Study Identifies Two Potential Biomarkers for Active Systemic Lupus Erythematosus Disease Activity

Because lupus is a chronic  autoimmune disease that affects several organ systems, routine laboratory test measures are often abnormal. A new study looked to understand the relationship between certain indicators of systemic lupus erythematosus (SLE) disease activity using a predictive model and found two biomarkers that may be useful in identifying active SLE in clinical practice. 

The health records of 108 people, 40 with active SLE and 68 with inactive SLE, were examined. Researchers collected the results from routine laboratory tests and looked at clinical symptoms of the study participants. Researchers found two specific indicators that, when used in combination, could help to predict active SLE: albumin to fibrinogen ratio (AFR) and prognostic nutritional index (PNI). AFR is calculated by looking at blood levels of albumin , which decrease during inflammation, and fibrinogen , a measure of a blood protein that plays a role in inflammation. PNI is calculated using blood levels of albumin and lymphocyte count. Together, AFR and PNI provide an estimate of SLE activity. 

In all, 12 biomarkers in the blood, including AFR and PNI, were lower in the group with active SLE, while the level of C-reactive protein to albumin ratio (CAR) was elevated. Notably, the group with active SLE was also more likely to have the following co-occurring illnesses or health complications, including: 

• Arthritis
• Fever
• Rash
• Alopecia
• Pleurisy (inflammation surrounding the lungs and chest cavity)
• Pericarditis (inflammation of the pericardium, the thin tissues surrounding the heart)
• Renal involvement 

Researchers further analyzed AFR and PNI using a predictive model. Their findings suggest that the combination of AFR and PNI may be useful as markers that are correlated with disease activity and may help predict active SLE clinical practice. Further studies with more participants are needed to validate the findings. Learn more about lab tests for lupus.