URINARY ALPHA(1)-MICROGLOBULIN DETECTS UROPATHY - A PROSPECTIVE-STUDYIN 483 UROLOGICAL PATIENTS

Purpose: The aim of the study was to evaluate prospectively urinary al pha(1)-microglobulin as a marker of proximal tubular damage following acute pyelonephritis and outflow disease of the upper urinary tract in a urological population with minimal exclusion criteria. We also meas ured the urinary gamma-glutamyltransferase activity, urinary albumin, urinary and serum creatinine, serum IgA and serum alpha(1)-microglobul in. Patients and methods: We studied 483 urological patients (age: 1 t o 92 years, 297 men, 186 women) excluding patients receiving nephrotox ic drugs, or suffering from type 1 diabetes or renal diseases. There w ere 141 patients with urinary tract infection but no fever, 36 patient s with high fever of non-renal origin, 51 patients with acute pyelonep hritis and 156 patients with outflow disease of the upper tract, and 9 9 patients were induced in the reference population.Results: For acute pyelonephritis, vesico-ureteral reflux, and ureteral obstruction, uri nary alpha(1)-microglobulin had a sensitivity of 94%, 90% and 63% resp ectively and a specificity of 67%, 77% and 76%. The area under the cur ve of the receiver operator characteristic curve was significantly (p < 0.001) higher for urinary alpha(1)-microglobulin than for albumin or gamma-glutamyltransferase activity. Unexpected positive results were found in acute prostatitis. The urinary alpha(1)-microglobulin was the only parameter which differentiated between acute prostatitis and pye lonephritis (p < 0.001). Creatinine clearance or age had little and ge nder had no influence on the urinary excretion of alpha(1)-microglobul in. Urine production rate significantly increases the urinary alpha(1) -microglobulin/creatinine ratio. Conclusion: Our results suggest that the urinary alpha(1)-microglobulin/creatinine ratio is a diagnosticall y useful marker of tubular damage in acute pyelonephritis and vesico-u reteral reflux in the urological population. Following renal colic and chronic ureteral obstruction, a significant increase in urinary alpha (1)-microglobulin excretion was observed.