Urinary plasma protein patterns in acute prostatitis
Faculty of Medicine and Health Sciences
Clinical chemistry and laboratory medicine. - Berlin
, p. 79-84
We evaluated the diagnostic utility of urinary α1-microglobulin, α2-macroglobulin and albumin in the diagnosis of acute prostatitis. We studied 133 men (43±17 years) with, and a reference population (n=36, 41±16 years) without, urinary tract infection. Prostatectomy samples were used to study the potential interference between prostatic proteins and protein analysis. Urinary α2-macroglobulin/albumin ratio was significantly lower in prostatitis compared to the reference population, cystitis or acute pyelonephritis (p <0.0001). Low α2-macroglobulin concentrations in prostatitis are due to inhibition (p = 0.0001) of the immune reaction between α2-macroglobulin in presence of polyclonal rabbit antibodies (used for immunonephelometry) by soluble prostatic proteins (± 60 kDa) which appear in urine in acute prostatitis. The urinary α1-microglobulin/creatinine ratio diagnoses acute pyelonephritis (sensitivity 100% and specificity 87%) and the urinary α2-macroglobulin/albumin ratio diagnoses acute prostatitis (sensitivity 100% and specificity of 90%). Stepwise multinomial logistic regression analysis reveals that urinary α1-microglobulin, α2-macroglobulin, albumin and creatinine provide optimal differentiation between acute pyelonephritis and acute prostatitis (pseudo R2=0.83; Loglikelihood −30.55, p <0.000001). In conclusion, the combination of hematuria and absence of urinary alpha-2-macroglobulin is diagnostic for acute prostatitis. Even without hematuria, α2-macroglobulin remains lower compared to patients without prostatitis.