Mononuclear cells in peripheral venous blood of patients with Crohn's disease: preoperative status and postoperative course, influence of duration, activity and extent of disease.

In Crohn's disease (CD) the intestinal lesion is supposed to be the cause of the observed systemic immunologic changes. Based on this assumption, peripheral blood mononuclear cells (PBMC) are of specific interest as a possible indicator of intestinal activity of the disease. From 151 surgical patients CD3+, CD4+, CD8+, B cells, macrophages, leucocytes and the relative number of lymphocytes were analysed preoperatively and 10 days, 3 and 6 months postoperatively. The cell data were correlated with the main clinical data of disease. There was a highly significant preoperative increase of leucocytes, macrophages, CD8+, and B cells in the CD group, and a marked decrease of CD3+, CD4+ cells, and the relative lymphocyte count in the same group. Six months postoperatively, highly elevated macrophages, and leucocytes, and a depressed number of CD4+ cells were the only changes. The preoperative cell data did not correlate with the duration of illness, CDAI, localisation, and extent of the intestinal lesion nor did they correlate with any modality of preoperative drug treatment. Thus, the determination of PBMC characteristics in CD is only of limited value for routine diagnostic purposes. However, the persistence of some pathological values long after operation might be caused by residual microscopic lesions and thus reflect the intestinal process.