Maths could replace invasive kidney biopsy for people with lupus

A maths model might be able to reduce the need for invasive biopsies in people with kidney damage related to lupus, suggests a study published in the Proceedings of the National Academy of Sciences.
Currently a kidney biopsy is the only way to reach a definitive diagnosis of the damage and its extent. But now researchers believe the model can predict the progression from nephritis (kidney inflammation) to interstitial fibrosis (scarring in the kidney that available treatments cannot reverse).
The model could also be used to monitor the effectiveness of experimental treatments for inflammation and fibrosis. This fibrosis can follow development of lupus nephritis, which occurs in about 60% of people with lupus. Inflammation is linked to the most common type of lupus, called systemic lupus erythematosus.
The maths model comprises a series of equations that account for the complex process that leads from nephritis to fibrosis in damaged kidneys. The researchers say as well as detecting the extent of kidney damage, it can predict how inflammatory processes will react to different therapies.
Better management of kidney damage in lupus is an urgent medical need because people with moderate or severe fibrosis are more likely to develop chronic or end-stage kidney disease.
“The most important use of this model will be improving the design of clinical trials for new medications to treat the kidneys before they develop fibrosis,” explains lead author, Prof Avner Friedman. “Establishing a dose of an experimental therapy is the most difficult part of testing new drugs. The model could give a starting point for an effective dose.”
Further validation and refinement of the model is needed, but the team has shown that in a comparison with human patient data, levels of inflammatory proteins in the urine of patients with mild, moderate or severe fibrosis matched levels predicted by the model.

Image credit: Tom Page