Chromatin antibody: Make sure you know your labs
Know your labs when you have lupus
– Elevated anti-chromatin antibodies are fairly specific for people who have lupus, but can occasionally be seen in other autoimmune disorders. They are related to anti-dsDNA antibodies.
– They are rare in healthy people
– They may possibly increase the risk of having lupus kidney inflammation (lupus nephritis), however, having them does not mean you will get nephritis. Just make sure to have a urine sample checked regularly
– In some people, they can fluctuate with disease activity and help monitor how someone with systemic lupus erythematosus (SLE) is responding to therapy.
I recommend that all patients get copies of their labs so they can understand more about their lupus. If you are chromatin antibody positive, then read this article to learn more.
What are anti-chromatin antibodies and what do they mean?
Chromatin refers to the complex of DNA and other proteins that form chromosomes inside the nuclei of cells. About 60% to 70% of people who have SLE are positive for these antibodies, and they appear more commonly in SLE than in other systemic autoimmune diseases. Initial studies suggested that patients with SLE who are positive for chromatin antibody may have an increased risk for developing inflammation of the kidneys (lupus nephritis); however, this has been questioned in subsequent studies.
Sometimes it can be difficult to tell if a patient may have SLE or Sjögren’s when they first come to a rheumatologist. One study showed that if that patient is positive for chromatin antibody and negative for SSA antibody, they most likely have SLE as their diagnosis. In some people with SLE, chromatin antibodies fluctuate with disease activity, decreasing in value when there is better control of lupus and increasing when it is worse. Chromatin antibodies can also occur in other systemic autoimmune diseases, including drug-induced lupus, mixed connective tissue disease, and scleroderma.
– The above excerpt comes from “The Lupus Encyclopedia” prior to printing of the second edition
– Mehra, S., & Fritzler, M. J. (2014). The spectrum of anti-chromatin/nucleosome autoantibodies: independent and interdependent biomarkers of disease. Journal of immunology research, 2014, 368274. https://doi.org/10.1155/2014/368274