Natural antibody against Thomsen-Friedenreich antigen in sera of patients with carcinomas and infectious diseases

A systematic review of serum autoantibodies as biomarkers for pancreatic cancer detection

Pancreatic cancer is a leading cause of cancer-related deaths in the western world. Patients with pancreatic cancer have poor prognosis, partly due to difficulties in detecting it at early stages. While different markers have been associated with pancreatic cancer, many of them show suboptimal sensitivity and specificity. Serum autoantibodies against tumor-associated antigens have recently emerged as early stage biomarkers for different types of cancers. Given the urgent need for early and reliable biomarkers for pancreatic cancer, we undertook a systematic review of the published literature to identify primary articles that evaluated serum autoantibodies in pancreatic cancer detection by searching PubMed and ISI Web of Knowledge. Two reviewers extracted data on study characteristics and results independently. Overall, 31 studies evaluating 124 individual serum autoantibodies in pancreatic cancer detection met the inclusion criteria. In general, single autoantibody markers showed relatively low sensitivities at high specificity. A combination of markers, either multiple serum autoantibodies or serum autoantibodies combined with tumor-associated markers, led to a better diagnostic performance. However, most of the analyzed autoantibodies have only been reported in single studies and therefore need to be independently validated. We conclude that serum autoantibodies might present an option as biomarkers for early detection of pancreatic cancer, but more work is needed to identify and validate autoantibody signatures that are associated with early stage pancreatic cancer.

Are natural antibodies involved in tumour defence?

Natural antibodies (NAb) are found in the serum of healthy individuals. These antibodies are produced without any apparent specific antigenic stimulation. They are one part of the circulating immunoglobulins and are found in virtually all vertebrate species. NAb react to various self- and non-self antigens. A protective function in different infection models could be demonstrated. Several groups have reported the ability of NAb to bind to tumour cells. Their possible role in tumour defence is documented in mice. The present status of attempts to characterise the role of NAb in tumour defence is discussed, particularly as regards the human immune system. This paper focuses on antibody cell interactions and discusses the genetic background of the Nab-producing B-cells.