The leucocyte chemotactic function in patients with ulcerative colitis.

The intermittent course of ulcerative colitis could hypothetically be be caused by fluctuations of the patients' natural systems of resistance. To evaluate this hypothesis the chemotactic function of leucocytes in ulcerative colitis patients has been investigated. The patient group comprised 59 patients, 24 men and 35 women. All activity stages were represented. The control group comprised 25 normal subjects, 10 men and 15 women. The chemotactic reaction was investigated in a double chamber with a cellulose-ester-micropore filter with a pore size of 3 mum as a diaphragm in which the migration takes place. The variable applied was the ratio between the number of cells 50 mum down in the filter and at the surface, calculated as a chemotactic Index. Casein was used as chemotactic agents. The corrected chemotactic was defined as the difference between stimulated and unstimulated Chemotactic Index. The chemotactic as well as the corrected chemotactic response of leucocytes from ulcerative colitis patients was significantly lower than in control subjects. The subgroup, active ulcerative colitis,showed the lowest corrected Chemotactic Index, whereas the unstimulated Control Index was significantly higher than in normal subjects. The results did not correlate with treatment. The investigation has shown that leucocytes in active ulcerative colitis cases have a high spontaneous mobility, whereas their chemotactic function after stimulation is significantly subnormal. Further investigation is needed to demonstrate whether this phenomenon plays a major role in the pathogenesis of ulcerative colitis.