Sensitivity of urinary mesothelin in patients with malignant mesothelioma.

INTRODUCTION: Malignant mesothelioma (MM) is an aggressive, uniformly fatal tumor usually caused by exposure to asbestos. Soluble mesothelin has been intensively investigated in the serum as a biomarker for this disease. As urine is less complex and less invasive to collect than serum and may be a more acceptable specimen for large-scale screening studies of asbestos-exposed individuals, we determined whether the sensitivity and specificity for MM could be improved by measuring soluble mesothelin in the urine. METHODS: Soluble mesothelin concentrations were determined using the MESOMARK assay in concurrent serum and urine samples from 70 patients with pleural MM, 111 patients with asbestos-related lung or pleural disease, and 45 patients with benign nonasbestos-related lung and pleural disease. Only patients with serum creatinine levels within the normal range were included in the study. Sensitivities were determined and receiver operator characteristic curves were generated to compare the diagnostic accuracy of mesothelin in the serum and urine. RESULTS: At a specificity of 95% relative to individuals with benign lung or pleural disease, serum mesothelin had a sensitivity of 66% and area under the curve of 0.882, whereas urinary mesothelin corrected for urine creatinine concentration had a sensitivity of 53% and area under the curve of 0.787. CONCLUSIONS: The sensitivity of urinary mesothelin does not warrant the use of urine as a biomarker specimen for MM diagnosis.

Altered composition of urinary heparan sulfate in patients with COPD.

In patients with emphysema the integrity of the extracellular matrix (connective tissue skeleton) is compromised. In this study we analyzed glycosaminoglycans, which are main constituents of this matrix, in urines from patients with chronic obstructive pulmonary disease (COPD)/emphysema. Glycosaminoglycans (GAGs) were purified by anion exchange chromatography and quantified using the 1,9-dimethylmethylene blue assay. Heparan sulfate (HS) was assayed using three different chemical methods: digestion with heparitinase or with nitrous acid and by use of an adapted 1,9-dimethylmethylene blue assay. A specific epitope on the HS molecule, defined by the monoclonal antibody JM403, was determined using an inhibition enzyme immunoassay. In patients with COPD total urinary glycosaminoglycan and HS content were not altered. The JM403 epitope of HS, however, was greatly decreased in patients (0.6 versus 4.1 units/mg creatinine for control subjects, p < 0.0001). A similar pattern was observed when patients with bronchial carcinoma with and without emphysema were compared (0.4 versus 2.4 units/mg creatinine respectively, p < 0.0005). Patients with sarcoidosis did not show a decreased epitope content. These results indicate a structural change or an altered processing of the HS molecule in patients with emphysema. Taking into consideration the importance of HS for the stability of the alveolar extracellular matrix, this change may be associated with the pathogenesis of emphysema.

Endothelin-1 excretion in urine in active pulmonary sarcoidosis and in other interstitial lung diseases.

Endothelin-1 (ET-1) is a vasoactive, mitogenic peptide that is variably increased in Bronchoalveolar Lavage Fluid (BALF) and immunohistochemically found in lung tissue of patients with Interstitial Lung Disease (ILD). To assess if endogenous ET-1 production is increased in ILD we evaluated 24 hour (24h) urine excretion of ET-1 in 20 patients with ILD and 10 healthy age-matched controls (HC). Eight patients with active pulmonary sarcoidosis (S), 6 with idiopathic pulmonary fibrosis (IPF) and 6 with focal lung fibrosis due to inactive pulmonary tuberculosis (hTB) were studied. Plasma ET-1 levels (ET-1pl, pg/ml) and 24h ET-1 levels in urine (ET-1ur, ng/24h) were measured by a specific radio-immunoassay. Determinations of ET-1p1 and ET-1ur were repeated in S and IPF patients after 30 days of prednisone (0.75 mg/kg/day) treatment. ET-1p1 concentrations were not different between HC (5.34 +/- 0.48), S (5.95 +/- 0.96), IPF (4.75 +/- 1.37) and hTB (5.97 +/- 1.05) groups. ET-1ur was significantly higher in S (189.50 +/- 60.57) than in HC (69.00 +/- 10.76), IPF (62.17 +/- 19.07) and hTB (82.00 +/- 24.97). After prednisone, ET-1ur in the S group decreased significantly (189.50 +/- 60.57 to 94.00 +/- 13.60), and the decrease paralleled the improved clinical status. In S patients, ET-1ur was not significantly correlated to the degree of respiratory impairment, but it was significantly correlated to the intensity of lymphocytic alveolitis (r = 0.80).(ABSTRACT TRUNCATED AT 250 WORDS)