Urinary macrophage counts and ratio to T lymphocytes: possible use in differential diagnosis and management of glomerular disease.

Abstract

The noninvasive method that can differentiate hematuria-positive patients has not yet been developed. We evaluated the clinical value of the analysis of mononuclear cells in urine in combination with urinary erythrocytes as a noninvasive differential diagnostic tool of glomerular disease. The number of macrophages (CD14+ cells/ml.urine) and T-lymphocytes (CD3+ cells/ml.urine) were measured by flow cytometry using samples of freshly voided urine from 203 patients with hematuria. They had various types of proliferative glomerular disease, including rapidly progressive glomerulonephritis (RPGN), IgA nephropathy (IgAN), and membranoproliferative glomerulonephritis (MPGN), or nonproliferative glomerulopathy including idiopathic renal hematuria and hereditary nephropathy. Urinary macrophage counts increased significantly with the severity of glomerulonephritis; their number consistently exceeded that of T-lymphocyte counts in patients with active proliferative glomerulonephritis. Urinary macrophage counts in patients with proliferative GN were consistently higher than those of hematuriamatched nonproliferative GN. Moreover, urinary macrophage counts in patients with RPGN were significantly higher than those of MPGN and IgAN. Most of the patients with inactive proliferative glomerulonephritis or with nonproliferative glomerulopathy showed no marked increase in urinary macrophages. Although some patients with nonproliferative glomerulopathy who exhibited gross hematuria showed a slight increase in urinary macrophage counts, such counts were consistently lower than those of T lymphocytes. These observations suggests that urinary macrophage count and its ratio to T-lymphocyte count may provide useful information for clinicians in managing patients with proliferative glomerular disease as well as deciding whether to conduct renal biopsy in patients with hematuria.