ABNORMAL RECTAL CELL-PROLIFERATION AND P52 P35 PROTEIN EXPRESSION IN PATIENTS WITH ULCERATIVE-COLITIS/

We evaluated the presence of cell proliferation and antigenic abnormal ities in rectal biopsies from 37 patients affected by ulcerative colit is and 15 controls. The study was carried out by thymidine labeling an d immunochemistry, using antibodies against specific cytoskeletal-asso ciated proteins (p52, p35, alpha-actinin). Among ulcerative colitis pa tients, 24 had an immunofluorescence pattern similar to that of contro ls, while 13 showed an abnormal distribution of one or more proteins ( p52 alone or p52 and either p35 or alpha-actinin) within the rectal cr ypts. Patients showed a shift of the proliferative compartment towards the top of the rectal crypts compared with controls. This finding was more evident in patients with p52 or p35 abnormalities. Proliferative and antigenic defects were not related either to age or the duration of colitis. These phenotypic changes might be a biomarker of increased risk of colon cancer in ulcerative colitis.