GSTM1 and anemia (phenotype): Children with non-atrophic changes had more often blood in stools and anemia, family history of celiac disease, and positive celiac serology than did those with normal duodenal mucosa, whereas the groups did not differ in the other clinical and laboratory parameters (Table 1) or median levels of Hb (123 vs. 128 g/l, p = 0.069; data available from n = 599), ESR (8 vs. 8 mm/h, p = 0.575; n = 480), albumin (40 vs. 38 g/l, p = 0.229; n = 307) and calprotectin (192 vs. 67 μg/g, p = 0.447; n = 293).