Higher anti-TNF serum levels are associated with perianal fistula closure in Crohn’s disease patients

Figures & data

Table 1. Patient characteristics IFX treated group.

	Closed fistulas (N = 32)	Draining fistulas (N = 15)	p-value
Sex [n (%)]			.87
Male	12 (37.5)	6 (40.0)
Female	20 (62.5)	9 (60.0)
Age (years)			.22
Mean ± SD (range)	40 ± 12.6 (18–65)	44.7 ± 11.1 (25–64)
Prior anti-TNF therapy [n (%)]			.03
No	25 (78.1)	7 (46.7)
Yes	7 (21.9)	8 (53.3)
Duration of anti-TNF therapy (years)			.80
Median (IQR)	3.5 (1–6.8)	3.0 (1–12)
Combination therapy [n (%)]			.04
No	18 (56.3)	13 (86.7)
Yes	14 (43.8)	2 (13.3)
Initiation of anti-TNF in combination with seton drainage [n (%)]			.20
No	25 (78.1)	9 (60.0)
Yes	7 (21.9)	6 (40.0)
Disease duration (years)			.01
Median (IQR)	12.5 (4.0–19.0)	23 (20.0–29.0)
Physical examination confirmed by MRI [n(%)]			.06
No	22 (68.8)	6 (40.0)
Yes	10 (31.3)	9 (60.0)
Proctitis [n(%)]			.001
No	31 (96.9)	9 (60.0)
Yes	1 (3.1)	6 (40.0)
Active smoking [n (%)]			.28
No	26 (81.3)	14 (93.3)
Yes	6 (18.8)	1 (6.7)

N: number of patients; IFX: infliximab; SD: standard deviation; IQR: interquartile range; MRI: Magnetic Resonance Imaging.

Table 2. Patient characteristics ADL treated group.

	Closed fistulas (N = 13)	Draining fistulas (N = 6)	p-value
Sex [n (%)]			.25
Male	8 (61.5)	2 (33.3)
Female	5 (38.5)	4 (66.7)
Age (years)			.69
Mean ± SD (range)	37.5 ± 10.4 (20–56)	39 ± 19.8 (25–78)
ADL dosing regimen
40 mg every other week	9 (69.2)	2 (33.3)
40 mg every week	4 (30.8)	4 (66.7)
Prior anti-TNF therapy [n (%)]			.25
No	8 (61.5)	2 (33.3)
Yes	5 (38.5)	4 (66.7)
Duration of anti-TNF therapy (years)			.04
Median (IQR)	15 (7.5–23.5)	4.5 (3.3–18.3)
Combination therapy [n (%)]			.83
No	8 (61.5)	4 (66.7)
Yes	5 (38.5)	2 (33.3)
Initiation of anti-TNF in combination with seton drainage [n (%)]			.04
No	12 (92.3)	3 (50.0)
Yes	1 (7.7)	3 (50.0)
Disease duration (years)			.09
Median (IQR)	15 (7.5–23.5)	4.5 (3.3–18.3)
Physical examination confirmed by MRI [n(%)]			.004
No	11 (84.6)	1 (16.7)
Yes	2 (15.4)	5 (83.3)
Proctitis [n(%)]			.03
No	13 (100)	4 (66.7)
Yes	0 (0)	2 (33.3)
Active smoking [n (%)]			.64
No	10 (76.9)	4 (66.7)
Yes	3 (23.1)	2 (33.3)

N: number of patients; ADL: adalimumab; SD: standard deviation; IQR: interquartile range; MRI: Magnetic Resonance Imaging.

Figure 1. Median IFX TLs of 47 patients with productive versus closed fistulas: 2.3 µg/ml versus 6.0 µg/ml. IFX: infliximab; TL: trough level; [IFX]: infliximab serum concentration; N: number of patients.

Figure 2. Correlation between serum IFX trough levels and fistula closure. AUC: 0.92 (95% CI: 0.82–1.00), p < .001. IFX: infliximab; AUC: area under the curve; CI: confidence interval; ROC: receiver operating characteristic.

Table 3. Dosing regimen of 47 patients treated with infliximab (IFX).

Dosing schedule IFX	Closed fistulas (N = 32)	Draining fistulas (N = 15)
Regular dosing schedule [n (%)]	16 (59)	11 (41)
Intensified dosing schedule [n (%)]	16 (80)	4 (20)

N: number of patients. Regular IFX dosing schedule: 5 mg/kg every 8 weeks. Intensified regimen varied from: 5 mg/kg every 6 weeks (n = 10), 5 mg/kg every 4 weeks (n = 3), 10 mg/kg every 6 weeks (n = 2), 10 mg/kg every 8 weeks (n = 1).

Figure 3. Median ADL serum levels of 19 patients with productive versus closed fistulas: 4.8 µg/ml versus 7.4 µg/ml. [IFX]: infliximab serum concentration; N: number of patients.

Figure 4. Correlation between serum ADL levels and fistula closure. AUC: 0.89 (95% CI: 0.71–1.00), p < .01. ADL: adalimumab; AUC: area under the curve; ROC: receiver operating characteristic.

Table 4. Dosing regimen of 19 patients treated with adalimumab (ADL).

ADL dosing regimen	Closed fistulas (N = 13)	Draining fistulas (N = 6)
40 mg every other week	9 (69.2)	2 (33.3)
40 mg every week	4 (30.8)	4 (66.7)

N: number of patients. Two types of dosing schedules: 40 mg every other week or 40 mg every week.