What Is a Histone AB Test?

Histone AB tests, also known as histone antibody tests, look for proteins in the blood. These histones are materials that bind DNA into cells. Histone AB tests are used to diagnose a number of autoimmune disorders and diseases, including lupus and rheumatoid arthritis. Endocrinologists, rheumatologists and even general practitioners use histone AB tests to help diagnose their patients.

How the Histone AB Test is Done

• In a histone AB test, a doctor, nurse or phlebotomist draws between 1 and 4 mls of blood from the patient into a tube containing centrifuge and aliquot serum. The blood sample is spun in a centrifuge machine to separate the different parts of the blood, such as the plasma and red and white cells. Scientists then apply the blood parts to a test called the Enzyme-Linked Immunosorbent Assay, or ELISA. Depending on the way the blood reacts with the test elements, the scientists and doctors can determine what histone antibodies are present in the blood sample.

Histone Antibodies

• Antibodies to histones show what conditions and diseases a person may have experienced. A person with a particular disease will have developed antibodies to it; this is how the body fights off the disease. Laboratories have identified and cataloged thousands of antibodies' characteristics and structures for testing and comparison.

Anti-histone Antibodies

• Scientists also look for elements called anti-histone antibodies. In diseases in which the body begins to attack its own cells, such as lupus, anti-histone antibodies appear in testing. Researchers are still working to figure out what causes these to develop and how they might play a role in the progress of an autoimmune disease.

Test Results

• Once a histone AB test has been conducted, the results show both histone antibodies and anti-histone antibodies. Doctors compare the test results to findings made by other researchers to help them identify the possibly cause of a patient's illness. Test results may show that a patient has more than one condition or disease, or may indicate that a suspected disease is not the cause of the patient's symptoms.

Using Histone AB Test Results

• Based on the test results, doctors often make recommendations for drug therapies. However, sometimes the therapies are for maintenance rather than cures. Many autoimmune diseases found through histone AB tests do not have cures. Rather, patients and doctors must do the best they can to manage the effects of the disease through analgesics, diet, exercise and/or physical therapy.