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 coul d explain the abnormal partition of IgA-producing cells in tonsils and bone marrow from patients with IgA nephropathy (IgAN), the expression of leucoc yte adhesion molecules (CD11a, CD29, CD49d, CD62L, CD31) was assessed using flow cytometry on peripheral blood leucocytes from patients with biopsy-pr oven IgAN and controls. Higher proportions of T and B lymphocytes expressin g higher amounts of L-selectin, as well as higher proportions of B cells ex pressing more CD31 were evidenced in IgAN patients. Conversely, serum level s of sCD62L were not different from controls, but significantly higher than serum levels in patients suffering from other renal diseases. We hypothesi ze that this over-expression of CD62L and CD31 may be involved in an enhanc ed efficiency of lymphoid cells homing to lymphoid tissues in this disease.