An anti-ubiquitin antibody response in transitional cell carcinoma of the urinary bladder.

Abstract

BackgroundTo use combinatorial epitope mapping ("fingerprinting") of the antibody response to identify targets of the humoral immune response in patients with transitional cell carcinoma (TCC) of the bladder.MethodsA combinatorial random peptide library was screened on the circulating pool of immunoglobulins purified from an index patient with a high risk TCC (pTa high grade plus carcinoma in situ) to identify corresponding target antigens. A patient cohort was investigated for antibody titers against ubiquitin.ResultsWe selected, isolated, and validated an immunogenic peptide motif from ubiquitin as a dominant epitope of the humoral response. Patients with TCC had significantly higher antibody titers against ubiquitin than healthy donors (pConclusionsThis is the first report to demonstrate an anti-ubiquitin antibody response in patients with TCC. Although sensitivity of antibody production was low, a high specificity and positive predictive value make ubiquitin an interesting candidate for further diagnostic and possibly immune modulating studies.