Improved diagnosis of colorectal cancer using a combination of fecal occult blood and novel fecal protein markers.

Background & Aims: Annual testing for fecal occult blood is recommended as first-line screening for the detection of colorectal cancer (CRC), but is affected by limited sensitivity. We initiated a proteomics-based search for novel biomarkers to improve the sensitivity of detection of CRC in stool samples.

Methods: Six markers, including immunologic fecal occult blood test (iFOBT), were evaluated in a collective of 551 samples (186 CRC, 113 advanced adenoma, and 252 control patients) to establish the diagnostic performance of each marker and marker combinations.

Diagnosis of rheumatoid arthritis: multivariate analysis of biomarkers.

Objective: To test if a combination of biomarkers can increase the classification power of autoantibodies to cyclic citrullinated peptides (anti-CCP) in the diagnosis of rheumatoid arthritis (RA) depending on the diagnostic situation.

Methods: Biomarkers were subject to three inclusion/exclusion criteria (discrimination between RA patients and healthy blood donors, ability to identify anti-CCP-negative RA patients, specificity in a panel with major non-rheumatological diseases) before univariate ranking and multivariate analysis was carried out using a modelling panel (n = 906). To enable the evaluation of the classification power in different diagnostic settings the disease controls (n = 542) were weighted according to the admission rates in rheumatology clinics modelling a clinic panel or according to the relative prevalences of musculoskeletal disorders in the general population seen by general practitioners modelling a GP panel.

Identification of PSME3 as a novel serum tumor marker for colorectal cancer by combining two-dimensional polyacrylamide gel electrophoresis with a strictly mass spectrometry-based approach for data analysis.

The purpose of this study was to identify and validate novel serological protein biomarkers of human colorectal cancer (CRC). Proteins from matched CRC and adjacent normal tissue samples were resolved by two-dimensional gel electrophoresis. From each gel all spots were excised, and enveloped proteins were identified by MS.

Depletion efficiency and recovery of trace markers from a multiparameter immunodepletion column.

The selective removal of high-abundance proteins is considered to be an important prerequisite for a sensitive proteome analysis in plasma. In this study, we examined the "multiaffinity removal system", an immunoaffinity depletion column targeted against six plasma proteins. As determined by sandwich ELISA, the depletion rate for each target protein is >99% over 200 cycles of regeneration.

Identification of nicotinamide N-methyltransferase as a novel serum tumor marker for colorectal cancer.

Purpose: The goal of this study was to identify and validate novel serum markers of human colorectal cancer as potential candidates for noninvasive detection of early colorectal neoplasm.

Experimental Design: Employing two-dimensional gel electrophoresis and mass spectrometry, we analyzed 16 matched colorectal cancer and adjacent normal tissue samples. Proteins found to be elevated in cancer tissue were further validated by generating antibodies which were used for immunoblotting of tissue samples and for the development of highly sensitive immunoassays for assessment of serum samples.

Use of mass spectrometry to identify protein biomarkers of disease severity in the synovial fluid and serum of patients with rheumatoid arthritis.

Objective: To identify a panel of candidate protein biomarkers of rheumatoid arthritis (RA) that can predict which patients will develop erosive, disabling disease.

Methods: A 2-step proteomic approach was used for biomarker discovery and verification. In the first step, 2-dimensional liquid chromatography-coupled tandem mass spectrometry was used to generate protein profiles of synovial fluid (SF) from patients with either erosive RA (n = 5) or nonerosive RA (n = 5).

Quantification of C-reactive protein in the serum of patients with rheumatoid arthritis using multiple reaction monitoring mass spectrometry and 13C-labeled peptide standards.

A general method for the quantification of proteins in human serum was developed using mass spectrometry (MS) and stable isotope-labeled synthetic peptides as internal standards. Using this approach, C-reactive protein (CRP), a diagnostic marker of rheumatoid arthritis (RA), was detected in serum samples taken from patients with either erosive or nonerosive RA and compared to healthy individuals. Small volumes of serum samples were enriched for low-abundance proteins through the selective removal of human serum albumin (HSA), immunoglobulin G (IgG), and haptoglobin.

How industry is approaching the search for new diagnostic markers and biomarkers.

In the diagnostic and the pharmaceutical industry there is a constant need for new diagnostic markers and biomarkers with improved sensitivity and specificity. During the last 5 years, only a few novel diagnostic markers have been introduced into the market. Proteomics technologies are now offering unique chances to identify new candidate markers.