Table 1. Demographics and haptoglobin phenotype of study participants.

Subject group	Number of subjects	Mean age, years (SD)	Female sex, n (%)	Haptoglobin phenotype: Hp1-1; Hp2-1; Hp2-2; n (%)
Non-coeliac wheat sensitivitya	36	42.6 (12.8)	30 (83)	4 (11); 18 (50); 14 (39)
Coeliac diseaseb	37	36.9 (15.7)	27 (73)	3 (8); 24 (65); 10 (27)
Ulcerative colitisc	20	36.9 (11.5)	9 (45)	1 (5); 14 (70); 5 (25)
Healthy	49	39.1 (12.9)	32 (65)	3 (6); 28 (57); 18 (37)

^aPatients had self-reported, non-coeliac wheat sensitivity and irritable bowel syndrome based on Rome III criteria, and did not have other significant gastrointestinal-related diseases. Coeliac disease was ruled out by the absence of HLA-DQ2 or HLA-DQ8 haplotype or by normal duodenal biopsy [17].

^bPatients were newly diagnosed and on a gluten-free diet for less than 4 weeks. All had duodenal histology showing a maximum severity of at least Marsh IIIA lesion [18].

^cPatients were hospitalised with acute severe disease, refractory to intravenous corticosteroid treatment and receiving medical rescue therapy with infliximab [19].