First we had!
Axtell etal. T helper type 1 and 17 cells determine efficacy of interferon-beta in multiple sclerosis and experimental encephalomyelitis. Nat Med. 2010;16:406-412.
A high IL-17F concentration in the serum of people with RRMS is associated with nonresponsiveness to therapy with IFN-beta.
Then the sort of retraction that the Nature Med paper conclusions was kind of mushroom food
Bushnell et al. Serum IL-17F does not predict poor response to IM IFNβ-1a in relapsing-remitting MS. Neurology. 2012;79:531-7. (by Biogen a maker of interferon beta)
We were unable to validate the finding that serum IL-17F is a predictor
of PR in a large independent cohort of subjects with RRMS. Differences
in patient populations and methodology might explain the failure to
validate the results from the Stanford (Steinman) study.
Now we have
Balasa R, Bajko Z, Hutanu A. Serum levels of IL-17A in patients with relapsing-remitting multiple sclerosis treated with interferon-β Mult Scler. 2012 Dec [Epub ahead of print]
Interleukin-17 (IL-17), which is secreted by
Th17 cells, is a proinflammatory cytokine that is implicated in the
pathogenesis of multiple sclerosis (MS) and plays a role in nonresponse of MS patients to interferon-β (IFN-β) therapy.
Conclusions, RRMS
patients with high serum IL-17A levels do not respond well to IFN-β
therapy and have shorter MS duration compared to patients with low
IL-17A levels.
Interleukin 17 is a cytokine that acts as a potent mediator in delayed-type reactions by increasing chemokine production in various tissues to recruit monocytes and neutrophils to the site of inflammation, similar to Interferon gamma. IL-17 is produced by T-helper (Th17) cells and is induced by IL–23.Interleukin 17 (IL-17A) comes in different isoforms and there is IL-17B, IL-17C, IL-17D, IL-17E (also called IL-25), and IL-17F. The original idea which was later questioned was based on IL-17F not IL-17A. So is this study also not robust. This is often the problem with some original papers published in high impact journals that they spawn a lot of other studies but when the original idea is questionable it takes ages to sort out the wheat from the chaff.