Blood-Based Biomarkers May Help Diagnose Neuropsychiatric Lupus

Research study background

Lupus is an autoimmune disease that affects many organs within the body and causes inflammation and injury in those organs. Neuropsychiatric systemic lupus erythematosus (NPSLE), also known as central nervous system lupus or neuropsychiatric lupus, is a severe complication of lupus when it starts affecting the brain, spine and nerves. This is associated with increased morbidity and mortality. Individuals affected by NPSLE experience a variety of symptoms, including seizures, strokes, cognitive difficulties, hallucinations, weakness, or trouble walking or sensing things.

The early warning signs of NPSLE are subtle and evaluation is often expensive and invasive. The lack of easily obtainable markers of this disease has been a major barrier to timely detection and treatment for these patients.

This study was a collaboration between a multidisciplinary team of experts in neurology, rheumatology and immunology at the Neuroimmunology Center for Children at Children’s Hospital Colorado and the University of Colorado School of Medicine. They sought to determine if two markers of nerve and brain injury — blood neurofilament light (NfL) and glial fibrillary acidic protein (GFAP) — could help detect NPSLE.

Researchers enrolled or identified participants with lupus who were 12 to 60 years old. They collected demographic and clinical data, including blood samples, and assessed the levels of NfL and GFAP in the blood from 13 patients with active NPSLE, 13 age/sex-matched persons without active NPSLE, and 13 age/sex matched persons without a known autoimmune or neurologic disease. Active NPSLE was defined as less than 6 months since the last new or worsening symptom of NPSLE.

Their analysis showed that both blood NfL and blood GFAP were significantly higher in persons with active NPSLE compared to those with lupus without NPSLE and to the participants without autoimmune/neurologic diseases. The blood levels decreased after persons with active NPSLE were started on immune therapy for treatment. There was also no difference between the levels in persons with lupus without NPSLE and the participants without autoimmune/neurologic diseases.

Clinical implications

These findings, presented at the 2024 Annual Meeting of the American Academy of Neurology, are the first to demonstrate these two biomarkers are elevated in active NPSLE compared to patients with lupus who do not have significant neurologic symptoms.

The team plans to conduct a larger study to assess NfL and GFAP levels in patients with lupus who have subtle or early disease. If the biomarkers can predict NPSLE, clinicians might be able to treat these patients before brain or nerve injury occurs.