Discovery Could Lead to Better Diagnosis and Treatment of Lupus in African Patients

Rare Daily Staff

Black Africans have a higher level of Lupus than previous known and identified an antibody previously unlinked to the disease that could help better diagnose and treat this population, according to a study in the journal BMJ Global Health.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that causes inflammation in connective tissues. The condition can affect many organs and systems throughout the body and causes progressive damage over time.

Researchers from the University of Edinburgh and partners in Zimbabwe found that blood tests in black African patients pinpointed a high prevalence of two types of the disease, one of which was previously unacknowledged. They said their results could enable better management of the disease in patients of African descent, particularly in southern Africa, where incidence and mortality rates are relatively high.

The study found new variants of the disease by analyzing antibodies that attack proteins in healthy cells. Some of the patients—almost half of those tested—carried an antibody already linked with lupus and used in its diagnosis. Patients with this antibody are more likely to have classic symptoms, including diseased organs and joints.

A second, larger group of patients—many of whom had skin-related symptoms—carried an antibody targeting a different protein in healthy cells. This antibody, which targets proliferating cell nuclear antigen (PCNA), was not previously known to be important for SLE and is not currently used in diagnosis.

The research suggests that diagnostic tests for lupus should be broadened to include the second antibody.

“For the first time, we have highlighted the importance of two variants of systemic lupus that affect black Africans, including one which was previously not defined in detail,” said Francisca Mutapi, of the School of Biological Sciences, University of Edinburgh. “Thanks to our research, we also have the means to diagnose and distinguish them.”

The current recommended diagnosis method tests for the first antibody only. Incorporating the second antibody in tests would allow earlier diagnosis of the more predominant variant of the disease, and improved outcomes for patients, researchers say.

“These findings will be valuable in diagnosing SLE in affected patients,” said Elopy Sibanda of the Asthma, Allergy and Immunology Clinic in Harare, Zimbabwe and leader of the clinical aspects of the study. “It is currently difficult to diagnose lupus erythematosus, as many symptoms overlap with those of other locally prevalent conditions, including HIV.”

October 1, 2018
Photo: Francisca Mutapi, of the School of Biological Sciences, University of Edinburgh.