Patients with early lupus nephritis show definite signs of deficient bone remodeling in a study that includes bone biopsies. They also have low vitamin D levels compared to healthy controls.
Resende AL, dos Reis LM, Dias CB et al. Bone disease in newly diagnosed lupus nephritis patients. PLoS One (2014) doi: 10.1371/journal.pone.0106728. Online September 17.
Newly diagnosed lupus nephritis (LN) patients, this study shows, present with adverse changes in bone metabolism such as impaired bone formation and mineralization and increased bone resorption. The cause of these disturbances may be a combination of glucocorticoid use, vitamin D insufficiency, and inflammation.
Researchers from the Sao Paulo University Medical School in Brazil studied 15 premenopausal patients who had been diagnosed with systemic lupus erythematosus (SLE) and LN two months or less before enrollment and then treated with glucocorticoids.
The purpose of the study: To evaluate the bone status of newly diagnosed LN patients and its correlation with inflammatory factors involved in LN physiopathology.
The LN patients, who had higher levels of IL-6, TNFÎ±, and MCP-1, reflecting high disease activity, also showed significantly reduced bone measures (osteoid volume, osteoid thickness, osteoid surface, mineralization surface, and bone formation rate) compared to matched healthy controls, indicating an increased eroded surface and osteoclast surface.
“Vitamin D insufficiency was observed in all of our patients and might also play a role in the bone metabolism disturbance,” the authors state.
They contend that glucocorticoid use and vitamin D insufficiency in their patients might have influenced bone disturbance, with a contribution from the inflammatory background. The results of bone biopsies suggest that the RANKL system addressed by bisphosphonates and osteoprotegerin are involved.