TOPIC DISCUSSION: Interferon and the kidney

A recent review in KI May 2010 Issue discussed the role of both interferon Aplha and Beta interferon in the role of kidney inflammation. Both of these play a major role in anti viral and auto immunity but their role in the kidney is unknown.  Few points made by this review that were fascinating and shed some thought for research

1. All cells produce Type 1 interferons during viral infections but no data in renal cells
2. Type 1 interferons are also central mediators of SLE. Studies are on going to treat lupus with IFN gamma neutralizing antibodies
3. What about in HIVAN, the most widely studied virus and the kidney? Only one study reported increased intrarenal IFN-gamma production in human HIVAN biopsies compared with non HIV FSGS.  This local release is probably what we see as tubuloreticular inclusions in HIVAN biopsies.
4. No data exists in Polyomavirus and such inclusions bodies.
5. Extrarenal viral infections like Hep C can trigger an immune complex GN with increased IFN-gamma production.  What about in other immune complex diseases, some virus instigates an IFN response and triggers IgA and MPGN, no one knows.
6. IFN -alpha has been identified now as a central mediator in lupus. Hence the similarities with viral infections in terms of symptoms such as fever, athralgias might be interferon effect.
7. One way we use to figure out if the membranous or the kidney disease is idiopathic vs lupus is the presence of tubuloreticular bodies( hence an interferon effect)
8. So in summary, little is known about the immunomodulary role in renal inflammation. in some cases, its harmful and in some cases such as Hep C and Renal Cell, it helps. The authors suggest that perhaps measuring urinary interferon levels might shed some light on the extent an interferon mediated process is involved.

Check out some other references

http://www.ncbi.nlm.nih.gov/pubmed/19773191
http://www.ncbi.nlm.nih.gov/pubmed/15320958
http://www.ncbi.nlm.nih.gov/pubmed/11256746