DETECTION OF URINARY INTERLEUKIN-8 IN GLOMERULAR-DISEASES

Detection of urinary interleukin-8 in glomerular diseases. To clarify the mechanism of neutrophil infiltration in glomerulonephritis, both u rinary and plasma levels of a potent neutrophil chemotactic cytokine, interleukin-8 (IL-8), were measured in 40 healthy volunteers and 96 pa tients with various renal diseases. The plasma IL-8 levels were less t han 16 pg/ml. The urinary IL-8 levels were elevated in several renal d iseases including IgA nephropathy (17 of 43), acute glomerulonephritis (4 of 6), lupus nephritis (11 of 15), purpura nephritis (2 of 4), mem branoproliferative glomerulonephritis (1 of 1), and cryoglobulinemia ( 2 of 2). IL-8 was detected immunohistochemically in diseased glomeruli , suggesting its local production. Elevated urinary IL-8 levels during the acute phase or exacerbations were found to be decreased during sp ontaneous or steroid pulse therapy-induced convalescence in all patien ts examined. The urinary IL-8 levels were higher in patients with glom erular leukocyte infiltration than in those without infiltration. Coll ectively, local production of IL-8 in diseased glomeruli might be invo lved in the pathogenesis of the glomerular diseases and measurement of IL-8 in the urine might be useful for monitoring the glomerular disea ses.