Correlations between ldh isoenzyme patterns and brushing cytology in ulcerative colitis.

Forty-one rectal samples from 22 patients with ulcerative colitis and eight rectal samples from normal controls were studied cytologically, histologically and histochemically (LDH isoenzyme pattern). The cytological specimens from patients were classified into three groups (A, B and C) and the degree of cellular atypia was compared with the modifications of LDH isoenzymogram. The differences between the polypeptide M levels of the group A, B and C were statistically significant, as well as those between groups B and C versus the normal controls. The highest percentages of M were observed in group C and correlate with the presence of large single or double nucleoli. These results most likely represent active cellular regeneration, and further investigations are needed to elucidate whether the histochemical alterations could be useful to detect precocious malignant changes in patients with long-standing ulcerative colitis.