Source of kidney disease biomarker identified

Researchers have identified that bone marrow-derived cells are the source of suPAR -- a protein recently identified as both a reliable marker for chronic kidney disease and a pathogen of the often deadly condition.

The place of origin of suPAR in the human body had been a mystery until now. 

"SuPAR is not just a biomarker; it may also be a cause of the disease," said Jochen Reiser, Professor at Rush University in Illinois, US.

Thus the new discovery may aid search for kidney disease treatment and prevent recurrence after transplant, the researchers said. 

The research showed a type of immature myeloid cell, located in the bone marrow, as the source of abnormal levels of suPAR.

"These immature myeloid cells appear as a main source of circulating suPAR," Reiser added.

Myeloid cells are one of three main types of blood cells. It appears that "these cells are producing high amounts of suPAR, which becomes the mediator that communicates between the immune system and the kidney. At high levels, suPAR travels to the kidneys, causes a reaction, and takes the kidney down," Reiser explained.

The researchers identified bone marrow GR-1lo, Sca1+ immature myeloid cells as the specific type of cells giving rise to suPAR.

"The benefit of knowing what we know about suPAR is that it will allow for much better risk stratification," Reiser said. 

While smoking cessation and losing weight can help bring suPAR levels down. SuPAR levels will likely require pharmacological intervention because "suPAR still won't go down to completely normal levels just because of a better lifestyle," Reiser says.

As for treatments, "stem cell transplantation may prove to be a viable approach to treat diseases such as suPAR-associated kidney disease," the study, published in the journal Nature Medicine, stated.