Colorectal goblet cell mucins in familial adenomatous polyposis

Ninety two tissue blocks from the left colon and 52 from the right colon were obtained from 112 patients with familial adenomatous polyposis (FAP). Tissues from 137 patients with other conditions served as controls. Within the main study a smaller investigation was performed to compare sections from the left and right colon in the same subject. Several well known histochemical techniques were used to investigate possible changes in sulphation, sialic acid structure (loss of O-acetyl substituents), and changes in the ratio of sialic acid to neutral sugars. In patients with FAP, as in controls, there was increased expression of periodic acid Schiff positive mucin and fucose in the right colon. The only difference between patients with FAP and controls was the indirect demonstration of less neutral mucin in the right colon in FAP, but this did not seem to affect neutral sugars binding to UEA-1, PNL, or HPA. As in the general population, a small proportion of patients with FAP showed a lack of O-acetyl substituted sialic acid. Sialic acid heterogeneity probably has a genetic basis, but this is not associated with the genetic defect underlying FAP.