Relationship between clinical remission of perianal fistulas in Crohn’s disease and serum adalimumab concentrations: A multi-center cross-sectional study

Table 1 Patients’ characteristics according to clinical remission status

	Clinical remission, n (%) unless otherwise specified
	No, n = 19	Yes, n = 15
Female sex	10 (53%)	6 (40%)
Age (yrs), Med [IQR]	34 [27-38]	35 [23-44]
BMI, Med [IQR]	28 [19-32]	22 [20-23]
Number of comorbidities1, Med [IQR]	0 [0-1]	0 [0-1]
Active smoking, 1 MD	9 (47%)	6 (43%)
Crohn’s disease phenotype (Montreal L)
Terminal ileum	3 (16%)	4 (27%)
Colon	8 (42%)	5 (33%)
Ileo-colon	8 (42%)	5 (33%)
Upper digestive tract	0 (0%)	1 (7%)
Crohn’s disease phenotype (Montreal B)
Non-stricturing, non-penetrating	12 (63%)	8 (53%)
Stricturing	4 (21%)	2 (13%)
Penetrating	2 (11%)	2 (13%)
Stricturing + penetrating	1 (5%)	3 (20%)
Number of fistulas, Med [IQR]	2 [1-2]	2 [1-2]
Complex fistula	17 (89%)	11 (73%)
Vaginal fistula	4 (21%)	1 (7%)
Previous treatment with infliximab	10 (53%)	7 (47%)
Previous treatment with another anti-TNF-α2	10 (53%)	7 (47%)
Previous treatment with another form of biotherapy3	10 (53%)	7 (47%)
Previous treatment with combination therapy	12 (63%)	5 (33%)
Previous abdominal surgery
No	14 (74%)	11 (73%)
Appendicectomy	0 (0%)	2 (13%)
Ileocecal resection	4 (21%)	2 (13%)
Colectomy	1 (6%)	0 (0%)
Previous fistulotomy	4 (21%)	6 (40%)
Previous seton	18 (95%)	13 (87%)
Previous flattening of abscesses	8 (42%)	10 (67%)
Previous closure techniques	3 (16%)	5 (33%)
Previous glue	2 (11%)	4 (27%)
Previous plug	0 (0%)	1 (7%)
Previous rectal advancement flap	1 (5%)	0 (0%)
Optimization at first visit	8 (42%)	9 (60%)
Combination therapy (with methotrexate or thiopurine) at first visit	12 (63%)	5 (33%)
Combination therapy and/or optimization at first evaluation	15 (79%)	9 (60%)

¹Cardiological disorders, Anxiety-depressive disorders, Acute pancreatitis, Asthma, Joint involvement, Hypothyroidism.

²Infliximab, certolizumab, golimumab.

³Infliximab, certolizumab, golimumab, vedolizumab, ustekinumab. BMI: Body mass index; IQR: Interquartile range; Med: Median; MD: Missing data.

Table 2 Characteristics of perianal fistulas at each visit according to the presence of clinical remission

	Clinical remission, n (%) unless otherwise specified
	No, n = 34	Yes, n = 22
PAF duration (Time from fistula diagnosis to date of visit) in mo, Med [IQR]	12 [8-23.5]	53.5 [32.75-81.75]
Drainage duration (Time from seton setting down to date of visit) in mo, Med [IQR]	9 [4.75-17]	8 [4-19]
Combination therapy (with methotrexate or thiopurine)	23 (68%)	7 (32%)
Optimization	19 (56%)	14 (64%)
Serum concentrations of ADA (μg/mL), Med [IQR]	10.7 [2.4-14.7]	14.1 [9.8-16]
C reactive protein (mg/L), Med [IQR]	2.7 [0.07-15.25]	0.9 [0-1.8]
Serum albumin (g/L), Med [IQR]	42 [38.25-47.3]	43 [41.85-44.25]
Length of treatment by ADA in mo, Med [IQR]	12 [6-34.75]	37.5 [23.75-46.75]

PAF: Perianal fistulas; Med: Median; ADA: Adalimumab.