From lupus rare gene variants to pathogenic mechanisms

Lupus patients with rare, inherited forms of the disease are helping scientists trace exactly which immune cells and molecular pathways go wrong. Systemic lupus erythematosus (SLE) is notoriously variable—some patients suffer kidney failure, others skin rashes, and treatments often fail because doctors cannot predict which pathway drives disease in a given person. The researchers have sequenced 200 early-onset patients to find disease-causing gene variants, built bespoke mouse models, and created new tools that can pinpoint the origin of autoantibodies—whether from B-1 or B-2 cells—and track how pathogenic B cells mature, whether through germinal centres or extrafollicular routes. They will also test whether four different ways the body senses stray DNA and RNA (via TLR9, TLR7, cGAS/STING, and MAVS) produce distinct interferon signatures and recruit different self-reactive B cells. If the work succeeds, it could reveal biomarkers that stratify lupus patients by their underlying immune defect. That would allow clinicians to match therapies—such as interferon blockers or B-cell-targeting drugs—to the specific mechanism at play, rather than treating all patients the same. The findings will be validated in adult-onset lupus patients who are untreated or in remission, directly testing whether the mechanisms discovered in rare genetic cases apply to the common form of the disease.