What Is MESOMARK?

The MESOMARK test is the first in vitro diagnostic test for patients with mesothelioma.

Mesothelioma is a rare form of cancer in which fluid accumulates in the lungs and chest cavity. Mesothelioma can also be found in the lining of the pleural cavity of the abdomen. It is primarily caused by work-related asbestos exposure, and it is estimated that 10,000 new cases are diagnosed each year among industrialized countries. Malignant mesothelioma is an extremely aggressive disease with a poor prognosis.

The MESOMARK assay is a manual enzyme-linked immunosorbent assay for the quantitative measurement of Soluble Mesothelin-Related Peptides (SMRP). SMRP is a biomarker that is released into the bloodstream by mesothelioma cells. SMRP can be elevated years before an actual diagnosis of mesothelioma is made. By measuring the amount of SMRP present in the bloodstream, the MESOMARK assay will help physicians routinely monitor individuals with the greatest risk of developing mesothelioma due to asbestos exposure.

The MESOMARK Assay

The MESOMARK assay is an Enzyme-Linked Immunosorbent Assay (ELISA) for the quantitative measurement of Soluble Mesothelin-Related Peptides (SMRP) in human serum. The MESOMARK assay measures soluble molecules that are related to the mesothelin/Megakaryocyte Potentiating Factor (MPF) family of proteins and recognized by the monoclonal antibody OV569. The reactivity of OV569 is low for normal human tissues except for the mesothelium. Soluble members of the mesothelin/MPF family of proteins have been reported in the sera of patients with tumors of mesothelial origin.

Analytical Performance

Distribution of SMRP Levels

SMRP values were determined on 1086 specimens; the sample distribution is shown below.

Distribution

In our studies, 99% of the healthy subjects had SMRP levels at or below 1.5 nM. It is recommended that each laboratory establish its own reference value for the population of interest. 

Precision

The MESOMARK assay precision is <15% total CV. A precision study was performed in which 3 panels were assayed, using 2 kit lots, in replicates of 2 at 2 separate times per day for 20 days at two sites. Below is a summary of the data collected from this study.

Precision

Analytical Sensitivity

The sensitivity of the MESOMARK assay is 0.3 nM. Analytical sensitivity corresponds to the upper limit of the 95% confidence interval of the zero calibrator and represents the lowest concentration of antigen that can be distinguished from zero.

References

Li Z-Q, Verch T, Allard WJ. MESOMARK® in vitro diagnostic test for mesothelioma. Expert Opin Med Diagn. 2007;1(1):137-142.

Scherpereel A, Grigoriu B. Conti M, et al. Soluble mesothelin-related peptides in the diagnosis of malignant pleural mesotheliomaAm J Respir Crit Care Med. 2006;173(10):  1155-1160. 

Scherpereel et al, tested a group of 137 patients, in which 74 had malignant pleural mesothelioma (MPM), 35 suffered from pleural metastasis of carcinomas and 28 were diagnosed with benign pleural lesions from hospitals throughout the northern and western regions of France. The MESOMARK assay (SMRP levels) was used to evaluate serum samples available from this group of patients. The results show a difference in SMRP levels among the three groups, in which the level of SMRP present in patients with MPM was significantly elevated, compared to other evaluated patients. This group concludes that a biomarker to help monitor disease will be a useful tool for physicians. The results of this study clearly show that SMRP values are raised significantly in patients diagnosed with MPM.      

Robinson BW, Creaney J, Lake R, et al. Mesothelin-family proteins and diagnosis of mesotheliomaLancet. 2003;362(9396):1612-1616.

This publication investigated the serum concentrations of MESOMARK (SMRP) in a group of patients diagnosed with mesothelioma, diagnosed with other cancers, presenting with pleural fluid not related to mesothelioma, diagnosed with lung inflammatory disease and healthy controls. Results showed that patients diagnosed with mesothelioma had increased concentrations of SMRP than patients who were asbestos exposed and the non-asbestos exposed controls. This research also correlated tumor mass with SMRP concentration, in which the concentrations of SMRP are elevated in patients with the largest tumor mass.  This paper proposes that the use of the SMRP serum value could be useful as an aid in the monitoring of tumor growth. 

Beyer H, Geschwindt R, et al. MESOMARK™: A Potential Test for Malignant Pleural Mesothelioma. Presented at the 19th International Congress of Clinical Chemistry and IFCC/AACC July 24-28, 2005; Orlando, FL. Click here to download the abstract.

Chang K, Pastan I. Molecular cloning of mesothelin, a differentiation antigen present on mesothelium, mesotheliomas, and ovarian cancersProc Natl Acad Sci USA. 1996;93:136-140.

Hassan R, Remaley AT, Sampson ML, et al. Detection and quantitation of serum mesothelin, a tumor marker for patients with mesothelioma and ovarian cancerClin Cancer Res. 2006;12(2):447-453.

Hellstrom I, J. Raycraft J, Kanan S, et al. Mesothelin variant 1 is released from tumor cells as a diagnostic markerCancer Epidemiol Biomarkers Prev. 2006;15(5):1014-1020.

Pass HI, Wolaniuk D, et al. Soluble Mesothelioma related peptides : A potential biomarker for malignant pleural mesothelioma. Presented at the 41st Annual Meeting of the American Society of Clinical Oncology; May 13-17,2005; Orlando. FL. 

Robinson BW, Musk AW, Lake RA. Malignant mesotheliomaLancet. 2005;366(9483):  397-408.

Robinson BW, Creaney J, Lake R, et al. Soluble mesothelin-related protein—a blood test for mesotheliomaLung Cancer. 2005;49(Suppl 1):S109-111.

Scholler N, Fu N, Yang Y, et al. Soluble member(s) of the mesothelin/megakaryocyte potentiating factor family are detectable in sera from patients with ovarian carcinoma.  Proc Natl Acad Sci USA. 1999;96(20):11531-11536.