Location-based prediction model for Crohn’s disease regarding a novel serological marker, anti-chitinase 3-like 1 autoantibodies

Table 6 Univariate and multivariate Cox regression analyses evaluating the association between clinical and serologic variables and the study end-point events (development of perianal complications) in Crohn’s disease patients. Subgroup analysis of B1 patients with colonic involvement is shown in the second half of the table

		Development of perianal penetrating complication in P0 patients at diagnosis							Development of perianal penetrating complication in P0 patients at diagnosis with colonic involvement
		n of subjects	CP of event (%)1	pLogRank	HR (95%CI)2	P value2	HR (95%CI)3	P value3	n of subjects	CP of event (%)1	pLogRank	HR (95%CI)2	P value2	HR (95%CI)3	P value3
Overall population		215	24						157	27.9
Clinical factors
Age at onset	A1	25	34.9	0.011	5.05 (1.44-17.7)	0.012			24	34.9	0.109	3.22 (0.92-11.31)	0.068
	A2	158	23.9		2.46 (0.76-8.01)	0.134			113	28.5		1.94 (0.59-6.33)	0.274
	A3	30	7			0.016			20	10.5			0.122
Gender	Male	90	23.1	0.584	0.85 (0.48-1.51)	0.585			68	27.2	0.474	0.81 (0.45-1.45)	0.475
	Female	123	24						89	28.7
Location	L1 + L3	147	20.5	0.066	0.60 (0.35-1.04)	0.640			91	27.1	0.634	0.87 (0.49-1.54)	0.635
	L2	66	28.8						66	28.8
	L2 + L3	157	27.9	0.002	4.25 (1.53-11.79)	0.001
	L1	56	8.9
Frequent relapse	No	160	18						115	22.3
	Yes	45	40.9	0.000	2.94 (1.68-5.15)	0.000			33	44.2	0.001	2.61 (1.45-4.68)	0.001
Antibodies against CHI3L1
aCHI3L1 IgG	Negative	187	22.3						138	25.0
	Positive	15	33.3	0.988	0.99 (0.36-2.76)	0.988			12	37.5	0.933	0.96 (0.34-2.68)	0.933
aCHI3L1 IgA	Negative	145	21.7						96	25.2
	Positive	57	25.8	0.624	1.16 (0.64-2.11)	0.624			54	26.7	0.862	0.95 (0.51-1.75)	0.862
aCHI3L1 sIgA	Negative	122	22.0						83	24.9
	Positive	80	24.7	0.746	0.91 (0.51-1.62)	0.746			67	27.6	0.645	0.87 (0.48-1.58)	0.645

¹Cumulative probability of event (%) corresponds to the median follow-up values.

²Univariate analysis.

³Multivariate analysis.

Rows corresponding to behaviour according to the Montreal classification at diagnosis, smoking habits, and familial inflammatory bowel disease were omitted because statistically significant differences for a given parameter were not obtained. HR: Hazard ratio; Age at onset: A1: ≤ 16 years, A2: 17-40 years, A3: > 40 years; Location: L1: Ileal, L2: Colonic, L3: Ileocolonic, L1 + L3: Ileal involvement, L2 + L3: Colonic involvement; Behavior: B1: Inflammatory/non-stricturing and non-penetrating; B2: Stenosing; B3: Internal penetrating; P0: Lack of perianal disease/involvement; P1: Perianal disease/involvement. IBD: Inflammatory bowel diseases; Ig: Immunoglobulin; sIgA: Secretory IgA; aCHI3L1: Anti-chitinase 3-like 1 autoantibodies; CP: Cumulative probability; CI: Confidence interval; HR: Hazard ratio.