Current treatments for lupus nephritis in children are toxic and sometimes ineffective. New tests for proteins that might be abnormal in lupus nephritis could help make the diagnosis earlier and might also point to new ways of treating the disease.
Protein Predicts Lupus-Related Organ Damage
A team of lupus researchers* that received funding from the Lupus Foundation of America’s Michael Jon Barlin Pediatric Lupus Research Program has identified a potential new biomarker that may be helpful in determining whether a person with lupus is at risk for developing organ damage.
Osteopontin, a protein important for tissue repair in the context of inflammation, has recently been identified as having a role in the development of autoimmune diseases, including lupus. Despite significant advances recently in the care of adults and children with lupus, researchers have yet to identify non-invasive biomarkers that can be used to predict organ damage.
Ornella J. Rullo, MD, Deborah McCurdy, MD, and other researchers at the University of California at Los Angeles School of Medicine, measured blood levels of osteopontin, and other indicators of lupus in the blood, over the course of one year in both adults and children with lupus, as well as in age-matched controls. The researchers also measured clinical and disease-related factors in the study participants every three months for one year.
The researchers compared the levels of osteopontin to measurements of lupus disease activity and organ damage scores. The results show that osteopontin levels were significantly elevated in both adults and children with lupus, when they began the study, as compared to their healthy, age-matched controls. This increase in osteopontin corresponded significantly with increased lupus disease activity during the next six months in both children and adults with lupus. In addition, in both adults and children with lupus, increases in organ damage over a one-year period were significantly associated with increased levels of osteopontin observed in these individuals when they entered the study. There was no overall relationship found, in the adults with lupus, between circulating levels of osteopontin and increasing age, suggesting that age alone is a not a factor for increased levels of osteopontin.
This study suggests, for the first time, that blood levels of osteopontin may be useful in predicting lupus-related organ damage over a one-year period in children with lupus, and similar results were obtained in adults. The results highlight the potential clinical usefulness of circulating osteopontin as a predictor of organ damage and possibly of poor prognosis in people with lupus. The researchers indicate that osteopontin may be important in contributing to the progression of lupus even if it is not a risk factor for its initial development. Larger studies over longer periods of time, and which include greater numbers of ethnically diverse patients, may help to validate these results and potentially identify additional predictive power of osteopontin.
About the Michael Jon Barlin Pediatric Research Program
The Lupus Foundation of America established the Michael Jon Barlin Pediatric Research Program with the generous support of the Wallace H. Coulter Foundation, in memory of Michael Jon Barlin, who passed away at the age of 24 following a long battle with lupus. With those funds, the Foundation became the first and only lupus advocacy organization in the United States with a dedicated childhood lupus research agenda. Through this program, the Foundation provides funding to facilitate childhood lupus research in areas where there is the greatest need, including lupus nephritis and neuropsychiatric lupus. The Foundation takes a strategic approach to investigating lupus in children by calling on some of the greatest minds in the field to address the most critical issues that have stood in the way of progress, and hold the greatest promise for accelerating our understanding of how lupus affects children and adolescents.
* Rullo OJ, Woo JMP, Parsa MF, Hoftman ADC, Maranian P, Elashoff DA, Niewold TB, Grossman JM, Hahn BH, McMahon M, McCurdy DK, and Tsao BP. (2013). Plasma levels of osteopontin identify patients at risk for organ damage in systemic lupus erythematosus. Arthritis Research & Therapy 15: R18. [epub ahead of print]
The researchers wanted to find out whether the amount of leptin, adiponectin, or ghrelin in children with lupus might be different than in children without lupus.