Enhanced expression of l-selectin on peripheral blood lymphocytes from patients with IgA nephropathy

To investigate the homing characteristics of T and B lymphocytes which could explain the abnormal partition of IgA-producing cells in tonsils and bone marrow from patients with IgA nephropathy (IgAN), the expression of leucocyte adhesion molecules (CD11a, CD29, CD49d, CD62L, CD31) was assessed using flow cytometry on peripheral blood leucocytes from patients with biopsy-proven IgAN and controls. Higher proportions of T and B lymphocytes expressing higher amounts of l-selectin, as well as higher proportions of B cells expressing more CD31 were evidenced in IgAN patients. Conversely, serum levels of sCD62L were not different from controls, but significantly higher than serum levels in patients suffering from other renal diseases. We hypothesize that this over-expression of CD62L and CD31 may be involved in an enhanced efficiency of lymphoid cells homing to lymphoid tissues in this disease

Two-color immunofluorescence and flow cytometric analysis of lamina propria lymphocyte subsets in ulcerative colitis and Crohn's disease.

By using two-color immunofluorescence with fluorescein isothiocyanate (FITC) and phycoerythrin (PE)-labelled monoclonal antibodies and multiparameter flow cytometry, we investigated lamina propria lymphocyte subsets of patients with ulcerative colitis (UC) and Crohn's disease (CD). Leu-3/Leu-2 (CD4/CD8) ratio of lamina propria lymphocytes (LPL) of CD (mean +/- SD: 1.9 +/- 0.8, P less than 0.01) was significantly decreased compared with controls (3.3 +/- 1.1), because of an increased number of CD8+ lymphocytes. The majority of lamina propria CD4+ cells were CD4+, Leu-8- and CD4+, CD45R- both in controls and IBD tissue. Many lamina propria T lymphocytes were activated, expressing HLA-DR antigen not only in IBD but also in controls. NK cells defined by CD16 and CD 56 (3.0 +/- 1.4%, P less than 0.01) were significantly decreased in patients with UC compared with controls (6.5 +/- 3.0%). A low proportion of B cells in the intestinal mucosa expressed Leu-8 antigen and CD23 antigen. The proportion of activated B cells of LPL was high in IBD mucosa as well as normal mucosa. These findings suggest that local activation of B cells leads to the loss of the expression of Leu-8 antigen and CD23