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.

SV40, JC and BK expression in tissue, urine and blood samples from patients with malignant and nonmalignant pleural disease.

BACKGROUND: Polyomaviruses are expressed in both human tumors and immunodepressed patients. Malignant and nonmalignant pleural effusions create an environment that could favor the expression of opportunistic viral infections. We studied if SV40, JC, and BK viral DNA can be amplified from biopsies obtained from different pleural diseases. MATERIALS AND METHODS: DNA was extracted from mesotheliomas (MM), nonspecific inflammatory and tubercular pleural biopsies, blood and urinary sediments from patients with MM, and pleural effusion cytological specimens. SV40, JC and BK viral early regions were amplified by PCR and analyzed by Southern Blot hybridization with specific probes. RESULTS: SV40 was positive in 9/23 MM, 5/18 tubercular and 1/7 nonspecific inflammatory biopsies, and 5/12 pleural effusion cytological specimens. JC was positive in 2/23 MM and in 7/15 urinary sediments. All blood samples were negative and BK was also negative in all samples. CONCLUSIONS: Tissue specific factors, characteristic of MM and TB, may contribute to expression of SV40 in these diseases.

Plasmacytoma of pleural origin associated with Bence Jones proteinuria.

A 33-year-old male presented with right side pleural plasmacytoma with secretion of Bence Jones (BJ) protein and deposition of amyloid. The pleural effusion contained a prominent peak of kappa-type BJ protein on the background of polyclonal gammopathy. Pleural biopsy disclosed features of plasmacytoma with amyloid deposition. A small peak of BJ protein was also present in serum electrophoretogram on the background of increased polyclonal IgG and IgA. Kidney function was impaired and urine protein ranged from 7.8 to 19.1 g/day with 92.5% bimodal BJ protein. There were no bone lesions by systemic bone survey, and repeated bone biopsies and marrow aspirations showed plasma cells of less than 5%. The clinical course worsened progressively; over the next five months the pleurisy became bilateral and peritoneal involvement supervened. This is believed to be the first report of primary plasmacytoma involving successively pleurae and peritoneum.