Enumeration of lymphocyte populations defined by surface markers in the whole blood of patients with Crohn's disease.

The proportions and absolute numbers of different lymphocyte populations were determined using alkaline phosphatase-labelled reagents in the whole peripheral blood of 22 patients with Crohn's disease. Monoclonal mouse anti-T cell antibody (OKT3) was used to identify T cells, polyvalent F(ab')2 anti-human immunoglobulin for B cells, C3b for C3b-receptor bearing cells, and soluble IgG antibody-antigen complexes for Fc(gamma)-receptor bearing cells. Endogenous myeloperoxidase served to distinguish monocytes. Application of this methodology to whole blood avoids the inevitable loss of cells which accompanies separation of mononuclear cells from blood and therefore permits precise enumeration of lymphocyte populations in the circulation. No significant difference from healthy adult controls was observed in any of the lymphocyte subsets tested.