The goal: identification and validation of early biomarkers for lupus.

Biomarkers defined

The cellular, molecular, or genetic alterations by which a normal or abnormal biologic process can be recognized or monitored are known as biomarkers.

How biomarkers can be used

In many fields, biomarkers are used to predict the risk of contracting a disease or to confirm a diagnosis. In some situations, biomarkers are used to formulate a prognosis, or monitor the response to therapy. For example, high blood pressure is a predictor of increased risk of heart disease. In addition to monitoring response to therapy, biomarkers in lupus may also prove useful to confirm remission and to determine which patients are more likely to relapse.

Surrogate markers explained

If validated at some point, some biomarkers may even become lupus outcomes surrogate markers—laboratory measurement or physical sign that gives an indication of how we are progressing in treating a disease. The marker signals, but does not directly measure, patients' progress in terms of how they feel, how they are functioning or for some diseases, if they will survive. For example, by measuring the level of virus in the blood for patients with AIDS, doctors are able to tell if the medicines are working. In addition, by measuring bone mineral density, the FDA can assess the effectiveness of drugs for treating osteoporosis.

The challenge of finding specific biomarkers for lupus

Many complications have delayed the development of reliable biomarkers. Lupus is unpredictable and manifests itself differently in each person. In addition, many lupus patients may have other diseases, even other autoimmune diseases, which make it difficult to determine whether the lupus or another disease is causing a certain change in the body. Furthermore, many of the studies have not been rigorous enough to provide useful information.

In other fields, this has involved large, multi-center studies to identify potential biomarkers, to validate that the candidate biomarker can be reproducibly measured in many sites, to document that the candidate biomarker actually measures what is intended, and then to correlate changes in the biomarker with variations in some aspect of lupus. Large studies requiring participation of numerous scientists with diverse backgrounds are necessary for this to be successful.

Examples of lupus biomarkers

It is hoped that anti-dsDNA (antibodies that attack the genes inside cells) levels will one day be considered a useful biomarker of therapy progression in treating lupus patients. Other examples include products of the complement system (proteins that function as part of the immune system), and detailed measurement of the status of particular sub-sets of white blood cells known to be involved in lupus activity.