Also Known As:
Histone Autoantibodies

Formal Name:
Antihistone Antibody

This article was last modified on January 27, 2021

Learn more about...

Autoantibodies

At a Glance

Why Get Tested?

To help in the diagnosis and monitoring of drug-induced lupus

When To Get Tested?

When you have symptoms associated with lupus that may be due to a drug that you are taking

Sample Required?

A blood sample drawn from a vein in your arm

Test Preparation Needed?

None

Looking For Test Results?

Looking For Reference Ranges?

You may be able to find your test results on your laboratory’s website or patient portal. However, you are currently at Testing.com. You may have been directed here by your lab’s website in order to provide you with background information about the test(s) you had performed. You will need to return to your lab’s website or portal, or contact your healthcare practitioner in order to obtain your test results.

Testing.com is an award-winning patient education website offering information on laboratory tests. The content on the site, which has been reviewed by laboratory scientists and other medical professionals, provides general explanations of what results might mean for each test listed on the site, such as what a high or low value might suggest to your healthcare practitioner about your health or medical condition.

The reference ranges for your tests can be found on your laboratory report. They are typically found to the right of your results.

If you do not have your lab report, consult your healthcare provider or the laboratory that performed the test(s) to obtain the reference range.

Laboratory test results are not meaningful by themselves. Their meaning comes from comparison to reference ranges. Reference ranges are the values expected for a healthy person. They are sometimes called “normal” values. By comparing your test results with reference values, you and your healthcare provider can see if any of your test results fall outside the range of expected values. Values that are outside expected ranges can provide clues to help identify possible conditions or diseases.

While accuracy of laboratory testing has significantly evolved over the past few decades, some lab-to-lab variability can occur due to differences in testing equipment, chemical reagents, and techniques. This is a reason why so few reference ranges are provided on this site. It is important to know that you must use the range supplied by the laboratory that performed your test to evaluate whether your results are “within normal limits.”

For more information, please read the article Reference Ranges and What They Mean.

What is being tested?

Histone antibodies are autoantibodies. These are antibodies produced by a person’s own immune system that target his or her own histones. Histones are proteins that are a part of chromatin, the genetic material present in the nucleus of almost all cells within the body. Because histones are found inside cells, this attack on “self” can cause symptoms throughout the body. This test detects the presence of histone antibodies in the blood.

Histone autoantibodies are one of several types of antinuclear antibodies (ANA). ANA are associated with a variety of autoimmune disorders. The presence or absence of specific antinuclear antibodies is used to help determine which disorder a person may have.

Drugs can stimulate the production of histone antibodies in some people and can cause a type of lupus called drug-induced lupus erythematosus. Up to 95% of those with drug-induced lupus will have histone antibodies. The autoantibodies may also develop in up to 50% of those with non-drug-induced lupus and in 20% of those with other connective tissue diseases.

Many drugs have been associated with drug-induced lupus in some people. Some of the more common examples include:

Hydralazine
Isoniazid
Minocycline
Penicillamine
Procainamide
Quinidine

Other types of medications associated with drug-induced lupus include:

Antibiotics
Anti-seizure medications
Anti-tumor necrosis factor (anti-TNF) agents
Interferon-alpha
Blood pressure medications
Methyldopa
Thyroid medications

Common Questions

How is the test used?

Histone antibody testing is primarily used to support a diagnosis of drug-induced lupus, particularly in a person who is taking one of the medications mentioned above in the “What is being tested?” section.

Testing is used to distinguish drug-induced lupus from other forms of lupus such as systemic lupus erythematosus (SLE), from another autoimmune disorder, or from another cause of a person’s symptoms. While it is not diagnostic of drug-induced lupus, its presence is consistent with this diagnosis.

The test is typically ordered with or following a positive ANA test and may be ordered along with a test for anti-double-stranded DNA (anti-dsDNA) to help establish a diagnosis.

If a person is diagnosed with drug-induced lupus, the identified drug may be discontinued upon the recommendation of the healthcare practitioner. One or more histone antibody tests may be used as follow up to monitor antibody levels (titers), if present.

When is it ordered?

A histone antibody test is ordered when a person has been taking a drug for several weeks to a couple of years and develops signs and symptoms that could be due to drug-induced lupus. This is especially true when the person affected did not have a prior personal or family history of an autoimmune disorder. Symptoms may include:

Arthritis-like pain in one or more joints (but no or little joint inflammation)
Fatigue
Fever
Muscle pain (myalgia)
Red rash that frequently resembles a butterfly across the nose and cheek areas (malar rash)
Sensitivity to sunlight
Weight loss

Symptoms and complications involving the central nervous system (CNS) and kidneys occur with SLE but are much rarer with drug-induced lupus.

The histone antibody test may be repeated at intervals after the drug has been discontinued to monitor for decreases in histone antibody levels.

What does the test result mean?

Results of histone antibody testing consider several factors. A positive result means that a person likely has drug-induced lupus if the person also has:

Symptoms associated with lupus
Been taking a drug, especially one associated with the condition, for several weeks to a couple of years
No identified autoimmune disorder prior to taking the drug
Positive ANA test
Low or negative anti-dsDNA and other autoantibodies
Signs and symptoms that resolve when the drug is discontinued
Histone antibody levels that begin to decrease when the drug is discontinued

A positive histone antibody result by itself does not establish a diagnosis. About 50% of those with SLE will have histone antibodies, though generally not induced by a specific drug. In these cases, the anti-dsDNA test will be positive and significantly elevated.

A negative result means that the individual’s signs and symptoms may be due to a condition other than drug-induced lupus, such as a drug allergy. However, a negative result does not rule out drug-induced lupus. A small portion of individuals may have drug-induced lupus even if they do not have histone antibodies.

Is there anything else I should know?

An individual with SLE may have a flare-up that is caused or exacerbated by drug therapy without having drug-induced lupus.

SLE tends to affect more women than men and tends to occur in people in their 20s to 40s. Drug-induced lupus affects both sexes equally and can affect anyone but occurs most frequently in those who are older.

What can I do to change my histone antibody level?

Talk to your health care practitioner about discontinuing the potentially offending drug. When this is done, the histone antibody level should drop over time. Histone antibody levels do not respond to lifestyle changes.

If the level of my histone antibodies decreases, can I take my drug again?

No. The antibodies may drop to very low or undetectable levels, but a small amount will still exist. If you resume taking your drug, your symptoms and increased antibody levels may reemerge.

Should I tell all my health care providers about being diagnosed with drug-induced lupus?

Yes, this is an important part of your medical history and needs to be shared as it will need to be taken into account by your health care practitioners whenever you are given medications.

How long will it take for my results?

It may take several days before your results are available. This is not a routine test and your sample will frequently need to be sent to a regional reference laboratory for testing.

View Sources

Sources Used in Current Review

(Updated: Jun 30, 2017) Kauffman C, Drug-Induced Lupus Erythematosus Medscape Reference. Available online at http://emedicine.medscape.com/article/1065086-overview Accessed May 2018.

(Updated 2011 June 28). Teitel, A. Drug-induced lupus erythematosus. MedlinePlus Medical Encyclopedia. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000446.htm Accessed May 2018.

(October 6, 207) Ho C; Chauhan, K Lupus Erythematosus, Drug-Induced, StatPearls https://www.ncbi.nlm.nih.gov/books/NBK441889/ Accessed May 2018.

Maidhof, W. and Hilas, O. (2012 April). Lupus: An Overview of the Disease And Management Options. P T. 2012 April; v 37(4): 240-246, 249. [On-line information]. Available online at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3351863/ Accessed May 2018.

Sources Used in Previous Reviews

Camacho, I. et. al. (Updated 2012 January 27). Drug-Induced Lupus Erythematosus. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/1065086-overview. Accessed September 2013.

Teitel, A. (Updated 2011 June 28). Drug-induced lupus erythematosus. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000446.htm. Accessed September 2013.

(© 1995 – 2013). Histone Autoantibodies, Serum. Mayo Clinic Mayo Medical Laboratories [On-line information]. Available online at http://www.mayomedicallaboratories.com/test-catalog/Overview/80944. Accessed September 2013 .

(© 2013). Laboratory Tests for Lupus. Lupus Foundation of America [On-line information]. Available online at http://www.lupus.org/webmodules/webarticlesnet/templates/new_learndiagnosing.aspx?articleid=2242&zoneid=524. Accessed September 2013.

(2013 May). Handout on Health: Systemic Lupus Erythematosus. National Institute of Arthritis and Musculoskeletal and Skin Disease [On-line information]. Available online at http://www.niams.nih.gov/Health_Info/Lupus/default.asp. Accessed September 2013.

Camilla Dalle Vedove, C. et. al. (2012 December). Drug-induced lupus erythematosus with emphasis on skin manifestations and the role of anti-TNFα agents. J Dtsch Dermatol Ges v 10 (12): 889–897. [On-line information]. Available online at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3561694/. Accessed September 2013.

Maidhof, W. and Hilas, O. (2012 April). Lupus: An Overview of the Disease and Management Options. P T. 2012 April; v 37(4): 240-246, 249. [On-line information]. Available online at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3351863/. Accessed September 2013.

Manocha, D. et. al. (2009 July 23). Vancomycin leading to lupus flare in an elderly lady: a case report. Cases J. 2009; 2: 6293. [On-line information]. Available online at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2740234/. Accessed September 2013.

Khattri, S. et. al. (2011). Isoniazid (INH)-Induced Eosinophilic Exudative Pleural Effusion and Lupus Erythematosus, A Clinical Reminder of Drug Side Effects. Bull NYU Hosp Jt Dis. 2011;69(2):181-4. [On-line information]. Available online at http://www.ncbi.nlm.nih.gov/pubmed/22035399. Accessed September 2013.

Ali, A. and Schmidt, M. (2013 May 10). Drug-Induced Pulmonary Toxicity. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/1343451-overview. Accessed September 2013.

Almoallim, H. et. al. (2012 November 16). Anti-Tumor Necrosis Factor-α Induced Systemic Lupus Erythematosus. Open Rheumatol J. 2012; v 6: 315–319. [On-line information]. Available online at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3504723/. Accessed September 2013.

Von Muhlen CA, Nakamura RM (2011). Clinical and laboratory evaluation of systemic rheumatic diseases, in Henry’s Clinical Diagnosis and Management by Laboratory Methods, 22nd ed. McPherson RA, Pincus MR, eds. Elsevier-Sanders:Philadelphia. Chapter 51.

Kumar V, Abbas AK, Fausto N, et al (2010). Robbins and Cotran Pathologic Basis of Disease, 8th ed. Saunders-Elseiver:Philadelphia. Chapter 6.

Ask a Laboratory Scientist

This form enables patients to ask specific questions about lab tests. Your questions will be answered by a laboratory scientist as part of a voluntary service provided by one of our partners, American Society for Clinical Laboratory Science. Please allow 2-3 business days for an email response from one of the volunteers on the Consumer Information Response Team.

Histone Antibody