A new study found two distinct biological patterns of lupus nephritis (LN), offering researchers a closer look at why kidney involvement may vary from person to person. One group showed greater activity in immune pathways, poorer kidney function, and more signs of long-term kidney damage. Researchers also identified a protein called APOL1 as a potential biomarker that may help distinguish between the two groups. 

Researchers analyzed kidney biopsy tissue from 292 people with lupus nephritis across four hospitals and found more than 1,000 proteins that differed between the two groups. One group showed greater activity in immune pathways linked to inflammation and had measures indicating poorer kidney function and greater chronic kidney damage. APOL1 levels were also higher in this group, including in a smaller analysis of blood samples from 40 participants. Additionally, researchers identified a five-protein combination that showed potential for distinguishing between two common forms of lupus nephritis, proliferative (class III/IV) and membranous (class V) LN. 

These findings suggest that studying proteins in kidney tissue may provide additional information that could support LN classification and risk. This approach can also help researchers better understand differences in the disease that are not always visible through traditional kidney biopsy classification alone. More research is needed to confirm whether APOL1 and the five-protein combination could eventually help classify or assess lupus nephritis. Learn more about lupus and the kidneys. 

Read the study