Ethnicity Impacts Lupus Manifestations and Underlying Immune Changes, According to 36-Year Study

Various ethnic groups differ in what specific symptoms of systemic lupus erythematosus (SLE) they display — a difference that might be linked to the presence of different immune factors, according to a new study. Understanding how ethnicity might influence these differences can pave the way for treatments that are better suited to the individual patient, improving both efficacy of treatment as well as safety concerns.

Lupus can present a multitude of symptoms, tied to an array of various immunological abnormalities. These differences are influenced by both genetic and environmental factors, including sociodemographic aspects.

A study of 624 lupus patients treated at University College London Hospitals over a 36-year period, from January 1978 to December 2013, was performed by researchers from the Hospital Pedro Hispano in Portugal, assessing demographic, clinical, and serological data in an attempt to detect potential links between these factors.

The group was composed mainly of women (91.5 percent), who had been diagnosed when they were, on average, 29 years old, plus or minus 6.5 years. The small group of men had a similar age at diagnosis, 29.4, but with a larger spread of 15 years.

The patients were also predominantly Europeans, making up 59 percent. Other ethnic groups represented were Afro-Caribbean (16 percent); East Asian (12 percent); South Asian (9 percent); and 3 percent had a mixed background.

Titled “A study of the influence of ethnicity on serology and clinical features in lupus,” the study demonstrated that patients from East Asia developed the disease at a younger age than other patients.

Other ethnicity differences also emerged, described in the journal Lupus. Afro-Caribbean patients did not experience rash and photosensitivity as often as other groups, and all non-Europeans had higher rates of spot baldness or alopecia, and kidney disease.

South Asian patients, on the other hand, more often had musculoskeletal and neurological disease, serositis — which is an inflammation of the linings of internal organs — Sicca syndrome, and blood involvement.

When investigating types of antibodies present, the research team observed that Afro-Caribbean patients had the highest rates of anti-Smith, anti-RNP, anti-Ro and anti-La antibodies. Anti-IgG anticardiolipin antibodies were mainly present in the non-East Asian groups, and hypocomplementemia — a deficiency of the immune complement system — was frequent in East Asians.

Comparing symptoms with serological data, researchers found that rash, alopecia, mouth ulcers, serositis, neurological, joint, and kidney involvement were linked with the presence of anti-Smith and anti-RNP antibodies, but only among Afro-Caribbeans, who also showed agreement between symptoms involving the joints with the presence of anti-Ro and anti-La antibodies.