Black Patients With CLE More Likely to Have Lupus Family History
Finding supports suggestion that a genetic component may be at play
Black patients with cutaneous lupus erythematosus (CLE) are more likely to have a family history of CLE and/or systemic lupus erythematosus (SLE) than those of other ethnicities, according to a recent study.
The prevalence of CLE and/or SLE was 64% in Black patients compared with 45% in non-Black patients.
“Providers can use this information to counsel patients with CLE on the risk of other family members having CLE and/or SLE,” the researchers wrote.
The study, “Black patients with cutaneous lupus are associated with positive family history of cutaneous lupus and systemic lupus,” was published in the journal Lupus Science & Medicine.
Lupus is a chronic, autoimmune disease that causes inflammation and pain in various body tissues, including the skin, joints, kidneys, and heart. When it affects multiple organs in the body, either short-term or long-term, it is called SLE; when it involves the skin only it is called CLE.
CLE may progress to SLE in some patients.
Several genetic mutations have been linked to an increased risk of CLE. However, it is unclear how often CLE is inherited in families and the factors that increase inheritance risk.
In an effort to learn more, researchers conducted a study to assess the rate of and risk factors associated with a positive family history of CLE or SLE in a large and diverse group of patients.
The study included a total of 338 patients with CLE who were attending dermatology clinics at the University of Texas Southwestern (UTSW) Medical Centre and Parkland Health, and who had enrolled in the UTSW CLE Registry from January 2009 to November 2020.
Patients’ demographics, smoking status, clinical data, autoantibodies, and CLE type were assessed. CLE was categorized into acute, subacute, and chronic. Patients also reported if their first-degree, second-degree, or more distant relatives had CLE or SLE.
Most patients were female (84%), and more than half (51%) were Black. They had a mean age of 40.43 years at the time of diagnosis.
Most patients (76%) had chronic CLE, and almost 50% had coexisting SLE. A total of 34% had a family history of CLE and/or SLE. Of those with a family history of CLE, 5% had a first-degree relative with CLE, and 15% had a first-degree relative with SLE. Of the 3% with a family history of both CLE and SLE, 91% had first-degree relatives with both CLE and SLE.
Patients with a family history of CLE and/or SLE were more likely to be Black and to be positive for anti-Smith antibodies, which often are found in high levels in SLE patients. Younger patients and those positive for anti-nuclear (ANA) or double-stranded (dsDNA) antibodies, which also are found in people with lupus, also tended to have a family history of CLE and/or SLE. Still, the association did not reach statistical significance in these cases.
The finding that Black patients with CLE were more likely to have a family member with CLE or SLE supports the suggestion that a genetic component may be at play. Indeed, previous studies have found a mutation on the short arm of chromosome 11 in Black families with SLE and discoid lupus erythematosus (DLE), but not in European families.
“We recommend asking patients with CLE about their family history of CLE and SLE, particularly Black patients, and raising awareness to prompt their family members to seek evaluation and workup,” the researchers wrote.
Collecting more family history data potentially could help identify new genetic mutations and improve risk assessment for CLE patients, they said.