[A fundamental study on clinical significance of measuring eosinophil protein X in spot urine in asthmatics].

To define the clinical significance of measuring eosinophil protein X (EPX) in spot urine in asthmatics, we undertook the fundamental study in 32 stable asthmatics having anti-asthmatic agents and 10 normal healthy controls, and obtained the following results. 1) Peripheral eosinophil counts, urinary EPX (u-EPX), urinary leukotriene E4 (u-LTE4), and serum eosinophil cationic protein (s-ECP) values were significantly higher in asthmatics than those in the controls. 2) U-EPX values were not associated with the type of asthma and severity of the disease. 3) A significant correlation was observed between u-EPX values and peripheral eosinophil counts, but not between s-ECP values and peripheral eosinophil counts. Furthermore, no correlation was observed between u-EPX and s-ECP values. 4) U-EPX values did not correlate with either u-LTE4, %FEV1, or histamine PC20 values. Accordingly, EPX value in spot urine may be a useful maker to assess the activation of eosinophils in asthmatics.