anti-TNF therapy, n (%)	10 (27.0)	1 (9.1)	-
Concurrent steroids, n (%)	0 (0.0)	0 (0.0)	-
Concurrent aminosalicylates, n (%)	4 (10.8)	1 (9.1)	0.849
Combination with immunomodulator, n (%)	25 (67.6)	4 (36.4)	0.048
Methotrexate, n (%)	7 (18.9)	1 (9.1)	0.424
6-mercaptopurine, n (%)	6 (16.2)	1 (9.1)	0.537
Azathioprine, n (%)	12 (32.4)	2 (18.2)	0.336
Concurrent allopurinol, n (%)	4 (10.8)	0 (0.0)	0.248
Mean albumin, g/L (SD)	40.5 (4.5)	40.0 (5.7)	0.608
Median CRP, mg/L (IQR)	2.1 (1.0-4.5)	5.4 (1.7-9.3)	0.070
Median trough level (IQR)	9.2 (6.5-12.0)	5.4 (2.5-8.3)	0.004
Detectable antibody, n (%)	1 (2.7)	1 (9.1)	0.352

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