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

Table 7 Univariate and multivariate Cox regression analyses evaluating the association between clinical and serologic variables and the study end-point events (need for resective surgery) in Crohn’s disease patients. Subgroup analysis of B1 patients with colonic involvement is shown in the second half of the table

		Need for resective surgery in B1 patients at diagnosis							Need for resective surgery in B1 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		209	38						160	36
Clinical factors
Age at onset	A1	27	29.1	0.937	0.94 (0.38-2.35)	0.896			26	29.1	0.989	0.96 (0.33-2.80)	0.945
	A2	157	39.8		1.06 (0.50-2.22)	0.887			118	37		1.01 (0.40-2.58)	0.980
	A3	25	40.4			0.937			16	43			0.989
Gender	Male	91	34.2	0.958	0.99 (0.62-1.57)	0.958			69	33.7	0.977	0.99 (0.59-1.66)	0.977
	Female	118	40.8						91	37.7
Location	L1 + L3	129	31.1	0.109	1.48 (0.91-2.40)	0.112			80	41.5	0.174	1.45 (0.85-2.43)	0.176
	L2	80	43.7						80	31.1
	L2 + L3	160	50.2	0.382	0.78 (0.44-1.38)	0.384
	L1	49	36.0
Frequent relapse	No	154	36.9	0.950					115	35.8
	Yes	45	38.7		0.98 (0.58-1.68)	0.950			38	32.4	0.602	0.85 (0.47-1.56)	0.852
Antibodies against CHI3L1
aCHI3L1 IgG	Negative	182	38.9						141	36.4
	Positive	17	34.7	0.997	1.00 (0.43-2.32)	0.997			14	39.9	0.623	1.24 (0.53-2.89)	0.624
aCHI3L1 IgA	Negative	145	34.1						103	30.3
	Positive	54	48.5	0.246	1.34 (0.82-2.18)	0.248			52	47.6	0.255	1.36 (0.80-2.29)	0.257
aCHI3L1 sIgA	Negative	127	33.8						92	29.8
	Positive	72	46.3	0.159	1.40 (0.88-2.24)	0.161			63	46.4	0.227	1.37 (0.82-2.31)	0.230

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

²Univariate analysis.

³Multivariate analysis.

Rows corresponding to perianal disease according to the Montreal classification at diagnosis, smoking habits, and familial inflammatory bowel diseases 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.