Measurement Of Leukotriene E4 Research Articles

Urinary excretion of leukotriene E4 and eosinophil protein X in children with atopic asthma.

Measurement of leukotriene E4 (LTE4) in urine is a noninvasive method for assessing changes in the rate of total body cysteinyl leukotriene production. Eosinophil protein X (EPX) has been used to assess eosinophil activity and monitor inflammation in bronchial asthma. The aim of the study was to look for differences in urinary LTE4 and EPX concentrations between children with stable atopic asthma and healthy controls and to compare asthmatic children with different disease severity. In addition the relationship was evaluated between urinary LTE4 and EPX levels and lung function. LTE4 was also measured (enzyme immunoassay) together with EPX (radioimmunoassay) in urine and lung function tests were carried out in children with mild asthma (steroid-naive) (n=49), moderate to severe asthma (using inhaled steroids) (n=31) and healthy control subjects (n=28). Urinary leukotriene E4 (LTE4) was significantly higher in children with asthma than in controls (median [25-75 percentile] 238.5 (126.5-375.7) SD 191.8 versus 189 (51-253.2) SD 131.7 pg.mg(-1) creatinine; p=0.021). Urinary EPX was also significantly increased in asthmatic children compared with controls (85.5 [64-131.5] SD 76.2 versus 48.5 [43.2-90] 112.1 microg x mmol(-1) creatinine; p=0.006). There were no differences in urinary LTE4 and EPX between the group of mild and the group of moderate to severe asthmatic children. There were significant associations between the urinary LTE4 and intrathoracic gas volume (ITGV), residual volume (RV), forced expiratory volume in one second (FEV1), forced expiratory capacity (FVC) and maximum expiratory flow rate at 25% of vital capacity (MEF25). Urinary EPX was only correlated with maximum expiratory flow rate at 75% of vital capacity (MEF75). Thus measurement of urinary LTE4 may predict the degree of airflow obstruction in asthmatic children. Urinary LTE4 and EPX are useful markers of airway inflammation and can be helpful in guiding asthma management. There was no correlation between LTE4 and EPX levels.

Cysteinyl leukotrienes in the urine of patients with liver diseases

The significance of cysteinyl leukotrienes was investigated in patients with liver diseases by measurements of leukotriene E4 and N-acetyl-leukotriene E4 in urine. A marked increase of renal cysteinyl leukotriene excretion was observed in patients with cirrhosis without and with ascites, intrahepatic cholestasis, and obstructive jaundice as compared with healthy subjects (leukotriene E4: means 82, 264, 221 and 142 versus 40 nmol/mol creatinine, respectively; N-acetyl-leukotriene E4: means 25, 64, 61 and 47 versus 13 nmol/mol creatinine, respectively). The urinary concentration of leukotriene E4 was positively correlated with the one of N-acetyl-leukotriene E4 (r = 0.81, p < 0.001). In patients with cirrhosis, the excretion of cysteinyl leukotrienes was strongly increased in patients in Child-Turcotte stage C as compared with those in Child-Turcotte stages A and B. In patients with intrahepatic cholestasis and in those with obstructive jaundice, the excretion of leukotriene E4 plus N-acetyl-leukotriene E4 was positively correlated with total serum bilirubin. In patients with cirrhosis and in those with obstructive jaundice, the cysteinyl leukotrienes in urine were negatively correlated with creatinine clearance. The elevated renal excretion of cysteinyl leukotrienes decreased after biliary drainage in patients with obstructive jaundice. These data support the concept that increased urinary excretion of cysteinyl leukotrienes in patients with cirrhosis is due to a reduced functional liver mass and that in patients with cholestasis it is mainly due to an impaired elimination into the biliary tract that results in a diversion to renal excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Urinary leukotriene E4 in bronchial asthma

Leukotriene E4 (LTE4) is excreted into the urine in a relatively constant proportion of 4-7% when either leukotriene C4 (LTC4) or LTE4 is intravenously infused, regardless of the magnitude of the infused dose. Measurement of LTE4 in urine is, therefore, a convenient and non-invasive method for assessing changes in the rate of total body sulphidopeptide leukotriene production. We assayed urinary LTE4 in 17 normal subjects, 31 subjects with asthma without aspirin sensitivity, and 10 aspirin-sensitive subjects. The relationship between urinary LTE4 and nonspecific bronchial hyperresponsiveness, as assessed by the provocative dose producing a 20% fall in forced expiratory volume in one second (PD20) to inhaled histamine, was examined in 19 non-aspirin-sensitive asthmatic subjects. The urinary LTE4 values were log-normally distributed. Urinary LTE4 was detected in 28 of the 31 non-aspirin-sensitive asthmatic subjects, and the geometric mean (95% confidence interval (CI) of 43 (32-57) pg.mg-1 creatinine was no different to that of 34 (25-48) pg.mg-1 creatinine measured in the normal subjects. The geometric mean of 101 (55-186) pg.mg-1 creatinine measured in the aspirin-sensitive asthmatics was significantly higher than that measured in the normal subjects (p less than 0.005) and in the asthmatic subjects who were non-aspirin-sensitive (p less than 0.002), but there was considerable overlap between the three groups. There was no relationship between urinary LTE4 and PD20, or between urinary LTE4 and baseline forced expiratory volume in one second (FEV1) (% predicted). Thus, measurement of LTE4 in a single sample of urine will not predict the extent of bronchial hyperresponsiveness or degree of airflow obstruction.